1 // SPDX-License-Identifier: GPL-2.0
2 // CAN bus driver for Bosch M_CAN controller
3 // Copyright (C) 2014 Freescale Semiconductor, Inc.
4 // Dong Aisheng <b29396@freescale.com>
5 // Copyright (C) 2018-19 Texas Instruments Incorporated - http://www.ti.com/
6
7 /* Bosch M_CAN user manual can be obtained from:
8 * https://github.com/linux-can/can-doc/tree/master/m_can
9 */
10
11 #include <linux/bitfield.h>
12 #include <linux/can/dev.h>
13 #include <linux/ethtool.h>
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/iopoll.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/netdevice.h>
20 #include <linux/of.h>
21 #include <linux/of_device.h>
22 #include <linux/phy/phy.h>
23 #include <linux/pinctrl/consumer.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm_runtime.h>
26
27 #include "m_can.h"
28
29 /* registers definition */
30 enum m_can_reg {
31 M_CAN_CREL = 0x0,
32 M_CAN_ENDN = 0x4,
33 M_CAN_CUST = 0x8,
34 M_CAN_DBTP = 0xc,
35 M_CAN_TEST = 0x10,
36 M_CAN_RWD = 0x14,
37 M_CAN_CCCR = 0x18,
38 M_CAN_NBTP = 0x1c,
39 M_CAN_TSCC = 0x20,
40 M_CAN_TSCV = 0x24,
41 M_CAN_TOCC = 0x28,
42 M_CAN_TOCV = 0x2c,
43 M_CAN_ECR = 0x40,
44 M_CAN_PSR = 0x44,
45 /* TDCR Register only available for version >=3.1.x */
46 M_CAN_TDCR = 0x48,
47 M_CAN_IR = 0x50,
48 M_CAN_IE = 0x54,
49 M_CAN_ILS = 0x58,
50 M_CAN_ILE = 0x5c,
51 M_CAN_GFC = 0x80,
52 M_CAN_SIDFC = 0x84,
53 M_CAN_XIDFC = 0x88,
54 M_CAN_XIDAM = 0x90,
55 M_CAN_HPMS = 0x94,
56 M_CAN_NDAT1 = 0x98,
57 M_CAN_NDAT2 = 0x9c,
58 M_CAN_RXF0C = 0xa0,
59 M_CAN_RXF0S = 0xa4,
60 M_CAN_RXF0A = 0xa8,
61 M_CAN_RXBC = 0xac,
62 M_CAN_RXF1C = 0xb0,
63 M_CAN_RXF1S = 0xb4,
64 M_CAN_RXF1A = 0xb8,
65 M_CAN_RXESC = 0xbc,
66 M_CAN_TXBC = 0xc0,
67 M_CAN_TXFQS = 0xc4,
68 M_CAN_TXESC = 0xc8,
69 M_CAN_TXBRP = 0xcc,
70 M_CAN_TXBAR = 0xd0,
71 M_CAN_TXBCR = 0xd4,
72 M_CAN_TXBTO = 0xd8,
73 M_CAN_TXBCF = 0xdc,
74 M_CAN_TXBTIE = 0xe0,
75 M_CAN_TXBCIE = 0xe4,
76 M_CAN_TXEFC = 0xf0,
77 M_CAN_TXEFS = 0xf4,
78 M_CAN_TXEFA = 0xf8,
79 };
80
81 /* message ram configuration data length */
82 #define MRAM_CFG_LEN 8
83
84 /* Core Release Register (CREL) */
85 #define CREL_REL_MASK GENMASK(31, 28)
86 #define CREL_STEP_MASK GENMASK(27, 24)
87 #define CREL_SUBSTEP_MASK GENMASK(23, 20)
88
89 /* Data Bit Timing & Prescaler Register (DBTP) */
90 #define DBTP_TDC BIT(23)
91 #define DBTP_DBRP_MASK GENMASK(20, 16)
92 #define DBTP_DTSEG1_MASK GENMASK(12, 8)
93 #define DBTP_DTSEG2_MASK GENMASK(7, 4)
94 #define DBTP_DSJW_MASK GENMASK(3, 0)
95
96 /* Transmitter Delay Compensation Register (TDCR) */
97 #define TDCR_TDCO_MASK GENMASK(14, 8)
98 #define TDCR_TDCF_MASK GENMASK(6, 0)
99
100 /* Test Register (TEST) */
101 #define TEST_LBCK BIT(4)
102
103 /* CC Control Register (CCCR) */
104 #define CCCR_TXP BIT(14)
105 #define CCCR_TEST BIT(7)
106 #define CCCR_DAR BIT(6)
107 #define CCCR_MON BIT(5)
108 #define CCCR_CSR BIT(4)
109 #define CCCR_CSA BIT(3)
110 #define CCCR_ASM BIT(2)
111 #define CCCR_CCE BIT(1)
112 #define CCCR_INIT BIT(0)
113 /* for version 3.0.x */
114 #define CCCR_CMR_MASK GENMASK(11, 10)
115 #define CCCR_CMR_CANFD 0x1
116 #define CCCR_CMR_CANFD_BRS 0x2
117 #define CCCR_CMR_CAN 0x3
118 #define CCCR_CME_MASK GENMASK(9, 8)
119 #define CCCR_CME_CAN 0
120 #define CCCR_CME_CANFD 0x1
121 #define CCCR_CME_CANFD_BRS 0x2
122 /* for version >=3.1.x */
123 #define CCCR_EFBI BIT(13)
124 #define CCCR_PXHD BIT(12)
125 #define CCCR_BRSE BIT(9)
126 #define CCCR_FDOE BIT(8)
127 /* for version >=3.2.x */
128 #define CCCR_NISO BIT(15)
129 /* for version >=3.3.x */
130 #define CCCR_WMM BIT(11)
131 #define CCCR_UTSU BIT(10)
132
133 /* Nominal Bit Timing & Prescaler Register (NBTP) */
134 #define NBTP_NSJW_MASK GENMASK(31, 25)
135 #define NBTP_NBRP_MASK GENMASK(24, 16)
136 #define NBTP_NTSEG1_MASK GENMASK(15, 8)
137 #define NBTP_NTSEG2_MASK GENMASK(6, 0)
138
139 /* Timestamp Counter Configuration Register (TSCC) */
140 #define TSCC_TCP_MASK GENMASK(19, 16)
141 #define TSCC_TSS_MASK GENMASK(1, 0)
142 #define TSCC_TSS_DISABLE 0x0
143 #define TSCC_TSS_INTERNAL 0x1
144 #define TSCC_TSS_EXTERNAL 0x2
145
146 /* Timestamp Counter Value Register (TSCV) */
147 #define TSCV_TSC_MASK GENMASK(15, 0)
148
149 /* Error Counter Register (ECR) */
150 #define ECR_RP BIT(15)
151 #define ECR_REC_MASK GENMASK(14, 8)
152 #define ECR_TEC_MASK GENMASK(7, 0)
153
154 /* Protocol Status Register (PSR) */
155 #define PSR_BO BIT(7)
156 #define PSR_EW BIT(6)
157 #define PSR_EP BIT(5)
158 #define PSR_LEC_MASK GENMASK(2, 0)
159 #define PSR_DLEC_MASK GENMASK(10, 8)
160
161 /* Interrupt Register (IR) */
162 #define IR_ALL_INT 0xffffffff
163
164 /* Renamed bits for versions > 3.1.x */
165 #define IR_ARA BIT(29)
166 #define IR_PED BIT(28)
167 #define IR_PEA BIT(27)
168
169 /* Bits for version 3.0.x */
170 #define IR_STE BIT(31)
171 #define IR_FOE BIT(30)
172 #define IR_ACKE BIT(29)
173 #define IR_BE BIT(28)
174 #define IR_CRCE BIT(27)
175 #define IR_WDI BIT(26)
176 #define IR_BO BIT(25)
177 #define IR_EW BIT(24)
178 #define IR_EP BIT(23)
179 #define IR_ELO BIT(22)
180 #define IR_BEU BIT(21)
181 #define IR_BEC BIT(20)
182 #define IR_DRX BIT(19)
183 #define IR_TOO BIT(18)
184 #define IR_MRAF BIT(17)
185 #define IR_TSW BIT(16)
186 #define IR_TEFL BIT(15)
187 #define IR_TEFF BIT(14)
188 #define IR_TEFW BIT(13)
189 #define IR_TEFN BIT(12)
190 #define IR_TFE BIT(11)
191 #define IR_TCF BIT(10)
192 #define IR_TC BIT(9)
193 #define IR_HPM BIT(8)
194 #define IR_RF1L BIT(7)
195 #define IR_RF1F BIT(6)
196 #define IR_RF1W BIT(5)
197 #define IR_RF1N BIT(4)
198 #define IR_RF0L BIT(3)
199 #define IR_RF0F BIT(2)
200 #define IR_RF0W BIT(1)
201 #define IR_RF0N BIT(0)
202 #define IR_ERR_STATE (IR_BO | IR_EW | IR_EP)
203
204 /* Interrupts for version 3.0.x */
205 #define IR_ERR_LEC_30X (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
206 #define IR_ERR_BUS_30X (IR_ERR_LEC_30X | IR_WDI | IR_BEU | IR_BEC | \
207 IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
208 IR_RF0L)
209 #define IR_ERR_ALL_30X (IR_ERR_STATE | IR_ERR_BUS_30X)
210
211 /* Interrupts for version >= 3.1.x */
212 #define IR_ERR_LEC_31X (IR_PED | IR_PEA)
213 #define IR_ERR_BUS_31X (IR_ERR_LEC_31X | IR_WDI | IR_BEU | IR_BEC | \
214 IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
215 IR_RF0L)
216 #define IR_ERR_ALL_31X (IR_ERR_STATE | IR_ERR_BUS_31X)
217
218 /* Interrupt Line Select (ILS) */
219 #define ILS_ALL_INT0 0x0
220 #define ILS_ALL_INT1 0xFFFFFFFF
221
222 /* Interrupt Line Enable (ILE) */
223 #define ILE_EINT1 BIT(1)
224 #define ILE_EINT0 BIT(0)
225
226 /* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
227 #define RXFC_FWM_MASK GENMASK(30, 24)
228 #define RXFC_FS_MASK GENMASK(22, 16)
229
230 /* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
231 #define RXFS_RFL BIT(25)
232 #define RXFS_FF BIT(24)
233 #define RXFS_FPI_MASK GENMASK(21, 16)
234 #define RXFS_FGI_MASK GENMASK(13, 8)
235 #define RXFS_FFL_MASK GENMASK(6, 0)
236
237 /* Rx Buffer / FIFO Element Size Configuration (RXESC) */
238 #define RXESC_RBDS_MASK GENMASK(10, 8)
239 #define RXESC_F1DS_MASK GENMASK(6, 4)
240 #define RXESC_F0DS_MASK GENMASK(2, 0)
241 #define RXESC_64B 0x7
242
243 /* Tx Buffer Configuration (TXBC) */
244 #define TXBC_TFQS_MASK GENMASK(29, 24)
245 #define TXBC_NDTB_MASK GENMASK(21, 16)
246
247 /* Tx FIFO/Queue Status (TXFQS) */
248 #define TXFQS_TFQF BIT(21)
249 #define TXFQS_TFQPI_MASK GENMASK(20, 16)
250 #define TXFQS_TFGI_MASK GENMASK(12, 8)
251 #define TXFQS_TFFL_MASK GENMASK(5, 0)
252
253 /* Tx Buffer Element Size Configuration (TXESC) */
254 #define TXESC_TBDS_MASK GENMASK(2, 0)
255 #define TXESC_TBDS_64B 0x7
256
257 /* Tx Event FIFO Configuration (TXEFC) */
258 #define TXEFC_EFS_MASK GENMASK(21, 16)
259
260 /* Tx Event FIFO Status (TXEFS) */
261 #define TXEFS_TEFL BIT(25)
262 #define TXEFS_EFF BIT(24)
263 #define TXEFS_EFGI_MASK GENMASK(12, 8)
264 #define TXEFS_EFFL_MASK GENMASK(5, 0)
265
266 /* Tx Event FIFO Acknowledge (TXEFA) */
267 #define TXEFA_EFAI_MASK GENMASK(4, 0)
268
269 /* Message RAM Configuration (in bytes) */
270 #define SIDF_ELEMENT_SIZE 4
271 #define XIDF_ELEMENT_SIZE 8
272 #define RXF0_ELEMENT_SIZE 72
273 #define RXF1_ELEMENT_SIZE 72
274 #define RXB_ELEMENT_SIZE 72
275 #define TXE_ELEMENT_SIZE 8
276 #define TXB_ELEMENT_SIZE 72
277
278 /* Message RAM Elements */
279 #define M_CAN_FIFO_ID 0x0
280 #define M_CAN_FIFO_DLC 0x4
281 #define M_CAN_FIFO_DATA 0x8
282
283 /* Rx Buffer Element */
284 /* R0 */
285 #define RX_BUF_ESI BIT(31)
286 #define RX_BUF_XTD BIT(30)
287 #define RX_BUF_RTR BIT(29)
288 /* R1 */
289 #define RX_BUF_ANMF BIT(31)
290 #define RX_BUF_FDF BIT(21)
291 #define RX_BUF_BRS BIT(20)
292 #define RX_BUF_RXTS_MASK GENMASK(15, 0)
293
294 /* Tx Buffer Element */
295 /* T0 */
296 #define TX_BUF_ESI BIT(31)
297 #define TX_BUF_XTD BIT(30)
298 #define TX_BUF_RTR BIT(29)
299 /* T1 */
300 #define TX_BUF_EFC BIT(23)
301 #define TX_BUF_FDF BIT(21)
302 #define TX_BUF_BRS BIT(20)
303 #define TX_BUF_MM_MASK GENMASK(31, 24)
304 #define TX_BUF_DLC_MASK GENMASK(19, 16)
305
306 /* Tx event FIFO Element */
307 /* E1 */
308 #define TX_EVENT_MM_MASK GENMASK(31, 24)
309 #define TX_EVENT_TXTS_MASK GENMASK(15, 0)
310
311 /* The ID and DLC registers are adjacent in M_CAN FIFO memory,
312 * and we can save a (potentially slow) bus round trip by combining
313 * reads and writes to them.
314 */
315 struct id_and_dlc {
316 u32 id;
317 u32 dlc;
318 };
319
m_can_read(struct m_can_classdev * cdev,enum m_can_reg reg)320 static inline u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg)
321 {
322 return cdev->ops->read_reg(cdev, reg);
323 }
324
m_can_write(struct m_can_classdev * cdev,enum m_can_reg reg,u32 val)325 static inline void m_can_write(struct m_can_classdev *cdev, enum m_can_reg reg,
326 u32 val)
327 {
328 cdev->ops->write_reg(cdev, reg, val);
329 }
330
331 static int
m_can_fifo_read(struct m_can_classdev * cdev,u32 fgi,unsigned int offset,void * val,size_t val_count)332 m_can_fifo_read(struct m_can_classdev *cdev,
333 u32 fgi, unsigned int offset, void *val, size_t val_count)
334 {
335 u32 addr_offset = cdev->mcfg[MRAM_RXF0].off + fgi * RXF0_ELEMENT_SIZE +
336 offset;
337
338 if (val_count == 0)
339 return 0;
340
341 return cdev->ops->read_fifo(cdev, addr_offset, val, val_count);
342 }
343
344 static int
m_can_fifo_write(struct m_can_classdev * cdev,u32 fpi,unsigned int offset,const void * val,size_t val_count)345 m_can_fifo_write(struct m_can_classdev *cdev,
346 u32 fpi, unsigned int offset, const void *val, size_t val_count)
347 {
348 u32 addr_offset = cdev->mcfg[MRAM_TXB].off + fpi * TXB_ELEMENT_SIZE +
349 offset;
350
351 if (val_count == 0)
352 return 0;
353
354 return cdev->ops->write_fifo(cdev, addr_offset, val, val_count);
355 }
356
m_can_fifo_write_no_off(struct m_can_classdev * cdev,u32 fpi,u32 val)357 static inline int m_can_fifo_write_no_off(struct m_can_classdev *cdev,
358 u32 fpi, u32 val)
359 {
360 return cdev->ops->write_fifo(cdev, fpi, &val, 1);
361 }
362
363 static int
m_can_txe_fifo_read(struct m_can_classdev * cdev,u32 fgi,u32 offset,u32 * val)364 m_can_txe_fifo_read(struct m_can_classdev *cdev, u32 fgi, u32 offset, u32 *val)
365 {
366 u32 addr_offset = cdev->mcfg[MRAM_TXE].off + fgi * TXE_ELEMENT_SIZE +
367 offset;
368
369 return cdev->ops->read_fifo(cdev, addr_offset, val, 1);
370 }
371
_m_can_tx_fifo_full(u32 txfqs)372 static inline bool _m_can_tx_fifo_full(u32 txfqs)
373 {
374 return !!(txfqs & TXFQS_TFQF);
375 }
376
m_can_tx_fifo_full(struct m_can_classdev * cdev)377 static inline bool m_can_tx_fifo_full(struct m_can_classdev *cdev)
378 {
379 return _m_can_tx_fifo_full(m_can_read(cdev, M_CAN_TXFQS));
380 }
381
m_can_config_endisable(struct m_can_classdev * cdev,bool enable)382 static void m_can_config_endisable(struct m_can_classdev *cdev, bool enable)
383 {
384 u32 cccr = m_can_read(cdev, M_CAN_CCCR);
385 u32 timeout = 10;
386 u32 val = 0;
387
388 /* Clear the Clock stop request if it was set */
389 if (cccr & CCCR_CSR)
390 cccr &= ~CCCR_CSR;
391
392 if (enable) {
393 /* enable m_can configuration */
394 m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT);
395 udelay(5);
396 /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
397 m_can_write(cdev, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
398 } else {
399 m_can_write(cdev, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
400 }
401
402 /* there's a delay for module initialization */
403 if (enable)
404 val = CCCR_INIT | CCCR_CCE;
405
406 while ((m_can_read(cdev, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
407 if (timeout == 0) {
408 netdev_warn(cdev->net, "Failed to init module\n");
409 return;
410 }
411 timeout--;
412 udelay(1);
413 }
414 }
415
m_can_enable_all_interrupts(struct m_can_classdev * cdev)416 static inline void m_can_enable_all_interrupts(struct m_can_classdev *cdev)
417 {
418 /* Only interrupt line 0 is used in this driver */
419 m_can_write(cdev, M_CAN_ILE, ILE_EINT0);
420 }
421
m_can_disable_all_interrupts(struct m_can_classdev * cdev)422 static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
423 {
424 m_can_write(cdev, M_CAN_ILE, 0x0);
425 }
426
427 /* Retrieve internal timestamp counter from TSCV.TSC, and shift it to 32-bit
428 * width.
429 */
m_can_get_timestamp(struct m_can_classdev * cdev)430 static u32 m_can_get_timestamp(struct m_can_classdev *cdev)
431 {
432 u32 tscv;
433 u32 tsc;
434
435 tscv = m_can_read(cdev, M_CAN_TSCV);
436 tsc = FIELD_GET(TSCV_TSC_MASK, tscv);
437
438 return (tsc << 16);
439 }
440
m_can_clean(struct net_device * net)441 static void m_can_clean(struct net_device *net)
442 {
443 struct m_can_classdev *cdev = netdev_priv(net);
444
445 if (cdev->tx_skb) {
446 int putidx = 0;
447
448 net->stats.tx_errors++;
449 if (cdev->version > 30)
450 putidx = FIELD_GET(TXFQS_TFQPI_MASK,
451 m_can_read(cdev, M_CAN_TXFQS));
452
453 can_free_echo_skb(cdev->net, putidx, NULL);
454 cdev->tx_skb = NULL;
455 }
456 }
457
458 /* For peripherals, pass skb to rx-offload, which will push skb from
459 * napi. For non-peripherals, RX is done in napi already, so push
460 * directly. timestamp is used to ensure good skb ordering in
461 * rx-offload and is ignored for non-peripherals.
462 */
m_can_receive_skb(struct m_can_classdev * cdev,struct sk_buff * skb,u32 timestamp)463 static void m_can_receive_skb(struct m_can_classdev *cdev,
464 struct sk_buff *skb,
465 u32 timestamp)
466 {
467 if (cdev->is_peripheral) {
468 struct net_device_stats *stats = &cdev->net->stats;
469 int err;
470
471 err = can_rx_offload_queue_timestamp(&cdev->offload, skb,
472 timestamp);
473 if (err)
474 stats->rx_fifo_errors++;
475 } else {
476 netif_receive_skb(skb);
477 }
478 }
479
m_can_read_fifo(struct net_device * dev,u32 fgi)480 static int m_can_read_fifo(struct net_device *dev, u32 fgi)
481 {
482 struct net_device_stats *stats = &dev->stats;
483 struct m_can_classdev *cdev = netdev_priv(dev);
484 struct canfd_frame *cf;
485 struct sk_buff *skb;
486 struct id_and_dlc fifo_header;
487 u32 timestamp = 0;
488 int err;
489
490 err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_ID, &fifo_header, 2);
491 if (err)
492 goto out_fail;
493
494 if (fifo_header.dlc & RX_BUF_FDF)
495 skb = alloc_canfd_skb(dev, &cf);
496 else
497 skb = alloc_can_skb(dev, (struct can_frame **)&cf);
498 if (!skb) {
499 stats->rx_dropped++;
500 return 0;
501 }
502
503 if (fifo_header.dlc & RX_BUF_FDF)
504 cf->len = can_fd_dlc2len((fifo_header.dlc >> 16) & 0x0F);
505 else
506 cf->len = can_cc_dlc2len((fifo_header.dlc >> 16) & 0x0F);
507
508 if (fifo_header.id & RX_BUF_XTD)
509 cf->can_id = (fifo_header.id & CAN_EFF_MASK) | CAN_EFF_FLAG;
510 else
511 cf->can_id = (fifo_header.id >> 18) & CAN_SFF_MASK;
512
513 if (fifo_header.id & RX_BUF_ESI) {
514 cf->flags |= CANFD_ESI;
515 netdev_dbg(dev, "ESI Error\n");
516 }
517
518 if (!(fifo_header.dlc & RX_BUF_FDF) && (fifo_header.id & RX_BUF_RTR)) {
519 cf->can_id |= CAN_RTR_FLAG;
520 } else {
521 if (fifo_header.dlc & RX_BUF_BRS)
522 cf->flags |= CANFD_BRS;
523
524 err = m_can_fifo_read(cdev, fgi, M_CAN_FIFO_DATA,
525 cf->data, DIV_ROUND_UP(cf->len, 4));
526 if (err)
527 goto out_free_skb;
528
529 stats->rx_bytes += cf->len;
530 }
531 stats->rx_packets++;
532
533 timestamp = FIELD_GET(RX_BUF_RXTS_MASK, fifo_header.dlc) << 16;
534
535 m_can_receive_skb(cdev, skb, timestamp);
536
537 return 0;
538
539 out_free_skb:
540 kfree_skb(skb);
541 out_fail:
542 netdev_err(dev, "FIFO read returned %d\n", err);
543 return err;
544 }
545
m_can_do_rx_poll(struct net_device * dev,int quota)546 static int m_can_do_rx_poll(struct net_device *dev, int quota)
547 {
548 struct m_can_classdev *cdev = netdev_priv(dev);
549 u32 pkts = 0;
550 u32 rxfs;
551 u32 rx_count;
552 u32 fgi;
553 int ack_fgi = -1;
554 int i;
555 int err = 0;
556
557 rxfs = m_can_read(cdev, M_CAN_RXF0S);
558 if (!(rxfs & RXFS_FFL_MASK)) {
559 netdev_dbg(dev, "no messages in fifo0\n");
560 return 0;
561 }
562
563 rx_count = FIELD_GET(RXFS_FFL_MASK, rxfs);
564 fgi = FIELD_GET(RXFS_FGI_MASK, rxfs);
565
566 for (i = 0; i < rx_count && quota > 0; ++i) {
567 err = m_can_read_fifo(dev, fgi);
568 if (err)
569 break;
570
571 quota--;
572 pkts++;
573 ack_fgi = fgi;
574 fgi = (++fgi >= cdev->mcfg[MRAM_RXF0].num ? 0 : fgi);
575 }
576
577 if (ack_fgi != -1)
578 m_can_write(cdev, M_CAN_RXF0A, ack_fgi);
579
580 if (err)
581 return err;
582
583 return pkts;
584 }
585
m_can_handle_lost_msg(struct net_device * dev)586 static int m_can_handle_lost_msg(struct net_device *dev)
587 {
588 struct m_can_classdev *cdev = netdev_priv(dev);
589 struct net_device_stats *stats = &dev->stats;
590 struct sk_buff *skb;
591 struct can_frame *frame;
592 u32 timestamp = 0;
593
594 netdev_err(dev, "msg lost in rxf0\n");
595
596 stats->rx_errors++;
597 stats->rx_over_errors++;
598
599 skb = alloc_can_err_skb(dev, &frame);
600 if (unlikely(!skb))
601 return 0;
602
603 frame->can_id |= CAN_ERR_CRTL;
604 frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
605
606 if (cdev->is_peripheral)
607 timestamp = m_can_get_timestamp(cdev);
608
609 m_can_receive_skb(cdev, skb, timestamp);
610
611 return 1;
612 }
613
m_can_handle_lec_err(struct net_device * dev,enum m_can_lec_type lec_type)614 static int m_can_handle_lec_err(struct net_device *dev,
615 enum m_can_lec_type lec_type)
616 {
617 struct m_can_classdev *cdev = netdev_priv(dev);
618 struct net_device_stats *stats = &dev->stats;
619 struct can_frame *cf;
620 struct sk_buff *skb;
621 u32 timestamp = 0;
622
623 cdev->can.can_stats.bus_error++;
624 stats->rx_errors++;
625
626 /* propagate the error condition to the CAN stack */
627 skb = alloc_can_err_skb(dev, &cf);
628 if (unlikely(!skb))
629 return 0;
630
631 /* check for 'last error code' which tells us the
632 * type of the last error to occur on the CAN bus
633 */
634 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
635
636 switch (lec_type) {
637 case LEC_STUFF_ERROR:
638 netdev_dbg(dev, "stuff error\n");
639 cf->data[2] |= CAN_ERR_PROT_STUFF;
640 break;
641 case LEC_FORM_ERROR:
642 netdev_dbg(dev, "form error\n");
643 cf->data[2] |= CAN_ERR_PROT_FORM;
644 break;
645 case LEC_ACK_ERROR:
646 netdev_dbg(dev, "ack error\n");
647 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
648 break;
649 case LEC_BIT1_ERROR:
650 netdev_dbg(dev, "bit1 error\n");
651 cf->data[2] |= CAN_ERR_PROT_BIT1;
652 break;
653 case LEC_BIT0_ERROR:
654 netdev_dbg(dev, "bit0 error\n");
655 cf->data[2] |= CAN_ERR_PROT_BIT0;
656 break;
657 case LEC_CRC_ERROR:
658 netdev_dbg(dev, "CRC error\n");
659 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
660 break;
661 default:
662 break;
663 }
664
665 if (cdev->is_peripheral)
666 timestamp = m_can_get_timestamp(cdev);
667
668 m_can_receive_skb(cdev, skb, timestamp);
669
670 return 1;
671 }
672
__m_can_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)673 static int __m_can_get_berr_counter(const struct net_device *dev,
674 struct can_berr_counter *bec)
675 {
676 struct m_can_classdev *cdev = netdev_priv(dev);
677 unsigned int ecr;
678
679 ecr = m_can_read(cdev, M_CAN_ECR);
680 bec->rxerr = FIELD_GET(ECR_REC_MASK, ecr);
681 bec->txerr = FIELD_GET(ECR_TEC_MASK, ecr);
682
683 return 0;
684 }
685
m_can_clk_start(struct m_can_classdev * cdev)686 static int m_can_clk_start(struct m_can_classdev *cdev)
687 {
688 if (cdev->pm_clock_support == 0)
689 return 0;
690
691 return pm_runtime_resume_and_get(cdev->dev);
692 }
693
m_can_clk_stop(struct m_can_classdev * cdev)694 static void m_can_clk_stop(struct m_can_classdev *cdev)
695 {
696 if (cdev->pm_clock_support)
697 pm_runtime_put_sync(cdev->dev);
698 }
699
m_can_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)700 static int m_can_get_berr_counter(const struct net_device *dev,
701 struct can_berr_counter *bec)
702 {
703 struct m_can_classdev *cdev = netdev_priv(dev);
704 int err;
705
706 err = m_can_clk_start(cdev);
707 if (err)
708 return err;
709
710 __m_can_get_berr_counter(dev, bec);
711
712 m_can_clk_stop(cdev);
713
714 return 0;
715 }
716
m_can_handle_state_change(struct net_device * dev,enum can_state new_state)717 static int m_can_handle_state_change(struct net_device *dev,
718 enum can_state new_state)
719 {
720 struct m_can_classdev *cdev = netdev_priv(dev);
721 struct can_frame *cf;
722 struct sk_buff *skb;
723 struct can_berr_counter bec;
724 unsigned int ecr;
725 u32 timestamp = 0;
726
727 switch (new_state) {
728 case CAN_STATE_ERROR_WARNING:
729 /* error warning state */
730 cdev->can.can_stats.error_warning++;
731 cdev->can.state = CAN_STATE_ERROR_WARNING;
732 break;
733 case CAN_STATE_ERROR_PASSIVE:
734 /* error passive state */
735 cdev->can.can_stats.error_passive++;
736 cdev->can.state = CAN_STATE_ERROR_PASSIVE;
737 break;
738 case CAN_STATE_BUS_OFF:
739 /* bus-off state */
740 cdev->can.state = CAN_STATE_BUS_OFF;
741 m_can_disable_all_interrupts(cdev);
742 cdev->can.can_stats.bus_off++;
743 can_bus_off(dev);
744 break;
745 default:
746 break;
747 }
748
749 /* propagate the error condition to the CAN stack */
750 skb = alloc_can_err_skb(dev, &cf);
751 if (unlikely(!skb))
752 return 0;
753
754 __m_can_get_berr_counter(dev, &bec);
755
756 switch (new_state) {
757 case CAN_STATE_ERROR_WARNING:
758 /* error warning state */
759 cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
760 cf->data[1] = (bec.txerr > bec.rxerr) ?
761 CAN_ERR_CRTL_TX_WARNING :
762 CAN_ERR_CRTL_RX_WARNING;
763 cf->data[6] = bec.txerr;
764 cf->data[7] = bec.rxerr;
765 break;
766 case CAN_STATE_ERROR_PASSIVE:
767 /* error passive state */
768 cf->can_id |= CAN_ERR_CRTL | CAN_ERR_CNT;
769 ecr = m_can_read(cdev, M_CAN_ECR);
770 if (ecr & ECR_RP)
771 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
772 if (bec.txerr > 127)
773 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
774 cf->data[6] = bec.txerr;
775 cf->data[7] = bec.rxerr;
776 break;
777 case CAN_STATE_BUS_OFF:
778 /* bus-off state */
779 cf->can_id |= CAN_ERR_BUSOFF;
780 break;
781 default:
782 break;
783 }
784
785 if (cdev->is_peripheral)
786 timestamp = m_can_get_timestamp(cdev);
787
788 m_can_receive_skb(cdev, skb, timestamp);
789
790 return 1;
791 }
792
m_can_handle_state_errors(struct net_device * dev,u32 psr)793 static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
794 {
795 struct m_can_classdev *cdev = netdev_priv(dev);
796 int work_done = 0;
797
798 if (psr & PSR_EW && cdev->can.state != CAN_STATE_ERROR_WARNING) {
799 netdev_dbg(dev, "entered error warning state\n");
800 work_done += m_can_handle_state_change(dev,
801 CAN_STATE_ERROR_WARNING);
802 }
803
804 if (psr & PSR_EP && cdev->can.state != CAN_STATE_ERROR_PASSIVE) {
805 netdev_dbg(dev, "entered error passive state\n");
806 work_done += m_can_handle_state_change(dev,
807 CAN_STATE_ERROR_PASSIVE);
808 }
809
810 if (psr & PSR_BO && cdev->can.state != CAN_STATE_BUS_OFF) {
811 netdev_dbg(dev, "entered error bus off state\n");
812 work_done += m_can_handle_state_change(dev,
813 CAN_STATE_BUS_OFF);
814 }
815
816 return work_done;
817 }
818
m_can_handle_other_err(struct net_device * dev,u32 irqstatus)819 static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
820 {
821 if (irqstatus & IR_WDI)
822 netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
823 if (irqstatus & IR_BEU)
824 netdev_err(dev, "Bit Error Uncorrected\n");
825 if (irqstatus & IR_BEC)
826 netdev_err(dev, "Bit Error Corrected\n");
827 if (irqstatus & IR_TOO)
828 netdev_err(dev, "Timeout reached\n");
829 if (irqstatus & IR_MRAF)
830 netdev_err(dev, "Message RAM access failure occurred\n");
831 }
832
is_lec_err(u8 lec)833 static inline bool is_lec_err(u8 lec)
834 {
835 return lec != LEC_NO_ERROR && lec != LEC_NO_CHANGE;
836 }
837
m_can_is_protocol_err(u32 irqstatus)838 static inline bool m_can_is_protocol_err(u32 irqstatus)
839 {
840 return irqstatus & IR_ERR_LEC_31X;
841 }
842
m_can_handle_protocol_error(struct net_device * dev,u32 irqstatus)843 static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus)
844 {
845 struct net_device_stats *stats = &dev->stats;
846 struct m_can_classdev *cdev = netdev_priv(dev);
847 struct can_frame *cf;
848 struct sk_buff *skb;
849 u32 timestamp = 0;
850
851 /* propagate the error condition to the CAN stack */
852 skb = alloc_can_err_skb(dev, &cf);
853
854 /* update tx error stats since there is protocol error */
855 stats->tx_errors++;
856
857 /* update arbitration lost status */
858 if (cdev->version >= 31 && (irqstatus & IR_PEA)) {
859 netdev_dbg(dev, "Protocol error in Arbitration fail\n");
860 cdev->can.can_stats.arbitration_lost++;
861 if (skb) {
862 cf->can_id |= CAN_ERR_LOSTARB;
863 cf->data[0] |= CAN_ERR_LOSTARB_UNSPEC;
864 }
865 }
866
867 if (unlikely(!skb)) {
868 netdev_dbg(dev, "allocation of skb failed\n");
869 return 0;
870 }
871
872 if (cdev->is_peripheral)
873 timestamp = m_can_get_timestamp(cdev);
874
875 m_can_receive_skb(cdev, skb, timestamp);
876
877 return 1;
878 }
879
m_can_handle_bus_errors(struct net_device * dev,u32 irqstatus,u32 psr)880 static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
881 u32 psr)
882 {
883 struct m_can_classdev *cdev = netdev_priv(dev);
884 int work_done = 0;
885
886 if (irqstatus & IR_RF0L)
887 work_done += m_can_handle_lost_msg(dev);
888
889 /* handle lec errors on the bus */
890 if (cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
891 u8 lec = FIELD_GET(PSR_LEC_MASK, psr);
892 u8 dlec = FIELD_GET(PSR_DLEC_MASK, psr);
893
894 if (is_lec_err(lec)) {
895 netdev_dbg(dev, "Arbitration phase error detected\n");
896 work_done += m_can_handle_lec_err(dev, lec);
897 }
898
899 if (is_lec_err(dlec)) {
900 netdev_dbg(dev, "Data phase error detected\n");
901 work_done += m_can_handle_lec_err(dev, dlec);
902 }
903 }
904
905 /* handle protocol errors in arbitration phase */
906 if ((cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
907 m_can_is_protocol_err(irqstatus))
908 work_done += m_can_handle_protocol_error(dev, irqstatus);
909
910 /* other unproccessed error interrupts */
911 m_can_handle_other_err(dev, irqstatus);
912
913 return work_done;
914 }
915
m_can_rx_handler(struct net_device * dev,int quota,u32 irqstatus)916 static int m_can_rx_handler(struct net_device *dev, int quota, u32 irqstatus)
917 {
918 struct m_can_classdev *cdev = netdev_priv(dev);
919 int rx_work_or_err;
920 int work_done = 0;
921
922 if (!irqstatus)
923 goto end;
924
925 /* Errata workaround for issue "Needless activation of MRAF irq"
926 * During frame reception while the MCAN is in Error Passive state
927 * and the Receive Error Counter has the value MCAN_ECR.REC = 127,
928 * it may happen that MCAN_IR.MRAF is set although there was no
929 * Message RAM access failure.
930 * If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is generated
931 * The Message RAM Access Failure interrupt routine needs to check
932 * whether MCAN_ECR.RP = ’1’ and MCAN_ECR.REC = 127.
933 * In this case, reset MCAN_IR.MRAF. No further action is required.
934 */
935 if (cdev->version <= 31 && irqstatus & IR_MRAF &&
936 m_can_read(cdev, M_CAN_ECR) & ECR_RP) {
937 struct can_berr_counter bec;
938
939 __m_can_get_berr_counter(dev, &bec);
940 if (bec.rxerr == 127) {
941 m_can_write(cdev, M_CAN_IR, IR_MRAF);
942 irqstatus &= ~IR_MRAF;
943 }
944 }
945
946 if (irqstatus & IR_ERR_STATE)
947 work_done += m_can_handle_state_errors(dev,
948 m_can_read(cdev, M_CAN_PSR));
949
950 if (irqstatus & IR_ERR_BUS_30X)
951 work_done += m_can_handle_bus_errors(dev, irqstatus,
952 m_can_read(cdev, M_CAN_PSR));
953
954 if (irqstatus & IR_RF0N) {
955 rx_work_or_err = m_can_do_rx_poll(dev, (quota - work_done));
956 if (rx_work_or_err < 0)
957 return rx_work_or_err;
958
959 work_done += rx_work_or_err;
960 }
961 end:
962 return work_done;
963 }
964
m_can_rx_peripheral(struct net_device * dev,u32 irqstatus)965 static int m_can_rx_peripheral(struct net_device *dev, u32 irqstatus)
966 {
967 struct m_can_classdev *cdev = netdev_priv(dev);
968 int work_done;
969
970 work_done = m_can_rx_handler(dev, NAPI_POLL_WEIGHT, irqstatus);
971
972 /* Don't re-enable interrupts if the driver had a fatal error
973 * (e.g., FIFO read failure).
974 */
975 if (work_done >= 0)
976 m_can_enable_all_interrupts(cdev);
977
978 return work_done;
979 }
980
m_can_poll(struct napi_struct * napi,int quota)981 static int m_can_poll(struct napi_struct *napi, int quota)
982 {
983 struct net_device *dev = napi->dev;
984 struct m_can_classdev *cdev = netdev_priv(dev);
985 int work_done;
986 u32 irqstatus;
987
988 irqstatus = cdev->irqstatus | m_can_read(cdev, M_CAN_IR);
989
990 work_done = m_can_rx_handler(dev, quota, irqstatus);
991
992 /* Don't re-enable interrupts if the driver had a fatal error
993 * (e.g., FIFO read failure).
994 */
995 if (work_done >= 0 && work_done < quota) {
996 napi_complete_done(napi, work_done);
997 m_can_enable_all_interrupts(cdev);
998 }
999
1000 return work_done;
1001 }
1002
1003 /* Echo tx skb and update net stats. Peripherals use rx-offload for
1004 * echo. timestamp is used for peripherals to ensure correct ordering
1005 * by rx-offload, and is ignored for non-peripherals.
1006 */
m_can_tx_update_stats(struct m_can_classdev * cdev,unsigned int msg_mark,u32 timestamp)1007 static void m_can_tx_update_stats(struct m_can_classdev *cdev,
1008 unsigned int msg_mark,
1009 u32 timestamp)
1010 {
1011 struct net_device *dev = cdev->net;
1012 struct net_device_stats *stats = &dev->stats;
1013
1014 if (cdev->is_peripheral)
1015 stats->tx_bytes +=
1016 can_rx_offload_get_echo_skb(&cdev->offload,
1017 msg_mark,
1018 timestamp,
1019 NULL);
1020 else
1021 stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
1022
1023 stats->tx_packets++;
1024 }
1025
m_can_echo_tx_event(struct net_device * dev)1026 static int m_can_echo_tx_event(struct net_device *dev)
1027 {
1028 u32 txe_count = 0;
1029 u32 m_can_txefs;
1030 u32 fgi = 0;
1031 int ack_fgi = -1;
1032 int i = 0;
1033 int err = 0;
1034 unsigned int msg_mark;
1035
1036 struct m_can_classdev *cdev = netdev_priv(dev);
1037
1038 /* read tx event fifo status */
1039 m_can_txefs = m_can_read(cdev, M_CAN_TXEFS);
1040
1041 /* Get Tx Event fifo element count */
1042 txe_count = FIELD_GET(TXEFS_EFFL_MASK, m_can_txefs);
1043 fgi = FIELD_GET(TXEFS_EFGI_MASK, m_can_txefs);
1044
1045 /* Get and process all sent elements */
1046 for (i = 0; i < txe_count; i++) {
1047 u32 txe, timestamp = 0;
1048
1049 /* get message marker, timestamp */
1050 err = m_can_txe_fifo_read(cdev, fgi, 4, &txe);
1051 if (err) {
1052 netdev_err(dev, "TXE FIFO read returned %d\n", err);
1053 break;
1054 }
1055
1056 msg_mark = FIELD_GET(TX_EVENT_MM_MASK, txe);
1057 timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe) << 16;
1058
1059 ack_fgi = fgi;
1060 fgi = (++fgi >= cdev->mcfg[MRAM_TXE].num ? 0 : fgi);
1061
1062 /* update stats */
1063 m_can_tx_update_stats(cdev, msg_mark, timestamp);
1064 }
1065
1066 if (ack_fgi != -1)
1067 m_can_write(cdev, M_CAN_TXEFA, FIELD_PREP(TXEFA_EFAI_MASK,
1068 ack_fgi));
1069
1070 return err;
1071 }
1072
m_can_isr(int irq,void * dev_id)1073 static irqreturn_t m_can_isr(int irq, void *dev_id)
1074 {
1075 struct net_device *dev = (struct net_device *)dev_id;
1076 struct m_can_classdev *cdev = netdev_priv(dev);
1077 u32 ir;
1078
1079 if (pm_runtime_suspended(cdev->dev))
1080 return IRQ_NONE;
1081 ir = m_can_read(cdev, M_CAN_IR);
1082 if (!ir)
1083 return IRQ_NONE;
1084
1085 /* ACK all irqs */
1086 if (ir & IR_ALL_INT)
1087 m_can_write(cdev, M_CAN_IR, ir);
1088
1089 if (cdev->ops->clear_interrupts)
1090 cdev->ops->clear_interrupts(cdev);
1091
1092 /* schedule NAPI in case of
1093 * - rx IRQ
1094 * - state change IRQ
1095 * - bus error IRQ and bus error reporting
1096 */
1097 if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
1098 cdev->irqstatus = ir;
1099 m_can_disable_all_interrupts(cdev);
1100 if (!cdev->is_peripheral)
1101 napi_schedule(&cdev->napi);
1102 else if (m_can_rx_peripheral(dev, ir) < 0)
1103 goto out_fail;
1104 }
1105
1106 if (cdev->version == 30) {
1107 if (ir & IR_TC) {
1108 /* Transmission Complete Interrupt*/
1109 u32 timestamp = 0;
1110
1111 if (cdev->is_peripheral)
1112 timestamp = m_can_get_timestamp(cdev);
1113 m_can_tx_update_stats(cdev, 0, timestamp);
1114 netif_wake_queue(dev);
1115 }
1116 } else {
1117 if (ir & IR_TEFN) {
1118 /* New TX FIFO Element arrived */
1119 if (m_can_echo_tx_event(dev) != 0)
1120 goto out_fail;
1121
1122 if (netif_queue_stopped(dev) &&
1123 !m_can_tx_fifo_full(cdev))
1124 netif_wake_queue(dev);
1125 }
1126 }
1127
1128 if (cdev->is_peripheral)
1129 can_rx_offload_threaded_irq_finish(&cdev->offload);
1130
1131 return IRQ_HANDLED;
1132
1133 out_fail:
1134 m_can_disable_all_interrupts(cdev);
1135 return IRQ_HANDLED;
1136 }
1137
1138 static const struct can_bittiming_const m_can_bittiming_const_30X = {
1139 .name = KBUILD_MODNAME,
1140 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
1141 .tseg1_max = 64,
1142 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
1143 .tseg2_max = 16,
1144 .sjw_max = 16,
1145 .brp_min = 1,
1146 .brp_max = 1024,
1147 .brp_inc = 1,
1148 };
1149
1150 static const struct can_bittiming_const m_can_data_bittiming_const_30X = {
1151 .name = KBUILD_MODNAME,
1152 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
1153 .tseg1_max = 16,
1154 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
1155 .tseg2_max = 8,
1156 .sjw_max = 4,
1157 .brp_min = 1,
1158 .brp_max = 32,
1159 .brp_inc = 1,
1160 };
1161
1162 static const struct can_bittiming_const m_can_bittiming_const_31X = {
1163 .name = KBUILD_MODNAME,
1164 .tseg1_min = 2, /* Time segment 1 = prop_seg + phase_seg1 */
1165 .tseg1_max = 256,
1166 .tseg2_min = 2, /* Time segment 2 = phase_seg2 */
1167 .tseg2_max = 128,
1168 .sjw_max = 128,
1169 .brp_min = 1,
1170 .brp_max = 512,
1171 .brp_inc = 1,
1172 };
1173
1174 static const struct can_bittiming_const m_can_data_bittiming_const_31X = {
1175 .name = KBUILD_MODNAME,
1176 .tseg1_min = 1, /* Time segment 1 = prop_seg + phase_seg1 */
1177 .tseg1_max = 32,
1178 .tseg2_min = 1, /* Time segment 2 = phase_seg2 */
1179 .tseg2_max = 16,
1180 .sjw_max = 16,
1181 .brp_min = 1,
1182 .brp_max = 32,
1183 .brp_inc = 1,
1184 };
1185
m_can_set_bittiming(struct net_device * dev)1186 static int m_can_set_bittiming(struct net_device *dev)
1187 {
1188 struct m_can_classdev *cdev = netdev_priv(dev);
1189 const struct can_bittiming *bt = &cdev->can.bittiming;
1190 const struct can_bittiming *dbt = &cdev->can.data_bittiming;
1191 u16 brp, sjw, tseg1, tseg2;
1192 u32 reg_btp;
1193
1194 brp = bt->brp - 1;
1195 sjw = bt->sjw - 1;
1196 tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
1197 tseg2 = bt->phase_seg2 - 1;
1198 reg_btp = FIELD_PREP(NBTP_NBRP_MASK, brp) |
1199 FIELD_PREP(NBTP_NSJW_MASK, sjw) |
1200 FIELD_PREP(NBTP_NTSEG1_MASK, tseg1) |
1201 FIELD_PREP(NBTP_NTSEG2_MASK, tseg2);
1202 m_can_write(cdev, M_CAN_NBTP, reg_btp);
1203
1204 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
1205 reg_btp = 0;
1206 brp = dbt->brp - 1;
1207 sjw = dbt->sjw - 1;
1208 tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
1209 tseg2 = dbt->phase_seg2 - 1;
1210
1211 /* TDC is only needed for bitrates beyond 2.5 MBit/s.
1212 * This is mentioned in the "Bit Time Requirements for CAN FD"
1213 * paper presented at the International CAN Conference 2013
1214 */
1215 if (dbt->bitrate > 2500000) {
1216 u32 tdco, ssp;
1217
1218 /* Use the same value of secondary sampling point
1219 * as the data sampling point
1220 */
1221 ssp = dbt->sample_point;
1222
1223 /* Equation based on Bosch's M_CAN User Manual's
1224 * Transmitter Delay Compensation Section
1225 */
1226 tdco = (cdev->can.clock.freq / 1000) *
1227 ssp / dbt->bitrate;
1228
1229 /* Max valid TDCO value is 127 */
1230 if (tdco > 127) {
1231 netdev_warn(dev, "TDCO value of %u is beyond maximum. Using maximum possible value\n",
1232 tdco);
1233 tdco = 127;
1234 }
1235
1236 reg_btp |= DBTP_TDC;
1237 m_can_write(cdev, M_CAN_TDCR,
1238 FIELD_PREP(TDCR_TDCO_MASK, tdco));
1239 }
1240
1241 reg_btp |= FIELD_PREP(DBTP_DBRP_MASK, brp) |
1242 FIELD_PREP(DBTP_DSJW_MASK, sjw) |
1243 FIELD_PREP(DBTP_DTSEG1_MASK, tseg1) |
1244 FIELD_PREP(DBTP_DTSEG2_MASK, tseg2);
1245
1246 m_can_write(cdev, M_CAN_DBTP, reg_btp);
1247 }
1248
1249 return 0;
1250 }
1251
1252 /* Configure M_CAN chip:
1253 * - set rx buffer/fifo element size
1254 * - configure rx fifo
1255 * - accept non-matching frame into fifo 0
1256 * - configure tx buffer
1257 * - >= v3.1.x: TX FIFO is used
1258 * - configure mode
1259 * - setup bittiming
1260 * - configure timestamp generation
1261 */
m_can_chip_config(struct net_device * dev)1262 static int m_can_chip_config(struct net_device *dev)
1263 {
1264 struct m_can_classdev *cdev = netdev_priv(dev);
1265 u32 cccr, test;
1266 int err;
1267
1268 err = m_can_init_ram(cdev);
1269 if (err) {
1270 dev_err(cdev->dev, "Message RAM configuration failed\n");
1271 return err;
1272 }
1273
1274 m_can_config_endisable(cdev, true);
1275
1276 /* RX Buffer/FIFO Element Size 64 bytes data field */
1277 m_can_write(cdev, M_CAN_RXESC,
1278 FIELD_PREP(RXESC_RBDS_MASK, RXESC_64B) |
1279 FIELD_PREP(RXESC_F1DS_MASK, RXESC_64B) |
1280 FIELD_PREP(RXESC_F0DS_MASK, RXESC_64B));
1281
1282 /* Accept Non-matching Frames Into FIFO 0 */
1283 m_can_write(cdev, M_CAN_GFC, 0x0);
1284
1285 if (cdev->version == 30) {
1286 /* only support one Tx Buffer currently */
1287 m_can_write(cdev, M_CAN_TXBC, FIELD_PREP(TXBC_NDTB_MASK, 1) |
1288 cdev->mcfg[MRAM_TXB].off);
1289 } else {
1290 /* TX FIFO is used for newer IP Core versions */
1291 m_can_write(cdev, M_CAN_TXBC,
1292 FIELD_PREP(TXBC_TFQS_MASK,
1293 cdev->mcfg[MRAM_TXB].num) |
1294 cdev->mcfg[MRAM_TXB].off);
1295 }
1296
1297 /* support 64 bytes payload */
1298 m_can_write(cdev, M_CAN_TXESC,
1299 FIELD_PREP(TXESC_TBDS_MASK, TXESC_TBDS_64B));
1300
1301 /* TX Event FIFO */
1302 if (cdev->version == 30) {
1303 m_can_write(cdev, M_CAN_TXEFC,
1304 FIELD_PREP(TXEFC_EFS_MASK, 1) |
1305 cdev->mcfg[MRAM_TXE].off);
1306 } else {
1307 /* Full TX Event FIFO is used */
1308 m_can_write(cdev, M_CAN_TXEFC,
1309 FIELD_PREP(TXEFC_EFS_MASK,
1310 cdev->mcfg[MRAM_TXE].num) |
1311 cdev->mcfg[MRAM_TXE].off);
1312 }
1313
1314 /* rx fifo configuration, blocking mode, fifo size 1 */
1315 m_can_write(cdev, M_CAN_RXF0C,
1316 FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF0].num) |
1317 cdev->mcfg[MRAM_RXF0].off);
1318
1319 m_can_write(cdev, M_CAN_RXF1C,
1320 FIELD_PREP(RXFC_FS_MASK, cdev->mcfg[MRAM_RXF1].num) |
1321 cdev->mcfg[MRAM_RXF1].off);
1322
1323 cccr = m_can_read(cdev, M_CAN_CCCR);
1324 test = m_can_read(cdev, M_CAN_TEST);
1325 test &= ~TEST_LBCK;
1326 if (cdev->version == 30) {
1327 /* Version 3.0.x */
1328
1329 cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_DAR |
1330 FIELD_PREP(CCCR_CMR_MASK, FIELD_MAX(CCCR_CMR_MASK)) |
1331 FIELD_PREP(CCCR_CME_MASK, FIELD_MAX(CCCR_CME_MASK)));
1332
1333 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
1334 cccr |= FIELD_PREP(CCCR_CME_MASK, CCCR_CME_CANFD_BRS);
1335
1336 } else {
1337 /* Version 3.1.x or 3.2.x */
1338 cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |
1339 CCCR_NISO | CCCR_DAR);
1340
1341 /* Only 3.2.x has NISO Bit implemented */
1342 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
1343 cccr |= CCCR_NISO;
1344
1345 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD)
1346 cccr |= (CCCR_BRSE | CCCR_FDOE);
1347 }
1348
1349 /* Loopback Mode */
1350 if (cdev->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
1351 cccr |= CCCR_TEST | CCCR_MON;
1352 test |= TEST_LBCK;
1353 }
1354
1355 /* Enable Monitoring (all versions) */
1356 if (cdev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1357 cccr |= CCCR_MON;
1358
1359 /* Disable Auto Retransmission (all versions) */
1360 if (cdev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
1361 cccr |= CCCR_DAR;
1362
1363 /* Write config */
1364 m_can_write(cdev, M_CAN_CCCR, cccr);
1365 m_can_write(cdev, M_CAN_TEST, test);
1366
1367 /* Enable interrupts */
1368 m_can_write(cdev, M_CAN_IR, IR_ALL_INT);
1369 if (!(cdev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
1370 if (cdev->version == 30)
1371 m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
1372 ~(IR_ERR_LEC_30X));
1373 else
1374 m_can_write(cdev, M_CAN_IE, IR_ALL_INT &
1375 ~(IR_ERR_LEC_31X));
1376 else
1377 m_can_write(cdev, M_CAN_IE, IR_ALL_INT);
1378
1379 /* route all interrupts to INT0 */
1380 m_can_write(cdev, M_CAN_ILS, ILS_ALL_INT0);
1381
1382 /* set bittiming params */
1383 m_can_set_bittiming(dev);
1384
1385 /* enable internal timestamp generation, with a prescaler of 16. The
1386 * prescaler is applied to the nominal bit timing
1387 */
1388 m_can_write(cdev, M_CAN_TSCC,
1389 FIELD_PREP(TSCC_TCP_MASK, 0xf) |
1390 FIELD_PREP(TSCC_TSS_MASK, TSCC_TSS_INTERNAL));
1391
1392 m_can_config_endisable(cdev, false);
1393
1394 if (cdev->ops->init)
1395 cdev->ops->init(cdev);
1396
1397 return 0;
1398 }
1399
m_can_start(struct net_device * dev)1400 static int m_can_start(struct net_device *dev)
1401 {
1402 struct m_can_classdev *cdev = netdev_priv(dev);
1403 int ret;
1404
1405 /* basic m_can configuration */
1406 ret = m_can_chip_config(dev);
1407 if (ret)
1408 return ret;
1409
1410 cdev->can.state = CAN_STATE_ERROR_ACTIVE;
1411
1412 m_can_enable_all_interrupts(cdev);
1413
1414 return 0;
1415 }
1416
m_can_set_mode(struct net_device * dev,enum can_mode mode)1417 static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
1418 {
1419 switch (mode) {
1420 case CAN_MODE_START:
1421 m_can_clean(dev);
1422 m_can_start(dev);
1423 netif_wake_queue(dev);
1424 break;
1425 default:
1426 return -EOPNOTSUPP;
1427 }
1428
1429 return 0;
1430 }
1431
1432 /* Checks core release number of M_CAN
1433 * returns 0 if an unsupported device is detected
1434 * else it returns the release and step coded as:
1435 * return value = 10 * <release> + 1 * <step>
1436 */
m_can_check_core_release(struct m_can_classdev * cdev)1437 static int m_can_check_core_release(struct m_can_classdev *cdev)
1438 {
1439 u32 crel_reg;
1440 u8 rel;
1441 u8 step;
1442 int res;
1443
1444 /* Read Core Release Version and split into version number
1445 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
1446 */
1447 crel_reg = m_can_read(cdev, M_CAN_CREL);
1448 rel = (u8)FIELD_GET(CREL_REL_MASK, crel_reg);
1449 step = (u8)FIELD_GET(CREL_STEP_MASK, crel_reg);
1450
1451 if (rel == 3) {
1452 /* M_CAN v3.x.y: create return value */
1453 res = 30 + step;
1454 } else {
1455 /* Unsupported M_CAN version */
1456 res = 0;
1457 }
1458
1459 return res;
1460 }
1461
1462 /* Selectable Non ISO support only in version 3.2.x
1463 * This function checks if the bit is writable.
1464 */
m_can_niso_supported(struct m_can_classdev * cdev)1465 static bool m_can_niso_supported(struct m_can_classdev *cdev)
1466 {
1467 u32 cccr_reg, cccr_poll = 0;
1468 int niso_timeout = -ETIMEDOUT;
1469 int i;
1470
1471 m_can_config_endisable(cdev, true);
1472 cccr_reg = m_can_read(cdev, M_CAN_CCCR);
1473 cccr_reg |= CCCR_NISO;
1474 m_can_write(cdev, M_CAN_CCCR, cccr_reg);
1475
1476 for (i = 0; i <= 10; i++) {
1477 cccr_poll = m_can_read(cdev, M_CAN_CCCR);
1478 if (cccr_poll == cccr_reg) {
1479 niso_timeout = 0;
1480 break;
1481 }
1482
1483 usleep_range(1, 5);
1484 }
1485
1486 /* Clear NISO */
1487 cccr_reg &= ~(CCCR_NISO);
1488 m_can_write(cdev, M_CAN_CCCR, cccr_reg);
1489
1490 m_can_config_endisable(cdev, false);
1491
1492 /* return false if time out (-ETIMEDOUT), else return true */
1493 return !niso_timeout;
1494 }
1495
m_can_dev_setup(struct m_can_classdev * cdev)1496 static int m_can_dev_setup(struct m_can_classdev *cdev)
1497 {
1498 struct net_device *dev = cdev->net;
1499 int m_can_version, err;
1500
1501 m_can_version = m_can_check_core_release(cdev);
1502 /* return if unsupported version */
1503 if (!m_can_version) {
1504 dev_err(cdev->dev, "Unsupported version number: %2d",
1505 m_can_version);
1506 return -EINVAL;
1507 }
1508
1509 if (!cdev->is_peripheral)
1510 netif_napi_add(dev, &cdev->napi, m_can_poll);
1511
1512 /* Shared properties of all M_CAN versions */
1513 cdev->version = m_can_version;
1514 cdev->can.do_set_mode = m_can_set_mode;
1515 cdev->can.do_get_berr_counter = m_can_get_berr_counter;
1516
1517 /* Set M_CAN supported operations */
1518 cdev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1519 CAN_CTRLMODE_LISTENONLY |
1520 CAN_CTRLMODE_BERR_REPORTING |
1521 CAN_CTRLMODE_FD |
1522 CAN_CTRLMODE_ONE_SHOT;
1523
1524 /* Set properties depending on M_CAN version */
1525 switch (cdev->version) {
1526 case 30:
1527 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
1528 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1529 if (err)
1530 return err;
1531 cdev->can.bittiming_const = &m_can_bittiming_const_30X;
1532 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_30X;
1533 break;
1534 case 31:
1535 /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
1536 err = can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1537 if (err)
1538 return err;
1539 cdev->can.bittiming_const = &m_can_bittiming_const_31X;
1540 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
1541 break;
1542 case 32:
1543 case 33:
1544 /* Support both MCAN version v3.2.x and v3.3.0 */
1545 cdev->can.bittiming_const = &m_can_bittiming_const_31X;
1546 cdev->can.data_bittiming_const = &m_can_data_bittiming_const_31X;
1547
1548 cdev->can.ctrlmode_supported |=
1549 (m_can_niso_supported(cdev) ?
1550 CAN_CTRLMODE_FD_NON_ISO : 0);
1551 break;
1552 default:
1553 dev_err(cdev->dev, "Unsupported version number: %2d",
1554 cdev->version);
1555 return -EINVAL;
1556 }
1557
1558 if (cdev->ops->init)
1559 cdev->ops->init(cdev);
1560
1561 return 0;
1562 }
1563
m_can_stop(struct net_device * dev)1564 static void m_can_stop(struct net_device *dev)
1565 {
1566 struct m_can_classdev *cdev = netdev_priv(dev);
1567
1568 /* disable all interrupts */
1569 m_can_disable_all_interrupts(cdev);
1570
1571 /* Set init mode to disengage from the network */
1572 m_can_config_endisable(cdev, true);
1573
1574 /* set the state as STOPPED */
1575 cdev->can.state = CAN_STATE_STOPPED;
1576 }
1577
m_can_close(struct net_device * dev)1578 static int m_can_close(struct net_device *dev)
1579 {
1580 struct m_can_classdev *cdev = netdev_priv(dev);
1581
1582 netif_stop_queue(dev);
1583
1584 if (!cdev->is_peripheral)
1585 napi_disable(&cdev->napi);
1586
1587 m_can_stop(dev);
1588 m_can_clk_stop(cdev);
1589 free_irq(dev->irq, dev);
1590
1591 if (cdev->is_peripheral) {
1592 cdev->tx_skb = NULL;
1593 destroy_workqueue(cdev->tx_wq);
1594 cdev->tx_wq = NULL;
1595 }
1596
1597 if (cdev->is_peripheral)
1598 can_rx_offload_disable(&cdev->offload);
1599
1600 close_candev(dev);
1601
1602 phy_power_off(cdev->transceiver);
1603
1604 return 0;
1605 }
1606
m_can_next_echo_skb_occupied(struct net_device * dev,int putidx)1607 static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
1608 {
1609 struct m_can_classdev *cdev = netdev_priv(dev);
1610 /*get wrap around for loopback skb index */
1611 unsigned int wrap = cdev->can.echo_skb_max;
1612 int next_idx;
1613
1614 /* calculate next index */
1615 next_idx = (++putidx >= wrap ? 0 : putidx);
1616
1617 /* check if occupied */
1618 return !!cdev->can.echo_skb[next_idx];
1619 }
1620
m_can_tx_handler(struct m_can_classdev * cdev)1621 static netdev_tx_t m_can_tx_handler(struct m_can_classdev *cdev)
1622 {
1623 struct canfd_frame *cf = (struct canfd_frame *)cdev->tx_skb->data;
1624 struct net_device *dev = cdev->net;
1625 struct sk_buff *skb = cdev->tx_skb;
1626 struct id_and_dlc fifo_header;
1627 u32 cccr, fdflags;
1628 u32 txfqs;
1629 int err;
1630 int putidx;
1631
1632 cdev->tx_skb = NULL;
1633
1634 /* Generate ID field for TX buffer Element */
1635 /* Common to all supported M_CAN versions */
1636 if (cf->can_id & CAN_EFF_FLAG) {
1637 fifo_header.id = cf->can_id & CAN_EFF_MASK;
1638 fifo_header.id |= TX_BUF_XTD;
1639 } else {
1640 fifo_header.id = ((cf->can_id & CAN_SFF_MASK) << 18);
1641 }
1642
1643 if (cf->can_id & CAN_RTR_FLAG)
1644 fifo_header.id |= TX_BUF_RTR;
1645
1646 if (cdev->version == 30) {
1647 netif_stop_queue(dev);
1648
1649 fifo_header.dlc = can_fd_len2dlc(cf->len) << 16;
1650
1651 /* Write the frame ID, DLC, and payload to the FIFO element. */
1652 err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_ID, &fifo_header, 2);
1653 if (err)
1654 goto out_fail;
1655
1656 err = m_can_fifo_write(cdev, 0, M_CAN_FIFO_DATA,
1657 cf->data, DIV_ROUND_UP(cf->len, 4));
1658 if (err)
1659 goto out_fail;
1660
1661 if (cdev->can.ctrlmode & CAN_CTRLMODE_FD) {
1662 cccr = m_can_read(cdev, M_CAN_CCCR);
1663 cccr &= ~CCCR_CMR_MASK;
1664 if (can_is_canfd_skb(skb)) {
1665 if (cf->flags & CANFD_BRS)
1666 cccr |= FIELD_PREP(CCCR_CMR_MASK,
1667 CCCR_CMR_CANFD_BRS);
1668 else
1669 cccr |= FIELD_PREP(CCCR_CMR_MASK,
1670 CCCR_CMR_CANFD);
1671 } else {
1672 cccr |= FIELD_PREP(CCCR_CMR_MASK, CCCR_CMR_CAN);
1673 }
1674 m_can_write(cdev, M_CAN_CCCR, cccr);
1675 }
1676 m_can_write(cdev, M_CAN_TXBTIE, 0x1);
1677
1678 can_put_echo_skb(skb, dev, 0, 0);
1679
1680 m_can_write(cdev, M_CAN_TXBAR, 0x1);
1681 /* End of xmit function for version 3.0.x */
1682 } else {
1683 /* Transmit routine for version >= v3.1.x */
1684
1685 txfqs = m_can_read(cdev, M_CAN_TXFQS);
1686
1687 /* Check if FIFO full */
1688 if (_m_can_tx_fifo_full(txfqs)) {
1689 /* This shouldn't happen */
1690 netif_stop_queue(dev);
1691 netdev_warn(dev,
1692 "TX queue active although FIFO is full.");
1693
1694 if (cdev->is_peripheral) {
1695 kfree_skb(skb);
1696 dev->stats.tx_dropped++;
1697 return NETDEV_TX_OK;
1698 } else {
1699 return NETDEV_TX_BUSY;
1700 }
1701 }
1702
1703 /* get put index for frame */
1704 putidx = FIELD_GET(TXFQS_TFQPI_MASK, txfqs);
1705
1706 /* Construct DLC Field, with CAN-FD configuration.
1707 * Use the put index of the fifo as the message marker,
1708 * used in the TX interrupt for sending the correct echo frame.
1709 */
1710
1711 /* get CAN FD configuration of frame */
1712 fdflags = 0;
1713 if (can_is_canfd_skb(skb)) {
1714 fdflags |= TX_BUF_FDF;
1715 if (cf->flags & CANFD_BRS)
1716 fdflags |= TX_BUF_BRS;
1717 }
1718
1719 fifo_header.dlc = FIELD_PREP(TX_BUF_MM_MASK, putidx) |
1720 FIELD_PREP(TX_BUF_DLC_MASK, can_fd_len2dlc(cf->len)) |
1721 fdflags | TX_BUF_EFC;
1722 err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_ID, &fifo_header, 2);
1723 if (err)
1724 goto out_fail;
1725
1726 err = m_can_fifo_write(cdev, putidx, M_CAN_FIFO_DATA,
1727 cf->data, DIV_ROUND_UP(cf->len, 4));
1728 if (err)
1729 goto out_fail;
1730
1731 /* Push loopback echo.
1732 * Will be looped back on TX interrupt based on message marker
1733 */
1734 can_put_echo_skb(skb, dev, putidx, 0);
1735
1736 /* Enable TX FIFO element to start transfer */
1737 m_can_write(cdev, M_CAN_TXBAR, (1 << putidx));
1738
1739 /* stop network queue if fifo full */
1740 if (m_can_tx_fifo_full(cdev) ||
1741 m_can_next_echo_skb_occupied(dev, putidx))
1742 netif_stop_queue(dev);
1743 }
1744
1745 return NETDEV_TX_OK;
1746
1747 out_fail:
1748 netdev_err(dev, "FIFO write returned %d\n", err);
1749 m_can_disable_all_interrupts(cdev);
1750 return NETDEV_TX_BUSY;
1751 }
1752
m_can_tx_work_queue(struct work_struct * ws)1753 static void m_can_tx_work_queue(struct work_struct *ws)
1754 {
1755 struct m_can_classdev *cdev = container_of(ws, struct m_can_classdev,
1756 tx_work);
1757
1758 m_can_tx_handler(cdev);
1759 }
1760
m_can_start_xmit(struct sk_buff * skb,struct net_device * dev)1761 static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
1762 struct net_device *dev)
1763 {
1764 struct m_can_classdev *cdev = netdev_priv(dev);
1765
1766 if (can_dev_dropped_skb(dev, skb))
1767 return NETDEV_TX_OK;
1768
1769 if (cdev->is_peripheral) {
1770 if (cdev->tx_skb) {
1771 netdev_err(dev, "hard_xmit called while tx busy\n");
1772 return NETDEV_TX_BUSY;
1773 }
1774
1775 if (cdev->can.state == CAN_STATE_BUS_OFF) {
1776 m_can_clean(dev);
1777 } else {
1778 /* Need to stop the queue to avoid numerous requests
1779 * from being sent. Suggested improvement is to create
1780 * a queueing mechanism that will queue the skbs and
1781 * process them in order.
1782 */
1783 cdev->tx_skb = skb;
1784 netif_stop_queue(cdev->net);
1785 queue_work(cdev->tx_wq, &cdev->tx_work);
1786 }
1787 } else {
1788 cdev->tx_skb = skb;
1789 return m_can_tx_handler(cdev);
1790 }
1791
1792 return NETDEV_TX_OK;
1793 }
1794
m_can_open(struct net_device * dev)1795 static int m_can_open(struct net_device *dev)
1796 {
1797 struct m_can_classdev *cdev = netdev_priv(dev);
1798 int err;
1799
1800 err = phy_power_on(cdev->transceiver);
1801 if (err)
1802 return err;
1803
1804 err = m_can_clk_start(cdev);
1805 if (err)
1806 goto out_phy_power_off;
1807
1808 /* open the can device */
1809 err = open_candev(dev);
1810 if (err) {
1811 netdev_err(dev, "failed to open can device\n");
1812 goto exit_disable_clks;
1813 }
1814
1815 if (cdev->is_peripheral)
1816 can_rx_offload_enable(&cdev->offload);
1817
1818 /* register interrupt handler */
1819 if (cdev->is_peripheral) {
1820 cdev->tx_skb = NULL;
1821 cdev->tx_wq = alloc_workqueue("mcan_wq",
1822 WQ_FREEZABLE | WQ_MEM_RECLAIM, 0);
1823 if (!cdev->tx_wq) {
1824 err = -ENOMEM;
1825 goto out_wq_fail;
1826 }
1827
1828 INIT_WORK(&cdev->tx_work, m_can_tx_work_queue);
1829
1830 err = request_threaded_irq(dev->irq, NULL, m_can_isr,
1831 IRQF_ONESHOT,
1832 dev->name, dev);
1833 } else {
1834 err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
1835 dev);
1836 }
1837
1838 if (err < 0) {
1839 netdev_err(dev, "failed to request interrupt\n");
1840 goto exit_irq_fail;
1841 }
1842
1843 /* start the m_can controller */
1844 err = m_can_start(dev);
1845 if (err)
1846 goto exit_irq_fail;
1847
1848 if (!cdev->is_peripheral)
1849 napi_enable(&cdev->napi);
1850
1851 netif_start_queue(dev);
1852
1853 return 0;
1854
1855 exit_irq_fail:
1856 if (cdev->is_peripheral)
1857 destroy_workqueue(cdev->tx_wq);
1858 out_wq_fail:
1859 if (cdev->is_peripheral)
1860 can_rx_offload_disable(&cdev->offload);
1861 close_candev(dev);
1862 exit_disable_clks:
1863 m_can_clk_stop(cdev);
1864 out_phy_power_off:
1865 phy_power_off(cdev->transceiver);
1866 return err;
1867 }
1868
1869 static const struct net_device_ops m_can_netdev_ops = {
1870 .ndo_open = m_can_open,
1871 .ndo_stop = m_can_close,
1872 .ndo_start_xmit = m_can_start_xmit,
1873 .ndo_change_mtu = can_change_mtu,
1874 };
1875
1876 static const struct ethtool_ops m_can_ethtool_ops = {
1877 .get_ts_info = ethtool_op_get_ts_info,
1878 };
1879
register_m_can_dev(struct net_device * dev)1880 static int register_m_can_dev(struct net_device *dev)
1881 {
1882 dev->flags |= IFF_ECHO; /* we support local echo */
1883 dev->netdev_ops = &m_can_netdev_ops;
1884 dev->ethtool_ops = &m_can_ethtool_ops;
1885
1886 return register_candev(dev);
1887 }
1888
m_can_of_parse_mram(struct m_can_classdev * cdev,const u32 * mram_config_vals)1889 static void m_can_of_parse_mram(struct m_can_classdev *cdev,
1890 const u32 *mram_config_vals)
1891 {
1892 cdev->mcfg[MRAM_SIDF].off = mram_config_vals[0];
1893 cdev->mcfg[MRAM_SIDF].num = mram_config_vals[1];
1894 cdev->mcfg[MRAM_XIDF].off = cdev->mcfg[MRAM_SIDF].off +
1895 cdev->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
1896 cdev->mcfg[MRAM_XIDF].num = mram_config_vals[2];
1897 cdev->mcfg[MRAM_RXF0].off = cdev->mcfg[MRAM_XIDF].off +
1898 cdev->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
1899 cdev->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
1900 FIELD_MAX(RXFC_FS_MASK);
1901 cdev->mcfg[MRAM_RXF1].off = cdev->mcfg[MRAM_RXF0].off +
1902 cdev->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
1903 cdev->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
1904 FIELD_MAX(RXFC_FS_MASK);
1905 cdev->mcfg[MRAM_RXB].off = cdev->mcfg[MRAM_RXF1].off +
1906 cdev->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
1907 cdev->mcfg[MRAM_RXB].num = mram_config_vals[5];
1908 cdev->mcfg[MRAM_TXE].off = cdev->mcfg[MRAM_RXB].off +
1909 cdev->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
1910 cdev->mcfg[MRAM_TXE].num = mram_config_vals[6];
1911 cdev->mcfg[MRAM_TXB].off = cdev->mcfg[MRAM_TXE].off +
1912 cdev->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
1913 cdev->mcfg[MRAM_TXB].num = mram_config_vals[7] &
1914 FIELD_MAX(TXBC_NDTB_MASK);
1915
1916 dev_dbg(cdev->dev,
1917 "sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
1918 cdev->mcfg[MRAM_SIDF].off, cdev->mcfg[MRAM_SIDF].num,
1919 cdev->mcfg[MRAM_XIDF].off, cdev->mcfg[MRAM_XIDF].num,
1920 cdev->mcfg[MRAM_RXF0].off, cdev->mcfg[MRAM_RXF0].num,
1921 cdev->mcfg[MRAM_RXF1].off, cdev->mcfg[MRAM_RXF1].num,
1922 cdev->mcfg[MRAM_RXB].off, cdev->mcfg[MRAM_RXB].num,
1923 cdev->mcfg[MRAM_TXE].off, cdev->mcfg[MRAM_TXE].num,
1924 cdev->mcfg[MRAM_TXB].off, cdev->mcfg[MRAM_TXB].num);
1925 }
1926
m_can_init_ram(struct m_can_classdev * cdev)1927 int m_can_init_ram(struct m_can_classdev *cdev)
1928 {
1929 int end, i, start;
1930 int err = 0;
1931
1932 /* initialize the entire Message RAM in use to avoid possible
1933 * ECC/parity checksum errors when reading an uninitialized buffer
1934 */
1935 start = cdev->mcfg[MRAM_SIDF].off;
1936 end = cdev->mcfg[MRAM_TXB].off +
1937 cdev->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
1938
1939 for (i = start; i < end; i += 4) {
1940 err = m_can_fifo_write_no_off(cdev, i, 0x0);
1941 if (err)
1942 break;
1943 }
1944
1945 return err;
1946 }
1947 EXPORT_SYMBOL_GPL(m_can_init_ram);
1948
m_can_class_get_clocks(struct m_can_classdev * cdev)1949 int m_can_class_get_clocks(struct m_can_classdev *cdev)
1950 {
1951 int ret = 0;
1952
1953 cdev->hclk = devm_clk_get(cdev->dev, "hclk");
1954 cdev->cclk = devm_clk_get(cdev->dev, "cclk");
1955
1956 if (IS_ERR(cdev->hclk) || IS_ERR(cdev->cclk)) {
1957 dev_err(cdev->dev, "no clock found\n");
1958 ret = -ENODEV;
1959 }
1960
1961 return ret;
1962 }
1963 EXPORT_SYMBOL_GPL(m_can_class_get_clocks);
1964
m_can_class_allocate_dev(struct device * dev,int sizeof_priv)1965 struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
1966 int sizeof_priv)
1967 {
1968 struct m_can_classdev *class_dev = NULL;
1969 u32 mram_config_vals[MRAM_CFG_LEN];
1970 struct net_device *net_dev;
1971 u32 tx_fifo_size;
1972 int ret;
1973
1974 ret = fwnode_property_read_u32_array(dev_fwnode(dev),
1975 "bosch,mram-cfg",
1976 mram_config_vals,
1977 sizeof(mram_config_vals) / 4);
1978 if (ret) {
1979 dev_err(dev, "Could not get Message RAM configuration.");
1980 goto out;
1981 }
1982
1983 /* Get TX FIFO size
1984 * Defines the total amount of echo buffers for loopback
1985 */
1986 tx_fifo_size = mram_config_vals[7];
1987
1988 /* allocate the m_can device */
1989 net_dev = alloc_candev(sizeof_priv, tx_fifo_size);
1990 if (!net_dev) {
1991 dev_err(dev, "Failed to allocate CAN device");
1992 goto out;
1993 }
1994
1995 class_dev = netdev_priv(net_dev);
1996 class_dev->net = net_dev;
1997 class_dev->dev = dev;
1998 SET_NETDEV_DEV(net_dev, dev);
1999
2000 m_can_of_parse_mram(class_dev, mram_config_vals);
2001 out:
2002 return class_dev;
2003 }
2004 EXPORT_SYMBOL_GPL(m_can_class_allocate_dev);
2005
m_can_class_free_dev(struct net_device * net)2006 void m_can_class_free_dev(struct net_device *net)
2007 {
2008 free_candev(net);
2009 }
2010 EXPORT_SYMBOL_GPL(m_can_class_free_dev);
2011
m_can_class_register(struct m_can_classdev * cdev)2012 int m_can_class_register(struct m_can_classdev *cdev)
2013 {
2014 int ret;
2015
2016 if (cdev->pm_clock_support) {
2017 ret = m_can_clk_start(cdev);
2018 if (ret)
2019 return ret;
2020 }
2021
2022 if (cdev->is_peripheral) {
2023 ret = can_rx_offload_add_manual(cdev->net, &cdev->offload,
2024 NAPI_POLL_WEIGHT);
2025 if (ret)
2026 goto clk_disable;
2027 }
2028
2029 ret = m_can_dev_setup(cdev);
2030 if (ret)
2031 goto rx_offload_del;
2032
2033 ret = register_m_can_dev(cdev->net);
2034 if (ret) {
2035 dev_err(cdev->dev, "registering %s failed (err=%d)\n",
2036 cdev->net->name, ret);
2037 goto rx_offload_del;
2038 }
2039
2040 of_can_transceiver(cdev->net);
2041
2042 dev_info(cdev->dev, "%s device registered (irq=%d, version=%d)\n",
2043 KBUILD_MODNAME, cdev->net->irq, cdev->version);
2044
2045 /* Probe finished
2046 * Stop clocks. They will be reactivated once the M_CAN device is opened
2047 */
2048 m_can_clk_stop(cdev);
2049
2050 return 0;
2051
2052 rx_offload_del:
2053 if (cdev->is_peripheral)
2054 can_rx_offload_del(&cdev->offload);
2055 clk_disable:
2056 m_can_clk_stop(cdev);
2057
2058 return ret;
2059 }
2060 EXPORT_SYMBOL_GPL(m_can_class_register);
2061
m_can_class_unregister(struct m_can_classdev * cdev)2062 void m_can_class_unregister(struct m_can_classdev *cdev)
2063 {
2064 if (cdev->is_peripheral)
2065 can_rx_offload_del(&cdev->offload);
2066 unregister_candev(cdev->net);
2067 }
2068 EXPORT_SYMBOL_GPL(m_can_class_unregister);
2069
m_can_class_suspend(struct device * dev)2070 int m_can_class_suspend(struct device *dev)
2071 {
2072 struct m_can_classdev *cdev = dev_get_drvdata(dev);
2073 struct net_device *ndev = cdev->net;
2074
2075 if (netif_running(ndev)) {
2076 netif_stop_queue(ndev);
2077 netif_device_detach(ndev);
2078 m_can_stop(ndev);
2079 m_can_clk_stop(cdev);
2080 }
2081
2082 pinctrl_pm_select_sleep_state(dev);
2083
2084 cdev->can.state = CAN_STATE_SLEEPING;
2085
2086 return 0;
2087 }
2088 EXPORT_SYMBOL_GPL(m_can_class_suspend);
2089
m_can_class_resume(struct device * dev)2090 int m_can_class_resume(struct device *dev)
2091 {
2092 struct m_can_classdev *cdev = dev_get_drvdata(dev);
2093 struct net_device *ndev = cdev->net;
2094
2095 pinctrl_pm_select_default_state(dev);
2096
2097 cdev->can.state = CAN_STATE_ERROR_ACTIVE;
2098
2099 if (netif_running(ndev)) {
2100 int ret;
2101
2102 ret = m_can_clk_start(cdev);
2103 if (ret)
2104 return ret;
2105 ret = m_can_start(ndev);
2106 if (ret) {
2107 m_can_clk_stop(cdev);
2108
2109 return ret;
2110 }
2111
2112 netif_device_attach(ndev);
2113 netif_start_queue(ndev);
2114 }
2115
2116 return 0;
2117 }
2118 EXPORT_SYMBOL_GPL(m_can_class_resume);
2119
2120 MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
2121 MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
2122 MODULE_LICENSE("GPL v2");
2123 MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
2124