xref: /linux/drivers/net/can/flexcan/flexcan-core.c (revision 1a9239bb4253f9076b5b4b2a1a4e8d7defd77a95)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // flexcan.c - FLEXCAN CAN controller driver
4 //
5 // Copyright (c) 2005-2006 Varma Electronics Oy
6 // Copyright (c) 2009 Sascha Hauer, Pengutronix
7 // Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
8 // Copyright (c) 2014 David Jander, Protonic Holland
9 //
10 // Based on code originally by Andrey Volkov <avolkov@varma-el.com>
11 
12 #include <dt-bindings/firmware/imx/rsrc.h>
13 #include <linux/bitfield.h>
14 #include <linux/can.h>
15 #include <linux/can/dev.h>
16 #include <linux/can/error.h>
17 #include <linux/clk.h>
18 #include <linux/delay.h>
19 #include <linux/firmware/imx/sci.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/netdevice.h>
25 #include <linux/of.h>
26 #include <linux/pinctrl/consumer.h>
27 #include <linux/platform_device.h>
28 #include <linux/can/platform/flexcan.h>
29 #include <linux/phy/phy.h>
30 #include <linux/pm_runtime.h>
31 #include <linux/property.h>
32 #include <linux/regmap.h>
33 #include <linux/regulator/consumer.h>
34 
35 #include "flexcan.h"
36 
37 #define DRV_NAME			"flexcan"
38 
39 /* 8 for RX fifo and 2 error handling */
40 #define FLEXCAN_NAPI_WEIGHT		(8 + 2)
41 
42 /* FLEXCAN module configuration register (CANMCR) bits */
43 #define FLEXCAN_MCR_MDIS		BIT(31)
44 #define FLEXCAN_MCR_FRZ			BIT(30)
45 #define FLEXCAN_MCR_FEN			BIT(29)
46 #define FLEXCAN_MCR_HALT		BIT(28)
47 #define FLEXCAN_MCR_NOT_RDY		BIT(27)
48 #define FLEXCAN_MCR_WAK_MSK		BIT(26)
49 #define FLEXCAN_MCR_SOFTRST		BIT(25)
50 #define FLEXCAN_MCR_FRZ_ACK		BIT(24)
51 #define FLEXCAN_MCR_SUPV		BIT(23)
52 #define FLEXCAN_MCR_SLF_WAK		BIT(22)
53 #define FLEXCAN_MCR_WRN_EN		BIT(21)
54 #define FLEXCAN_MCR_LPM_ACK		BIT(20)
55 #define FLEXCAN_MCR_WAK_SRC		BIT(19)
56 #define FLEXCAN_MCR_DOZE		BIT(18)
57 #define FLEXCAN_MCR_SRX_DIS		BIT(17)
58 #define FLEXCAN_MCR_IRMQ		BIT(16)
59 #define FLEXCAN_MCR_LPRIO_EN		BIT(13)
60 #define FLEXCAN_MCR_AEN			BIT(12)
61 #define FLEXCAN_MCR_FDEN		BIT(11)
62 /* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
63 #define FLEXCAN_MCR_MAXMB(x)		((x) & 0x7f)
64 #define FLEXCAN_MCR_IDAM_A		(0x0 << 8)
65 #define FLEXCAN_MCR_IDAM_B		(0x1 << 8)
66 #define FLEXCAN_MCR_IDAM_C		(0x2 << 8)
67 #define FLEXCAN_MCR_IDAM_D		(0x3 << 8)
68 
69 /* FLEXCAN control register (CANCTRL) bits */
70 #define FLEXCAN_CTRL_PRESDIV(x)		(((x) & 0xff) << 24)
71 #define FLEXCAN_CTRL_RJW(x)		(((x) & 0x03) << 22)
72 #define FLEXCAN_CTRL_PSEG1(x)		(((x) & 0x07) << 19)
73 #define FLEXCAN_CTRL_PSEG2(x)		(((x) & 0x07) << 16)
74 #define FLEXCAN_CTRL_BOFF_MSK		BIT(15)
75 #define FLEXCAN_CTRL_ERR_MSK		BIT(14)
76 #define FLEXCAN_CTRL_CLK_SRC		BIT(13)
77 #define FLEXCAN_CTRL_LPB		BIT(12)
78 #define FLEXCAN_CTRL_TWRN_MSK		BIT(11)
79 #define FLEXCAN_CTRL_RWRN_MSK		BIT(10)
80 #define FLEXCAN_CTRL_SMP		BIT(7)
81 #define FLEXCAN_CTRL_BOFF_REC		BIT(6)
82 #define FLEXCAN_CTRL_TSYN		BIT(5)
83 #define FLEXCAN_CTRL_LBUF		BIT(4)
84 #define FLEXCAN_CTRL_LOM		BIT(3)
85 #define FLEXCAN_CTRL_PROPSEG(x)		((x) & 0x07)
86 #define FLEXCAN_CTRL_ERR_BUS		(FLEXCAN_CTRL_ERR_MSK)
87 #define FLEXCAN_CTRL_ERR_STATE \
88 	(FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
89 	 FLEXCAN_CTRL_BOFF_MSK)
90 #define FLEXCAN_CTRL_ERR_ALL \
91 	(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
92 
93 /* FLEXCAN control register 2 (CTRL2) bits */
94 #define FLEXCAN_CTRL2_ECRWRE		BIT(29)
95 #define FLEXCAN_CTRL2_WRMFRZ		BIT(28)
96 #define FLEXCAN_CTRL2_RFFN(x)		(((x) & 0x0f) << 24)
97 #define FLEXCAN_CTRL2_TASD(x)		(((x) & 0x1f) << 19)
98 #define FLEXCAN_CTRL2_MRP		BIT(18)
99 #define FLEXCAN_CTRL2_RRS		BIT(17)
100 #define FLEXCAN_CTRL2_EACEN		BIT(16)
101 #define FLEXCAN_CTRL2_ISOCANFDEN	BIT(12)
102 
103 /* FLEXCAN memory error control register (MECR) bits */
104 #define FLEXCAN_MECR_ECRWRDIS		BIT(31)
105 #define FLEXCAN_MECR_HANCEI_MSK		BIT(19)
106 #define FLEXCAN_MECR_FANCEI_MSK		BIT(18)
107 #define FLEXCAN_MECR_CEI_MSK		BIT(16)
108 #define FLEXCAN_MECR_HAERRIE		BIT(15)
109 #define FLEXCAN_MECR_FAERRIE		BIT(14)
110 #define FLEXCAN_MECR_EXTERRIE		BIT(13)
111 #define FLEXCAN_MECR_RERRDIS		BIT(9)
112 #define FLEXCAN_MECR_ECCDIS		BIT(8)
113 #define FLEXCAN_MECR_NCEFAFRZ		BIT(7)
114 
115 /* FLEXCAN error and status register (ESR) bits */
116 #define FLEXCAN_ESR_TWRN_INT		BIT(17)
117 #define FLEXCAN_ESR_RWRN_INT		BIT(16)
118 #define FLEXCAN_ESR_BIT1_ERR		BIT(15)
119 #define FLEXCAN_ESR_BIT0_ERR		BIT(14)
120 #define FLEXCAN_ESR_ACK_ERR		BIT(13)
121 #define FLEXCAN_ESR_CRC_ERR		BIT(12)
122 #define FLEXCAN_ESR_FRM_ERR		BIT(11)
123 #define FLEXCAN_ESR_STF_ERR		BIT(10)
124 #define FLEXCAN_ESR_TX_WRN		BIT(9)
125 #define FLEXCAN_ESR_RX_WRN		BIT(8)
126 #define FLEXCAN_ESR_IDLE		BIT(7)
127 #define FLEXCAN_ESR_TXRX		BIT(6)
128 #define FLEXCAN_EST_FLT_CONF_SHIFT	(4)
129 #define FLEXCAN_ESR_FLT_CONF_MASK	(0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
130 #define FLEXCAN_ESR_FLT_CONF_ACTIVE	(0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
131 #define FLEXCAN_ESR_FLT_CONF_PASSIVE	(0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
132 #define FLEXCAN_ESR_BOFF_INT		BIT(2)
133 #define FLEXCAN_ESR_ERR_INT		BIT(1)
134 #define FLEXCAN_ESR_WAK_INT		BIT(0)
135 #define FLEXCAN_ESR_ERR_BUS \
136 	(FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
137 	 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
138 	 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
139 #define FLEXCAN_ESR_ERR_STATE \
140 	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
141 #define FLEXCAN_ESR_ERR_ALL \
142 	(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
143 #define FLEXCAN_ESR_ALL_INT \
144 	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
145 	 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
146 
147 /* FLEXCAN Bit Timing register (CBT) bits */
148 #define FLEXCAN_CBT_BTF			BIT(31)
149 #define FLEXCAN_CBT_EPRESDIV_MASK	GENMASK(30, 21)
150 #define FLEXCAN_CBT_ERJW_MASK		GENMASK(20, 16)
151 #define FLEXCAN_CBT_EPROPSEG_MASK	GENMASK(15, 10)
152 #define FLEXCAN_CBT_EPSEG1_MASK		GENMASK(9, 5)
153 #define FLEXCAN_CBT_EPSEG2_MASK		GENMASK(4, 0)
154 
155 /* FLEXCAN FD control register (FDCTRL) bits */
156 #define FLEXCAN_FDCTRL_FDRATE		BIT(31)
157 #define FLEXCAN_FDCTRL_MBDSR1		GENMASK(20, 19)
158 #define FLEXCAN_FDCTRL_MBDSR0		GENMASK(17, 16)
159 #define FLEXCAN_FDCTRL_MBDSR_8		0x0
160 #define FLEXCAN_FDCTRL_MBDSR_12		0x1
161 #define FLEXCAN_FDCTRL_MBDSR_32		0x2
162 #define FLEXCAN_FDCTRL_MBDSR_64		0x3
163 #define FLEXCAN_FDCTRL_TDCEN		BIT(15)
164 #define FLEXCAN_FDCTRL_TDCFAIL		BIT(14)
165 #define FLEXCAN_FDCTRL_TDCOFF		GENMASK(12, 8)
166 #define FLEXCAN_FDCTRL_TDCVAL		GENMASK(5, 0)
167 
168 /* FLEXCAN FD Bit Timing register (FDCBT) bits */
169 #define FLEXCAN_FDCBT_FPRESDIV_MASK	GENMASK(29, 20)
170 #define FLEXCAN_FDCBT_FRJW_MASK		GENMASK(18, 16)
171 #define FLEXCAN_FDCBT_FPROPSEG_MASK	GENMASK(14, 10)
172 #define FLEXCAN_FDCBT_FPSEG1_MASK	GENMASK(7, 5)
173 #define FLEXCAN_FDCBT_FPSEG2_MASK	GENMASK(2, 0)
174 
175 /* FLEXCAN interrupt flag register (IFLAG) bits */
176 /* Errata ERR005829 step7: Reserve first valid MB */
177 #define FLEXCAN_TX_MB_RESERVED_RX_FIFO	8
178 #define FLEXCAN_TX_MB_RESERVED_RX_MAILBOX	0
179 #define FLEXCAN_RX_MB_RX_MAILBOX_FIRST	(FLEXCAN_TX_MB_RESERVED_RX_MAILBOX + 1)
180 #define FLEXCAN_IFLAG_MB(x)		BIT_ULL(x)
181 #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW	BIT(7)
182 #define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
183 #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
184 
185 /* FLEXCAN message buffers */
186 #define FLEXCAN_MB_CODE_MASK		(0xf << 24)
187 #define FLEXCAN_MB_CODE_RX_BUSY_BIT	(0x1 << 24)
188 #define FLEXCAN_MB_CODE_RX_INACTIVE	(0x0 << 24)
189 #define FLEXCAN_MB_CODE_RX_EMPTY	(0x4 << 24)
190 #define FLEXCAN_MB_CODE_RX_FULL		(0x2 << 24)
191 #define FLEXCAN_MB_CODE_RX_OVERRUN	(0x6 << 24)
192 #define FLEXCAN_MB_CODE_RX_RANSWER	(0xa << 24)
193 
194 #define FLEXCAN_MB_CODE_TX_INACTIVE	(0x8 << 24)
195 #define FLEXCAN_MB_CODE_TX_ABORT	(0x9 << 24)
196 #define FLEXCAN_MB_CODE_TX_DATA		(0xc << 24)
197 #define FLEXCAN_MB_CODE_TX_TANSWER	(0xe << 24)
198 
199 #define FLEXCAN_MB_CNT_EDL		BIT(31)
200 #define FLEXCAN_MB_CNT_BRS		BIT(30)
201 #define FLEXCAN_MB_CNT_ESI		BIT(29)
202 #define FLEXCAN_MB_CNT_SRR		BIT(22)
203 #define FLEXCAN_MB_CNT_IDE		BIT(21)
204 #define FLEXCAN_MB_CNT_RTR		BIT(20)
205 #define FLEXCAN_MB_CNT_LENGTH(x)	(((x) & 0xf) << 16)
206 #define FLEXCAN_MB_CNT_TIMESTAMP(x)	((x) & 0xffff)
207 
208 #define FLEXCAN_TIMEOUT_US		(250)
209 
210 /* Structure of the message buffer */
211 struct flexcan_mb {
212 	u32 can_ctrl;
213 	u32 can_id;
214 	u32 data[];
215 };
216 
217 /* Structure of the hardware registers */
218 struct flexcan_regs {
219 	u32 mcr;		/* 0x00 */
220 	u32 ctrl;		/* 0x04 - Not affected by Soft Reset */
221 	u32 timer;		/* 0x08 */
222 	u32 tcr;		/* 0x0c */
223 	u32 rxgmask;		/* 0x10 - Not affected by Soft Reset */
224 	u32 rx14mask;		/* 0x14 - Not affected by Soft Reset */
225 	u32 rx15mask;		/* 0x18 - Not affected by Soft Reset */
226 	u32 ecr;		/* 0x1c */
227 	u32 esr;		/* 0x20 */
228 	u32 imask2;		/* 0x24 */
229 	u32 imask1;		/* 0x28 */
230 	u32 iflag2;		/* 0x2c */
231 	u32 iflag1;		/* 0x30 */
232 	union {			/* 0x34 */
233 		u32 gfwr_mx28;	/* MX28, MX53 */
234 		u32 ctrl2;	/* MX6, VF610 - Not affected by Soft Reset */
235 	};
236 	u32 esr2;		/* 0x38 */
237 	u32 imeur;		/* 0x3c */
238 	u32 lrfr;		/* 0x40 */
239 	u32 crcr;		/* 0x44 */
240 	u32 rxfgmask;		/* 0x48 */
241 	u32 rxfir;		/* 0x4c - Not affected by Soft Reset */
242 	u32 cbt;		/* 0x50 - Not affected by Soft Reset */
243 	u32 _reserved2;		/* 0x54 */
244 	u32 dbg1;		/* 0x58 */
245 	u32 dbg2;		/* 0x5c */
246 	u32 _reserved3[8];	/* 0x60 */
247 	struct_group(init,
248 		u8 mb[2][512];		/* 0x80 - Not affected by Soft Reset */
249 		/* FIFO-mode:
250 		 *			MB
251 		 * 0x080...0x08f	0	RX message buffer
252 		 * 0x090...0x0df	1-5	reserved
253 		 * 0x0e0...0x0ff	6-7	8 entry ID table
254 		 *				(mx25, mx28, mx35, mx53)
255 		 * 0x0e0...0x2df	6-7..37	8..128 entry ID table
256 		 *				size conf'ed via ctrl2::RFFN
257 		 *				(mx6, vf610)
258 		 */
259 		u32 _reserved4[256];	/* 0x480 */
260 		u32 rximr[64];		/* 0x880 - Not affected by Soft Reset */
261 		u32 _reserved5[24];	/* 0x980 */
262 		u32 gfwr_mx6;		/* 0x9e0 - MX6 */
263 		u32 _reserved6[39];	/* 0x9e4 */
264 		u32 _rxfir[6];		/* 0xa80 */
265 		u32 _reserved8[2];	/* 0xa98 */
266 		u32 _rxmgmask;		/* 0xaa0 */
267 		u32 _rxfgmask;		/* 0xaa4 */
268 		u32 _rx14mask;		/* 0xaa8 */
269 		u32 _rx15mask;		/* 0xaac */
270 		u32 tx_smb[4];		/* 0xab0 */
271 		u32 rx_smb0[4];		/* 0xac0 */
272 		u32 rx_smb1[4];		/* 0xad0 */
273 	);
274 	u32 mecr;		/* 0xae0 */
275 	u32 erriar;		/* 0xae4 */
276 	u32 erridpr;		/* 0xae8 */
277 	u32 errippr;		/* 0xaec */
278 	u32 rerrar;		/* 0xaf0 */
279 	u32 rerrdr;		/* 0xaf4 */
280 	u32 rerrsynr;		/* 0xaf8 */
281 	u32 errsr;		/* 0xafc */
282 	u32 _reserved7[64];	/* 0xb00 */
283 	u32 fdctrl;		/* 0xc00 - Not affected by Soft Reset */
284 	u32 fdcbt;		/* 0xc04 - Not affected by Soft Reset */
285 	u32 fdcrc;		/* 0xc08 */
286 	u32 _reserved9[199];	/* 0xc0c */
287 	struct_group(init_fd,
288 		u32 tx_smb_fd[18];	/* 0xf28 */
289 		u32 rx_smb0_fd[18];	/* 0xf70 */
290 		u32 rx_smb1_fd[18];	/* 0xfb8 */
291 	);
292 };
293 
294 static_assert(sizeof(struct flexcan_regs) ==  0x4 * 18 + 0xfb8);
295 
296 static const struct flexcan_devtype_data fsl_mcf5441x_devtype_data = {
297 	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE |
298 		FLEXCAN_QUIRK_NR_IRQ_3 | FLEXCAN_QUIRK_NR_MB_16 |
299 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
300 		FLEXCAN_QUIRK_SUPPORT_RX_FIFO,
301 };
302 
303 static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
304 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
305 		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
306 		FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN |
307 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
308 		FLEXCAN_QUIRK_SUPPORT_RX_FIFO,
309 };
310 
311 static const struct flexcan_devtype_data fsl_imx25_devtype_data = {
312 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
313 		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
314 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
315 		FLEXCAN_QUIRK_SUPPORT_RX_FIFO,
316 };
317 
318 static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
319 	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE |
320 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
321 		FLEXCAN_QUIRK_SUPPORT_RX_FIFO,
322 };
323 
324 static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
325 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
326 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
327 		FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR |
328 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
329 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
330 };
331 
332 static const struct flexcan_devtype_data fsl_imx8qm_devtype_data = {
333 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
334 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
335 		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW |
336 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
337 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
338 };
339 
340 static struct flexcan_devtype_data fsl_imx8mp_devtype_data = {
341 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
342 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
343 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR |
344 		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC |
345 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
346 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
347 };
348 
349 static struct flexcan_devtype_data fsl_imx93_devtype_data = {
350 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
351 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
352 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR |
353 		FLEXCAN_QUIRK_SUPPORT_FD | FLEXCAN_QUIRK_SUPPORT_ECC |
354 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
355 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
356 };
357 
358 static const struct flexcan_devtype_data fsl_imx95_devtype_data = {
359 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
360 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
361 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SUPPORT_FD |
362 		FLEXCAN_QUIRK_SUPPORT_ECC | FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
363 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR | FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI,
364 };
365 
366 static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
367 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
368 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_RX_MAILBOX |
369 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_SUPPORT_ECC |
370 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
371 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
372 };
373 
374 static const struct flexcan_devtype_data fsl_ls1021a_r2_devtype_data = {
375 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
376 		FLEXCAN_QUIRK_BROKEN_PERR_STATE | FLEXCAN_QUIRK_USE_RX_MAILBOX |
377 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
378 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
379 };
380 
381 static const struct flexcan_devtype_data fsl_lx2160a_r1_devtype_data = {
382 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
383 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
384 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_SUPPORT_FD |
385 		FLEXCAN_QUIRK_SUPPORT_ECC |
386 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
387 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR,
388 };
389 
390 static const struct flexcan_devtype_data nxp_s32g2_devtype_data = {
391 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
392 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
393 		FLEXCAN_QUIRK_USE_RX_MAILBOX | FLEXCAN_QUIRK_SUPPORT_FD |
394 		FLEXCAN_QUIRK_SUPPORT_ECC | FLEXCAN_QUIRK_NR_IRQ_3 |
395 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
396 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR |
397 		FLEXCAN_QUIRK_SECONDARY_MB_IRQ,
398 };
399 
400 static const struct can_bittiming_const flexcan_bittiming_const = {
401 	.name = DRV_NAME,
402 	.tseg1_min = 4,
403 	.tseg1_max = 16,
404 	.tseg2_min = 2,
405 	.tseg2_max = 8,
406 	.sjw_max = 4,
407 	.brp_min = 1,
408 	.brp_max = 256,
409 	.brp_inc = 1,
410 };
411 
412 static const struct can_bittiming_const flexcan_fd_bittiming_const = {
413 	.name = DRV_NAME,
414 	.tseg1_min = 2,
415 	.tseg1_max = 96,
416 	.tseg2_min = 2,
417 	.tseg2_max = 32,
418 	.sjw_max = 16,
419 	.brp_min = 1,
420 	.brp_max = 1024,
421 	.brp_inc = 1,
422 };
423 
424 static const struct can_bittiming_const flexcan_fd_data_bittiming_const = {
425 	.name = DRV_NAME,
426 	.tseg1_min = 2,
427 	.tseg1_max = 39,
428 	.tseg2_min = 2,
429 	.tseg2_max = 8,
430 	.sjw_max = 4,
431 	.brp_min = 1,
432 	.brp_max = 1024,
433 	.brp_inc = 1,
434 };
435 
436 /* FlexCAN module is essentially modelled as a little-endian IP in most
437  * SoCs, i.e the registers as well as the message buffer areas are
438  * implemented in a little-endian fashion.
439  *
440  * However there are some SoCs (e.g. LS1021A) which implement the FlexCAN
441  * module in a big-endian fashion (i.e the registers as well as the
442  * message buffer areas are implemented in a big-endian way).
443  *
444  * In addition, the FlexCAN module can be found on SoCs having ARM or
445  * PPC cores. So, we need to abstract off the register read/write
446  * functions, ensuring that these cater to all the combinations of module
447  * endianness and underlying CPU endianness.
448  */
flexcan_read_be(void __iomem * addr)449 static inline u32 flexcan_read_be(void __iomem *addr)
450 {
451 	return ioread32be(addr);
452 }
453 
flexcan_write_be(u32 val,void __iomem * addr)454 static inline void flexcan_write_be(u32 val, void __iomem *addr)
455 {
456 	iowrite32be(val, addr);
457 }
458 
flexcan_read_le(void __iomem * addr)459 static inline u32 flexcan_read_le(void __iomem *addr)
460 {
461 	return ioread32(addr);
462 }
463 
flexcan_write_le(u32 val,void __iomem * addr)464 static inline void flexcan_write_le(u32 val, void __iomem *addr)
465 {
466 	iowrite32(val, addr);
467 }
468 
flexcan_get_mb(const struct flexcan_priv * priv,u8 mb_index)469 static struct flexcan_mb __iomem *flexcan_get_mb(const struct flexcan_priv *priv,
470 						 u8 mb_index)
471 {
472 	u8 bank_size;
473 	bool bank;
474 
475 	if (WARN_ON(mb_index >= priv->mb_count))
476 		return NULL;
477 
478 	bank_size = sizeof(priv->regs->mb[0]) / priv->mb_size;
479 
480 	bank = mb_index >= bank_size;
481 	if (bank)
482 		mb_index -= bank_size;
483 
484 	return (struct flexcan_mb __iomem *)
485 		(&priv->regs->mb[bank][priv->mb_size * mb_index]);
486 }
487 
flexcan_low_power_enter_ack(struct flexcan_priv * priv)488 static int flexcan_low_power_enter_ack(struct flexcan_priv *priv)
489 {
490 	struct flexcan_regs __iomem *regs = priv->regs;
491 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
492 
493 	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
494 		udelay(10);
495 
496 	if (!(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
497 		return -ETIMEDOUT;
498 
499 	return 0;
500 }
501 
flexcan_low_power_exit_ack(struct flexcan_priv * priv)502 static int flexcan_low_power_exit_ack(struct flexcan_priv *priv)
503 {
504 	struct flexcan_regs __iomem *regs = priv->regs;
505 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
506 
507 	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
508 		udelay(10);
509 
510 	if (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
511 		return -ETIMEDOUT;
512 
513 	return 0;
514 }
515 
flexcan_enable_wakeup_irq(struct flexcan_priv * priv,bool enable)516 static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
517 {
518 	struct flexcan_regs __iomem *regs = priv->regs;
519 	u32 reg_mcr;
520 
521 	reg_mcr = priv->read(&regs->mcr);
522 
523 	if (enable)
524 		reg_mcr |= FLEXCAN_MCR_WAK_MSK;
525 	else
526 		reg_mcr &= ~FLEXCAN_MCR_WAK_MSK;
527 
528 	priv->write(reg_mcr, &regs->mcr);
529 }
530 
flexcan_stop_mode_enable_scfw(struct flexcan_priv * priv,bool enabled)531 static int flexcan_stop_mode_enable_scfw(struct flexcan_priv *priv, bool enabled)
532 {
533 	u8 idx = priv->scu_idx;
534 	u32 rsrc_id, val;
535 
536 	rsrc_id = IMX_SC_R_CAN(idx);
537 
538 	if (enabled)
539 		val = 1;
540 	else
541 		val = 0;
542 
543 	/* stop mode request via scu firmware */
544 	return imx_sc_misc_set_control(priv->sc_ipc_handle, rsrc_id,
545 				       IMX_SC_C_IPG_STOP, val);
546 }
547 
flexcan_enter_stop_mode(struct flexcan_priv * priv)548 static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
549 {
550 	struct flexcan_regs __iomem *regs = priv->regs;
551 	u32 reg_mcr;
552 	int ret;
553 
554 	reg_mcr = priv->read(&regs->mcr);
555 	reg_mcr |= FLEXCAN_MCR_SLF_WAK;
556 	priv->write(reg_mcr, &regs->mcr);
557 
558 	/* enable stop request */
559 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
560 		ret = flexcan_stop_mode_enable_scfw(priv, true);
561 		if (ret < 0)
562 			return ret;
563 	} else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR) {
564 		regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
565 				   1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
566 	} else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI) {
567 		/* For the SCMI mode, driver do nothing, ATF will send request to
568 		 * SM(system manager, M33 core) through SCMI protocol after linux
569 		 * suspend. Once SM get this request, it will send IPG_STOP signal
570 		 * to Flex_CAN, let CAN in STOP mode.
571 		 */
572 		return 0;
573 	}
574 
575 	return flexcan_low_power_enter_ack(priv);
576 }
577 
flexcan_exit_stop_mode(struct flexcan_priv * priv)578 static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
579 {
580 	struct flexcan_regs __iomem *regs = priv->regs;
581 	u32 reg_mcr;
582 	int ret;
583 
584 	/* Remove stop request, for FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI,
585 	 * do nothing here, because ATF already send request to SM before
586 	 * linux resume. Once SM get this request, it will deassert the
587 	 * IPG_STOP signal to Flex_CAN.
588 	 */
589 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW) {
590 		ret = flexcan_stop_mode_enable_scfw(priv, false);
591 		if (ret < 0)
592 			return ret;
593 	} else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR) {
594 		regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
595 				   1 << priv->stm.req_bit, 0);
596 	}
597 
598 	reg_mcr = priv->read(&regs->mcr);
599 	reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
600 	priv->write(reg_mcr, &regs->mcr);
601 
602 	return flexcan_low_power_exit_ack(priv);
603 }
604 
flexcan_error_irq_enable(const struct flexcan_priv * priv)605 static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
606 {
607 	struct flexcan_regs __iomem *regs = priv->regs;
608 	u32 reg_ctrl = (priv->reg_ctrl_default | FLEXCAN_CTRL_ERR_MSK);
609 
610 	priv->write(reg_ctrl, &regs->ctrl);
611 }
612 
flexcan_error_irq_disable(const struct flexcan_priv * priv)613 static inline void flexcan_error_irq_disable(const struct flexcan_priv *priv)
614 {
615 	struct flexcan_regs __iomem *regs = priv->regs;
616 	u32 reg_ctrl = (priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK);
617 
618 	priv->write(reg_ctrl, &regs->ctrl);
619 }
620 
flexcan_clks_enable(const struct flexcan_priv * priv)621 static int flexcan_clks_enable(const struct flexcan_priv *priv)
622 {
623 	int err = 0;
624 
625 	if (priv->clk_ipg) {
626 		err = clk_prepare_enable(priv->clk_ipg);
627 		if (err)
628 			return err;
629 	}
630 
631 	if (priv->clk_per) {
632 		err = clk_prepare_enable(priv->clk_per);
633 		if (err)
634 			clk_disable_unprepare(priv->clk_ipg);
635 	}
636 
637 	return err;
638 }
639 
flexcan_clks_disable(const struct flexcan_priv * priv)640 static void flexcan_clks_disable(const struct flexcan_priv *priv)
641 {
642 	clk_disable_unprepare(priv->clk_per);
643 	clk_disable_unprepare(priv->clk_ipg);
644 }
645 
flexcan_transceiver_enable(const struct flexcan_priv * priv)646 static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
647 {
648 	if (priv->reg_xceiver)
649 		return regulator_enable(priv->reg_xceiver);
650 	else if (priv->transceiver)
651 		return phy_power_on(priv->transceiver);
652 
653 	return 0;
654 }
655 
flexcan_transceiver_disable(const struct flexcan_priv * priv)656 static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
657 {
658 	if (priv->reg_xceiver)
659 		return regulator_disable(priv->reg_xceiver);
660 	else if (priv->transceiver)
661 		return phy_power_off(priv->transceiver);
662 
663 	return 0;
664 }
665 
flexcan_chip_enable(struct flexcan_priv * priv)666 static int flexcan_chip_enable(struct flexcan_priv *priv)
667 {
668 	struct flexcan_regs __iomem *regs = priv->regs;
669 	u32 reg;
670 
671 	reg = priv->read(&regs->mcr);
672 	reg &= ~FLEXCAN_MCR_MDIS;
673 	priv->write(reg, &regs->mcr);
674 
675 	return flexcan_low_power_exit_ack(priv);
676 }
677 
flexcan_chip_disable(struct flexcan_priv * priv)678 static int flexcan_chip_disable(struct flexcan_priv *priv)
679 {
680 	struct flexcan_regs __iomem *regs = priv->regs;
681 	u32 reg;
682 
683 	reg = priv->read(&regs->mcr);
684 	reg |= FLEXCAN_MCR_MDIS;
685 	priv->write(reg, &regs->mcr);
686 
687 	return flexcan_low_power_enter_ack(priv);
688 }
689 
flexcan_chip_freeze(struct flexcan_priv * priv)690 static int flexcan_chip_freeze(struct flexcan_priv *priv)
691 {
692 	struct flexcan_regs __iomem *regs = priv->regs;
693 	unsigned int timeout;
694 	u32 bitrate = priv->can.bittiming.bitrate;
695 	u32 reg;
696 
697 	if (bitrate)
698 		timeout = 1000 * 1000 * 10 / bitrate;
699 	else
700 		timeout = FLEXCAN_TIMEOUT_US / 10;
701 
702 	reg = priv->read(&regs->mcr);
703 	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT;
704 	priv->write(reg, &regs->mcr);
705 
706 	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
707 		udelay(100);
708 
709 	if (!(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
710 		return -ETIMEDOUT;
711 
712 	return 0;
713 }
714 
flexcan_chip_unfreeze(struct flexcan_priv * priv)715 static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
716 {
717 	struct flexcan_regs __iomem *regs = priv->regs;
718 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
719 	u32 reg;
720 
721 	reg = priv->read(&regs->mcr);
722 	reg &= ~FLEXCAN_MCR_HALT;
723 	priv->write(reg, &regs->mcr);
724 
725 	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
726 		udelay(10);
727 
728 	if (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
729 		return -ETIMEDOUT;
730 
731 	return 0;
732 }
733 
flexcan_chip_softreset(struct flexcan_priv * priv)734 static int flexcan_chip_softreset(struct flexcan_priv *priv)
735 {
736 	struct flexcan_regs __iomem *regs = priv->regs;
737 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
738 
739 	priv->write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
740 	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
741 		udelay(10);
742 
743 	if (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
744 		return -ETIMEDOUT;
745 
746 	return 0;
747 }
748 
__flexcan_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)749 static int __flexcan_get_berr_counter(const struct net_device *dev,
750 				      struct can_berr_counter *bec)
751 {
752 	const struct flexcan_priv *priv = netdev_priv(dev);
753 	struct flexcan_regs __iomem *regs = priv->regs;
754 	u32 reg = priv->read(&regs->ecr);
755 
756 	bec->txerr = (reg >> 0) & 0xff;
757 	bec->rxerr = (reg >> 8) & 0xff;
758 
759 	return 0;
760 }
761 
flexcan_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)762 static int flexcan_get_berr_counter(const struct net_device *dev,
763 				    struct can_berr_counter *bec)
764 {
765 	const struct flexcan_priv *priv = netdev_priv(dev);
766 	int err;
767 
768 	err = pm_runtime_resume_and_get(priv->dev);
769 	if (err < 0)
770 		return err;
771 
772 	err = __flexcan_get_berr_counter(dev, bec);
773 
774 	pm_runtime_put(priv->dev);
775 
776 	return err;
777 }
778 
flexcan_start_xmit(struct sk_buff * skb,struct net_device * dev)779 static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
780 {
781 	const struct flexcan_priv *priv = netdev_priv(dev);
782 	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
783 	u32 can_id;
784 	u32 data;
785 	u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | ((can_fd_len2dlc(cfd->len)) << 16);
786 	int i;
787 
788 	if (can_dev_dropped_skb(dev, skb))
789 		return NETDEV_TX_OK;
790 
791 	netif_stop_queue(dev);
792 
793 	if (cfd->can_id & CAN_EFF_FLAG) {
794 		can_id = cfd->can_id & CAN_EFF_MASK;
795 		ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
796 	} else {
797 		can_id = (cfd->can_id & CAN_SFF_MASK) << 18;
798 	}
799 
800 	if (cfd->can_id & CAN_RTR_FLAG)
801 		ctrl |= FLEXCAN_MB_CNT_RTR;
802 
803 	if (can_is_canfd_skb(skb)) {
804 		ctrl |= FLEXCAN_MB_CNT_EDL;
805 
806 		if (cfd->flags & CANFD_BRS)
807 			ctrl |= FLEXCAN_MB_CNT_BRS;
808 	}
809 
810 	for (i = 0; i < cfd->len; i += sizeof(u32)) {
811 		data = be32_to_cpup((__be32 *)&cfd->data[i]);
812 		priv->write(data, &priv->tx_mb->data[i / sizeof(u32)]);
813 	}
814 
815 	can_put_echo_skb(skb, dev, 0, 0);
816 
817 	priv->write(can_id, &priv->tx_mb->can_id);
818 	priv->write(ctrl, &priv->tx_mb->can_ctrl);
819 
820 	/* Errata ERR005829 step8:
821 	 * Write twice INACTIVE(0x8) code to first MB.
822 	 */
823 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
824 		    &priv->tx_mb_reserved->can_ctrl);
825 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
826 		    &priv->tx_mb_reserved->can_ctrl);
827 
828 	return NETDEV_TX_OK;
829 }
830 
flexcan_irq_bus_err(struct net_device * dev,u32 reg_esr)831 static void flexcan_irq_bus_err(struct net_device *dev, u32 reg_esr)
832 {
833 	struct flexcan_priv *priv = netdev_priv(dev);
834 	struct flexcan_regs __iomem *regs = priv->regs;
835 	struct sk_buff *skb;
836 	struct can_frame *cf;
837 	bool rx_errors = false, tx_errors = false;
838 	u32 timestamp;
839 	int err;
840 
841 	timestamp = priv->read(&regs->timer) << 16;
842 
843 	skb = alloc_can_err_skb(dev, &cf);
844 	if (unlikely(!skb))
845 		return;
846 
847 	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
848 
849 	if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
850 		netdev_dbg(dev, "BIT1_ERR irq\n");
851 		cf->data[2] |= CAN_ERR_PROT_BIT1;
852 		tx_errors = true;
853 	}
854 	if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
855 		netdev_dbg(dev, "BIT0_ERR irq\n");
856 		cf->data[2] |= CAN_ERR_PROT_BIT0;
857 		tx_errors = true;
858 	}
859 	if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
860 		netdev_dbg(dev, "ACK_ERR irq\n");
861 		cf->can_id |= CAN_ERR_ACK;
862 		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
863 		tx_errors = true;
864 	}
865 	if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
866 		netdev_dbg(dev, "CRC_ERR irq\n");
867 		cf->data[2] |= CAN_ERR_PROT_BIT;
868 		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
869 		rx_errors = true;
870 	}
871 	if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
872 		netdev_dbg(dev, "FRM_ERR irq\n");
873 		cf->data[2] |= CAN_ERR_PROT_FORM;
874 		rx_errors = true;
875 	}
876 	if (reg_esr & FLEXCAN_ESR_STF_ERR) {
877 		netdev_dbg(dev, "STF_ERR irq\n");
878 		cf->data[2] |= CAN_ERR_PROT_STUFF;
879 		rx_errors = true;
880 	}
881 
882 	priv->can.can_stats.bus_error++;
883 	if (rx_errors)
884 		dev->stats.rx_errors++;
885 	if (tx_errors)
886 		dev->stats.tx_errors++;
887 
888 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
889 	if (err)
890 		dev->stats.rx_fifo_errors++;
891 }
892 
flexcan_irq_state(struct net_device * dev,u32 reg_esr)893 static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
894 {
895 	struct flexcan_priv *priv = netdev_priv(dev);
896 	struct flexcan_regs __iomem *regs = priv->regs;
897 	struct sk_buff *skb;
898 	struct can_frame *cf;
899 	enum can_state new_state, rx_state, tx_state;
900 	int flt;
901 	struct can_berr_counter bec;
902 	u32 timestamp;
903 	int err;
904 
905 	flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
906 	if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
907 		tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
908 			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
909 		rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
910 			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
911 		new_state = max(tx_state, rx_state);
912 	} else {
913 		__flexcan_get_berr_counter(dev, &bec);
914 		new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
915 			CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
916 		rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
917 		tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
918 	}
919 
920 	/* state hasn't changed */
921 	if (likely(new_state == priv->can.state))
922 		return;
923 
924 	timestamp = priv->read(&regs->timer) << 16;
925 
926 	skb = alloc_can_err_skb(dev, &cf);
927 	if (unlikely(!skb))
928 		return;
929 
930 	can_change_state(dev, cf, tx_state, rx_state);
931 
932 	if (unlikely(new_state == CAN_STATE_BUS_OFF))
933 		can_bus_off(dev);
934 
935 	err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp);
936 	if (err)
937 		dev->stats.rx_fifo_errors++;
938 }
939 
flexcan_read64_mask(struct flexcan_priv * priv,void __iomem * addr,u64 mask)940 static inline u64 flexcan_read64_mask(struct flexcan_priv *priv, void __iomem *addr, u64 mask)
941 {
942 	u64 reg = 0;
943 
944 	if (upper_32_bits(mask))
945 		reg = (u64)priv->read(addr - 4) << 32;
946 	if (lower_32_bits(mask))
947 		reg |= priv->read(addr);
948 
949 	return reg & mask;
950 }
951 
flexcan_write64(struct flexcan_priv * priv,u64 val,void __iomem * addr)952 static inline void flexcan_write64(struct flexcan_priv *priv, u64 val, void __iomem *addr)
953 {
954 	if (upper_32_bits(val))
955 		priv->write(upper_32_bits(val), addr - 4);
956 	if (lower_32_bits(val))
957 		priv->write(lower_32_bits(val), addr);
958 }
959 
flexcan_read_reg_iflag_rx(struct flexcan_priv * priv)960 static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
961 {
962 	return flexcan_read64_mask(priv, &priv->regs->iflag1, priv->rx_mask);
963 }
964 
flexcan_read_reg_iflag_tx(struct flexcan_priv * priv)965 static inline u64 flexcan_read_reg_iflag_tx(struct flexcan_priv *priv)
966 {
967 	return flexcan_read64_mask(priv, &priv->regs->iflag1, priv->tx_mask);
968 }
969 
rx_offload_to_priv(struct can_rx_offload * offload)970 static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *offload)
971 {
972 	return container_of(offload, struct flexcan_priv, offload);
973 }
974 
flexcan_mailbox_read(struct can_rx_offload * offload,unsigned int n,u32 * timestamp,bool drop)975 static struct sk_buff *flexcan_mailbox_read(struct can_rx_offload *offload,
976 					    unsigned int n, u32 *timestamp,
977 					    bool drop)
978 {
979 	struct flexcan_priv *priv = rx_offload_to_priv(offload);
980 	struct flexcan_regs __iomem *regs = priv->regs;
981 	struct flexcan_mb __iomem *mb;
982 	struct sk_buff *skb;
983 	struct canfd_frame *cfd;
984 	u32 reg_ctrl, reg_id, reg_iflag1;
985 	int i;
986 
987 	mb = flexcan_get_mb(priv, n);
988 
989 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
990 		u32 code;
991 
992 		do {
993 			reg_ctrl = priv->read(&mb->can_ctrl);
994 		} while (reg_ctrl & FLEXCAN_MB_CODE_RX_BUSY_BIT);
995 
996 		/* is this MB empty? */
997 		code = reg_ctrl & FLEXCAN_MB_CODE_MASK;
998 		if ((code != FLEXCAN_MB_CODE_RX_FULL) &&
999 		    (code != FLEXCAN_MB_CODE_RX_OVERRUN))
1000 			return NULL;
1001 
1002 		if (code == FLEXCAN_MB_CODE_RX_OVERRUN) {
1003 			/* This MB was overrun, we lost data */
1004 			offload->dev->stats.rx_over_errors++;
1005 			offload->dev->stats.rx_errors++;
1006 		}
1007 	} else {
1008 		reg_iflag1 = priv->read(&regs->iflag1);
1009 		if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
1010 			return NULL;
1011 
1012 		reg_ctrl = priv->read(&mb->can_ctrl);
1013 	}
1014 
1015 	if (unlikely(drop)) {
1016 		skb = ERR_PTR(-ENOBUFS);
1017 		goto mark_as_read;
1018 	}
1019 
1020 	if (reg_ctrl & FLEXCAN_MB_CNT_EDL)
1021 		skb = alloc_canfd_skb(offload->dev, &cfd);
1022 	else
1023 		skb = alloc_can_skb(offload->dev, (struct can_frame **)&cfd);
1024 	if (unlikely(!skb)) {
1025 		skb = ERR_PTR(-ENOMEM);
1026 		goto mark_as_read;
1027 	}
1028 
1029 	/* increase timstamp to full 32 bit */
1030 	*timestamp = reg_ctrl << 16;
1031 
1032 	reg_id = priv->read(&mb->can_id);
1033 	if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
1034 		cfd->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
1035 	else
1036 		cfd->can_id = (reg_id >> 18) & CAN_SFF_MASK;
1037 
1038 	if (reg_ctrl & FLEXCAN_MB_CNT_EDL) {
1039 		cfd->len = can_fd_dlc2len((reg_ctrl >> 16) & 0xf);
1040 
1041 		if (reg_ctrl & FLEXCAN_MB_CNT_BRS)
1042 			cfd->flags |= CANFD_BRS;
1043 	} else {
1044 		cfd->len = can_cc_dlc2len((reg_ctrl >> 16) & 0xf);
1045 
1046 		if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
1047 			cfd->can_id |= CAN_RTR_FLAG;
1048 	}
1049 
1050 	if (reg_ctrl & FLEXCAN_MB_CNT_ESI)
1051 		cfd->flags |= CANFD_ESI;
1052 
1053 	for (i = 0; i < cfd->len; i += sizeof(u32)) {
1054 		__be32 data = cpu_to_be32(priv->read(&mb->data[i / sizeof(u32)]));
1055 		*(__be32 *)(cfd->data + i) = data;
1056 	}
1057 
1058  mark_as_read:
1059 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
1060 		flexcan_write64(priv, FLEXCAN_IFLAG_MB(n), &regs->iflag1);
1061 	else
1062 		priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
1063 
1064 	/* Read the Free Running Timer. It is optional but recommended
1065 	 * to unlock Mailbox as soon as possible and make it available
1066 	 * for reception.
1067 	 */
1068 	priv->read(&regs->timer);
1069 
1070 	return skb;
1071 }
1072 
flexcan_irq(int irq,void * dev_id)1073 static irqreturn_t flexcan_irq(int irq, void *dev_id)
1074 {
1075 	struct net_device *dev = dev_id;
1076 	struct net_device_stats *stats = &dev->stats;
1077 	struct flexcan_priv *priv = netdev_priv(dev);
1078 	struct flexcan_regs __iomem *regs = priv->regs;
1079 	irqreturn_t handled = IRQ_NONE;
1080 	u64 reg_iflag_tx;
1081 	u32 reg_esr;
1082 	enum can_state last_state = priv->can.state;
1083 
1084 	/* reception interrupt */
1085 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
1086 		u64 reg_iflag_rx;
1087 		int ret;
1088 
1089 		while ((reg_iflag_rx = flexcan_read_reg_iflag_rx(priv))) {
1090 			handled = IRQ_HANDLED;
1091 			ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
1092 								   reg_iflag_rx);
1093 			if (!ret)
1094 				break;
1095 		}
1096 	} else {
1097 		u32 reg_iflag1;
1098 
1099 		reg_iflag1 = priv->read(&regs->iflag1);
1100 		if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
1101 			handled = IRQ_HANDLED;
1102 			can_rx_offload_irq_offload_fifo(&priv->offload);
1103 		}
1104 
1105 		/* FIFO overflow interrupt */
1106 		if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
1107 			handled = IRQ_HANDLED;
1108 			priv->write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW,
1109 				    &regs->iflag1);
1110 			dev->stats.rx_over_errors++;
1111 			dev->stats.rx_errors++;
1112 		}
1113 	}
1114 
1115 	reg_iflag_tx = flexcan_read_reg_iflag_tx(priv);
1116 
1117 	/* transmission complete interrupt */
1118 	if (reg_iflag_tx & priv->tx_mask) {
1119 		u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
1120 
1121 		handled = IRQ_HANDLED;
1122 		stats->tx_bytes +=
1123 			can_rx_offload_get_echo_skb_queue_timestamp(&priv->offload, 0,
1124 								    reg_ctrl << 16, NULL);
1125 		stats->tx_packets++;
1126 
1127 		/* after sending a RTR frame MB is in RX mode */
1128 		priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
1129 			    &priv->tx_mb->can_ctrl);
1130 		flexcan_write64(priv, priv->tx_mask, &regs->iflag1);
1131 		netif_wake_queue(dev);
1132 	}
1133 
1134 	reg_esr = priv->read(&regs->esr);
1135 
1136 	/* ACK all bus error, state change and wake IRQ sources */
1137 	if (reg_esr & (FLEXCAN_ESR_ALL_INT | FLEXCAN_ESR_WAK_INT)) {
1138 		handled = IRQ_HANDLED;
1139 		priv->write(reg_esr & (FLEXCAN_ESR_ALL_INT | FLEXCAN_ESR_WAK_INT), &regs->esr);
1140 	}
1141 
1142 	/* state change interrupt or broken error state quirk fix is enabled */
1143 	if ((reg_esr & FLEXCAN_ESR_ERR_STATE) ||
1144 	    (priv->devtype_data.quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
1145 					   FLEXCAN_QUIRK_BROKEN_PERR_STATE)))
1146 		flexcan_irq_state(dev, reg_esr);
1147 
1148 	/* bus error IRQ - handle if bus error reporting is activated */
1149 	if ((reg_esr & FLEXCAN_ESR_ERR_BUS) &&
1150 	    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
1151 		flexcan_irq_bus_err(dev, reg_esr);
1152 
1153 	/* availability of error interrupt among state transitions in case
1154 	 * bus error reporting is de-activated and
1155 	 * FLEXCAN_QUIRK_BROKEN_PERR_STATE is enabled:
1156 	 *  +--------------------------------------------------------------+
1157 	 *  | +----------------------------------------------+ [stopped /  |
1158 	 *  | |                                              |  sleeping] -+
1159 	 *  +-+-> active <-> warning <-> passive -> bus off -+
1160 	 *        ___________^^^^^^^^^^^^_______________________________
1161 	 *        disabled(1)  enabled             disabled
1162 	 *
1163 	 * (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled
1164 	 */
1165 	if ((last_state != priv->can.state) &&
1166 	    (priv->devtype_data.quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
1167 	    !(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
1168 		switch (priv->can.state) {
1169 		case CAN_STATE_ERROR_ACTIVE:
1170 			if (priv->devtype_data.quirks &
1171 			    FLEXCAN_QUIRK_BROKEN_WERR_STATE)
1172 				flexcan_error_irq_enable(priv);
1173 			else
1174 				flexcan_error_irq_disable(priv);
1175 			break;
1176 
1177 		case CAN_STATE_ERROR_WARNING:
1178 			flexcan_error_irq_enable(priv);
1179 			break;
1180 
1181 		case CAN_STATE_ERROR_PASSIVE:
1182 		case CAN_STATE_BUS_OFF:
1183 			flexcan_error_irq_disable(priv);
1184 			break;
1185 
1186 		default:
1187 			break;
1188 		}
1189 	}
1190 
1191 	if (handled)
1192 		can_rx_offload_irq_finish(&priv->offload);
1193 
1194 	return handled;
1195 }
1196 
flexcan_set_bittiming_ctrl(const struct net_device * dev)1197 static void flexcan_set_bittiming_ctrl(const struct net_device *dev)
1198 {
1199 	const struct flexcan_priv *priv = netdev_priv(dev);
1200 	const struct can_bittiming *bt = &priv->can.bittiming;
1201 	struct flexcan_regs __iomem *regs = priv->regs;
1202 	u32 reg;
1203 
1204 	reg = priv->read(&regs->ctrl);
1205 	reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
1206 		 FLEXCAN_CTRL_RJW(0x3) |
1207 		 FLEXCAN_CTRL_PSEG1(0x7) |
1208 		 FLEXCAN_CTRL_PSEG2(0x7) |
1209 		 FLEXCAN_CTRL_PROPSEG(0x7));
1210 
1211 	reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
1212 		FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
1213 		FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
1214 		FLEXCAN_CTRL_RJW(bt->sjw - 1) |
1215 		FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
1216 
1217 	netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
1218 	priv->write(reg, &regs->ctrl);
1219 
1220 	/* print chip status */
1221 	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
1222 		   priv->read(&regs->mcr), priv->read(&regs->ctrl));
1223 }
1224 
flexcan_set_bittiming_cbt(const struct net_device * dev)1225 static void flexcan_set_bittiming_cbt(const struct net_device *dev)
1226 {
1227 	struct flexcan_priv *priv = netdev_priv(dev);
1228 	struct can_bittiming *bt = &priv->can.bittiming;
1229 	struct can_bittiming *dbt = &priv->can.data_bittiming;
1230 	struct flexcan_regs __iomem *regs = priv->regs;
1231 	u32 reg_cbt, reg_fdctrl;
1232 
1233 	/* CBT */
1234 	/* CBT[EPSEG1] is 5 bit long and CBT[EPROPSEG] is 6 bit
1235 	 * long. The can_calc_bittiming() tries to divide the tseg1
1236 	 * equally between phase_seg1 and prop_seg, which may not fit
1237 	 * in CBT register. Therefore, if phase_seg1 is more than
1238 	 * possible value, increase prop_seg and decrease phase_seg1.
1239 	 */
1240 	if (bt->phase_seg1 > 0x20) {
1241 		bt->prop_seg += (bt->phase_seg1 - 0x20);
1242 		bt->phase_seg1 = 0x20;
1243 	}
1244 
1245 	reg_cbt = FLEXCAN_CBT_BTF |
1246 		FIELD_PREP(FLEXCAN_CBT_EPRESDIV_MASK, bt->brp - 1) |
1247 		FIELD_PREP(FLEXCAN_CBT_ERJW_MASK, bt->sjw - 1) |
1248 		FIELD_PREP(FLEXCAN_CBT_EPROPSEG_MASK, bt->prop_seg - 1) |
1249 		FIELD_PREP(FLEXCAN_CBT_EPSEG1_MASK, bt->phase_seg1 - 1) |
1250 		FIELD_PREP(FLEXCAN_CBT_EPSEG2_MASK, bt->phase_seg2 - 1);
1251 
1252 	netdev_dbg(dev, "writing cbt=0x%08x\n", reg_cbt);
1253 	priv->write(reg_cbt, &regs->cbt);
1254 
1255 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1256 		u32 reg_fdcbt, reg_ctrl2;
1257 
1258 		if (bt->brp != dbt->brp)
1259 			netdev_warn(dev, "Data brp=%d and brp=%d don't match, this may result in a phase error. Consider using different bitrate and/or data bitrate.\n",
1260 				    dbt->brp, bt->brp);
1261 
1262 		/* FDCBT */
1263 		/* FDCBT[FPSEG1] is 3 bit long and FDCBT[FPROPSEG] is
1264 		 * 5 bit long. The can_calc_bittiming tries to divide
1265 		 * the tseg1 equally between phase_seg1 and prop_seg,
1266 		 * which may not fit in FDCBT register. Therefore, if
1267 		 * phase_seg1 is more than possible value, increase
1268 		 * prop_seg and decrease phase_seg1
1269 		 */
1270 		if (dbt->phase_seg1 > 0x8) {
1271 			dbt->prop_seg += (dbt->phase_seg1 - 0x8);
1272 			dbt->phase_seg1 = 0x8;
1273 		}
1274 
1275 		reg_fdcbt = priv->read(&regs->fdcbt);
1276 		reg_fdcbt &= ~(FIELD_PREP(FLEXCAN_FDCBT_FPRESDIV_MASK, 0x3ff) |
1277 			       FIELD_PREP(FLEXCAN_FDCBT_FRJW_MASK, 0x7) |
1278 			       FIELD_PREP(FLEXCAN_FDCBT_FPROPSEG_MASK, 0x1f) |
1279 			       FIELD_PREP(FLEXCAN_FDCBT_FPSEG1_MASK, 0x7) |
1280 			       FIELD_PREP(FLEXCAN_FDCBT_FPSEG2_MASK, 0x7));
1281 
1282 		reg_fdcbt |= FIELD_PREP(FLEXCAN_FDCBT_FPRESDIV_MASK, dbt->brp - 1) |
1283 			FIELD_PREP(FLEXCAN_FDCBT_FRJW_MASK, dbt->sjw - 1) |
1284 			FIELD_PREP(FLEXCAN_FDCBT_FPROPSEG_MASK, dbt->prop_seg) |
1285 			FIELD_PREP(FLEXCAN_FDCBT_FPSEG1_MASK, dbt->phase_seg1 - 1) |
1286 			FIELD_PREP(FLEXCAN_FDCBT_FPSEG2_MASK, dbt->phase_seg2 - 1);
1287 
1288 		netdev_dbg(dev, "writing fdcbt=0x%08x\n", reg_fdcbt);
1289 		priv->write(reg_fdcbt, &regs->fdcbt);
1290 
1291 		/* CTRL2 */
1292 		reg_ctrl2 = priv->read(&regs->ctrl2);
1293 		reg_ctrl2 &= ~FLEXCAN_CTRL2_ISOCANFDEN;
1294 		if (!(priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO))
1295 			reg_ctrl2 |= FLEXCAN_CTRL2_ISOCANFDEN;
1296 
1297 		netdev_dbg(dev, "writing ctrl2=0x%08x\n", reg_ctrl2);
1298 		priv->write(reg_ctrl2, &regs->ctrl2);
1299 	}
1300 
1301 	/* FDCTRL */
1302 	reg_fdctrl = priv->read(&regs->fdctrl);
1303 	reg_fdctrl &= ~(FLEXCAN_FDCTRL_FDRATE |
1304 			FIELD_PREP(FLEXCAN_FDCTRL_TDCOFF, 0x1f));
1305 
1306 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1307 		reg_fdctrl |= FLEXCAN_FDCTRL_FDRATE;
1308 
1309 		if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
1310 			/* TDC must be disabled for Loop Back mode */
1311 			reg_fdctrl &= ~FLEXCAN_FDCTRL_TDCEN;
1312 		} else {
1313 			reg_fdctrl |= FLEXCAN_FDCTRL_TDCEN |
1314 				FIELD_PREP(FLEXCAN_FDCTRL_TDCOFF,
1315 					   ((dbt->phase_seg1 - 1) +
1316 					    dbt->prop_seg + 2) *
1317 					   ((dbt->brp - 1 ) + 1));
1318 		}
1319 	}
1320 
1321 	netdev_dbg(dev, "writing fdctrl=0x%08x\n", reg_fdctrl);
1322 	priv->write(reg_fdctrl, &regs->fdctrl);
1323 
1324 	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x ctrl2=0x%08x fdctrl=0x%08x cbt=0x%08x fdcbt=0x%08x\n",
1325 		   __func__,
1326 		   priv->read(&regs->mcr), priv->read(&regs->ctrl),
1327 		   priv->read(&regs->ctrl2), priv->read(&regs->fdctrl),
1328 		   priv->read(&regs->cbt), priv->read(&regs->fdcbt));
1329 }
1330 
flexcan_set_bittiming(struct net_device * dev)1331 static void flexcan_set_bittiming(struct net_device *dev)
1332 {
1333 	const struct flexcan_priv *priv = netdev_priv(dev);
1334 	struct flexcan_regs __iomem *regs = priv->regs;
1335 	u32 reg;
1336 
1337 	reg = priv->read(&regs->ctrl);
1338 	reg &= ~(FLEXCAN_CTRL_LPB | FLEXCAN_CTRL_SMP |
1339 		 FLEXCAN_CTRL_LOM);
1340 
1341 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
1342 		reg |= FLEXCAN_CTRL_LPB;
1343 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1344 		reg |= FLEXCAN_CTRL_LOM;
1345 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1346 		reg |= FLEXCAN_CTRL_SMP;
1347 
1348 	netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
1349 	priv->write(reg, &regs->ctrl);
1350 
1351 	if (priv->can.ctrlmode_supported & CAN_CTRLMODE_FD)
1352 		return flexcan_set_bittiming_cbt(dev);
1353 	else
1354 		return flexcan_set_bittiming_ctrl(dev);
1355 }
1356 
flexcan_ram_init(struct net_device * dev)1357 static void flexcan_ram_init(struct net_device *dev)
1358 {
1359 	struct flexcan_priv *priv = netdev_priv(dev);
1360 	struct flexcan_regs __iomem *regs = priv->regs;
1361 	u32 reg_ctrl2;
1362 
1363 	/* 11.8.3.13 Detection and correction of memory errors:
1364 	 * CTRL2[WRMFRZ] grants write access to all memory positions
1365 	 * that require initialization, ranging from 0x080 to 0xADF
1366 	 * and from 0xF28 to 0xFFF when the CAN FD feature is enabled.
1367 	 * The RXMGMASK, RX14MASK, RX15MASK, and RXFGMASK registers
1368 	 * need to be initialized as well. MCR[RFEN] must not be set
1369 	 * during memory initialization.
1370 	 */
1371 	reg_ctrl2 = priv->read(&regs->ctrl2);
1372 	reg_ctrl2 |= FLEXCAN_CTRL2_WRMFRZ;
1373 	priv->write(reg_ctrl2, &regs->ctrl2);
1374 
1375 	memset_io(&regs->init, 0, sizeof(regs->init));
1376 
1377 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
1378 		memset_io(&regs->init_fd, 0, sizeof(regs->init_fd));
1379 
1380 	reg_ctrl2 &= ~FLEXCAN_CTRL2_WRMFRZ;
1381 	priv->write(reg_ctrl2, &regs->ctrl2);
1382 }
1383 
flexcan_rx_offload_setup(struct net_device * dev)1384 static int flexcan_rx_offload_setup(struct net_device *dev)
1385 {
1386 	struct flexcan_priv *priv = netdev_priv(dev);
1387 	int err;
1388 
1389 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
1390 		priv->mb_size = sizeof(struct flexcan_mb) + CANFD_MAX_DLEN;
1391 	else
1392 		priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
1393 
1394 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_MB_16)
1395 		priv->mb_count = 16;
1396 	else
1397 		priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
1398 				 (sizeof(priv->regs->mb[1]) / priv->mb_size);
1399 
1400 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
1401 		priv->tx_mb_reserved =
1402 			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_RX_MAILBOX);
1403 	else
1404 		priv->tx_mb_reserved =
1405 			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_RX_FIFO);
1406 	priv->tx_mb_idx = priv->mb_count - 1;
1407 	priv->tx_mb = flexcan_get_mb(priv, priv->tx_mb_idx);
1408 	priv->tx_mask = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
1409 
1410 	priv->offload.mailbox_read = flexcan_mailbox_read;
1411 
1412 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
1413 		priv->offload.mb_first = FLEXCAN_RX_MB_RX_MAILBOX_FIRST;
1414 		priv->offload.mb_last = priv->mb_count - 2;
1415 
1416 		priv->rx_mask = GENMASK_ULL(priv->offload.mb_last,
1417 					    priv->offload.mb_first);
1418 		err = can_rx_offload_add_timestamp(dev, &priv->offload);
1419 	} else {
1420 		priv->rx_mask = FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
1421 			FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
1422 		err = can_rx_offload_add_fifo(dev, &priv->offload,
1423 					      FLEXCAN_NAPI_WEIGHT);
1424 	}
1425 
1426 	return err;
1427 }
1428 
flexcan_chip_interrupts_enable(const struct net_device * dev)1429 static void flexcan_chip_interrupts_enable(const struct net_device *dev)
1430 {
1431 	const struct flexcan_priv *priv = netdev_priv(dev);
1432 	struct flexcan_regs __iomem *regs = priv->regs;
1433 	u64 reg_imask;
1434 
1435 	disable_irq(dev->irq);
1436 	priv->write(priv->reg_ctrl_default, &regs->ctrl);
1437 	reg_imask = priv->rx_mask | priv->tx_mask;
1438 	priv->write(upper_32_bits(reg_imask), &regs->imask2);
1439 	priv->write(lower_32_bits(reg_imask), &regs->imask1);
1440 	enable_irq(dev->irq);
1441 }
1442 
flexcan_chip_interrupts_disable(const struct net_device * dev)1443 static void flexcan_chip_interrupts_disable(const struct net_device *dev)
1444 {
1445 	const struct flexcan_priv *priv = netdev_priv(dev);
1446 	struct flexcan_regs __iomem *regs = priv->regs;
1447 
1448 	priv->write(0, &regs->imask2);
1449 	priv->write(0, &regs->imask1);
1450 	priv->write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
1451 		    &regs->ctrl);
1452 }
1453 
1454 /* flexcan_chip_start
1455  *
1456  * this functions is entered with clocks enabled
1457  *
1458  */
flexcan_chip_start(struct net_device * dev)1459 static int flexcan_chip_start(struct net_device *dev)
1460 {
1461 	struct flexcan_priv *priv = netdev_priv(dev);
1462 	struct flexcan_regs __iomem *regs = priv->regs;
1463 	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
1464 	int err, i;
1465 	struct flexcan_mb __iomem *mb;
1466 
1467 	/* enable module */
1468 	err = flexcan_chip_enable(priv);
1469 	if (err)
1470 		return err;
1471 
1472 	/* soft reset */
1473 	err = flexcan_chip_softreset(priv);
1474 	if (err)
1475 		goto out_chip_disable;
1476 
1477 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SUPPORT_ECC)
1478 		flexcan_ram_init(dev);
1479 
1480 	flexcan_set_bittiming(dev);
1481 
1482 	/* set freeze, halt */
1483 	err = flexcan_chip_freeze(priv);
1484 	if (err)
1485 		goto out_chip_disable;
1486 
1487 	/* MCR
1488 	 *
1489 	 * only supervisor access
1490 	 * enable warning int
1491 	 * enable individual RX masking
1492 	 * choose format C
1493 	 * set max mailbox number
1494 	 */
1495 	reg_mcr = priv->read(&regs->mcr);
1496 	reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
1497 	reg_mcr |= FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IRMQ |
1498 		FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
1499 
1500 	/* MCR
1501 	 *
1502 	 * FIFO:
1503 	 * - disable for mailbox mode
1504 	 * - enable for FIFO mode
1505 	 */
1506 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX)
1507 		reg_mcr &= ~FLEXCAN_MCR_FEN;
1508 	else
1509 		reg_mcr |= FLEXCAN_MCR_FEN;
1510 
1511 	/* MCR
1512 	 *
1513 	 * NOTE: In loopback mode, the CAN_MCR[SRXDIS] cannot be
1514 	 *       asserted because this will impede the self reception
1515 	 *       of a transmitted message. This is not documented in
1516 	 *       earlier versions of flexcan block guide.
1517 	 *
1518 	 * Self Reception:
1519 	 * - enable Self Reception for loopback mode
1520 	 *   (by clearing "Self Reception Disable" bit)
1521 	 * - disable for normal operation
1522 	 */
1523 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
1524 		reg_mcr &= ~FLEXCAN_MCR_SRX_DIS;
1525 	else
1526 		reg_mcr |= FLEXCAN_MCR_SRX_DIS;
1527 
1528 	/* MCR - CAN-FD */
1529 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
1530 		reg_mcr |= FLEXCAN_MCR_FDEN;
1531 	else
1532 		reg_mcr &= ~FLEXCAN_MCR_FDEN;
1533 
1534 	netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
1535 	priv->write(reg_mcr, &regs->mcr);
1536 
1537 	/* CTRL
1538 	 *
1539 	 * disable timer sync feature
1540 	 *
1541 	 * disable auto busoff recovery
1542 	 * transmit lowest buffer first
1543 	 *
1544 	 * enable tx and rx warning interrupt
1545 	 * enable bus off interrupt
1546 	 * (== FLEXCAN_CTRL_ERR_STATE)
1547 	 */
1548 	reg_ctrl = priv->read(&regs->ctrl);
1549 	reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
1550 	reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
1551 		FLEXCAN_CTRL_ERR_STATE;
1552 
1553 	/* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
1554 	 * on most Flexcan cores, too. Otherwise we don't get
1555 	 * any error warning or passive interrupts.
1556 	 */
1557 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
1558 	    priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
1559 		reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
1560 	else
1561 		reg_ctrl &= ~FLEXCAN_CTRL_ERR_MSK;
1562 
1563 	/* save for later use */
1564 	priv->reg_ctrl_default = reg_ctrl;
1565 	/* leave interrupts disabled for now */
1566 	reg_ctrl &= ~FLEXCAN_CTRL_ERR_ALL;
1567 	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
1568 	priv->write(reg_ctrl, &regs->ctrl);
1569 
1570 	if ((priv->devtype_data.quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
1571 		reg_ctrl2 = priv->read(&regs->ctrl2);
1572 		reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
1573 		priv->write(reg_ctrl2, &regs->ctrl2);
1574 	}
1575 
1576 	if (priv->can.ctrlmode_supported & CAN_CTRLMODE_FD) {
1577 		u32 reg_fdctrl;
1578 
1579 		reg_fdctrl = priv->read(&regs->fdctrl);
1580 		reg_fdctrl &= ~(FIELD_PREP(FLEXCAN_FDCTRL_MBDSR1, 0x3) |
1581 				FIELD_PREP(FLEXCAN_FDCTRL_MBDSR0, 0x3));
1582 
1583 		if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1584 			reg_fdctrl |=
1585 				FIELD_PREP(FLEXCAN_FDCTRL_MBDSR1,
1586 					   FLEXCAN_FDCTRL_MBDSR_64) |
1587 				FIELD_PREP(FLEXCAN_FDCTRL_MBDSR0,
1588 					   FLEXCAN_FDCTRL_MBDSR_64);
1589 		} else {
1590 			reg_fdctrl |=
1591 				FIELD_PREP(FLEXCAN_FDCTRL_MBDSR1,
1592 					   FLEXCAN_FDCTRL_MBDSR_8) |
1593 				FIELD_PREP(FLEXCAN_FDCTRL_MBDSR0,
1594 					   FLEXCAN_FDCTRL_MBDSR_8);
1595 		}
1596 
1597 		netdev_dbg(dev, "%s: writing fdctrl=0x%08x",
1598 			   __func__, reg_fdctrl);
1599 		priv->write(reg_fdctrl, &regs->fdctrl);
1600 	}
1601 
1602 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_USE_RX_MAILBOX) {
1603 		for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++) {
1604 			mb = flexcan_get_mb(priv, i);
1605 			priv->write(FLEXCAN_MB_CODE_RX_EMPTY,
1606 				    &mb->can_ctrl);
1607 		}
1608 	} else {
1609 		/* clear and invalidate unused mailboxes first */
1610 		for (i = FLEXCAN_TX_MB_RESERVED_RX_FIFO; i < priv->mb_count; i++) {
1611 			mb = flexcan_get_mb(priv, i);
1612 			priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
1613 				    &mb->can_ctrl);
1614 		}
1615 	}
1616 
1617 	/* Errata ERR005829: mark first TX mailbox as INACTIVE */
1618 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
1619 		    &priv->tx_mb_reserved->can_ctrl);
1620 
1621 	/* mark TX mailbox as INACTIVE */
1622 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
1623 		    &priv->tx_mb->can_ctrl);
1624 
1625 	/* acceptance mask/acceptance code (accept everything) */
1626 	priv->write(0x0, &regs->rxgmask);
1627 	priv->write(0x0, &regs->rx14mask);
1628 	priv->write(0x0, &regs->rx15mask);
1629 
1630 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
1631 		priv->write(0x0, &regs->rxfgmask);
1632 
1633 	/* clear acceptance filters */
1634 	for (i = 0; i < priv->mb_count; i++)
1635 		priv->write(0, &regs->rximr[i]);
1636 
1637 	/* On Vybrid, disable non-correctable errors interrupt and
1638 	 * freeze mode. It still can correct the correctable errors
1639 	 * when HW supports ECC.
1640 	 *
1641 	 * This also works around errata e5295 which generates false
1642 	 * positive memory errors and put the device in freeze mode.
1643 	 */
1644 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
1645 		/* Follow the protocol as described in "Detection
1646 		 * and Correction of Memory Errors" to write to
1647 		 * MECR register (step 1 - 5)
1648 		 *
1649 		 * 1. By default, CTRL2[ECRWRE] = 0, MECR[ECRWRDIS] = 1
1650 		 * 2. set CTRL2[ECRWRE]
1651 		 */
1652 		reg_ctrl2 = priv->read(&regs->ctrl2);
1653 		reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE;
1654 		priv->write(reg_ctrl2, &regs->ctrl2);
1655 
1656 		/* 3. clear MECR[ECRWRDIS] */
1657 		reg_mecr = priv->read(&regs->mecr);
1658 		reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
1659 		priv->write(reg_mecr, &regs->mecr);
1660 
1661 		/* 4. all writes to MECR must keep MECR[ECRWRDIS] cleared */
1662 		reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
1663 			      FLEXCAN_MECR_FANCEI_MSK);
1664 		priv->write(reg_mecr, &regs->mecr);
1665 
1666 		/* 5. after configuration done, lock MECR by either
1667 		 * setting MECR[ECRWRDIS] or clearing CTRL2[ECRWRE]
1668 		 */
1669 		reg_mecr |= FLEXCAN_MECR_ECRWRDIS;
1670 		priv->write(reg_mecr, &regs->mecr);
1671 
1672 		reg_ctrl2 &= ~FLEXCAN_CTRL2_ECRWRE;
1673 		priv->write(reg_ctrl2, &regs->ctrl2);
1674 	}
1675 
1676 	/* synchronize with the can bus */
1677 	err = flexcan_chip_unfreeze(priv);
1678 	if (err)
1679 		goto out_chip_disable;
1680 
1681 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1682 
1683 	/* print chip status */
1684 	netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
1685 		   priv->read(&regs->mcr), priv->read(&regs->ctrl));
1686 
1687 	return 0;
1688 
1689  out_chip_disable:
1690 	flexcan_chip_disable(priv);
1691 	return err;
1692 }
1693 
1694 /* __flexcan_chip_stop
1695  *
1696  * this function is entered with clocks enabled
1697  */
__flexcan_chip_stop(struct net_device * dev,bool disable_on_error)1698 static int __flexcan_chip_stop(struct net_device *dev, bool disable_on_error)
1699 {
1700 	struct flexcan_priv *priv = netdev_priv(dev);
1701 	int err;
1702 
1703 	/* freeze + disable module */
1704 	err = flexcan_chip_freeze(priv);
1705 	if (err && !disable_on_error)
1706 		return err;
1707 	err = flexcan_chip_disable(priv);
1708 	if (err && !disable_on_error)
1709 		goto out_chip_unfreeze;
1710 
1711 	priv->can.state = CAN_STATE_STOPPED;
1712 
1713 	return 0;
1714 
1715  out_chip_unfreeze:
1716 	flexcan_chip_unfreeze(priv);
1717 
1718 	return err;
1719 }
1720 
flexcan_chip_stop_disable_on_error(struct net_device * dev)1721 static inline int flexcan_chip_stop_disable_on_error(struct net_device *dev)
1722 {
1723 	return __flexcan_chip_stop(dev, true);
1724 }
1725 
flexcan_chip_stop(struct net_device * dev)1726 static inline int flexcan_chip_stop(struct net_device *dev)
1727 {
1728 	return __flexcan_chip_stop(dev, false);
1729 }
1730 
flexcan_open(struct net_device * dev)1731 static int flexcan_open(struct net_device *dev)
1732 {
1733 	struct flexcan_priv *priv = netdev_priv(dev);
1734 	int err;
1735 
1736 	if ((priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) &&
1737 	    (priv->can.ctrlmode & CAN_CTRLMODE_FD)) {
1738 		netdev_err(dev, "Three Samples mode and CAN-FD mode can't be used together\n");
1739 		return -EINVAL;
1740 	}
1741 
1742 	err = pm_runtime_resume_and_get(priv->dev);
1743 	if (err < 0)
1744 		return err;
1745 
1746 	err = open_candev(dev);
1747 	if (err)
1748 		goto out_runtime_put;
1749 
1750 	err = flexcan_transceiver_enable(priv);
1751 	if (err)
1752 		goto out_close;
1753 
1754 	err = flexcan_rx_offload_setup(dev);
1755 	if (err)
1756 		goto out_transceiver_disable;
1757 
1758 	err = flexcan_chip_start(dev);
1759 	if (err)
1760 		goto out_can_rx_offload_del;
1761 
1762 	can_rx_offload_enable(&priv->offload);
1763 
1764 	err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
1765 	if (err)
1766 		goto out_can_rx_offload_disable;
1767 
1768 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
1769 		err = request_irq(priv->irq_boff,
1770 				  flexcan_irq, IRQF_SHARED, dev->name, dev);
1771 		if (err)
1772 			goto out_free_irq;
1773 
1774 		err = request_irq(priv->irq_err,
1775 				  flexcan_irq, IRQF_SHARED, dev->name, dev);
1776 		if (err)
1777 			goto out_free_irq_boff;
1778 	}
1779 
1780 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SECONDARY_MB_IRQ) {
1781 		err = request_irq(priv->irq_secondary_mb,
1782 				  flexcan_irq, IRQF_SHARED, dev->name, dev);
1783 		if (err)
1784 			goto out_free_irq_err;
1785 	}
1786 
1787 	flexcan_chip_interrupts_enable(dev);
1788 
1789 	netif_start_queue(dev);
1790 
1791 	return 0;
1792 
1793  out_free_irq_err:
1794 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3)
1795 		free_irq(priv->irq_err, dev);
1796  out_free_irq_boff:
1797 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3)
1798 		free_irq(priv->irq_boff, dev);
1799  out_free_irq:
1800 	free_irq(dev->irq, dev);
1801  out_can_rx_offload_disable:
1802 	can_rx_offload_disable(&priv->offload);
1803 	flexcan_chip_stop(dev);
1804  out_can_rx_offload_del:
1805 	can_rx_offload_del(&priv->offload);
1806  out_transceiver_disable:
1807 	flexcan_transceiver_disable(priv);
1808  out_close:
1809 	close_candev(dev);
1810  out_runtime_put:
1811 	pm_runtime_put(priv->dev);
1812 
1813 	return err;
1814 }
1815 
flexcan_close(struct net_device * dev)1816 static int flexcan_close(struct net_device *dev)
1817 {
1818 	struct flexcan_priv *priv = netdev_priv(dev);
1819 
1820 	netif_stop_queue(dev);
1821 	flexcan_chip_interrupts_disable(dev);
1822 
1823 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SECONDARY_MB_IRQ)
1824 		free_irq(priv->irq_secondary_mb, dev);
1825 
1826 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
1827 		free_irq(priv->irq_err, dev);
1828 		free_irq(priv->irq_boff, dev);
1829 	}
1830 
1831 	free_irq(dev->irq, dev);
1832 	can_rx_offload_disable(&priv->offload);
1833 	flexcan_chip_stop_disable_on_error(dev);
1834 
1835 	can_rx_offload_del(&priv->offload);
1836 	flexcan_transceiver_disable(priv);
1837 	close_candev(dev);
1838 
1839 	pm_runtime_put(priv->dev);
1840 
1841 	return 0;
1842 }
1843 
flexcan_set_mode(struct net_device * dev,enum can_mode mode)1844 static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
1845 {
1846 	int err;
1847 
1848 	switch (mode) {
1849 	case CAN_MODE_START:
1850 		err = flexcan_chip_start(dev);
1851 		if (err)
1852 			return err;
1853 
1854 		flexcan_chip_interrupts_enable(dev);
1855 
1856 		netif_wake_queue(dev);
1857 		break;
1858 
1859 	default:
1860 		return -EOPNOTSUPP;
1861 	}
1862 
1863 	return 0;
1864 }
1865 
1866 static const struct net_device_ops flexcan_netdev_ops = {
1867 	.ndo_open	= flexcan_open,
1868 	.ndo_stop	= flexcan_close,
1869 	.ndo_start_xmit	= flexcan_start_xmit,
1870 	.ndo_change_mtu = can_change_mtu,
1871 };
1872 
register_flexcandev(struct net_device * dev)1873 static int register_flexcandev(struct net_device *dev)
1874 {
1875 	struct flexcan_priv *priv = netdev_priv(dev);
1876 	struct flexcan_regs __iomem *regs = priv->regs;
1877 	u32 reg, err;
1878 
1879 	err = flexcan_clks_enable(priv);
1880 	if (err)
1881 		return err;
1882 
1883 	/* select "bus clock", chip must be disabled */
1884 	err = flexcan_chip_disable(priv);
1885 	if (err)
1886 		goto out_clks_disable;
1887 
1888 	reg = priv->read(&regs->ctrl);
1889 	if (priv->clk_src)
1890 		reg |= FLEXCAN_CTRL_CLK_SRC;
1891 	else
1892 		reg &= ~FLEXCAN_CTRL_CLK_SRC;
1893 	priv->write(reg, &regs->ctrl);
1894 
1895 	err = flexcan_chip_enable(priv);
1896 	if (err)
1897 		goto out_chip_disable;
1898 
1899 	/* set freeze, halt */
1900 	err = flexcan_chip_freeze(priv);
1901 	if (err)
1902 		goto out_chip_disable;
1903 
1904 	/* activate FIFO, restrict register access */
1905 	reg = priv->read(&regs->mcr);
1906 	reg |=  FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
1907 	priv->write(reg, &regs->mcr);
1908 
1909 	/* Currently we only support newer versions of this core
1910 	 * featuring a RX hardware FIFO (although this driver doesn't
1911 	 * make use of it on some cores). Older cores, found on some
1912 	 * Coldfire derivates are not tested.
1913 	 */
1914 	reg = priv->read(&regs->mcr);
1915 	if (!(reg & FLEXCAN_MCR_FEN)) {
1916 		netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
1917 		err = -ENODEV;
1918 		goto out_chip_disable;
1919 	}
1920 
1921 	err = register_candev(dev);
1922 	if (err)
1923 		goto out_chip_disable;
1924 
1925 	/* Disable core and let pm_runtime_put() disable the clocks.
1926 	 * If CONFIG_PM is not enabled, the clocks will stay powered.
1927 	 */
1928 	flexcan_chip_disable(priv);
1929 	pm_runtime_put(priv->dev);
1930 
1931 	return 0;
1932 
1933  out_chip_disable:
1934 	flexcan_chip_disable(priv);
1935  out_clks_disable:
1936 	flexcan_clks_disable(priv);
1937 	return err;
1938 }
1939 
unregister_flexcandev(struct net_device * dev)1940 static void unregister_flexcandev(struct net_device *dev)
1941 {
1942 	unregister_candev(dev);
1943 }
1944 
flexcan_setup_stop_mode_gpr(struct platform_device * pdev)1945 static int flexcan_setup_stop_mode_gpr(struct platform_device *pdev)
1946 {
1947 	struct net_device *dev = platform_get_drvdata(pdev);
1948 	struct device_node *np = pdev->dev.of_node;
1949 	struct device_node *gpr_np;
1950 	struct flexcan_priv *priv;
1951 	phandle phandle;
1952 	u32 out_val[3];
1953 	int ret;
1954 
1955 	if (!np)
1956 		return -EINVAL;
1957 
1958 	/* stop mode property format is:
1959 	 * <&gpr req_gpr req_bit>.
1960 	 */
1961 	ret = of_property_read_u32_array(np, "fsl,stop-mode", out_val,
1962 					 ARRAY_SIZE(out_val));
1963 	if (ret) {
1964 		dev_dbg(&pdev->dev, "no stop-mode property\n");
1965 		return ret;
1966 	}
1967 	phandle = *out_val;
1968 
1969 	gpr_np = of_find_node_by_phandle(phandle);
1970 	if (!gpr_np) {
1971 		dev_dbg(&pdev->dev, "could not find gpr node by phandle\n");
1972 		return -ENODEV;
1973 	}
1974 
1975 	priv = netdev_priv(dev);
1976 	priv->stm.gpr = syscon_node_to_regmap(gpr_np);
1977 	if (IS_ERR(priv->stm.gpr)) {
1978 		dev_dbg(&pdev->dev, "could not find gpr regmap\n");
1979 		ret = PTR_ERR(priv->stm.gpr);
1980 		goto out_put_node;
1981 	}
1982 
1983 	priv->stm.req_gpr = out_val[1];
1984 	priv->stm.req_bit = out_val[2];
1985 
1986 	dev_dbg(&pdev->dev,
1987 		"gpr %s req_gpr=0x02%x req_bit=%u\n",
1988 		gpr_np->full_name, priv->stm.req_gpr, priv->stm.req_bit);
1989 
1990 	return 0;
1991 
1992 out_put_node:
1993 	of_node_put(gpr_np);
1994 	return ret;
1995 }
1996 
flexcan_setup_stop_mode_scfw(struct platform_device * pdev)1997 static int flexcan_setup_stop_mode_scfw(struct platform_device *pdev)
1998 {
1999 	struct net_device *dev = platform_get_drvdata(pdev);
2000 	struct flexcan_priv *priv;
2001 	u8 scu_idx;
2002 	int ret;
2003 
2004 	ret = of_property_read_u8(pdev->dev.of_node, "fsl,scu-index", &scu_idx);
2005 	if (ret < 0) {
2006 		dev_dbg(&pdev->dev, "failed to get scu index\n");
2007 		return ret;
2008 	}
2009 
2010 	priv = netdev_priv(dev);
2011 	priv->scu_idx = scu_idx;
2012 
2013 	/* this function could be deferred probe, return -EPROBE_DEFER */
2014 	return imx_scu_get_handle(&priv->sc_ipc_handle);
2015 }
2016 
2017 /* flexcan_setup_stop_mode - Setup stop mode for wakeup
2018  *
2019  * Return: = 0 setup stop mode successfully or doesn't support this feature
2020  *         < 0 fail to setup stop mode (could be deferred probe)
2021  */
flexcan_setup_stop_mode(struct platform_device * pdev)2022 static int flexcan_setup_stop_mode(struct platform_device *pdev)
2023 {
2024 	struct net_device *dev = platform_get_drvdata(pdev);
2025 	struct flexcan_priv *priv;
2026 	int ret;
2027 
2028 	priv = netdev_priv(dev);
2029 
2030 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCFW)
2031 		ret = flexcan_setup_stop_mode_scfw(pdev);
2032 	else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR)
2033 		ret = flexcan_setup_stop_mode_gpr(pdev);
2034 	else if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)
2035 		/* ATF will handle all STOP_IPG related work */
2036 		ret = 0;
2037 	else
2038 		/* return 0 directly if doesn't support stop mode feature */
2039 		return 0;
2040 
2041 	/* If ret is -EINVAL, this means SoC claim to support stop mode, but
2042 	 * dts file lack the stop mode property definition. For this case,
2043 	 * directly return 0, this will skip the wakeup capable setting and
2044 	 * will not block the driver probe.
2045 	 */
2046 	if (ret == -EINVAL)
2047 		return 0;
2048 	else if (ret)
2049 		return ret;
2050 
2051 	device_set_wakeup_capable(&pdev->dev, true);
2052 
2053 	if (of_property_read_bool(pdev->dev.of_node, "wakeup-source"))
2054 		device_set_wakeup_enable(&pdev->dev, true);
2055 
2056 	return 0;
2057 }
2058 
2059 static const struct of_device_id flexcan_of_match[] = {
2060 	{ .compatible = "fsl,imx8qm-flexcan", .data = &fsl_imx8qm_devtype_data, },
2061 	{ .compatible = "fsl,imx8mp-flexcan", .data = &fsl_imx8mp_devtype_data, },
2062 	{ .compatible = "fsl,imx93-flexcan", .data = &fsl_imx93_devtype_data, },
2063 	{ .compatible = "fsl,imx95-flexcan", .data = &fsl_imx95_devtype_data, },
2064 	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
2065 	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
2066 	{ .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
2067 	{ .compatible = "fsl,imx35-flexcan", .data = &fsl_imx25_devtype_data, },
2068 	{ .compatible = "fsl,imx25-flexcan", .data = &fsl_imx25_devtype_data, },
2069 	{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
2070 	{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
2071 	{ .compatible = "fsl,ls1021ar2-flexcan", .data = &fsl_ls1021a_r2_devtype_data, },
2072 	{ .compatible = "fsl,lx2160ar1-flexcan", .data = &fsl_lx2160a_r1_devtype_data, },
2073 	{ .compatible = "nxp,s32g2-flexcan", .data = &nxp_s32g2_devtype_data, },
2074 	{ /* sentinel */ },
2075 };
2076 MODULE_DEVICE_TABLE(of, flexcan_of_match);
2077 
2078 static const struct platform_device_id flexcan_id_table[] = {
2079 	{
2080 		.name = "flexcan-mcf5441x",
2081 		.driver_data = (kernel_ulong_t)&fsl_mcf5441x_devtype_data,
2082 	}, {
2083 		/* sentinel */
2084 	},
2085 };
2086 MODULE_DEVICE_TABLE(platform, flexcan_id_table);
2087 
flexcan_probe(struct platform_device * pdev)2088 static int flexcan_probe(struct platform_device *pdev)
2089 {
2090 	const struct flexcan_devtype_data *devtype_data;
2091 	struct net_device *dev;
2092 	struct flexcan_priv *priv;
2093 	struct regulator *reg_xceiver;
2094 	struct phy *transceiver;
2095 	struct clk *clk_ipg = NULL, *clk_per = NULL;
2096 	struct flexcan_regs __iomem *regs;
2097 	struct flexcan_platform_data *pdata;
2098 	int err, irq;
2099 	u8 clk_src = 1;
2100 	u32 clock_freq = 0;
2101 
2102 	reg_xceiver = devm_regulator_get_optional(&pdev->dev, "xceiver");
2103 	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
2104 		return -EPROBE_DEFER;
2105 	else if (PTR_ERR(reg_xceiver) == -ENODEV)
2106 		reg_xceiver = NULL;
2107 	else if (IS_ERR(reg_xceiver))
2108 		return PTR_ERR(reg_xceiver);
2109 
2110 	transceiver = devm_phy_optional_get(&pdev->dev, NULL);
2111 	if (IS_ERR(transceiver))
2112 		return dev_err_probe(&pdev->dev, PTR_ERR(transceiver),
2113 				     "failed to get phy\n");
2114 
2115 	if (pdev->dev.of_node) {
2116 		of_property_read_u32(pdev->dev.of_node,
2117 				     "clock-frequency", &clock_freq);
2118 		of_property_read_u8(pdev->dev.of_node,
2119 				    "fsl,clk-source", &clk_src);
2120 	} else {
2121 		pdata = dev_get_platdata(&pdev->dev);
2122 		if (pdata) {
2123 			clock_freq = pdata->clock_frequency;
2124 			clk_src = pdata->clk_src;
2125 		}
2126 	}
2127 
2128 	if (!clock_freq) {
2129 		clk_ipg = devm_clk_get(&pdev->dev, "ipg");
2130 		if (IS_ERR(clk_ipg)) {
2131 			dev_err(&pdev->dev, "no ipg clock defined\n");
2132 			return PTR_ERR(clk_ipg);
2133 		}
2134 
2135 		clk_per = devm_clk_get(&pdev->dev, "per");
2136 		if (IS_ERR(clk_per)) {
2137 			dev_err(&pdev->dev, "no per clock defined\n");
2138 			return PTR_ERR(clk_per);
2139 		}
2140 		clock_freq = clk_get_rate(clk_per);
2141 	}
2142 
2143 	irq = platform_get_irq(pdev, 0);
2144 	if (irq < 0)
2145 		return irq;
2146 
2147 	regs = devm_platform_ioremap_resource(pdev, 0);
2148 	if (IS_ERR(regs))
2149 		return PTR_ERR(regs);
2150 
2151 	devtype_data = device_get_match_data(&pdev->dev);
2152 
2153 	if ((devtype_data->quirks & FLEXCAN_QUIRK_SUPPORT_FD) &&
2154 	    !((devtype_data->quirks &
2155 	       (FLEXCAN_QUIRK_USE_RX_MAILBOX |
2156 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
2157 		FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR |
2158 		FLEXCAN_QUIRK_SUPPORT_RX_FIFO)) ==
2159 	      (FLEXCAN_QUIRK_USE_RX_MAILBOX |
2160 	       FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
2161 	       FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR))) {
2162 		dev_err(&pdev->dev, "CAN-FD mode doesn't work in RX-FIFO mode!\n");
2163 		return -EINVAL;
2164 	}
2165 
2166 	if ((devtype_data->quirks &
2167 	     (FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX |
2168 	      FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR)) ==
2169 	    FLEXCAN_QUIRK_SUPPORT_RX_MAILBOX_RTR) {
2170 		dev_err(&pdev->dev,
2171 			"Quirks (0x%08x) inconsistent: RX_MAILBOX_RX supported but not RX_MAILBOX\n",
2172 			devtype_data->quirks);
2173 		return -EINVAL;
2174 	}
2175 
2176 	dev = alloc_candev(sizeof(struct flexcan_priv), 1);
2177 	if (!dev)
2178 		return -ENOMEM;
2179 
2180 	platform_set_drvdata(pdev, dev);
2181 	SET_NETDEV_DEV(dev, &pdev->dev);
2182 
2183 	dev->netdev_ops = &flexcan_netdev_ops;
2184 	dev->ethtool_ops = &flexcan_ethtool_ops;
2185 	dev->irq = irq;
2186 	dev->flags |= IFF_ECHO;
2187 
2188 	priv = netdev_priv(dev);
2189 	priv->devtype_data = *devtype_data;
2190 
2191 	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
2192 	    priv->devtype_data.quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
2193 		priv->read = flexcan_read_be;
2194 		priv->write = flexcan_write_be;
2195 	} else {
2196 		priv->read = flexcan_read_le;
2197 		priv->write = flexcan_write_le;
2198 	}
2199 
2200 	priv->dev = &pdev->dev;
2201 	priv->can.clock.freq = clock_freq;
2202 	priv->can.do_set_mode = flexcan_set_mode;
2203 	priv->can.do_get_berr_counter = flexcan_get_berr_counter;
2204 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
2205 		CAN_CTRLMODE_LISTENONLY	| CAN_CTRLMODE_3_SAMPLES |
2206 		CAN_CTRLMODE_BERR_REPORTING;
2207 	priv->regs = regs;
2208 	priv->clk_ipg = clk_ipg;
2209 	priv->clk_per = clk_per;
2210 	priv->clk_src = clk_src;
2211 	priv->reg_xceiver = reg_xceiver;
2212 	priv->transceiver = transceiver;
2213 
2214 	if (transceiver)
2215 		priv->can.bitrate_max = transceiver->attrs.max_link_rate;
2216 
2217 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_NR_IRQ_3) {
2218 		priv->irq_boff = platform_get_irq(pdev, 1);
2219 		if (priv->irq_boff < 0) {
2220 			err = priv->irq_boff;
2221 			goto failed_platform_get_irq;
2222 		}
2223 		priv->irq_err = platform_get_irq(pdev, 2);
2224 		if (priv->irq_err < 0) {
2225 			err = priv->irq_err;
2226 			goto failed_platform_get_irq;
2227 		}
2228 	}
2229 
2230 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SECONDARY_MB_IRQ) {
2231 		priv->irq_secondary_mb = platform_get_irq_byname(pdev, "mb-1");
2232 		if (priv->irq_secondary_mb < 0) {
2233 			err = priv->irq_secondary_mb;
2234 			goto failed_platform_get_irq;
2235 		}
2236 	}
2237 
2238 	if (priv->devtype_data.quirks & FLEXCAN_QUIRK_SUPPORT_FD) {
2239 		priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD |
2240 			CAN_CTRLMODE_FD_NON_ISO;
2241 		priv->can.bittiming_const = &flexcan_fd_bittiming_const;
2242 		priv->can.data_bittiming_const =
2243 			&flexcan_fd_data_bittiming_const;
2244 	} else {
2245 		priv->can.bittiming_const = &flexcan_bittiming_const;
2246 	}
2247 
2248 	pm_runtime_get_noresume(&pdev->dev);
2249 	pm_runtime_set_active(&pdev->dev);
2250 	pm_runtime_enable(&pdev->dev);
2251 
2252 	err = register_flexcandev(dev);
2253 	if (err) {
2254 		dev_err(&pdev->dev, "registering netdev failed\n");
2255 		goto failed_register;
2256 	}
2257 
2258 	err = flexcan_setup_stop_mode(pdev);
2259 	if (err < 0) {
2260 		dev_err_probe(&pdev->dev, err, "setup stop mode failed\n");
2261 		goto failed_setup_stop_mode;
2262 	}
2263 
2264 	of_can_transceiver(dev);
2265 
2266 	return 0;
2267 
2268  failed_setup_stop_mode:
2269 	unregister_flexcandev(dev);
2270  failed_register:
2271 	pm_runtime_put_noidle(&pdev->dev);
2272 	pm_runtime_disable(&pdev->dev);
2273  failed_platform_get_irq:
2274 	free_candev(dev);
2275 	return err;
2276 }
2277 
flexcan_remove(struct platform_device * pdev)2278 static void flexcan_remove(struct platform_device *pdev)
2279 {
2280 	struct net_device *dev = platform_get_drvdata(pdev);
2281 
2282 	device_set_wakeup_enable(&pdev->dev, false);
2283 	device_set_wakeup_capable(&pdev->dev, false);
2284 	unregister_flexcandev(dev);
2285 	pm_runtime_disable(&pdev->dev);
2286 	free_candev(dev);
2287 }
2288 
flexcan_suspend(struct device * device)2289 static int __maybe_unused flexcan_suspend(struct device *device)
2290 {
2291 	struct net_device *dev = dev_get_drvdata(device);
2292 	struct flexcan_priv *priv = netdev_priv(dev);
2293 	int err;
2294 
2295 	if (netif_running(dev)) {
2296 		/* if wakeup is enabled, enter stop mode
2297 		 * else enter disabled mode.
2298 		 */
2299 		if (device_may_wakeup(device)) {
2300 			enable_irq_wake(dev->irq);
2301 			err = flexcan_enter_stop_mode(priv);
2302 			if (err)
2303 				return err;
2304 		} else {
2305 			err = flexcan_chip_stop(dev);
2306 			if (err)
2307 				return err;
2308 
2309 			flexcan_chip_interrupts_disable(dev);
2310 
2311 			err = flexcan_transceiver_disable(priv);
2312 			if (err)
2313 				return err;
2314 
2315 			err = pinctrl_pm_select_sleep_state(device);
2316 			if (err)
2317 				return err;
2318 		}
2319 		netif_stop_queue(dev);
2320 		netif_device_detach(dev);
2321 
2322 		priv->can.state = CAN_STATE_SLEEPING;
2323 	}
2324 
2325 	return 0;
2326 }
2327 
flexcan_resume(struct device * device)2328 static int __maybe_unused flexcan_resume(struct device *device)
2329 {
2330 	struct net_device *dev = dev_get_drvdata(device);
2331 	struct flexcan_priv *priv = netdev_priv(dev);
2332 	int err;
2333 
2334 	if (netif_running(dev)) {
2335 		netif_device_attach(dev);
2336 		netif_start_queue(dev);
2337 		if (device_may_wakeup(device)) {
2338 			disable_irq_wake(dev->irq);
2339 			err = flexcan_exit_stop_mode(priv);
2340 			if (err)
2341 				return err;
2342 		} else {
2343 			err = pinctrl_pm_select_default_state(device);
2344 			if (err)
2345 				return err;
2346 
2347 			err = flexcan_transceiver_enable(priv);
2348 			if (err)
2349 				return err;
2350 
2351 			err = flexcan_chip_start(dev);
2352 			if (err) {
2353 				flexcan_transceiver_disable(priv);
2354 				return err;
2355 			}
2356 
2357 			flexcan_chip_interrupts_enable(dev);
2358 		}
2359 
2360 		priv->can.state = CAN_STATE_ERROR_ACTIVE;
2361 	}
2362 
2363 	return 0;
2364 }
2365 
flexcan_runtime_suspend(struct device * device)2366 static int __maybe_unused flexcan_runtime_suspend(struct device *device)
2367 {
2368 	struct net_device *dev = dev_get_drvdata(device);
2369 	struct flexcan_priv *priv = netdev_priv(dev);
2370 
2371 	flexcan_clks_disable(priv);
2372 
2373 	return 0;
2374 }
2375 
flexcan_runtime_resume(struct device * device)2376 static int __maybe_unused flexcan_runtime_resume(struct device *device)
2377 {
2378 	struct net_device *dev = dev_get_drvdata(device);
2379 	struct flexcan_priv *priv = netdev_priv(dev);
2380 
2381 	return flexcan_clks_enable(priv);
2382 }
2383 
flexcan_noirq_suspend(struct device * device)2384 static int __maybe_unused flexcan_noirq_suspend(struct device *device)
2385 {
2386 	struct net_device *dev = dev_get_drvdata(device);
2387 	struct flexcan_priv *priv = netdev_priv(dev);
2388 
2389 	if (netif_running(dev)) {
2390 		int err;
2391 
2392 		if (device_may_wakeup(device))
2393 			flexcan_enable_wakeup_irq(priv, true);
2394 
2395 		/* For FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI, it need ATF to send
2396 		 * to SM through SCMI protocol, SM will assert the IPG_STOP
2397 		 * signal. But all this works need the CAN clocks keep on.
2398 		 * After the CAN module get the IPG_STOP mode, and switch to
2399 		 * STOP mode, whether still keep the CAN clocks on or gate them
2400 		 * off depend on the Hardware design.
2401 		 */
2402 		if (!(device_may_wakeup(device) &&
2403 		      priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)) {
2404 			err = pm_runtime_force_suspend(device);
2405 			if (err)
2406 				return err;
2407 		}
2408 	}
2409 
2410 	return 0;
2411 }
2412 
flexcan_noirq_resume(struct device * device)2413 static int __maybe_unused flexcan_noirq_resume(struct device *device)
2414 {
2415 	struct net_device *dev = dev_get_drvdata(device);
2416 	struct flexcan_priv *priv = netdev_priv(dev);
2417 
2418 	if (netif_running(dev)) {
2419 		int err;
2420 
2421 		if (!(device_may_wakeup(device) &&
2422 		      priv->devtype_data.quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE_SCMI)) {
2423 			err = pm_runtime_force_resume(device);
2424 			if (err)
2425 				return err;
2426 		}
2427 
2428 		if (device_may_wakeup(device))
2429 			flexcan_enable_wakeup_irq(priv, false);
2430 	}
2431 
2432 	return 0;
2433 }
2434 
2435 static const struct dev_pm_ops flexcan_pm_ops = {
2436 	SET_SYSTEM_SLEEP_PM_OPS(flexcan_suspend, flexcan_resume)
2437 	SET_RUNTIME_PM_OPS(flexcan_runtime_suspend, flexcan_runtime_resume, NULL)
2438 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(flexcan_noirq_suspend, flexcan_noirq_resume)
2439 };
2440 
2441 static struct platform_driver flexcan_driver = {
2442 	.driver = {
2443 		.name = DRV_NAME,
2444 		.pm = &flexcan_pm_ops,
2445 		.of_match_table = flexcan_of_match,
2446 	},
2447 	.probe = flexcan_probe,
2448 	.remove = flexcan_remove,
2449 	.id_table = flexcan_id_table,
2450 };
2451 
2452 module_platform_driver(flexcan_driver);
2453 
2454 MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
2455 	      "Marc Kleine-Budde <kernel@pengutronix.de>");
2456 MODULE_LICENSE("GPL v2");
2457 MODULE_DESCRIPTION("CAN port driver for flexcan based chip");
2458