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Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[deliverable/linux.git] / drivers / net / can / flexcan.c
1 /*
2 * flexcan.c - FLEXCAN CAN controller driver
3 *
4 * Copyright (c) 2005-2006 Varma Electronics Oy
5 * Copyright (c) 2009 Sascha Hauer, Pengutronix
6 * Copyright (c) 2010 Marc Kleine-Budde, Pengutronix
7 *
8 * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
9 *
10 * LICENCE:
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation version 2.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 */
21
22 #include <linux/netdevice.h>
23 #include <linux/can.h>
24 #include <linux/can/dev.h>
25 #include <linux/can/error.h>
26 #include <linux/can/led.h>
27 #include <linux/clk.h>
28 #include <linux/delay.h>
29 #include <linux/if_arp.h>
30 #include <linux/if_ether.h>
31 #include <linux/interrupt.h>
32 #include <linux/io.h>
33 #include <linux/kernel.h>
34 #include <linux/list.h>
35 #include <linux/module.h>
36 #include <linux/of.h>
37 #include <linux/of_device.h>
38 #include <linux/platform_device.h>
39 #include <linux/regulator/consumer.h>
40
41 #define DRV_NAME "flexcan"
42
43 /* 8 for RX fifo and 2 error handling */
44 #define FLEXCAN_NAPI_WEIGHT (8 + 2)
45
46 /* FLEXCAN module configuration register (CANMCR) bits */
47 #define FLEXCAN_MCR_MDIS BIT(31)
48 #define FLEXCAN_MCR_FRZ BIT(30)
49 #define FLEXCAN_MCR_FEN BIT(29)
50 #define FLEXCAN_MCR_HALT BIT(28)
51 #define FLEXCAN_MCR_NOT_RDY BIT(27)
52 #define FLEXCAN_MCR_WAK_MSK BIT(26)
53 #define FLEXCAN_MCR_SOFTRST BIT(25)
54 #define FLEXCAN_MCR_FRZ_ACK BIT(24)
55 #define FLEXCAN_MCR_SUPV BIT(23)
56 #define FLEXCAN_MCR_SLF_WAK BIT(22)
57 #define FLEXCAN_MCR_WRN_EN BIT(21)
58 #define FLEXCAN_MCR_LPM_ACK BIT(20)
59 #define FLEXCAN_MCR_WAK_SRC BIT(19)
60 #define FLEXCAN_MCR_DOZE BIT(18)
61 #define FLEXCAN_MCR_SRX_DIS BIT(17)
62 #define FLEXCAN_MCR_BCC BIT(16)
63 #define FLEXCAN_MCR_LPRIO_EN BIT(13)
64 #define FLEXCAN_MCR_AEN BIT(12)
65 #define FLEXCAN_MCR_MAXMB(x) ((x) & 0x1f)
66 #define FLEXCAN_MCR_IDAM_A (0 << 8)
67 #define FLEXCAN_MCR_IDAM_B (1 << 8)
68 #define FLEXCAN_MCR_IDAM_C (2 << 8)
69 #define FLEXCAN_MCR_IDAM_D (3 << 8)
70
71 /* FLEXCAN control register (CANCTRL) bits */
72 #define FLEXCAN_CTRL_PRESDIV(x) (((x) & 0xff) << 24)
73 #define FLEXCAN_CTRL_RJW(x) (((x) & 0x03) << 22)
74 #define FLEXCAN_CTRL_PSEG1(x) (((x) & 0x07) << 19)
75 #define FLEXCAN_CTRL_PSEG2(x) (((x) & 0x07) << 16)
76 #define FLEXCAN_CTRL_BOFF_MSK BIT(15)
77 #define FLEXCAN_CTRL_ERR_MSK BIT(14)
78 #define FLEXCAN_CTRL_CLK_SRC BIT(13)
79 #define FLEXCAN_CTRL_LPB BIT(12)
80 #define FLEXCAN_CTRL_TWRN_MSK BIT(11)
81 #define FLEXCAN_CTRL_RWRN_MSK BIT(10)
82 #define FLEXCAN_CTRL_SMP BIT(7)
83 #define FLEXCAN_CTRL_BOFF_REC BIT(6)
84 #define FLEXCAN_CTRL_TSYN BIT(5)
85 #define FLEXCAN_CTRL_LBUF BIT(4)
86 #define FLEXCAN_CTRL_LOM BIT(3)
87 #define FLEXCAN_CTRL_PROPSEG(x) ((x) & 0x07)
88 #define FLEXCAN_CTRL_ERR_BUS (FLEXCAN_CTRL_ERR_MSK)
89 #define FLEXCAN_CTRL_ERR_STATE \
90 (FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
91 FLEXCAN_CTRL_BOFF_MSK)
92 #define FLEXCAN_CTRL_ERR_ALL \
93 (FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
94
95 /* FLEXCAN error and status register (ESR) bits */
96 #define FLEXCAN_ESR_TWRN_INT BIT(17)
97 #define FLEXCAN_ESR_RWRN_INT BIT(16)
98 #define FLEXCAN_ESR_BIT1_ERR BIT(15)
99 #define FLEXCAN_ESR_BIT0_ERR BIT(14)
100 #define FLEXCAN_ESR_ACK_ERR BIT(13)
101 #define FLEXCAN_ESR_CRC_ERR BIT(12)
102 #define FLEXCAN_ESR_FRM_ERR BIT(11)
103 #define FLEXCAN_ESR_STF_ERR BIT(10)
104 #define FLEXCAN_ESR_TX_WRN BIT(9)
105 #define FLEXCAN_ESR_RX_WRN BIT(8)
106 #define FLEXCAN_ESR_IDLE BIT(7)
107 #define FLEXCAN_ESR_TXRX BIT(6)
108 #define FLEXCAN_EST_FLT_CONF_SHIFT (4)
109 #define FLEXCAN_ESR_FLT_CONF_MASK (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
110 #define FLEXCAN_ESR_FLT_CONF_ACTIVE (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
111 #define FLEXCAN_ESR_FLT_CONF_PASSIVE (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
112 #define FLEXCAN_ESR_BOFF_INT BIT(2)
113 #define FLEXCAN_ESR_ERR_INT BIT(1)
114 #define FLEXCAN_ESR_WAK_INT BIT(0)
115 #define FLEXCAN_ESR_ERR_BUS \
116 (FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
117 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
118 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
119 #define FLEXCAN_ESR_ERR_STATE \
120 (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
121 #define FLEXCAN_ESR_ERR_ALL \
122 (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
123 #define FLEXCAN_ESR_ALL_INT \
124 (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
125 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
126
127 /* FLEXCAN interrupt flag register (IFLAG) bits */
128 #define FLEXCAN_TX_BUF_ID 8
129 #define FLEXCAN_IFLAG_BUF(x) BIT(x)
130 #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7)
131 #define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6)
132 #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
133 #define FLEXCAN_IFLAG_DEFAULT \
134 (FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \
135 FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID))
136
137 /* FLEXCAN message buffers */
138 #define FLEXCAN_MB_CNT_CODE(x) (((x) & 0xf) << 24)
139 #define FLEXCAN_MB_CNT_SRR BIT(22)
140 #define FLEXCAN_MB_CNT_IDE BIT(21)
141 #define FLEXCAN_MB_CNT_RTR BIT(20)
142 #define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16)
143 #define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff)
144
145 #define FLEXCAN_MB_CODE_MASK (0xf0ffffff)
146
147 /*
148 * FLEXCAN hardware feature flags
149 *
150 * Below is some version info we got:
151 * SOC Version IP-Version Glitch- [TR]WRN_INT
152 * Filter? connected?
153 * MX25 FlexCAN2 03.00.00.00 no no
154 * MX28 FlexCAN2 03.00.04.00 yes yes
155 * MX35 FlexCAN2 03.00.00.00 no no
156 * MX53 FlexCAN2 03.00.00.00 yes no
157 * MX6s FlexCAN3 10.00.12.00 yes yes
158 *
159 * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
160 */
161 #define FLEXCAN_HAS_V10_FEATURES BIT(1) /* For core version >= 10 */
162 #define FLEXCAN_HAS_BROKEN_ERR_STATE BIT(2) /* [TR]WRN_INT not connected */
163
164 /* Structure of the message buffer */
165 struct flexcan_mb {
166 u32 can_ctrl;
167 u32 can_id;
168 u32 data[2];
169 };
170
171 /* Structure of the hardware registers */
172 struct flexcan_regs {
173 u32 mcr; /* 0x00 */
174 u32 ctrl; /* 0x04 */
175 u32 timer; /* 0x08 */
176 u32 _reserved1; /* 0x0c */
177 u32 rxgmask; /* 0x10 */
178 u32 rx14mask; /* 0x14 */
179 u32 rx15mask; /* 0x18 */
180 u32 ecr; /* 0x1c */
181 u32 esr; /* 0x20 */
182 u32 imask2; /* 0x24 */
183 u32 imask1; /* 0x28 */
184 u32 iflag2; /* 0x2c */
185 u32 iflag1; /* 0x30 */
186 u32 crl2; /* 0x34 */
187 u32 esr2; /* 0x38 */
188 u32 imeur; /* 0x3c */
189 u32 lrfr; /* 0x40 */
190 u32 crcr; /* 0x44 */
191 u32 rxfgmask; /* 0x48 */
192 u32 rxfir; /* 0x4c */
193 u32 _reserved3[12];
194 struct flexcan_mb cantxfg[64];
195 };
196
197 struct flexcan_devtype_data {
198 u32 features; /* hardware controller features */
199 };
200
201 struct flexcan_priv {
202 struct can_priv can;
203 struct net_device *dev;
204 struct napi_struct napi;
205
206 void __iomem *base;
207 u32 reg_esr;
208 u32 reg_ctrl_default;
209
210 struct clk *clk_ipg;
211 struct clk *clk_per;
212 struct flexcan_platform_data *pdata;
213 const struct flexcan_devtype_data *devtype_data;
214 struct regulator *reg_xceiver;
215 };
216
217 static struct flexcan_devtype_data fsl_p1010_devtype_data = {
218 .features = FLEXCAN_HAS_BROKEN_ERR_STATE,
219 };
220 static struct flexcan_devtype_data fsl_imx28_devtype_data;
221 static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
222 .features = FLEXCAN_HAS_V10_FEATURES,
223 };
224
225 static const struct can_bittiming_const flexcan_bittiming_const = {
226 .name = DRV_NAME,
227 .tseg1_min = 4,
228 .tseg1_max = 16,
229 .tseg2_min = 2,
230 .tseg2_max = 8,
231 .sjw_max = 4,
232 .brp_min = 1,
233 .brp_max = 256,
234 .brp_inc = 1,
235 };
236
237 /*
238 * Abstract off the read/write for arm versus ppc.
239 */
240 #if defined(__BIG_ENDIAN)
241 static inline u32 flexcan_read(void __iomem *addr)
242 {
243 return in_be32(addr);
244 }
245
246 static inline void flexcan_write(u32 val, void __iomem *addr)
247 {
248 out_be32(addr, val);
249 }
250 #else
251 static inline u32 flexcan_read(void __iomem *addr)
252 {
253 return readl(addr);
254 }
255
256 static inline void flexcan_write(u32 val, void __iomem *addr)
257 {
258 writel(val, addr);
259 }
260 #endif
261
262 static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
263 u32 reg_esr)
264 {
265 return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
266 (reg_esr & FLEXCAN_ESR_ERR_BUS);
267 }
268
269 static inline void flexcan_chip_enable(struct flexcan_priv *priv)
270 {
271 struct flexcan_regs __iomem *regs = priv->base;
272 u32 reg;
273
274 reg = flexcan_read(&regs->mcr);
275 reg &= ~FLEXCAN_MCR_MDIS;
276 flexcan_write(reg, &regs->mcr);
277
278 udelay(10);
279 }
280
281 static inline void flexcan_chip_disable(struct flexcan_priv *priv)
282 {
283 struct flexcan_regs __iomem *regs = priv->base;
284 u32 reg;
285
286 reg = flexcan_read(&regs->mcr);
287 reg |= FLEXCAN_MCR_MDIS;
288 flexcan_write(reg, &regs->mcr);
289 }
290
291 static int flexcan_get_berr_counter(const struct net_device *dev,
292 struct can_berr_counter *bec)
293 {
294 const struct flexcan_priv *priv = netdev_priv(dev);
295 struct flexcan_regs __iomem *regs = priv->base;
296 u32 reg = flexcan_read(&regs->ecr);
297
298 bec->txerr = (reg >> 0) & 0xff;
299 bec->rxerr = (reg >> 8) & 0xff;
300
301 return 0;
302 }
303
304 static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
305 {
306 const struct flexcan_priv *priv = netdev_priv(dev);
307 struct flexcan_regs __iomem *regs = priv->base;
308 struct can_frame *cf = (struct can_frame *)skb->data;
309 u32 can_id;
310 u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16);
311
312 if (can_dropped_invalid_skb(dev, skb))
313 return NETDEV_TX_OK;
314
315 netif_stop_queue(dev);
316
317 if (cf->can_id & CAN_EFF_FLAG) {
318 can_id = cf->can_id & CAN_EFF_MASK;
319 ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
320 } else {
321 can_id = (cf->can_id & CAN_SFF_MASK) << 18;
322 }
323
324 if (cf->can_id & CAN_RTR_FLAG)
325 ctrl |= FLEXCAN_MB_CNT_RTR;
326
327 if (cf->can_dlc > 0) {
328 u32 data = be32_to_cpup((__be32 *)&cf->data[0]);
329 flexcan_write(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
330 }
331 if (cf->can_dlc > 3) {
332 u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
333 flexcan_write(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
334 }
335
336 can_put_echo_skb(skb, dev, 0);
337
338 flexcan_write(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
339 flexcan_write(ctrl, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
340
341 return NETDEV_TX_OK;
342 }
343
344 static void do_bus_err(struct net_device *dev,
345 struct can_frame *cf, u32 reg_esr)
346 {
347 struct flexcan_priv *priv = netdev_priv(dev);
348 int rx_errors = 0, tx_errors = 0;
349
350 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
351
352 if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
353 netdev_dbg(dev, "BIT1_ERR irq\n");
354 cf->data[2] |= CAN_ERR_PROT_BIT1;
355 tx_errors = 1;
356 }
357 if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
358 netdev_dbg(dev, "BIT0_ERR irq\n");
359 cf->data[2] |= CAN_ERR_PROT_BIT0;
360 tx_errors = 1;
361 }
362 if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
363 netdev_dbg(dev, "ACK_ERR irq\n");
364 cf->can_id |= CAN_ERR_ACK;
365 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
366 tx_errors = 1;
367 }
368 if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
369 netdev_dbg(dev, "CRC_ERR irq\n");
370 cf->data[2] |= CAN_ERR_PROT_BIT;
371 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
372 rx_errors = 1;
373 }
374 if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
375 netdev_dbg(dev, "FRM_ERR irq\n");
376 cf->data[2] |= CAN_ERR_PROT_FORM;
377 rx_errors = 1;
378 }
379 if (reg_esr & FLEXCAN_ESR_STF_ERR) {
380 netdev_dbg(dev, "STF_ERR irq\n");
381 cf->data[2] |= CAN_ERR_PROT_STUFF;
382 rx_errors = 1;
383 }
384
385 priv->can.can_stats.bus_error++;
386 if (rx_errors)
387 dev->stats.rx_errors++;
388 if (tx_errors)
389 dev->stats.tx_errors++;
390 }
391
392 static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
393 {
394 struct sk_buff *skb;
395 struct can_frame *cf;
396
397 skb = alloc_can_err_skb(dev, &cf);
398 if (unlikely(!skb))
399 return 0;
400
401 do_bus_err(dev, cf, reg_esr);
402 netif_receive_skb(skb);
403
404 dev->stats.rx_packets++;
405 dev->stats.rx_bytes += cf->can_dlc;
406
407 return 1;
408 }
409
410 static void do_state(struct net_device *dev,
411 struct can_frame *cf, enum can_state new_state)
412 {
413 struct flexcan_priv *priv = netdev_priv(dev);
414 struct can_berr_counter bec;
415
416 flexcan_get_berr_counter(dev, &bec);
417
418 switch (priv->can.state) {
419 case CAN_STATE_ERROR_ACTIVE:
420 /*
421 * from: ERROR_ACTIVE
422 * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
423 * => : there was a warning int
424 */
425 if (new_state >= CAN_STATE_ERROR_WARNING &&
426 new_state <= CAN_STATE_BUS_OFF) {
427 netdev_dbg(dev, "Error Warning IRQ\n");
428 priv->can.can_stats.error_warning++;
429
430 cf->can_id |= CAN_ERR_CRTL;
431 cf->data[1] = (bec.txerr > bec.rxerr) ?
432 CAN_ERR_CRTL_TX_WARNING :
433 CAN_ERR_CRTL_RX_WARNING;
434 }
435 case CAN_STATE_ERROR_WARNING: /* fallthrough */
436 /*
437 * from: ERROR_ACTIVE, ERROR_WARNING
438 * to : ERROR_PASSIVE, BUS_OFF
439 * => : error passive int
440 */
441 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
442 new_state <= CAN_STATE_BUS_OFF) {
443 netdev_dbg(dev, "Error Passive IRQ\n");
444 priv->can.can_stats.error_passive++;
445
446 cf->can_id |= CAN_ERR_CRTL;
447 cf->data[1] = (bec.txerr > bec.rxerr) ?
448 CAN_ERR_CRTL_TX_PASSIVE :
449 CAN_ERR_CRTL_RX_PASSIVE;
450 }
451 break;
452 case CAN_STATE_BUS_OFF:
453 netdev_err(dev, "BUG! "
454 "hardware recovered automatically from BUS_OFF\n");
455 break;
456 default:
457 break;
458 }
459
460 /* process state changes depending on the new state */
461 switch (new_state) {
462 case CAN_STATE_ERROR_ACTIVE:
463 netdev_dbg(dev, "Error Active\n");
464 cf->can_id |= CAN_ERR_PROT;
465 cf->data[2] = CAN_ERR_PROT_ACTIVE;
466 break;
467 case CAN_STATE_BUS_OFF:
468 cf->can_id |= CAN_ERR_BUSOFF;
469 can_bus_off(dev);
470 break;
471 default:
472 break;
473 }
474 }
475
476 static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
477 {
478 struct flexcan_priv *priv = netdev_priv(dev);
479 struct sk_buff *skb;
480 struct can_frame *cf;
481 enum can_state new_state;
482 int flt;
483
484 flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
485 if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
486 if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN |
487 FLEXCAN_ESR_RX_WRN))))
488 new_state = CAN_STATE_ERROR_ACTIVE;
489 else
490 new_state = CAN_STATE_ERROR_WARNING;
491 } else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE))
492 new_state = CAN_STATE_ERROR_PASSIVE;
493 else
494 new_state = CAN_STATE_BUS_OFF;
495
496 /* state hasn't changed */
497 if (likely(new_state == priv->can.state))
498 return 0;
499
500 skb = alloc_can_err_skb(dev, &cf);
501 if (unlikely(!skb))
502 return 0;
503
504 do_state(dev, cf, new_state);
505 priv->can.state = new_state;
506 netif_receive_skb(skb);
507
508 dev->stats.rx_packets++;
509 dev->stats.rx_bytes += cf->can_dlc;
510
511 return 1;
512 }
513
514 static void flexcan_read_fifo(const struct net_device *dev,
515 struct can_frame *cf)
516 {
517 const struct flexcan_priv *priv = netdev_priv(dev);
518 struct flexcan_regs __iomem *regs = priv->base;
519 struct flexcan_mb __iomem *mb = &regs->cantxfg[0];
520 u32 reg_ctrl, reg_id;
521
522 reg_ctrl = flexcan_read(&mb->can_ctrl);
523 reg_id = flexcan_read(&mb->can_id);
524 if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
525 cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
526 else
527 cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
528
529 if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
530 cf->can_id |= CAN_RTR_FLAG;
531 cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
532
533 *(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
534 *(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
535
536 /* mark as read */
537 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
538 flexcan_read(&regs->timer);
539 }
540
541 static int flexcan_read_frame(struct net_device *dev)
542 {
543 struct net_device_stats *stats = &dev->stats;
544 struct can_frame *cf;
545 struct sk_buff *skb;
546
547 skb = alloc_can_skb(dev, &cf);
548 if (unlikely(!skb)) {
549 stats->rx_dropped++;
550 return 0;
551 }
552
553 flexcan_read_fifo(dev, cf);
554 netif_receive_skb(skb);
555
556 stats->rx_packets++;
557 stats->rx_bytes += cf->can_dlc;
558
559 can_led_event(dev, CAN_LED_EVENT_RX);
560
561 return 1;
562 }
563
564 static int flexcan_poll(struct napi_struct *napi, int quota)
565 {
566 struct net_device *dev = napi->dev;
567 const struct flexcan_priv *priv = netdev_priv(dev);
568 struct flexcan_regs __iomem *regs = priv->base;
569 u32 reg_iflag1, reg_esr;
570 int work_done = 0;
571
572 /*
573 * The error bits are cleared on read,
574 * use saved value from irq handler.
575 */
576 reg_esr = flexcan_read(&regs->esr) | priv->reg_esr;
577
578 /* handle state changes */
579 work_done += flexcan_poll_state(dev, reg_esr);
580
581 /* handle RX-FIFO */
582 reg_iflag1 = flexcan_read(&regs->iflag1);
583 while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
584 work_done < quota) {
585 work_done += flexcan_read_frame(dev);
586 reg_iflag1 = flexcan_read(&regs->iflag1);
587 }
588
589 /* report bus errors */
590 if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
591 work_done += flexcan_poll_bus_err(dev, reg_esr);
592
593 if (work_done < quota) {
594 napi_complete(napi);
595 /* enable IRQs */
596 flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
597 flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
598 }
599
600 return work_done;
601 }
602
603 static irqreturn_t flexcan_irq(int irq, void *dev_id)
604 {
605 struct net_device *dev = dev_id;
606 struct net_device_stats *stats = &dev->stats;
607 struct flexcan_priv *priv = netdev_priv(dev);
608 struct flexcan_regs __iomem *regs = priv->base;
609 u32 reg_iflag1, reg_esr;
610
611 reg_iflag1 = flexcan_read(&regs->iflag1);
612 reg_esr = flexcan_read(&regs->esr);
613 /* ACK all bus error and state change IRQ sources */
614 if (reg_esr & FLEXCAN_ESR_ALL_INT)
615 flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
616
617 /*
618 * schedule NAPI in case of:
619 * - rx IRQ
620 * - state change IRQ
621 * - bus error IRQ and bus error reporting is activated
622 */
623 if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
624 (reg_esr & FLEXCAN_ESR_ERR_STATE) ||
625 flexcan_has_and_handle_berr(priv, reg_esr)) {
626 /*
627 * The error bits are cleared on read,
628 * save them for later use.
629 */
630 priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
631 flexcan_write(FLEXCAN_IFLAG_DEFAULT &
632 ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->imask1);
633 flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
634 &regs->ctrl);
635 napi_schedule(&priv->napi);
636 }
637
638 /* FIFO overflow */
639 if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
640 flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
641 dev->stats.rx_over_errors++;
642 dev->stats.rx_errors++;
643 }
644
645 /* transmission complete interrupt */
646 if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
647 stats->tx_bytes += can_get_echo_skb(dev, 0);
648 stats->tx_packets++;
649 can_led_event(dev, CAN_LED_EVENT_TX);
650 flexcan_write((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
651 netif_wake_queue(dev);
652 }
653
654 return IRQ_HANDLED;
655 }
656
657 static void flexcan_set_bittiming(struct net_device *dev)
658 {
659 const struct flexcan_priv *priv = netdev_priv(dev);
660 const struct can_bittiming *bt = &priv->can.bittiming;
661 struct flexcan_regs __iomem *regs = priv->base;
662 u32 reg;
663
664 reg = flexcan_read(&regs->ctrl);
665 reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
666 FLEXCAN_CTRL_RJW(0x3) |
667 FLEXCAN_CTRL_PSEG1(0x7) |
668 FLEXCAN_CTRL_PSEG2(0x7) |
669 FLEXCAN_CTRL_PROPSEG(0x7) |
670 FLEXCAN_CTRL_LPB |
671 FLEXCAN_CTRL_SMP |
672 FLEXCAN_CTRL_LOM);
673
674 reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
675 FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
676 FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
677 FLEXCAN_CTRL_RJW(bt->sjw - 1) |
678 FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
679
680 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
681 reg |= FLEXCAN_CTRL_LPB;
682 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
683 reg |= FLEXCAN_CTRL_LOM;
684 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
685 reg |= FLEXCAN_CTRL_SMP;
686
687 netdev_info(dev, "writing ctrl=0x%08x\n", reg);
688 flexcan_write(reg, &regs->ctrl);
689
690 /* print chip status */
691 netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
692 flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
693 }
694
695 /*
696 * flexcan_chip_start
697 *
698 * this functions is entered with clocks enabled
699 *
700 */
701 static int flexcan_chip_start(struct net_device *dev)
702 {
703 struct flexcan_priv *priv = netdev_priv(dev);
704 struct flexcan_regs __iomem *regs = priv->base;
705 int err;
706 u32 reg_mcr, reg_ctrl;
707
708 /* enable module */
709 flexcan_chip_enable(priv);
710
711 /* soft reset */
712 flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
713 udelay(10);
714
715 reg_mcr = flexcan_read(&regs->mcr);
716 if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
717 netdev_err(dev, "Failed to softreset can module (mcr=0x%08x)\n",
718 reg_mcr);
719 err = -ENODEV;
720 goto out;
721 }
722
723 flexcan_set_bittiming(dev);
724
725 /*
726 * MCR
727 *
728 * enable freeze
729 * enable fifo
730 * halt now
731 * only supervisor access
732 * enable warning int
733 * choose format C
734 * disable local echo
735 *
736 */
737 reg_mcr = flexcan_read(&regs->mcr);
738 reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
739 reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
740 FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
741 FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_SRX_DIS |
742 FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID);
743 netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
744 flexcan_write(reg_mcr, &regs->mcr);
745
746 /*
747 * CTRL
748 *
749 * disable timer sync feature
750 *
751 * disable auto busoff recovery
752 * transmit lowest buffer first
753 *
754 * enable tx and rx warning interrupt
755 * enable bus off interrupt
756 * (== FLEXCAN_CTRL_ERR_STATE)
757 */
758 reg_ctrl = flexcan_read(&regs->ctrl);
759 reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
760 reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
761 FLEXCAN_CTRL_ERR_STATE;
762 /*
763 * enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
764 * on most Flexcan cores, too. Otherwise we don't get
765 * any error warning or passive interrupts.
766 */
767 if (priv->devtype_data->features & FLEXCAN_HAS_BROKEN_ERR_STATE ||
768 priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
769 reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
770
771 /* save for later use */
772 priv->reg_ctrl_default = reg_ctrl;
773 netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
774 flexcan_write(reg_ctrl, &regs->ctrl);
775
776 /* Abort any pending TX, mark Mailbox as INACTIVE */
777 flexcan_write(FLEXCAN_MB_CNT_CODE(0x4),
778 &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
779
780 /* acceptance mask/acceptance code (accept everything) */
781 flexcan_write(0x0, &regs->rxgmask);
782 flexcan_write(0x0, &regs->rx14mask);
783 flexcan_write(0x0, &regs->rx15mask);
784
785 if (priv->devtype_data->features & FLEXCAN_HAS_V10_FEATURES)
786 flexcan_write(0x0, &regs->rxfgmask);
787
788 if (priv->reg_xceiver) {
789 err = regulator_enable(priv->reg_xceiver);
790 if (err)
791 goto out;
792 }
793
794 /* synchronize with the can bus */
795 reg_mcr = flexcan_read(&regs->mcr);
796 reg_mcr &= ~FLEXCAN_MCR_HALT;
797 flexcan_write(reg_mcr, &regs->mcr);
798
799 priv->can.state = CAN_STATE_ERROR_ACTIVE;
800
801 /* enable FIFO interrupts */
802 flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
803
804 /* print chip status */
805 netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
806 flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
807
808 return 0;
809
810 out:
811 flexcan_chip_disable(priv);
812 return err;
813 }
814
815 /*
816 * flexcan_chip_stop
817 *
818 * this functions is entered with clocks enabled
819 *
820 */
821 static void flexcan_chip_stop(struct net_device *dev)
822 {
823 struct flexcan_priv *priv = netdev_priv(dev);
824 struct flexcan_regs __iomem *regs = priv->base;
825 u32 reg;
826
827 /* Disable all interrupts */
828 flexcan_write(0, &regs->imask1);
829
830 /* Disable + halt module */
831 reg = flexcan_read(&regs->mcr);
832 reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
833 flexcan_write(reg, &regs->mcr);
834
835 if (priv->reg_xceiver)
836 regulator_disable(priv->reg_xceiver);
837 priv->can.state = CAN_STATE_STOPPED;
838
839 return;
840 }
841
842 static int flexcan_open(struct net_device *dev)
843 {
844 struct flexcan_priv *priv = netdev_priv(dev);
845 int err;
846
847 err = clk_prepare_enable(priv->clk_ipg);
848 if (err)
849 return err;
850
851 err = clk_prepare_enable(priv->clk_per);
852 if (err)
853 goto out_disable_ipg;
854
855 err = open_candev(dev);
856 if (err)
857 goto out_disable_per;
858
859 err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
860 if (err)
861 goto out_close;
862
863 /* start chip and queuing */
864 err = flexcan_chip_start(dev);
865 if (err)
866 goto out_close;
867
868 can_led_event(dev, CAN_LED_EVENT_OPEN);
869
870 napi_enable(&priv->napi);
871 netif_start_queue(dev);
872
873 return 0;
874
875 out_close:
876 close_candev(dev);
877 out_disable_per:
878 clk_disable_unprepare(priv->clk_per);
879 out_disable_ipg:
880 clk_disable_unprepare(priv->clk_ipg);
881
882 return err;
883 }
884
885 static int flexcan_close(struct net_device *dev)
886 {
887 struct flexcan_priv *priv = netdev_priv(dev);
888
889 netif_stop_queue(dev);
890 napi_disable(&priv->napi);
891 flexcan_chip_stop(dev);
892
893 free_irq(dev->irq, dev);
894 clk_disable_unprepare(priv->clk_per);
895 clk_disable_unprepare(priv->clk_ipg);
896
897 close_candev(dev);
898
899 can_led_event(dev, CAN_LED_EVENT_STOP);
900
901 return 0;
902 }
903
904 static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
905 {
906 int err;
907
908 switch (mode) {
909 case CAN_MODE_START:
910 err = flexcan_chip_start(dev);
911 if (err)
912 return err;
913
914 netif_wake_queue(dev);
915 break;
916
917 default:
918 return -EOPNOTSUPP;
919 }
920
921 return 0;
922 }
923
924 static const struct net_device_ops flexcan_netdev_ops = {
925 .ndo_open = flexcan_open,
926 .ndo_stop = flexcan_close,
927 .ndo_start_xmit = flexcan_start_xmit,
928 };
929
930 static int register_flexcandev(struct net_device *dev)
931 {
932 struct flexcan_priv *priv = netdev_priv(dev);
933 struct flexcan_regs __iomem *regs = priv->base;
934 u32 reg, err;
935
936 err = clk_prepare_enable(priv->clk_ipg);
937 if (err)
938 return err;
939
940 err = clk_prepare_enable(priv->clk_per);
941 if (err)
942 goto out_disable_ipg;
943
944 /* select "bus clock", chip must be disabled */
945 flexcan_chip_disable(priv);
946 reg = flexcan_read(&regs->ctrl);
947 reg |= FLEXCAN_CTRL_CLK_SRC;
948 flexcan_write(reg, &regs->ctrl);
949
950 flexcan_chip_enable(priv);
951
952 /* set freeze, halt and activate FIFO, restrict register access */
953 reg = flexcan_read(&regs->mcr);
954 reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
955 FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
956 flexcan_write(reg, &regs->mcr);
957
958 /*
959 * Currently we only support newer versions of this core
960 * featuring a RX FIFO. Older cores found on some Coldfire
961 * derivates are not yet supported.
962 */
963 reg = flexcan_read(&regs->mcr);
964 if (!(reg & FLEXCAN_MCR_FEN)) {
965 netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
966 err = -ENODEV;
967 goto out_disable_per;
968 }
969
970 err = register_candev(dev);
971
972 out_disable_per:
973 /* disable core and turn off clocks */
974 flexcan_chip_disable(priv);
975 clk_disable_unprepare(priv->clk_per);
976 out_disable_ipg:
977 clk_disable_unprepare(priv->clk_ipg);
978
979 return err;
980 }
981
982 static void unregister_flexcandev(struct net_device *dev)
983 {
984 unregister_candev(dev);
985 }
986
987 static const struct of_device_id flexcan_of_match[] = {
988 { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
989 { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
990 { .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
991 { /* sentinel */ },
992 };
993 MODULE_DEVICE_TABLE(of, flexcan_of_match);
994
995 static const struct platform_device_id flexcan_id_table[] = {
996 { .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
997 { /* sentinel */ },
998 };
999 MODULE_DEVICE_TABLE(platform, flexcan_id_table);
1000
1001 static int flexcan_probe(struct platform_device *pdev)
1002 {
1003 const struct of_device_id *of_id;
1004 const struct flexcan_devtype_data *devtype_data;
1005 struct net_device *dev;
1006 struct flexcan_priv *priv;
1007 struct resource *mem;
1008 struct clk *clk_ipg = NULL, *clk_per = NULL;
1009 void __iomem *base;
1010 int err, irq;
1011 u32 clock_freq = 0;
1012
1013 if (pdev->dev.of_node)
1014 of_property_read_u32(pdev->dev.of_node,
1015 "clock-frequency", &clock_freq);
1016
1017 if (!clock_freq) {
1018 clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1019 if (IS_ERR(clk_ipg)) {
1020 dev_err(&pdev->dev, "no ipg clock defined\n");
1021 return PTR_ERR(clk_ipg);
1022 }
1023 clock_freq = clk_get_rate(clk_ipg);
1024
1025 clk_per = devm_clk_get(&pdev->dev, "per");
1026 if (IS_ERR(clk_per)) {
1027 dev_err(&pdev->dev, "no per clock defined\n");
1028 return PTR_ERR(clk_per);
1029 }
1030 }
1031
1032 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1033 irq = platform_get_irq(pdev, 0);
1034 if (irq <= 0)
1035 return -ENODEV;
1036
1037 base = devm_ioremap_resource(&pdev->dev, mem);
1038 if (IS_ERR(base))
1039 return PTR_ERR(base);
1040
1041 of_id = of_match_device(flexcan_of_match, &pdev->dev);
1042 if (of_id) {
1043 devtype_data = of_id->data;
1044 } else if (pdev->id_entry->driver_data) {
1045 devtype_data = (struct flexcan_devtype_data *)
1046 pdev->id_entry->driver_data;
1047 } else {
1048 return -ENODEV;
1049 }
1050
1051 dev = alloc_candev(sizeof(struct flexcan_priv), 1);
1052 if (!dev)
1053 return -ENOMEM;
1054
1055 dev->netdev_ops = &flexcan_netdev_ops;
1056 dev->irq = irq;
1057 dev->flags |= IFF_ECHO;
1058
1059 priv = netdev_priv(dev);
1060 priv->can.clock.freq = clock_freq;
1061 priv->can.bittiming_const = &flexcan_bittiming_const;
1062 priv->can.do_set_mode = flexcan_set_mode;
1063 priv->can.do_get_berr_counter = flexcan_get_berr_counter;
1064 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1065 CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
1066 CAN_CTRLMODE_BERR_REPORTING;
1067 priv->base = base;
1068 priv->dev = dev;
1069 priv->clk_ipg = clk_ipg;
1070 priv->clk_per = clk_per;
1071 priv->pdata = dev_get_platdata(&pdev->dev);
1072 priv->devtype_data = devtype_data;
1073
1074 priv->reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
1075 if (IS_ERR(priv->reg_xceiver))
1076 priv->reg_xceiver = NULL;
1077
1078 netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
1079
1080 platform_set_drvdata(pdev, dev);
1081 SET_NETDEV_DEV(dev, &pdev->dev);
1082
1083 err = register_flexcandev(dev);
1084 if (err) {
1085 dev_err(&pdev->dev, "registering netdev failed\n");
1086 goto failed_register;
1087 }
1088
1089 devm_can_led_init(dev);
1090
1091 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1092 priv->base, dev->irq);
1093
1094 return 0;
1095
1096 failed_register:
1097 free_candev(dev);
1098 return err;
1099 }
1100
1101 static int flexcan_remove(struct platform_device *pdev)
1102 {
1103 struct net_device *dev = platform_get_drvdata(pdev);
1104
1105 unregister_flexcandev(dev);
1106
1107 free_candev(dev);
1108
1109 return 0;
1110 }
1111
1112 #ifdef CONFIG_PM_SLEEP
1113 static int flexcan_suspend(struct device *device)
1114 {
1115 struct net_device *dev = dev_get_drvdata(device);
1116 struct flexcan_priv *priv = netdev_priv(dev);
1117
1118 flexcan_chip_disable(priv);
1119
1120 if (netif_running(dev)) {
1121 netif_stop_queue(dev);
1122 netif_device_detach(dev);
1123 }
1124 priv->can.state = CAN_STATE_SLEEPING;
1125
1126 return 0;
1127 }
1128
1129 static int flexcan_resume(struct device *device)
1130 {
1131 struct net_device *dev = dev_get_drvdata(device);
1132 struct flexcan_priv *priv = netdev_priv(dev);
1133
1134 priv->can.state = CAN_STATE_ERROR_ACTIVE;
1135 if (netif_running(dev)) {
1136 netif_device_attach(dev);
1137 netif_start_queue(dev);
1138 }
1139 flexcan_chip_enable(priv);
1140
1141 return 0;
1142 }
1143 #endif /* CONFIG_PM_SLEEP */
1144
1145 static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
1146
1147 static struct platform_driver flexcan_driver = {
1148 .driver = {
1149 .name = DRV_NAME,
1150 .owner = THIS_MODULE,
1151 .pm = &flexcan_pm_ops,
1152 .of_match_table = flexcan_of_match,
1153 },
1154 .probe = flexcan_probe,
1155 .remove = flexcan_remove,
1156 .id_table = flexcan_id_table,
1157 };
1158
1159 module_platform_driver(flexcan_driver);
1160
1161 MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1162 "Marc Kleine-Budde <kernel@pengutronix.de>");
1163 MODULE_LICENSE("GPL v2");
1164 MODULE_DESCRIPTION("CAN port driver for flexcan based chip");
Linux kernel - Deliverables
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