xref: /linux/drivers/net/can/esd/esdacc.h (revision 55d0969c451159cff86949b38c39171cab962069)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* Copyright (C) 2015 - 2016 Thomas Körper, esd electronic system design gmbh
3  * Copyright (C) 2017 - 2023 Stefan Mätje, esd electronics gmbh
4  */
5 
6 #include <linux/bits.h>
7 #include <linux/can/dev.h>
8 #include <linux/kernel.h>
9 #include <linux/netdevice.h>
10 #include <linux/units.h>
11 
12 #define ACC_TS_FREQ_80MHZ (80 * HZ_PER_MHZ)
13 #define ACC_I2C_ADDON_DETECT_DELAY_MS 10
14 
15 /* esdACC Overview Module */
16 #define ACC_OV_OF_PROBE	0x0000
17 #define ACC_OV_OF_VERSION 0x0004
18 #define ACC_OV_OF_INFO 0x0008
19 #define ACC_OV_OF_CANCORE_FREQ 0x000c
20 #define ACC_OV_OF_TS_FREQ_LO 0x0010
21 #define ACC_OV_OF_TS_FREQ_HI 0x0014
22 #define ACC_OV_OF_IRQ_STATUS_CORES 0x0018
23 #define ACC_OV_OF_TS_CURR_LO 0x001c
24 #define ACC_OV_OF_TS_CURR_HI 0x0020
25 #define ACC_OV_OF_IRQ_STATUS 0x0028
26 #define ACC_OV_OF_MODE 0x002c
27 #define ACC_OV_OF_BM_IRQ_COUNTER 0x0070
28 #define ACC_OV_OF_BM_IRQ_MASK 0x0074
29 #define ACC_OV_OF_MSI_DATA 0x0080
30 #define ACC_OV_OF_MSI_ADDRESSOFFSET 0x0084
31 
32 /* Feature flags are contained in the upper 16 bit of the version
33  * register at ACC_OV_OF_VERSION but only used with these masks after
34  * extraction into an extra variable => (xx - 16).
35  */
36 #define ACC_OV_REG_FEAT_MASK_CANFD BIT(27 - 16)
37 #define ACC_OV_REG_FEAT_MASK_NEW_PSC BIT(28 - 16)
38 #define ACC_OV_REG_FEAT_MASK_DAR BIT(30 - 16)
39 
40 #define ACC_OV_REG_MODE_MASK_ENDIAN_LITTLE BIT(0)
41 #define ACC_OV_REG_MODE_MASK_BM_ENABLE BIT(1)
42 #define ACC_OV_REG_MODE_MASK_MODE_LED BIT(2)
43 #define ACC_OV_REG_MODE_MASK_TIMER_ENABLE BIT(4)
44 #define ACC_OV_REG_MODE_MASK_TIMER_ONE_SHOT BIT(5)
45 #define ACC_OV_REG_MODE_MASK_TIMER_ABSOLUTE BIT(6)
46 #define ACC_OV_REG_MODE_MASK_TIMER GENMASK(6, 4)
47 #define ACC_OV_REG_MODE_MASK_TS_SRC GENMASK(8, 7)
48 #define ACC_OV_REG_MODE_MASK_I2C_ENABLE BIT(11)
49 #define ACC_OV_REG_MODE_MASK_MSI_ENABLE BIT(14)
50 #define ACC_OV_REG_MODE_MASK_NEW_PSC_ENABLE BIT(15)
51 #define ACC_OV_REG_MODE_MASK_FPGA_RESET BIT(31)
52 
53 /* esdACC CAN Core Module */
54 #define ACC_CORE_OF_CTRL 0x0000
55 #define ACC_CORE_OF_STATUS_IRQ 0x0008
56 #define ACC_CORE_OF_BRP	0x000c
57 #define ACC_CORE_OF_BTR	0x0010
58 #define ACC_CORE_OF_FBTR 0x0014
59 #define ACC_CORE_OF_STATUS 0x0030
60 #define ACC_CORE_OF_TXFIFO_CONFIG 0x0048
61 #define ACC_CORE_OF_TXFIFO_STATUS 0x004c
62 #define ACC_CORE_OF_TX_STATUS_IRQ 0x0050
63 #define ACC_CORE_OF_TX_ABORT_MASK 0x0054
64 #define ACC_CORE_OF_BM_IRQ_COUNTER 0x0070
65 #define ACC_CORE_OF_TXFIFO_ID 0x00c0
66 #define ACC_CORE_OF_TXFIFO_DLC 0x00c4
67 #define ACC_CORE_OF_TXFIFO_DATA_0 0x00c8
68 #define ACC_CORE_OF_TXFIFO_DATA_1 0x00cc
69 
70 /* CTRL register layout */
71 #define ACC_REG_CTRL_MASK_RESETMODE BIT(0)
72 #define ACC_REG_CTRL_MASK_LOM BIT(1)
73 #define ACC_REG_CTRL_MASK_STM BIT(2)
74 #define ACC_REG_CTRL_MASK_TRANSEN BIT(5)
75 #define ACC_REG_CTRL_MASK_TS BIT(6)
76 #define ACC_REG_CTRL_MASK_SCHEDULE BIT(7)
77 
78 #define ACC_REG_CTRL_MASK_IE_RXTX BIT(8)
79 #define ACC_REG_CTRL_MASK_IE_TXERROR BIT(9)
80 #define ACC_REG_CTRL_MASK_IE_ERRWARN BIT(10)
81 #define ACC_REG_CTRL_MASK_IE_OVERRUN BIT(11)
82 #define ACC_REG_CTRL_MASK_IE_TSI BIT(12)
83 #define ACC_REG_CTRL_MASK_IE_ERRPASS BIT(13)
84 #define ACC_REG_CTRL_MASK_IE_ALI BIT(14)
85 #define ACC_REG_CTRL_MASK_IE_BUSERR BIT(15)
86 
87 /* BRP and BTR register layout for CAN-Classic version */
88 #define ACC_REG_BRP_CL_MASK_BRP GENMASK(8, 0)
89 #define ACC_REG_BTR_CL_MASK_TSEG1 GENMASK(3, 0)
90 #define ACC_REG_BTR_CL_MASK_TSEG2 GENMASK(18, 16)
91 #define ACC_REG_BTR_CL_MASK_SJW GENMASK(25, 24)
92 
93 /* BRP and BTR register layout for CAN-FD version */
94 #define ACC_REG_BRP_FD_MASK_BRP GENMASK(7, 0)
95 #define ACC_REG_BTR_FD_MASK_TSEG1 GENMASK(7, 0)
96 #define ACC_REG_BTR_FD_MASK_TSEG2 GENMASK(22, 16)
97 #define ACC_REG_BTR_FD_MASK_SJW GENMASK(30, 24)
98 
99 /* 256 BM_MSGs of 32 byte size */
100 #define ACC_CORE_DMAMSG_SIZE 32U
101 #define ACC_CORE_DMABUF_SIZE (256U * ACC_CORE_DMAMSG_SIZE)
102 
103 enum acc_bmmsg_id {
104 	BM_MSG_ID_RXTXDONE = 0x01,
105 	BM_MSG_ID_TXABORT = 0x02,
106 	BM_MSG_ID_OVERRUN = 0x03,
107 	BM_MSG_ID_BUSERR = 0x04,
108 	BM_MSG_ID_ERRPASSIVE = 0x05,
109 	BM_MSG_ID_ERRWARN = 0x06,
110 	BM_MSG_ID_TIMESLICE = 0x07,
111 	BM_MSG_ID_HWTIMER = 0x08,
112 	BM_MSG_ID_HOTPLUG = 0x09,
113 };
114 
115 /* The struct acc_bmmsg_* structure declarations that follow here provide
116  * access to the ring buffer of bus master messages maintained by the FPGA
117  * bus master engine. All bus master messages have the same size of
118  * ACC_CORE_DMAMSG_SIZE and a minimum alignment of ACC_CORE_DMAMSG_SIZE in
119  * memory.
120  *
121  * All structure members are natural aligned. Therefore we should not need
122  * a __packed attribute. All struct acc_bmmsg_* declarations have at least
123  * reserved* members to fill the structure to the full ACC_CORE_DMAMSG_SIZE.
124  *
125  * A failure of this property due padding will be detected at compile time
126  * by static_assert(sizeof(union acc_bmmsg) == ACC_CORE_DMAMSG_SIZE).
127  */
128 
129 struct acc_bmmsg_rxtxdone {
130 	u8 msg_id;
131 	u8 txfifo_level;
132 	u8 reserved1[2];
133 	u8 txtsfifo_level;
134 	u8 reserved2[3];
135 	u32 id;
136 	struct {
137 		u8 len;
138 		u8 txdfifo_idx;
139 		u8 zeroes8;
140 		u8 reserved;
141 	} acc_dlc;
142 	u8 data[CAN_MAX_DLEN];
143 	/* Time stamps in struct acc_ov::timestamp_frequency ticks. */
144 	u64 ts;
145 };
146 
147 struct acc_bmmsg_txabort {
148 	u8 msg_id;
149 	u8 txfifo_level;
150 	u16 abort_mask;
151 	u8 txtsfifo_level;
152 	u8 reserved2[1];
153 	u16 abort_mask_txts;
154 	u64 ts;
155 	u32 reserved3[4];
156 };
157 
158 struct acc_bmmsg_overrun {
159 	u8 msg_id;
160 	u8 txfifo_level;
161 	u8 lost_cnt;
162 	u8 reserved1;
163 	u8 txtsfifo_level;
164 	u8 reserved2[3];
165 	u64 ts;
166 	u32 reserved3[4];
167 };
168 
169 struct acc_bmmsg_buserr {
170 	u8 msg_id;
171 	u8 txfifo_level;
172 	u8 ecc;
173 	u8 reserved1;
174 	u8 txtsfifo_level;
175 	u8 reserved2[3];
176 	u64 ts;
177 	u32 reg_status;
178 	u32 reg_btr;
179 	u32 reserved3[2];
180 };
181 
182 struct acc_bmmsg_errstatechange {
183 	u8 msg_id;
184 	u8 txfifo_level;
185 	u8 reserved1[2];
186 	u8 txtsfifo_level;
187 	u8 reserved2[3];
188 	u64 ts;
189 	u32 reg_status;
190 	u32 reserved3[3];
191 };
192 
193 struct acc_bmmsg_timeslice {
194 	u8 msg_id;
195 	u8 txfifo_level;
196 	u8 reserved1[2];
197 	u8 txtsfifo_level;
198 	u8 reserved2[3];
199 	u64 ts;
200 	u32 reserved3[4];
201 };
202 
203 struct acc_bmmsg_hwtimer {
204 	u8 msg_id;
205 	u8 reserved1[3];
206 	u32 reserved2[1];
207 	u64 timer;
208 	u32 reserved3[4];
209 };
210 
211 struct acc_bmmsg_hotplug {
212 	u8 msg_id;
213 	u8 reserved1[3];
214 	u32 reserved2[7];
215 };
216 
217 union acc_bmmsg {
218 	u8 msg_id;
219 	struct acc_bmmsg_rxtxdone rxtxdone;
220 	struct acc_bmmsg_txabort txabort;
221 	struct acc_bmmsg_overrun overrun;
222 	struct acc_bmmsg_buserr buserr;
223 	struct acc_bmmsg_errstatechange errstatechange;
224 	struct acc_bmmsg_timeslice timeslice;
225 	struct acc_bmmsg_hwtimer hwtimer;
226 };
227 
228 /* Check size of union acc_bmmsg to be of expected size. */
229 static_assert(sizeof(union acc_bmmsg) == ACC_CORE_DMAMSG_SIZE);
230 
231 struct acc_bmfifo {
232 	const union acc_bmmsg *messages;
233 	/* irq_cnt points to an u32 value where the esdACC FPGA deposits
234 	 * the bm_fifo head index in coherent DMA memory. Only bits 7..0
235 	 * are valid. Use READ_ONCE() to access this memory location.
236 	 */
237 	const u32 *irq_cnt;
238 	u32 local_irq_cnt;
239 	u32 msg_fifo_tail;
240 };
241 
242 struct acc_core {
243 	void __iomem *addr;
244 	struct net_device *netdev;
245 	struct acc_bmfifo bmfifo;
246 	u8 tx_fifo_size;
247 	u8 tx_fifo_head;
248 	u8 tx_fifo_tail;
249 };
250 
251 struct acc_ov {
252 	void __iomem *addr;
253 	struct acc_bmfifo bmfifo;
254 	u32 timestamp_frequency;
255 	u32 core_frequency;
256 	u16 version;
257 	u16 features;
258 	u8 total_cores;
259 	u8 active_cores;
260 };
261 
262 struct acc_net_priv {
263 	struct can_priv can; /* must be the first member! */
264 	struct acc_core *core;
265 	struct acc_ov *ov;
266 };
267 
268 static inline u32 acc_read32(struct acc_core *core, unsigned short offs)
269 {
270 	return ioread32be(core->addr + offs);
271 }
272 
273 static inline void acc_write32(struct acc_core *core,
274 			       unsigned short offs, u32 v)
275 {
276 	iowrite32be(v, core->addr + offs);
277 }
278 
279 static inline void acc_write32_noswap(struct acc_core *core,
280 				      unsigned short offs, u32 v)
281 {
282 	iowrite32(v, core->addr + offs);
283 }
284 
285 static inline void acc_set_bits(struct acc_core *core,
286 				unsigned short offs, u32 mask)
287 {
288 	u32 v = acc_read32(core, offs);
289 
290 	v |= mask;
291 	acc_write32(core, offs, v);
292 }
293 
294 static inline void acc_clear_bits(struct acc_core *core,
295 				  unsigned short offs, u32 mask)
296 {
297 	u32 v = acc_read32(core, offs);
298 
299 	v &= ~mask;
300 	acc_write32(core, offs, v);
301 }
302 
303 static inline int acc_resetmode_entered(struct acc_core *core)
304 {
305 	u32 ctrl = acc_read32(core, ACC_CORE_OF_CTRL);
306 
307 	return (ctrl & ACC_REG_CTRL_MASK_RESETMODE) != 0;
308 }
309 
310 static inline u32 acc_ov_read32(struct acc_ov *ov, unsigned short offs)
311 {
312 	return ioread32be(ov->addr + offs);
313 }
314 
315 static inline void acc_ov_write32(struct acc_ov *ov,
316 				  unsigned short offs, u32 v)
317 {
318 	iowrite32be(v, ov->addr + offs);
319 }
320 
321 static inline void acc_ov_set_bits(struct acc_ov *ov,
322 				   unsigned short offs, u32 b)
323 {
324 	u32 v = acc_ov_read32(ov, offs);
325 
326 	v |= b;
327 	acc_ov_write32(ov, offs, v);
328 }
329 
330 static inline void acc_ov_clear_bits(struct acc_ov *ov,
331 				     unsigned short offs, u32 b)
332 {
333 	u32 v = acc_ov_read32(ov, offs);
334 
335 	v &= ~b;
336 	acc_ov_write32(ov, offs, v);
337 }
338 
339 static inline void acc_reset_fpga(struct acc_ov *ov)
340 {
341 	acc_ov_write32(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_FPGA_RESET);
342 
343 	/* (Re-)start and wait for completion of addon detection on the I^2C bus */
344 	acc_ov_set_bits(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_I2C_ENABLE);
345 	mdelay(ACC_I2C_ADDON_DETECT_DELAY_MS);
346 }
347 
348 void acc_init_ov(struct acc_ov *ov, struct device *dev);
349 void acc_init_bm_ptr(struct acc_ov *ov, struct acc_core *cores,
350 		     const void *mem);
351 int acc_open(struct net_device *netdev);
352 int acc_close(struct net_device *netdev);
353 netdev_tx_t acc_start_xmit(struct sk_buff *skb, struct net_device *netdev);
354 int acc_get_berr_counter(const struct net_device *netdev,
355 			 struct can_berr_counter *bec);
356 int acc_set_mode(struct net_device *netdev, enum can_mode mode);
357 int acc_set_bittiming(struct net_device *netdev);
358 irqreturn_t acc_card_interrupt(struct acc_ov *ov, struct acc_core *cores);
359