xref: /linux/drivers/net/can/esd/esdacc.h (revision ae22a94997b8a03dcb3c922857c203246711f9d4)
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 
39 #define ACC_OV_REG_MODE_MASK_ENDIAN_LITTLE BIT(0)
40 #define ACC_OV_REG_MODE_MASK_BM_ENABLE BIT(1)
41 #define ACC_OV_REG_MODE_MASK_MODE_LED BIT(2)
42 #define ACC_OV_REG_MODE_MASK_TIMER_ENABLE BIT(4)
43 #define ACC_OV_REG_MODE_MASK_TIMER_ONE_SHOT BIT(5)
44 #define ACC_OV_REG_MODE_MASK_TIMER_ABSOLUTE BIT(6)
45 #define ACC_OV_REG_MODE_MASK_TIMER GENMASK(6, 4)
46 #define ACC_OV_REG_MODE_MASK_TS_SRC GENMASK(8, 7)
47 #define ACC_OV_REG_MODE_MASK_I2C_ENABLE BIT(11)
48 #define ACC_OV_REG_MODE_MASK_MSI_ENABLE BIT(14)
49 #define ACC_OV_REG_MODE_MASK_NEW_PSC_ENABLE BIT(15)
50 #define ACC_OV_REG_MODE_MASK_FPGA_RESET BIT(31)
51 
52 /* esdACC CAN Core Module */
53 #define ACC_CORE_OF_CTRL_MODE 0x0000
54 #define ACC_CORE_OF_STATUS_IRQ 0x0008
55 #define ACC_CORE_OF_BRP	0x000c
56 #define ACC_CORE_OF_BTR	0x0010
57 #define ACC_CORE_OF_FBTR 0x0014
58 #define ACC_CORE_OF_STATUS 0x0030
59 #define ACC_CORE_OF_TXFIFO_CONFIG 0x0048
60 #define ACC_CORE_OF_TXFIFO_STATUS 0x004c
61 #define ACC_CORE_OF_TX_STATUS_IRQ 0x0050
62 #define ACC_CORE_OF_TX_ABORT_MASK 0x0054
63 #define ACC_CORE_OF_BM_IRQ_COUNTER 0x0070
64 #define ACC_CORE_OF_TXFIFO_ID 0x00c0
65 #define ACC_CORE_OF_TXFIFO_DLC 0x00c4
66 #define ACC_CORE_OF_TXFIFO_DATA_0 0x00c8
67 #define ACC_CORE_OF_TXFIFO_DATA_1 0x00cc
68 
69 #define ACC_REG_CONTROL_MASK_MODE_RESETMODE BIT(0)
70 #define ACC_REG_CONTROL_MASK_MODE_LOM BIT(1)
71 #define ACC_REG_CONTROL_MASK_MODE_STM BIT(2)
72 #define ACC_REG_CONTROL_MASK_MODE_TRANSEN BIT(5)
73 #define ACC_REG_CONTROL_MASK_MODE_TS BIT(6)
74 #define ACC_REG_CONTROL_MASK_MODE_SCHEDULE BIT(7)
75 
76 #define ACC_REG_CONTROL_MASK_IE_RXTX BIT(8)
77 #define ACC_REG_CONTROL_MASK_IE_TXERROR BIT(9)
78 #define ACC_REG_CONTROL_MASK_IE_ERRWARN BIT(10)
79 #define ACC_REG_CONTROL_MASK_IE_OVERRUN BIT(11)
80 #define ACC_REG_CONTROL_MASK_IE_TSI BIT(12)
81 #define ACC_REG_CONTROL_MASK_IE_ERRPASS BIT(13)
82 #define ACC_REG_CONTROL_MASK_IE_ALI BIT(14)
83 #define ACC_REG_CONTROL_MASK_IE_BUSERR BIT(15)
84 
85 /* BRP and BTR register layout for CAN-Classic version */
86 #define ACC_REG_BRP_CL_MASK_BRP GENMASK(8, 0)
87 #define ACC_REG_BTR_CL_MASK_TSEG1 GENMASK(3, 0)
88 #define ACC_REG_BTR_CL_MASK_TSEG2 GENMASK(18, 16)
89 #define ACC_REG_BTR_CL_MASK_SJW GENMASK(25, 24)
90 
91 /* BRP and BTR register layout for CAN-FD version */
92 #define ACC_REG_BRP_FD_MASK_BRP GENMASK(7, 0)
93 #define ACC_REG_BTR_FD_MASK_TSEG1 GENMASK(7, 0)
94 #define ACC_REG_BTR_FD_MASK_TSEG2 GENMASK(22, 16)
95 #define ACC_REG_BTR_FD_MASK_SJW GENMASK(30, 24)
96 
97 /* 256 BM_MSGs of 32 byte size */
98 #define ACC_CORE_DMAMSG_SIZE 32U
99 #define ACC_CORE_DMABUF_SIZE (256U * ACC_CORE_DMAMSG_SIZE)
100 
101 enum acc_bmmsg_id {
102 	BM_MSG_ID_RXTXDONE = 0x01,
103 	BM_MSG_ID_TXABORT = 0x02,
104 	BM_MSG_ID_OVERRUN = 0x03,
105 	BM_MSG_ID_BUSERR = 0x04,
106 	BM_MSG_ID_ERRPASSIVE = 0x05,
107 	BM_MSG_ID_ERRWARN = 0x06,
108 	BM_MSG_ID_TIMESLICE = 0x07,
109 	BM_MSG_ID_HWTIMER = 0x08,
110 	BM_MSG_ID_HOTPLUG = 0x09,
111 };
112 
113 /* The struct acc_bmmsg_* structure declarations that follow here provide
114  * access to the ring buffer of bus master messages maintained by the FPGA
115  * bus master engine. All bus master messages have the same size of
116  * ACC_CORE_DMAMSG_SIZE and a minimum alignment of ACC_CORE_DMAMSG_SIZE in
117  * memory.
118  *
119  * All structure members are natural aligned. Therefore we should not need
120  * a __packed attribute. All struct acc_bmmsg_* declarations have at least
121  * reserved* members to fill the structure to the full ACC_CORE_DMAMSG_SIZE.
122  *
123  * A failure of this property due padding will be detected at compile time
124  * by static_assert(sizeof(union acc_bmmsg) == ACC_CORE_DMAMSG_SIZE).
125  */
126 
127 struct acc_bmmsg_rxtxdone {
128 	u8 msg_id;
129 	u8 txfifo_level;
130 	u8 reserved1[2];
131 	u8 txtsfifo_level;
132 	u8 reserved2[3];
133 	u32 id;
134 	struct {
135 		u8 len;
136 		u8 txdfifo_idx;
137 		u8 zeroes8;
138 		u8 reserved;
139 	} acc_dlc;
140 	u8 data[CAN_MAX_DLEN];
141 	/* Time stamps in struct acc_ov::timestamp_frequency ticks. */
142 	u64 ts;
143 };
144 
145 struct acc_bmmsg_txabort {
146 	u8 msg_id;
147 	u8 txfifo_level;
148 	u16 abort_mask;
149 	u8 txtsfifo_level;
150 	u8 reserved2[1];
151 	u16 abort_mask_txts;
152 	u64 ts;
153 	u32 reserved3[4];
154 };
155 
156 struct acc_bmmsg_overrun {
157 	u8 msg_id;
158 	u8 txfifo_level;
159 	u8 lost_cnt;
160 	u8 reserved1;
161 	u8 txtsfifo_level;
162 	u8 reserved2[3];
163 	u64 ts;
164 	u32 reserved3[4];
165 };
166 
167 struct acc_bmmsg_buserr {
168 	u8 msg_id;
169 	u8 txfifo_level;
170 	u8 ecc;
171 	u8 reserved1;
172 	u8 txtsfifo_level;
173 	u8 reserved2[3];
174 	u64 ts;
175 	u32 reg_status;
176 	u32 reg_btr;
177 	u32 reserved3[2];
178 };
179 
180 struct acc_bmmsg_errstatechange {
181 	u8 msg_id;
182 	u8 txfifo_level;
183 	u8 reserved1[2];
184 	u8 txtsfifo_level;
185 	u8 reserved2[3];
186 	u64 ts;
187 	u32 reg_status;
188 	u32 reserved3[3];
189 };
190 
191 struct acc_bmmsg_timeslice {
192 	u8 msg_id;
193 	u8 txfifo_level;
194 	u8 reserved1[2];
195 	u8 txtsfifo_level;
196 	u8 reserved2[3];
197 	u64 ts;
198 	u32 reserved3[4];
199 };
200 
201 struct acc_bmmsg_hwtimer {
202 	u8 msg_id;
203 	u8 reserved1[3];
204 	u32 reserved2[1];
205 	u64 timer;
206 	u32 reserved3[4];
207 };
208 
209 struct acc_bmmsg_hotplug {
210 	u8 msg_id;
211 	u8 reserved1[3];
212 	u32 reserved2[7];
213 };
214 
215 union acc_bmmsg {
216 	u8 msg_id;
217 	struct acc_bmmsg_rxtxdone rxtxdone;
218 	struct acc_bmmsg_txabort txabort;
219 	struct acc_bmmsg_overrun overrun;
220 	struct acc_bmmsg_buserr buserr;
221 	struct acc_bmmsg_errstatechange errstatechange;
222 	struct acc_bmmsg_timeslice timeslice;
223 	struct acc_bmmsg_hwtimer hwtimer;
224 };
225 
226 /* Check size of union acc_bmmsg to be of expected size. */
227 static_assert(sizeof(union acc_bmmsg) == ACC_CORE_DMAMSG_SIZE);
228 
229 struct acc_bmfifo {
230 	const union acc_bmmsg *messages;
231 	/* irq_cnt points to an u32 value where the esdACC FPGA deposits
232 	 * the bm_fifo head index in coherent DMA memory. Only bits 7..0
233 	 * are valid. Use READ_ONCE() to access this memory location.
234 	 */
235 	const u32 *irq_cnt;
236 	u32 local_irq_cnt;
237 	u32 msg_fifo_tail;
238 };
239 
240 struct acc_core {
241 	void __iomem *addr;
242 	struct net_device *netdev;
243 	struct acc_bmfifo bmfifo;
244 	u8 tx_fifo_size;
245 	u8 tx_fifo_head;
246 	u8 tx_fifo_tail;
247 };
248 
249 struct acc_ov {
250 	void __iomem *addr;
251 	struct acc_bmfifo bmfifo;
252 	u32 timestamp_frequency;
253 	u32 core_frequency;
254 	u16 version;
255 	u16 features;
256 	u8 total_cores;
257 	u8 active_cores;
258 };
259 
260 struct acc_net_priv {
261 	struct can_priv can; /* must be the first member! */
262 	struct acc_core *core;
263 	struct acc_ov *ov;
264 };
265 
266 static inline u32 acc_read32(struct acc_core *core, unsigned short offs)
267 {
268 	return ioread32be(core->addr + offs);
269 }
270 
271 static inline void acc_write32(struct acc_core *core,
272 			       unsigned short offs, u32 v)
273 {
274 	iowrite32be(v, core->addr + offs);
275 }
276 
277 static inline void acc_write32_noswap(struct acc_core *core,
278 				      unsigned short offs, u32 v)
279 {
280 	iowrite32(v, core->addr + offs);
281 }
282 
283 static inline void acc_set_bits(struct acc_core *core,
284 				unsigned short offs, u32 mask)
285 {
286 	u32 v = acc_read32(core, offs);
287 
288 	v |= mask;
289 	acc_write32(core, offs, v);
290 }
291 
292 static inline void acc_clear_bits(struct acc_core *core,
293 				  unsigned short offs, u32 mask)
294 {
295 	u32 v = acc_read32(core, offs);
296 
297 	v &= ~mask;
298 	acc_write32(core, offs, v);
299 }
300 
301 static inline int acc_resetmode_entered(struct acc_core *core)
302 {
303 	u32 ctrl = acc_read32(core, ACC_CORE_OF_CTRL_MODE);
304 
305 	return (ctrl & ACC_REG_CONTROL_MASK_MODE_RESETMODE) != 0;
306 }
307 
308 static inline u32 acc_ov_read32(struct acc_ov *ov, unsigned short offs)
309 {
310 	return ioread32be(ov->addr + offs);
311 }
312 
313 static inline void acc_ov_write32(struct acc_ov *ov,
314 				  unsigned short offs, u32 v)
315 {
316 	iowrite32be(v, ov->addr + offs);
317 }
318 
319 static inline void acc_ov_set_bits(struct acc_ov *ov,
320 				   unsigned short offs, u32 b)
321 {
322 	u32 v = acc_ov_read32(ov, offs);
323 
324 	v |= b;
325 	acc_ov_write32(ov, offs, v);
326 }
327 
328 static inline void acc_ov_clear_bits(struct acc_ov *ov,
329 				     unsigned short offs, u32 b)
330 {
331 	u32 v = acc_ov_read32(ov, offs);
332 
333 	v &= ~b;
334 	acc_ov_write32(ov, offs, v);
335 }
336 
337 static inline void acc_reset_fpga(struct acc_ov *ov)
338 {
339 	acc_ov_write32(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_FPGA_RESET);
340 
341 	/* (Re-)start and wait for completion of addon detection on the I^2C bus */
342 	acc_ov_set_bits(ov, ACC_OV_OF_MODE, ACC_OV_REG_MODE_MASK_I2C_ENABLE);
343 	mdelay(ACC_I2C_ADDON_DETECT_DELAY_MS);
344 }
345 
346 void acc_init_ov(struct acc_ov *ov, struct device *dev);
347 void acc_init_bm_ptr(struct acc_ov *ov, struct acc_core *cores,
348 		     const void *mem);
349 int acc_open(struct net_device *netdev);
350 int acc_close(struct net_device *netdev);
351 netdev_tx_t acc_start_xmit(struct sk_buff *skb, struct net_device *netdev);
352 int acc_get_berr_counter(const struct net_device *netdev,
353 			 struct can_berr_counter *bec);
354 int acc_set_mode(struct net_device *netdev, enum can_mode mode);
355 int acc_set_bittiming(struct net_device *netdev);
356 irqreturn_t acc_card_interrupt(struct acc_ov *ov, struct acc_core *cores);
357