?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / net / can / rcar / rcar_can.c
blob48575900adb75f68e3a427212c655e8194c07ba2
1 // SPDX-License-Identifier: GPL-2.0+
2 /* Renesas R-Car CAN device driver
3 *
4 * Copyright (C) 2013 Cogent Embedded, Inc. <source@cogentembedded.com>
5 * Copyright (C) 2013 Renesas Solutions Corp.
6 */
7
8 #include <linux/module.h>
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/interrupt.h>
12 #include <linux/errno.h>
13 #include <linux/netdevice.h>
14 #include <linux/platform_device.h>
15 #include <linux/can/led.h>
16 #include <linux/can/dev.h>
17 #include <linux/clk.h>
18 #include <linux/of.h>
19
20 #define RCAR_CAN_DRV_NAME "rcar_can"
21
22 /* Clock Select Register settings */
23 enum CLKR {
24 CLKR_CLKP1 = 0, /* Peripheral clock (clkp1) */
25 CLKR_CLKP2 = 1, /* Peripheral clock (clkp2) */
26 CLKR_CLKEXT = 3, /* Externally input clock */
27 };
28
29 #define RCAR_SUPPORTED_CLOCKS (BIT(CLKR_CLKP1) | BIT(CLKR_CLKP2) | \
30 BIT(CLKR_CLKEXT))
31
32 /* Mailbox configuration:
33 * mailbox 60 - 63 - Rx FIFO mailboxes
34 * mailbox 56 - 59 - Tx FIFO mailboxes
35 * non-FIFO mailboxes are not used
36 */
37 #define RCAR_CAN_N_MBX 64 /* Number of mailboxes in non-FIFO mode */
38 #define RCAR_CAN_RX_FIFO_MBX 60 /* Mailbox - window to Rx FIFO */
39 #define RCAR_CAN_TX_FIFO_MBX 56 /* Mailbox - window to Tx FIFO */
40 #define RCAR_CAN_FIFO_DEPTH 4
41
42 /* Mailbox registers structure */
43 struct rcar_can_mbox_regs {
44 u32 id; /* IDE and RTR bits, SID and EID */
45 u8 stub; /* Not used */
46 u8 dlc; /* Data Length Code - bits [0..3] */
47 u8 data[8]; /* Data Bytes */
48 u8 tsh; /* Time Stamp Higher Byte */
49 u8 tsl; /* Time Stamp Lower Byte */
50 };
51
52 struct rcar_can_regs {
53 struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */
54 u32 mkr_2_9[8]; /* Mask Registers 2-9 */
55 u32 fidcr[2]; /* FIFO Received ID Compare Register */
56 u32 mkivlr1; /* Mask Invalid Register 1 */
57 u32 mier1; /* Mailbox Interrupt Enable Register 1 */
58 u32 mkr_0_1[2]; /* Mask Registers 0-1 */
59 u32 mkivlr0; /* Mask Invalid Register 0*/
60 u32 mier0; /* Mailbox Interrupt Enable Register 0 */
61 u8 pad_440[0x3c0];
62 u8 mctl[64]; /* Message Control Registers */
63 u16 ctlr; /* Control Register */
64 u16 str; /* Status register */
65 u8 bcr[3]; /* Bit Configuration Register */
66 u8 clkr; /* Clock Select Register */
67 u8 rfcr; /* Receive FIFO Control Register */
68 u8 rfpcr; /* Receive FIFO Pointer Control Register */
69 u8 tfcr; /* Transmit FIFO Control Register */
70 u8 tfpcr; /* Transmit FIFO Pointer Control Register */
71 u8 eier; /* Error Interrupt Enable Register */
72 u8 eifr; /* Error Interrupt Factor Judge Register */
73 u8 recr; /* Receive Error Count Register */
74 u8 tecr; /* Transmit Error Count Register */
75 u8 ecsr; /* Error Code Store Register */
76 u8 cssr; /* Channel Search Support Register */
77 u8 mssr; /* Mailbox Search Status Register */
78 u8 msmr; /* Mailbox Search Mode Register */
79 u16 tsr; /* Time Stamp Register */
80 u8 afsr; /* Acceptance Filter Support Register */
81 u8 pad_857;
82 u8 tcr; /* Test Control Register */
83 u8 pad_859[7];
84 u8 ier; /* Interrupt Enable Register */
85 u8 isr; /* Interrupt Status Register */
86 u8 pad_862;
87 u8 mbsmr; /* Mailbox Search Mask Register */
88 };
89
90 struct rcar_can_priv {
91 struct can_priv can; /* Must be the first member! */
92 struct net_device *ndev;
93 struct napi_struct napi;
94 struct rcar_can_regs __iomem *regs;
95 struct clk *clk;
96 struct clk *can_clk;
97 u8 tx_dlc[RCAR_CAN_FIFO_DEPTH];
98 u32 tx_head;
99 u32 tx_tail;
100 u8 clock_select;
101 u8 ier;
102 };
103
104 static const struct can_bittiming_const rcar_can_bittiming_const = {
105 .name = RCAR_CAN_DRV_NAME,
106 .tseg1_min = 4,
107 .tseg1_max = 16,
108 .tseg2_min = 2,
109 .tseg2_max = 8,
110 .sjw_max = 4,
111 .brp_min = 1,
112 .brp_max = 1024,
113 .brp_inc = 1,
114 };
115
116 /* Control Register bits */
117 #define RCAR_CAN_CTLR_BOM (3 << 11) /* Bus-Off Recovery Mode Bits */
118 #define RCAR_CAN_CTLR_BOM_ENT (1 << 11) /* Entry to halt mode */
119 /* at bus-off entry */
120 #define RCAR_CAN_CTLR_SLPM (1 << 10)
121 #define RCAR_CAN_CTLR_CANM (3 << 8) /* Operating Mode Select Bit */
122 #define RCAR_CAN_CTLR_CANM_HALT (1 << 9)
123 #define RCAR_CAN_CTLR_CANM_RESET (1 << 8)
124 #define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8)
125 #define RCAR_CAN_CTLR_MLM (1 << 3) /* Message Lost Mode Select */
126 #define RCAR_CAN_CTLR_IDFM (3 << 1) /* ID Format Mode Select Bits */
127 #define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */
128 #define RCAR_CAN_CTLR_MBM (1 << 0) /* Mailbox Mode select */
129
130 /* Status Register bits */
131 #define RCAR_CAN_STR_RSTST (1 << 8) /* Reset Status Bit */
132
133 /* FIFO Received ID Compare Registers 0 and 1 bits */
134 #define RCAR_CAN_FIDCR_IDE (1 << 31) /* ID Extension Bit */
135 #define RCAR_CAN_FIDCR_RTR (1 << 30) /* Remote Transmission Request Bit */
136
137 /* Receive FIFO Control Register bits */
138 #define RCAR_CAN_RFCR_RFEST (1 << 7) /* Receive FIFO Empty Status Flag */
139 #define RCAR_CAN_RFCR_RFE (1 << 0) /* Receive FIFO Enable */
140
141 /* Transmit FIFO Control Register bits */
142 #define RCAR_CAN_TFCR_TFUST (7 << 1) /* Transmit FIFO Unsent Message */
143 /* Number Status Bits */
144 #define RCAR_CAN_TFCR_TFUST_SHIFT 1 /* Offset of Transmit FIFO Unsent */
145 /* Message Number Status Bits */
146 #define RCAR_CAN_TFCR_TFE (1 << 0) /* Transmit FIFO Enable */
147
148 #define RCAR_CAN_N_RX_MKREGS1 2 /* Number of mask registers */
149 /* for Rx mailboxes 0-31 */
150 #define RCAR_CAN_N_RX_MKREGS2 8
151
152 /* Bit Configuration Register settings */
153 #define RCAR_CAN_BCR_TSEG1(x) (((x) & 0x0f) << 20)
154 #define RCAR_CAN_BCR_BPR(x) (((x) & 0x3ff) << 8)
155 #define RCAR_CAN_BCR_SJW(x) (((x) & 0x3) << 4)
156 #define RCAR_CAN_BCR_TSEG2(x) ((x) & 0x07)
157
158 /* Mailbox and Mask Registers bits */
159 #define RCAR_CAN_IDE (1 << 31)
160 #define RCAR_CAN_RTR (1 << 30)
161 #define RCAR_CAN_SID_SHIFT 18
162
163 /* Mailbox Interrupt Enable Register 1 bits */
164 #define RCAR_CAN_MIER1_RXFIE (1 << 28) /* Receive FIFO Interrupt Enable */
165 #define RCAR_CAN_MIER1_TXFIE (1 << 24) /* Transmit FIFO Interrupt Enable */
166
167 /* Interrupt Enable Register bits */
168 #define RCAR_CAN_IER_ERSIE (1 << 5) /* Error (ERS) Interrupt Enable Bit */
169 #define RCAR_CAN_IER_RXFIE (1 << 4) /* Reception FIFO Interrupt */
170 /* Enable Bit */
171 #define RCAR_CAN_IER_TXFIE (1 << 3) /* Transmission FIFO Interrupt */
172 /* Enable Bit */
173 /* Interrupt Status Register bits */
174 #define RCAR_CAN_ISR_ERSF (1 << 5) /* Error (ERS) Interrupt Status Bit */
175 #define RCAR_CAN_ISR_RXFF (1 << 4) /* Reception FIFO Interrupt */
176 /* Status Bit */
177 #define RCAR_CAN_ISR_TXFF (1 << 3) /* Transmission FIFO Interrupt */
178 /* Status Bit */
179
180 /* Error Interrupt Enable Register bits */
181 #define RCAR_CAN_EIER_BLIE (1 << 7) /* Bus Lock Interrupt Enable */
182 #define RCAR_CAN_EIER_OLIE (1 << 6) /* Overload Frame Transmit */
183 /* Interrupt Enable */
184 #define RCAR_CAN_EIER_ORIE (1 << 5) /* Receive Overrun Interrupt Enable */
185 #define RCAR_CAN_EIER_BORIE (1 << 4) /* Bus-Off Recovery Interrupt Enable */
186 #define RCAR_CAN_EIER_BOEIE (1 << 3) /* Bus-Off Entry Interrupt Enable */
187 #define RCAR_CAN_EIER_EPIE (1 << 2) /* Error Passive Interrupt Enable */
188 #define RCAR_CAN_EIER_EWIE (1 << 1) /* Error Warning Interrupt Enable */
189 #define RCAR_CAN_EIER_BEIE (1 << 0) /* Bus Error Interrupt Enable */
190
191 /* Error Interrupt Factor Judge Register bits */
192 #define RCAR_CAN_EIFR_BLIF (1 << 7) /* Bus Lock Detect Flag */
193 #define RCAR_CAN_EIFR_OLIF (1 << 6) /* Overload Frame Transmission */
194 /* Detect Flag */
195 #define RCAR_CAN_EIFR_ORIF (1 << 5) /* Receive Overrun Detect Flag */
196 #define RCAR_CAN_EIFR_BORIF (1 << 4) /* Bus-Off Recovery Detect Flag */
197 #define RCAR_CAN_EIFR_BOEIF (1 << 3) /* Bus-Off Entry Detect Flag */
198 #define RCAR_CAN_EIFR_EPIF (1 << 2) /* Error Passive Detect Flag */
199 #define RCAR_CAN_EIFR_EWIF (1 << 1) /* Error Warning Detect Flag */
200 #define RCAR_CAN_EIFR_BEIF (1 << 0) /* Bus Error Detect Flag */
201
202 /* Error Code Store Register bits */
203 #define RCAR_CAN_ECSR_EDPM (1 << 7) /* Error Display Mode Select Bit */
204 #define RCAR_CAN_ECSR_ADEF (1 << 6) /* ACK Delimiter Error Flag */
205 #define RCAR_CAN_ECSR_BE0F (1 << 5) /* Bit Error (dominant) Flag */
206 #define RCAR_CAN_ECSR_BE1F (1 << 4) /* Bit Error (recessive) Flag */
207 #define RCAR_CAN_ECSR_CEF (1 << 3) /* CRC Error Flag */
208 #define RCAR_CAN_ECSR_AEF (1 << 2) /* ACK Error Flag */
209 #define RCAR_CAN_ECSR_FEF (1 << 1) /* Form Error Flag */
210 #define RCAR_CAN_ECSR_SEF (1 << 0) /* Stuff Error Flag */
211
212 #define RCAR_CAN_NAPI_WEIGHT 4
213 #define MAX_STR_READS 0x100
214
215 static void tx_failure_cleanup(struct net_device *ndev)
216 {
217 int i;
218
219 for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
220 can_free_echo_skb(ndev, i);
221 }
222
223 static void rcar_can_error(struct net_device *ndev)
224 {
225 struct rcar_can_priv *priv = netdev_priv(ndev);
226 struct net_device_stats *stats = &ndev->stats;
227 struct can_frame *cf;
228 struct sk_buff *skb;
229 u8 eifr, txerr = 0, rxerr = 0;
230
231 /* Propagate the error condition to the CAN stack */
232 skb = alloc_can_err_skb(ndev, &cf);
233
234 eifr = readb(&priv->regs->eifr);
235 if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) {
236 txerr = readb(&priv->regs->tecr);
237 rxerr = readb(&priv->regs->recr);
238 if (skb) {
239 cf->can_id |= CAN_ERR_CRTL;
240 cf->data[6] = txerr;
241 cf->data[7] = rxerr;
242 }
243 }
244 if (eifr & RCAR_CAN_EIFR_BEIF) {
245 int rx_errors = 0, tx_errors = 0;
246 u8 ecsr;
247
248 netdev_dbg(priv->ndev, "Bus error interrupt:\n");
249 if (skb)
250 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
251
252 ecsr = readb(&priv->regs->ecsr);
253 if (ecsr & RCAR_CAN_ECSR_ADEF) {
254 netdev_dbg(priv->ndev, "ACK Delimiter Error\n");
255 tx_errors++;
256 writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr);
257 if (skb)
258 cf->data[3] = CAN_ERR_PROT_LOC_ACK_DEL;
259 }
260 if (ecsr & RCAR_CAN_ECSR_BE0F) {
261 netdev_dbg(priv->ndev, "Bit Error (dominant)\n");
262 tx_errors++;
263 writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr);
264 if (skb)
265 cf->data[2] |= CAN_ERR_PROT_BIT0;
266 }
267 if (ecsr & RCAR_CAN_ECSR_BE1F) {
268 netdev_dbg(priv->ndev, "Bit Error (recessive)\n");
269 tx_errors++;
270 writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr);
271 if (skb)
272 cf->data[2] |= CAN_ERR_PROT_BIT1;
273 }
274 if (ecsr & RCAR_CAN_ECSR_CEF) {
275 netdev_dbg(priv->ndev, "CRC Error\n");
276 rx_errors++;
277 writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr);
278 if (skb)
279 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
280 }
281 if (ecsr & RCAR_CAN_ECSR_AEF) {
282 netdev_dbg(priv->ndev, "ACK Error\n");
283 tx_errors++;
284 writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr);
285 if (skb) {
286 cf->can_id |= CAN_ERR_ACK;
287 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
288 }
289 }
290 if (ecsr & RCAR_CAN_ECSR_FEF) {
291 netdev_dbg(priv->ndev, "Form Error\n");
292 rx_errors++;
293 writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr);
294 if (skb)
295 cf->data[2] |= CAN_ERR_PROT_FORM;
296 }
297 if (ecsr & RCAR_CAN_ECSR_SEF) {
298 netdev_dbg(priv->ndev, "Stuff Error\n");
299 rx_errors++;
300 writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr);
301 if (skb)
302 cf->data[2] |= CAN_ERR_PROT_STUFF;
303 }
304
305 priv->can.can_stats.bus_error++;
306 ndev->stats.rx_errors += rx_errors;
307 ndev->stats.tx_errors += tx_errors;
308 writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr);
309 }
310 if (eifr & RCAR_CAN_EIFR_EWIF) {
311 netdev_dbg(priv->ndev, "Error warning interrupt\n");
312 priv->can.state = CAN_STATE_ERROR_WARNING;
313 priv->can.can_stats.error_warning++;
314 /* Clear interrupt condition */
315 writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr);
316 if (skb)
317 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
318 CAN_ERR_CRTL_RX_WARNING;
319 }
320 if (eifr & RCAR_CAN_EIFR_EPIF) {
321 netdev_dbg(priv->ndev, "Error passive interrupt\n");
322 priv->can.state = CAN_STATE_ERROR_PASSIVE;
323 priv->can.can_stats.error_passive++;
324 /* Clear interrupt condition */
325 writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr);
326 if (skb)
327 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
328 CAN_ERR_CRTL_RX_PASSIVE;
329 }
330 if (eifr & RCAR_CAN_EIFR_BOEIF) {
331 netdev_dbg(priv->ndev, "Bus-off entry interrupt\n");
332 tx_failure_cleanup(ndev);
333 priv->ier = RCAR_CAN_IER_ERSIE;
334 writeb(priv->ier, &priv->regs->ier);
335 priv->can.state = CAN_STATE_BUS_OFF;
336 /* Clear interrupt condition */
337 writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr);
338 priv->can.can_stats.bus_off++;
339 can_bus_off(ndev);
340 if (skb)
341 cf->can_id |= CAN_ERR_BUSOFF;
342 }
343 if (eifr & RCAR_CAN_EIFR_ORIF) {
344 netdev_dbg(priv->ndev, "Receive overrun error interrupt\n");
345 ndev->stats.rx_over_errors++;
346 ndev->stats.rx_errors++;
347 writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr);
348 if (skb) {
349 cf->can_id |= CAN_ERR_CRTL;
350 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
351 }
352 }
353 if (eifr & RCAR_CAN_EIFR_OLIF) {
354 netdev_dbg(priv->ndev,
355 "Overload Frame Transmission error interrupt\n");
356 ndev->stats.rx_over_errors++;
357 ndev->stats.rx_errors++;
358 writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr);
359 if (skb) {
360 cf->can_id |= CAN_ERR_PROT;
361 cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
362 }
363 }
364
365 if (skb) {
366 stats->rx_packets++;
367 stats->rx_bytes += cf->can_dlc;
368 netif_rx(skb);
369 }
370 }
371
372 static void rcar_can_tx_done(struct net_device *ndev)
373 {
374 struct rcar_can_priv *priv = netdev_priv(ndev);
375 struct net_device_stats *stats = &ndev->stats;
376 u8 isr;
377
378 while (1) {
379 u8 unsent = readb(&priv->regs->tfcr);
380
381 unsent = (unsent & RCAR_CAN_TFCR_TFUST) >>
382 RCAR_CAN_TFCR_TFUST_SHIFT;
383 if (priv->tx_head - priv->tx_tail <= unsent)
384 break;
385 stats->tx_packets++;
386 stats->tx_bytes += priv->tx_dlc[priv->tx_tail %
387 RCAR_CAN_FIFO_DEPTH];
388 priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0;
389 can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH);
390 priv->tx_tail++;
391 netif_wake_queue(ndev);
392 }
393 /* Clear interrupt */
394 isr = readb(&priv->regs->isr);
395 writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr);
396 can_led_event(ndev, CAN_LED_EVENT_TX);
397 }
398
399 static irqreturn_t rcar_can_interrupt(int irq, void *dev_id)
400 {
401 struct net_device *ndev = dev_id;
402 struct rcar_can_priv *priv = netdev_priv(ndev);
403 u8 isr;
404
405 isr = readb(&priv->regs->isr);
406 if (!(isr & priv->ier))
407 return IRQ_NONE;
408
409 if (isr & RCAR_CAN_ISR_ERSF)
410 rcar_can_error(ndev);
411
412 if (isr & RCAR_CAN_ISR_TXFF)
413 rcar_can_tx_done(ndev);
414
415 if (isr & RCAR_CAN_ISR_RXFF) {
416 if (napi_schedule_prep(&priv->napi)) {
417 /* Disable Rx FIFO interrupts */
418 priv->ier &= ~RCAR_CAN_IER_RXFIE;
419 writeb(priv->ier, &priv->regs->ier);
420 __napi_schedule(&priv->napi);
421 }
422 }
423
424 return IRQ_HANDLED;
425 }
426
427 static void rcar_can_set_bittiming(struct net_device *dev)
428 {
429 struct rcar_can_priv *priv = netdev_priv(dev);
430 struct can_bittiming *bt = &priv->can.bittiming;
431 u32 bcr;
432
433 bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) |
434 RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) |
435 RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1);
436 /* Don't overwrite CLKR with 32-bit BCR access; CLKR has 8-bit access.
437 * All the registers are big-endian but they get byte-swapped on 32-bit
438 * read/write (but not on 8-bit, contrary to the manuals)...
439 */
440 writel((bcr << 8) | priv->clock_select, &priv->regs->bcr);
441 }
442
443 static void rcar_can_start(struct net_device *ndev)
444 {
445 struct rcar_can_priv *priv = netdev_priv(ndev);
446 u16 ctlr;
447 int i;
448
449 /* Set controller to known mode:
450 * - FIFO mailbox mode
451 * - accept all messages
452 * - overrun mode
453 * CAN is in sleep mode after MCU hardware or software reset.
454 */
455 ctlr = readw(&priv->regs->ctlr);
456 ctlr &= ~RCAR_CAN_CTLR_SLPM;
457 writew(ctlr, &priv->regs->ctlr);
458 /* Go to reset mode */
459 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
460 writew(ctlr, &priv->regs->ctlr);
461 for (i = 0; i < MAX_STR_READS; i++) {
462 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
463 break;
464 }
465 rcar_can_set_bittiming(ndev);
466 ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */
467 ctlr |= RCAR_CAN_CTLR_BOM_ENT; /* Entry to halt mode automatically */
468 /* at bus-off */
469 ctlr |= RCAR_CAN_CTLR_MBM; /* Select FIFO mailbox mode */
470 ctlr |= RCAR_CAN_CTLR_MLM; /* Overrun mode */
471 writew(ctlr, &priv->regs->ctlr);
472
473 /* Accept all SID and EID */
474 writel(0, &priv->regs->mkr_2_9[6]);
475 writel(0, &priv->regs->mkr_2_9[7]);
476 /* In FIFO mailbox mode, write "0" to bits 24 to 31 */
477 writel(0, &priv->regs->mkivlr1);
478 /* Accept all frames */
479 writel(0, &priv->regs->fidcr[0]);
480 writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]);
481 /* Enable and configure FIFO mailbox interrupts */
482 writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1);
483
484 priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE |
485 RCAR_CAN_IER_TXFIE;
486 writeb(priv->ier, &priv->regs->ier);
487
488 /* Accumulate error codes */
489 writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr);
490 /* Enable error interrupts */
491 writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE |
492 (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ?
493 RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE |
494 RCAR_CAN_EIER_OLIE, &priv->regs->eier);
495 priv->can.state = CAN_STATE_ERROR_ACTIVE;
496
497 /* Go to operation mode */
498 writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr);
499 for (i = 0; i < MAX_STR_READS; i++) {
500 if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST))
501 break;
502 }
503 /* Enable Rx and Tx FIFO */
504 writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr);
505 writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr);
506 }
507
508 static int rcar_can_open(struct net_device *ndev)
509 {
510 struct rcar_can_priv *priv = netdev_priv(ndev);
511 int err;
512
513 err = clk_prepare_enable(priv->clk);
514 if (err) {
515 netdev_err(ndev,
516 "failed to enable peripheral clock, error %d\n",
517 err);
518 goto out;
519 }
520 err = clk_prepare_enable(priv->can_clk);
521 if (err) {
522 netdev_err(ndev, "failed to enable CAN clock, error %d\n",
523 err);
524 goto out_clock;
525 }
526 err = open_candev(ndev);
527 if (err) {
528 netdev_err(ndev, "open_candev() failed, error %d\n", err);
529 goto out_can_clock;
530 }
531 napi_enable(&priv->napi);
532 err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev);
533 if (err) {
534 netdev_err(ndev, "request_irq(%d) failed, error %d\n",
535 ndev->irq, err);
536 goto out_close;
537 }
538 can_led_event(ndev, CAN_LED_EVENT_OPEN);
539 rcar_can_start(ndev);
540 netif_start_queue(ndev);
541 return 0;
542 out_close:
543 napi_disable(&priv->napi);
544 close_candev(ndev);
545 out_can_clock:
546 clk_disable_unprepare(priv->can_clk);
547 out_clock:
548 clk_disable_unprepare(priv->clk);
549 out:
550 return err;
551 }
552
553 static void rcar_can_stop(struct net_device *ndev)
554 {
555 struct rcar_can_priv *priv = netdev_priv(ndev);
556 u16 ctlr;
557 int i;
558
559 /* Go to (force) reset mode */
560 ctlr = readw(&priv->regs->ctlr);
561 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
562 writew(ctlr, &priv->regs->ctlr);
563 for (i = 0; i < MAX_STR_READS; i++) {
564 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
565 break;
566 }
567 writel(0, &priv->regs->mier0);
568 writel(0, &priv->regs->mier1);
569 writeb(0, &priv->regs->ier);
570 writeb(0, &priv->regs->eier);
571 /* Go to sleep mode */
572 ctlr |= RCAR_CAN_CTLR_SLPM;
573 writew(ctlr, &priv->regs->ctlr);
574 priv->can.state = CAN_STATE_STOPPED;
575 }
576
577 static int rcar_can_close(struct net_device *ndev)
578 {
579 struct rcar_can_priv *priv = netdev_priv(ndev);
580
581 netif_stop_queue(ndev);
582 rcar_can_stop(ndev);
583 free_irq(ndev->irq, ndev);
584 napi_disable(&priv->napi);
585 clk_disable_unprepare(priv->can_clk);
586 clk_disable_unprepare(priv->clk);
587 close_candev(ndev);
588 can_led_event(ndev, CAN_LED_EVENT_STOP);
589 return 0;
590 }
591
592 static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
593 struct net_device *ndev)
594 {
595 struct rcar_can_priv *priv = netdev_priv(ndev);
596 struct can_frame *cf = (struct can_frame *)skb->data;
597 u32 data, i;
598
599 if (can_dropped_invalid_skb(ndev, skb))
600 return NETDEV_TX_OK;
601
602 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
603 data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE;
604 else /* Standard frame format */
605 data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT;
606
607 if (cf->can_id & CAN_RTR_FLAG) { /* Remote transmission request */
608 data |= RCAR_CAN_RTR;
609 } else {
610 for (i = 0; i < cf->can_dlc; i++)
611 writeb(cf->data[i],
612 &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]);
613 }
614
615 writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id);
616
617 writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
618
619 priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->can_dlc;
620 can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH);
621 priv->tx_head++;
622 /* Start Tx: write 0xff to the TFPCR register to increment
623 * the CPU-side pointer for the transmit FIFO to the next
624 * mailbox location
625 */
626 writeb(0xff, &priv->regs->tfpcr);
627 /* Stop the queue if we've filled all FIFO entries */
628 if (priv->tx_head - priv->tx_tail >= RCAR_CAN_FIFO_DEPTH)
629 netif_stop_queue(ndev);
630
631 return NETDEV_TX_OK;
632 }
633
634 static const struct net_device_ops rcar_can_netdev_ops = {
635 .ndo_open = rcar_can_open,
636 .ndo_stop = rcar_can_close,
637 .ndo_start_xmit = rcar_can_start_xmit,
638 .ndo_change_mtu = can_change_mtu,
639 };
640
641 static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
642 {
643 struct net_device_stats *stats = &priv->ndev->stats;
644 struct can_frame *cf;
645 struct sk_buff *skb;
646 u32 data;
647 u8 dlc;
648
649 skb = alloc_can_skb(priv->ndev, &cf);
650 if (!skb) {
651 stats->rx_dropped++;
652 return;
653 }
654
655 data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id);
656 if (data & RCAR_CAN_IDE)
657 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
658 else
659 cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK;
660
661 dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc);
662 cf->can_dlc = get_can_dlc(dlc);
663 if (data & RCAR_CAN_RTR) {
664 cf->can_id |= CAN_RTR_FLAG;
665 } else {
666 for (dlc = 0; dlc < cf->can_dlc; dlc++)
667 cf->data[dlc] =
668 readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
669 }
670
671 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
672
673 stats->rx_bytes += cf->can_dlc;
674 stats->rx_packets++;
675 netif_receive_skb(skb);
676 }
677
678 static int rcar_can_rx_poll(struct napi_struct *napi, int quota)
679 {
680 struct rcar_can_priv *priv = container_of(napi,
681 struct rcar_can_priv, napi);
682 int num_pkts;
683
684 for (num_pkts = 0; num_pkts < quota; num_pkts++) {
685 u8 rfcr, isr;
686
687 isr = readb(&priv->regs->isr);
688 /* Clear interrupt bit */
689 if (isr & RCAR_CAN_ISR_RXFF)
690 writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr);
691 rfcr = readb(&priv->regs->rfcr);
692 if (rfcr & RCAR_CAN_RFCR_RFEST)
693 break;
694 rcar_can_rx_pkt(priv);
695 /* Write 0xff to the RFPCR register to increment
696 * the CPU-side pointer for the receive FIFO
697 * to the next mailbox location
698 */
699 writeb(0xff, &priv->regs->rfpcr);
700 }
701 /* All packets processed */
702 if (num_pkts < quota) {
703 napi_complete_done(napi, num_pkts);
704 priv->ier |= RCAR_CAN_IER_RXFIE;
705 writeb(priv->ier, &priv->regs->ier);
706 }
707 return num_pkts;
708 }
709
710 static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
711 {
712 switch (mode) {
713 case CAN_MODE_START:
714 rcar_can_start(ndev);
715 netif_wake_queue(ndev);
716 return 0;
717 default:
718 return -EOPNOTSUPP;
719 }
720 }
721
722 static int rcar_can_get_berr_counter(const struct net_device *dev,
723 struct can_berr_counter *bec)
724 {
725 struct rcar_can_priv *priv = netdev_priv(dev);
726 int err;
727
728 err = clk_prepare_enable(priv->clk);
729 if (err)
730 return err;
731 bec->txerr = readb(&priv->regs->tecr);
732 bec->rxerr = readb(&priv->regs->recr);
733 clk_disable_unprepare(priv->clk);
734 return 0;
735 }
736
737 static const char * const clock_names[] = {
738 [CLKR_CLKP1] = "clkp1",
739 [CLKR_CLKP2] = "clkp2",
740 [CLKR_CLKEXT] = "can_clk",
741 };
742
743 static int rcar_can_probe(struct platform_device *pdev)
744 {
745 struct rcar_can_priv *priv;
746 struct net_device *ndev;
747 void __iomem *addr;
748 u32 clock_select = CLKR_CLKP1;
749 int err = -ENODEV;
750 int irq;
751
752 of_property_read_u32(pdev->dev.of_node, "renesas,can-clock-select",
753 &clock_select);
754
755 irq = platform_get_irq(pdev, 0);
756 if (irq < 0) {
757 err = irq;
758 goto fail;
759 }
760
761 addr = devm_platform_ioremap_resource(pdev, 0);
762 if (IS_ERR(addr)) {
763 err = PTR_ERR(addr);
764 goto fail;
765 }
766
767 ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH);
768 if (!ndev) {
769 dev_err(&pdev->dev, "alloc_candev() failed\n");
770 err = -ENOMEM;
771 goto fail;
772 }
773
774 priv = netdev_priv(ndev);
775
776 priv->clk = devm_clk_get(&pdev->dev, "clkp1");
777 if (IS_ERR(priv->clk)) {
778 err = PTR_ERR(priv->clk);
779 dev_err(&pdev->dev, "cannot get peripheral clock, error %d\n",
780 err);
781 goto fail_clk;
782 }
783
784 if (!(BIT(clock_select) & RCAR_SUPPORTED_CLOCKS)) {
785 err = -EINVAL;
786 dev_err(&pdev->dev, "invalid CAN clock selected\n");
787 goto fail_clk;
788 }
789 priv->can_clk = devm_clk_get(&pdev->dev, clock_names[clock_select]);
790 if (IS_ERR(priv->can_clk)) {
791 err = PTR_ERR(priv->can_clk);
792 dev_err(&pdev->dev, "cannot get CAN clock, error %d\n", err);
793 goto fail_clk;
794 }
795
796 ndev->netdev_ops = &rcar_can_netdev_ops;
797 ndev->irq = irq;
798 ndev->flags |= IFF_ECHO;
799 priv->ndev = ndev;
800 priv->regs = addr;
801 priv->clock_select = clock_select;
802 priv->can.clock.freq = clk_get_rate(priv->can_clk);
803 priv->can.bittiming_const = &rcar_can_bittiming_const;
804 priv->can.do_set_mode = rcar_can_do_set_mode;
805 priv->can.do_get_berr_counter = rcar_can_get_berr_counter;
806 priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
807 platform_set_drvdata(pdev, ndev);
808 SET_NETDEV_DEV(ndev, &pdev->dev);
809
810 netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll,
811 RCAR_CAN_NAPI_WEIGHT);
812 err = register_candev(ndev);
813 if (err) {
814 dev_err(&pdev->dev, "register_candev() failed, error %d\n",
815 err);
816 goto fail_candev;
817 }
818
819 devm_can_led_init(ndev);
820
821 dev_info(&pdev->dev, "device registered (IRQ%d)\n", ndev->irq);
822
823 return 0;
824 fail_candev:
825 netif_napi_del(&priv->napi);
826 fail_clk:
827 free_candev(ndev);
828 fail:
829 return err;
830 }
831
832 static int rcar_can_remove(struct platform_device *pdev)
833 {
834 struct net_device *ndev = platform_get_drvdata(pdev);
835 struct rcar_can_priv *priv = netdev_priv(ndev);
836
837 unregister_candev(ndev);
838 netif_napi_del(&priv->napi);
839 free_candev(ndev);
840 return 0;
841 }
842
843 static int __maybe_unused rcar_can_suspend(struct device *dev)
844 {
845 struct net_device *ndev = dev_get_drvdata(dev);
846 struct rcar_can_priv *priv = netdev_priv(ndev);
847 u16 ctlr;
848
849 if (netif_running(ndev)) {
850 netif_stop_queue(ndev);
851 netif_device_detach(ndev);
852 }
853 ctlr = readw(&priv->regs->ctlr);
854 ctlr |= RCAR_CAN_CTLR_CANM_HALT;
855 writew(ctlr, &priv->regs->ctlr);
856 ctlr |= RCAR_CAN_CTLR_SLPM;
857 writew(ctlr, &priv->regs->ctlr);
858 priv->can.state = CAN_STATE_SLEEPING;
859
860 clk_disable(priv->clk);
861 return 0;
862 }
863
864 static int __maybe_unused rcar_can_resume(struct device *dev)
865 {
866 struct net_device *ndev = dev_get_drvdata(dev);
867 struct rcar_can_priv *priv = netdev_priv(ndev);
868 u16 ctlr;
869 int err;
870
871 err = clk_enable(priv->clk);
872 if (err) {
873 netdev_err(ndev, "clk_enable() failed, error %d\n", err);
874 return err;
875 }
876
877 ctlr = readw(&priv->regs->ctlr);
878 ctlr &= ~RCAR_CAN_CTLR_SLPM;
879 writew(ctlr, &priv->regs->ctlr);
880 ctlr &= ~RCAR_CAN_CTLR_CANM;
881 writew(ctlr, &priv->regs->ctlr);
882 priv->can.state = CAN_STATE_ERROR_ACTIVE;
883
884 if (netif_running(ndev)) {
885 netif_device_attach(ndev);
886 netif_start_queue(ndev);
887 }
888 return 0;
889 }
890
891 static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
892
893 static const struct of_device_id rcar_can_of_table[] __maybe_unused = {
894 { .compatible = "renesas,can-r8a7778" },
895 { .compatible = "renesas,can-r8a7779" },
896 { .compatible = "renesas,can-r8a7790" },
897 { .compatible = "renesas,can-r8a7791" },
898 { .compatible = "renesas,rcar-gen1-can" },
899 { .compatible = "renesas,rcar-gen2-can" },
900 { .compatible = "renesas,rcar-gen3-can" },
901 { }
902 };
903 MODULE_DEVICE_TABLE(of, rcar_can_of_table);
904
905 static struct platform_driver rcar_can_driver = {
906 .driver = {
907 .name = RCAR_CAN_DRV_NAME,
908 .of_match_table = of_match_ptr(rcar_can_of_table),
909 .pm = &rcar_can_pm_ops,
910 },
911 .probe = rcar_can_probe,
912 .remove = rcar_can_remove,
913 };
914
915 module_platform_driver(rcar_can_driver);
916
917 MODULE_AUTHOR("Cogent Embedded, Inc.");
918 MODULE_LICENSE("GPL");
919 MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC");
920 MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);
Linux with added FPC-III support