1 /* Renesas R-Car CAN device driver
2 *
3 * Copyright (C) 2013 Cogent Embedded, Inc. <source@cogentembedded.com>
4 * Copyright (C) 2013 Renesas Solutions Corp.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version.
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/interrupt.h>
16 #include <linux/errno.h>
17 #include <linux/netdevice.h>
18 #include <linux/platform_device.h>
19 #include <linux/can/led.h>
20 #include <linux/can/dev.h>
21 #include <linux/clk.h>
22 #include <linux/can/platform/rcar_can.h>
23 #include <linux/of.h>
24
25 #define RCAR_CAN_DRV_NAME "rcar_can"
26
27 #define RCAR_SUPPORTED_CLOCKS (BIT(CLKR_CLKP1) | BIT(CLKR_CLKP2) | \
28 BIT(CLKR_CLKEXT))
29
30 /* Mailbox configuration:
31 * mailbox 60 - 63 - Rx FIFO mailboxes
32 * mailbox 56 - 59 - Tx FIFO mailboxes
33 * non-FIFO mailboxes are not used
34 */
35 #define RCAR_CAN_N_MBX 64 /* Number of mailboxes in non-FIFO mode */
36 #define RCAR_CAN_RX_FIFO_MBX 60 /* Mailbox - window to Rx FIFO */
37 #define RCAR_CAN_TX_FIFO_MBX 56 /* Mailbox - window to Tx FIFO */
38 #define RCAR_CAN_FIFO_DEPTH 4
39
40 /* Mailbox registers structure */
41 struct rcar_can_mbox_regs {
42 u32 id; /* IDE and RTR bits, SID and EID */
43 u8 stub; /* Not used */
44 u8 dlc; /* Data Length Code - bits [0..3] */
45 u8 data[8]; /* Data Bytes */
46 u8 tsh; /* Time Stamp Higher Byte */
47 u8 tsl; /* Time Stamp Lower Byte */
48 };
49
50 struct rcar_can_regs {
51 struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */
52 u32 mkr_2_9[8]; /* Mask Registers 2-9 */
53 u32 fidcr[2]; /* FIFO Received ID Compare Register */
54 u32 mkivlr1; /* Mask Invalid Register 1 */
55 u32 mier1; /* Mailbox Interrupt Enable Register 1 */
56 u32 mkr_0_1[2]; /* Mask Registers 0-1 */
57 u32 mkivlr0; /* Mask Invalid Register 0*/
58 u32 mier0; /* Mailbox Interrupt Enable Register 0 */
59 u8 pad_440[0x3c0];
60 u8 mctl[64]; /* Message Control Registers */
61 u16 ctlr; /* Control Register */
62 u16 str; /* Status register */
63 u8 bcr[3]; /* Bit Configuration Register */
64 u8 clkr; /* Clock Select Register */
65 u8 rfcr; /* Receive FIFO Control Register */
66 u8 rfpcr; /* Receive FIFO Pointer Control Register */
67 u8 tfcr; /* Transmit FIFO Control Register */
68 u8 tfpcr; /* Transmit FIFO Pointer Control Register */
69 u8 eier; /* Error Interrupt Enable Register */
70 u8 eifr; /* Error Interrupt Factor Judge Register */
71 u8 recr; /* Receive Error Count Register */
72 u8 tecr; /* Transmit Error Count Register */
73 u8 ecsr; /* Error Code Store Register */
74 u8 cssr; /* Channel Search Support Register */
75 u8 mssr; /* Mailbox Search Status Register */
76 u8 msmr; /* Mailbox Search Mode Register */
77 u16 tsr; /* Time Stamp Register */
78 u8 afsr; /* Acceptance Filter Support Register */
79 u8 pad_857;
80 u8 tcr; /* Test Control Register */
81 u8 pad_859[7];
82 u8 ier; /* Interrupt Enable Register */
83 u8 isr; /* Interrupt Status Register */
84 u8 pad_862;
85 u8 mbsmr; /* Mailbox Search Mask Register */
86 };
87
88 struct rcar_can_priv {
89 struct can_priv can; /* Must be the first member! */
90 struct net_device *ndev;
91 struct napi_struct napi;
92 struct rcar_can_regs __iomem *regs;
93 struct clk *clk;
94 struct clk *can_clk;
95 u8 tx_dlc[RCAR_CAN_FIFO_DEPTH];
96 u32 tx_head;
97 u32 tx_tail;
98 u8 clock_select;
99 u8 ier;
100 };
101
102 static const struct can_bittiming_const rcar_can_bittiming_const = {
103 .name = RCAR_CAN_DRV_NAME,
104 .tseg1_min = 4,
105 .tseg1_max = 16,
106 .tseg2_min = 2,
107 .tseg2_max = 8,
108 .sjw_max = 4,
109 .brp_min = 1,
110 .brp_max = 1024,
111 .brp_inc = 1,
112 };
113
114 /* Control Register bits */
115 #define RCAR_CAN_CTLR_BOM (3 << 11) /* Bus-Off Recovery Mode Bits */
116 #define RCAR_CAN_CTLR_BOM_ENT (1 << 11) /* Entry to halt mode */
117 /* at bus-off entry */
118 #define RCAR_CAN_CTLR_SLPM (1 << 10)
119 #define RCAR_CAN_CTLR_CANM (3 << 8) /* Operating Mode Select Bit */
120 #define RCAR_CAN_CTLR_CANM_HALT (1 << 9)
121 #define RCAR_CAN_CTLR_CANM_RESET (1 << 8)
122 #define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8)
123 #define RCAR_CAN_CTLR_MLM (1 << 3) /* Message Lost Mode Select */
124 #define RCAR_CAN_CTLR_IDFM (3 << 1) /* ID Format Mode Select Bits */
125 #define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */
126 #define RCAR_CAN_CTLR_MBM (1 << 0) /* Mailbox Mode select */
127
128 /* Status Register bits */
129 #define RCAR_CAN_STR_RSTST (1 << 8) /* Reset Status Bit */
130
131 /* FIFO Received ID Compare Registers 0 and 1 bits */
132 #define RCAR_CAN_FIDCR_IDE (1 << 31) /* ID Extension Bit */
133 #define RCAR_CAN_FIDCR_RTR (1 << 30) /* Remote Transmission Request Bit */
134
135 /* Receive FIFO Control Register bits */
136 #define RCAR_CAN_RFCR_RFEST (1 << 7) /* Receive FIFO Empty Status Flag */
137 #define RCAR_CAN_RFCR_RFE (1 << 0) /* Receive FIFO Enable */
138
139 /* Transmit FIFO Control Register bits */
140 #define RCAR_CAN_TFCR_TFUST (7 << 1) /* Transmit FIFO Unsent Message */
141 /* Number Status Bits */
142 #define RCAR_CAN_TFCR_TFUST_SHIFT 1 /* Offset of Transmit FIFO Unsent */
143 /* Message Number Status Bits */
144 #define RCAR_CAN_TFCR_TFE (1 << 0) /* Transmit FIFO Enable */
145
146 #define RCAR_CAN_N_RX_MKREGS1 2 /* Number of mask registers */
147 /* for Rx mailboxes 0-31 */
148 #define RCAR_CAN_N_RX_MKREGS2 8
149
150 /* Bit Configuration Register settings */
151 #define RCAR_CAN_BCR_TSEG1(x) (((x) & 0x0f) << 20)
152 #define RCAR_CAN_BCR_BPR(x) (((x) & 0x3ff) << 8)
153 #define RCAR_CAN_BCR_SJW(x) (((x) & 0x3) << 4)
154 #define RCAR_CAN_BCR_TSEG2(x) ((x) & 0x07)
155
156 /* Mailbox and Mask Registers bits */
157 #define RCAR_CAN_IDE (1 << 31)
158 #define RCAR_CAN_RTR (1 << 30)
159 #define RCAR_CAN_SID_SHIFT 18
160
161 /* Mailbox Interrupt Enable Register 1 bits */
162 #define RCAR_CAN_MIER1_RXFIE (1 << 28) /* Receive FIFO Interrupt Enable */
163 #define RCAR_CAN_MIER1_TXFIE (1 << 24) /* Transmit FIFO Interrupt Enable */
164
165 /* Interrupt Enable Register bits */
166 #define RCAR_CAN_IER_ERSIE (1 << 5) /* Error (ERS) Interrupt Enable Bit */
167 #define RCAR_CAN_IER_RXFIE (1 << 4) /* Reception FIFO Interrupt */
168 /* Enable Bit */
169 #define RCAR_CAN_IER_TXFIE (1 << 3) /* Transmission FIFO Interrupt */
170 /* Enable Bit */
171 /* Interrupt Status Register bits */
172 #define RCAR_CAN_ISR_ERSF (1 << 5) /* Error (ERS) Interrupt Status Bit */
173 #define RCAR_CAN_ISR_RXFF (1 << 4) /* Reception FIFO Interrupt */
174 /* Status Bit */
175 #define RCAR_CAN_ISR_TXFF (1 << 3) /* Transmission FIFO Interrupt */
176 /* Status Bit */
177
178 /* Error Interrupt Enable Register bits */
179 #define RCAR_CAN_EIER_BLIE (1 << 7) /* Bus Lock Interrupt Enable */
180 #define RCAR_CAN_EIER_OLIE (1 << 6) /* Overload Frame Transmit */
181 /* Interrupt Enable */
182 #define RCAR_CAN_EIER_ORIE (1 << 5) /* Receive Overrun Interrupt Enable */
183 #define RCAR_CAN_EIER_BORIE (1 << 4) /* Bus-Off Recovery Interrupt Enable */
184 #define RCAR_CAN_EIER_BOEIE (1 << 3) /* Bus-Off Entry Interrupt Enable */
185 #define RCAR_CAN_EIER_EPIE (1 << 2) /* Error Passive Interrupt Enable */
186 #define RCAR_CAN_EIER_EWIE (1 << 1) /* Error Warning Interrupt Enable */
187 #define RCAR_CAN_EIER_BEIE (1 << 0) /* Bus Error Interrupt Enable */
188
189 /* Error Interrupt Factor Judge Register bits */
190 #define RCAR_CAN_EIFR_BLIF (1 << 7) /* Bus Lock Detect Flag */
191 #define RCAR_CAN_EIFR_OLIF (1 << 6) /* Overload Frame Transmission */
192 /* Detect Flag */
193 #define RCAR_CAN_EIFR_ORIF (1 << 5) /* Receive Overrun Detect Flag */
194 #define RCAR_CAN_EIFR_BORIF (1 << 4) /* Bus-Off Recovery Detect Flag */
195 #define RCAR_CAN_EIFR_BOEIF (1 << 3) /* Bus-Off Entry Detect Flag */
196 #define RCAR_CAN_EIFR_EPIF (1 << 2) /* Error Passive Detect Flag */
197 #define RCAR_CAN_EIFR_EWIF (1 << 1) /* Error Warning Detect Flag */
198 #define RCAR_CAN_EIFR_BEIF (1 << 0) /* Bus Error Detect Flag */
199
200 /* Error Code Store Register bits */
201 #define RCAR_CAN_ECSR_EDPM (1 << 7) /* Error Display Mode Select Bit */
202 #define RCAR_CAN_ECSR_ADEF (1 << 6) /* ACK Delimiter Error Flag */
203 #define RCAR_CAN_ECSR_BE0F (1 << 5) /* Bit Error (dominant) Flag */
204 #define RCAR_CAN_ECSR_BE1F (1 << 4) /* Bit Error (recessive) Flag */
205 #define RCAR_CAN_ECSR_CEF (1 << 3) /* CRC Error Flag */
206 #define RCAR_CAN_ECSR_AEF (1 << 2) /* ACK Error Flag */
207 #define RCAR_CAN_ECSR_FEF (1 << 1) /* Form Error Flag */
208 #define RCAR_CAN_ECSR_SEF (1 << 0) /* Stuff Error Flag */
209
210 #define RCAR_CAN_NAPI_WEIGHT 4
211 #define MAX_STR_READS 0x100
212
tx_failure_cleanup(struct net_device * ndev)213 static void tx_failure_cleanup(struct net_device *ndev)
214 {
215 int i;
216
217 for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
218 can_free_echo_skb(ndev, i);
219 }
220
rcar_can_error(struct net_device * ndev)221 static void rcar_can_error(struct net_device *ndev)
222 {
223 struct rcar_can_priv *priv = netdev_priv(ndev);
224 struct net_device_stats *stats = &ndev->stats;
225 struct can_frame *cf;
226 struct sk_buff *skb;
227 u8 eifr, txerr = 0, rxerr = 0;
228
229 /* Propagate the error condition to the CAN stack */
230 skb = alloc_can_err_skb(ndev, &cf);
231
232 eifr = readb(&priv->regs->eifr);
233 if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) {
234 txerr = readb(&priv->regs->tecr);
235 rxerr = readb(&priv->regs->recr);
236 if (skb) {
237 cf->can_id |= CAN_ERR_CRTL;
238 cf->data[6] = txerr;
239 cf->data[7] = rxerr;
240 }
241 }
242 if (eifr & RCAR_CAN_EIFR_BEIF) {
243 int rx_errors = 0, tx_errors = 0;
244 u8 ecsr;
245
246 netdev_dbg(priv->ndev, "Bus error interrupt:\n");
247 if (skb)
248 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
249
250 ecsr = readb(&priv->regs->ecsr);
251 if (ecsr & RCAR_CAN_ECSR_ADEF) {
252 netdev_dbg(priv->ndev, "ACK Delimiter Error\n");
253 tx_errors++;
254 writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr);
255 if (skb)
256 cf->data[3] = CAN_ERR_PROT_LOC_ACK_DEL;
257 }
258 if (ecsr & RCAR_CAN_ECSR_BE0F) {
259 netdev_dbg(priv->ndev, "Bit Error (dominant)\n");
260 tx_errors++;
261 writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr);
262 if (skb)
263 cf->data[2] |= CAN_ERR_PROT_BIT0;
264 }
265 if (ecsr & RCAR_CAN_ECSR_BE1F) {
266 netdev_dbg(priv->ndev, "Bit Error (recessive)\n");
267 tx_errors++;
268 writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr);
269 if (skb)
270 cf->data[2] |= CAN_ERR_PROT_BIT1;
271 }
272 if (ecsr & RCAR_CAN_ECSR_CEF) {
273 netdev_dbg(priv->ndev, "CRC Error\n");
274 rx_errors++;
275 writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr);
276 if (skb)
277 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
278 }
279 if (ecsr & RCAR_CAN_ECSR_AEF) {
280 netdev_dbg(priv->ndev, "ACK Error\n");
281 tx_errors++;
282 writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr);
283 if (skb) {
284 cf->can_id |= CAN_ERR_ACK;
285 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
286 }
287 }
288 if (ecsr & RCAR_CAN_ECSR_FEF) {
289 netdev_dbg(priv->ndev, "Form Error\n");
290 rx_errors++;
291 writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr);
292 if (skb)
293 cf->data[2] |= CAN_ERR_PROT_FORM;
294 }
295 if (ecsr & RCAR_CAN_ECSR_SEF) {
296 netdev_dbg(priv->ndev, "Stuff Error\n");
297 rx_errors++;
298 writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr);
299 if (skb)
300 cf->data[2] |= CAN_ERR_PROT_STUFF;
301 }
302
303 priv->can.can_stats.bus_error++;
304 ndev->stats.rx_errors += rx_errors;
305 ndev->stats.tx_errors += tx_errors;
306 writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr);
307 }
308 if (eifr & RCAR_CAN_EIFR_EWIF) {
309 netdev_dbg(priv->ndev, "Error warning interrupt\n");
310 priv->can.state = CAN_STATE_ERROR_WARNING;
311 priv->can.can_stats.error_warning++;
312 /* Clear interrupt condition */
313 writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr);
314 if (skb)
315 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
316 CAN_ERR_CRTL_RX_WARNING;
317 }
318 if (eifr & RCAR_CAN_EIFR_EPIF) {
319 netdev_dbg(priv->ndev, "Error passive interrupt\n");
320 priv->can.state = CAN_STATE_ERROR_PASSIVE;
321 priv->can.can_stats.error_passive++;
322 /* Clear interrupt condition */
323 writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr);
324 if (skb)
325 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
326 CAN_ERR_CRTL_RX_PASSIVE;
327 }
328 if (eifr & RCAR_CAN_EIFR_BOEIF) {
329 netdev_dbg(priv->ndev, "Bus-off entry interrupt\n");
330 tx_failure_cleanup(ndev);
331 priv->ier = RCAR_CAN_IER_ERSIE;
332 writeb(priv->ier, &priv->regs->ier);
333 priv->can.state = CAN_STATE_BUS_OFF;
334 /* Clear interrupt condition */
335 writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr);
336 priv->can.can_stats.bus_off++;
337 can_bus_off(ndev);
338 if (skb)
339 cf->can_id |= CAN_ERR_BUSOFF;
340 }
341 if (eifr & RCAR_CAN_EIFR_ORIF) {
342 netdev_dbg(priv->ndev, "Receive overrun error interrupt\n");
343 ndev->stats.rx_over_errors++;
344 ndev->stats.rx_errors++;
345 writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr);
346 if (skb) {
347 cf->can_id |= CAN_ERR_CRTL;
348 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
349 }
350 }
351 if (eifr & RCAR_CAN_EIFR_OLIF) {
352 netdev_dbg(priv->ndev,
353 "Overload Frame Transmission error interrupt\n");
354 ndev->stats.rx_over_errors++;
355 ndev->stats.rx_errors++;
356 writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr);
357 if (skb) {
358 cf->can_id |= CAN_ERR_PROT;
359 cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
360 }
361 }
362
363 if (skb) {
364 stats->rx_packets++;
365 stats->rx_bytes += cf->can_dlc;
366 netif_rx(skb);
367 }
368 }
369
rcar_can_tx_done(struct net_device * ndev)370 static void rcar_can_tx_done(struct net_device *ndev)
371 {
372 struct rcar_can_priv *priv = netdev_priv(ndev);
373 struct net_device_stats *stats = &ndev->stats;
374 u8 isr;
375
376 while (1) {
377 u8 unsent = readb(&priv->regs->tfcr);
378
379 unsent = (unsent & RCAR_CAN_TFCR_TFUST) >>
380 RCAR_CAN_TFCR_TFUST_SHIFT;
381 if (priv->tx_head - priv->tx_tail <= unsent)
382 break;
383 stats->tx_packets++;
384 stats->tx_bytes += priv->tx_dlc[priv->tx_tail %
385 RCAR_CAN_FIFO_DEPTH];
386 priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0;
387 can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH);
388 priv->tx_tail++;
389 netif_wake_queue(ndev);
390 }
391 /* Clear interrupt */
392 isr = readb(&priv->regs->isr);
393 writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr);
394 can_led_event(ndev, CAN_LED_EVENT_TX);
395 }
396
rcar_can_interrupt(int irq,void * dev_id)397 static irqreturn_t rcar_can_interrupt(int irq, void *dev_id)
398 {
399 struct net_device *ndev = dev_id;
400 struct rcar_can_priv *priv = netdev_priv(ndev);
401 u8 isr;
402
403 isr = readb(&priv->regs->isr);
404 if (!(isr & priv->ier))
405 return IRQ_NONE;
406
407 if (isr & RCAR_CAN_ISR_ERSF)
408 rcar_can_error(ndev);
409
410 if (isr & RCAR_CAN_ISR_TXFF)
411 rcar_can_tx_done(ndev);
412
413 if (isr & RCAR_CAN_ISR_RXFF) {
414 if (napi_schedule_prep(&priv->napi)) {
415 /* Disable Rx FIFO interrupts */
416 priv->ier &= ~RCAR_CAN_IER_RXFIE;
417 writeb(priv->ier, &priv->regs->ier);
418 __napi_schedule(&priv->napi);
419 }
420 }
421
422 return IRQ_HANDLED;
423 }
424
rcar_can_set_bittiming(struct net_device * dev)425 static void rcar_can_set_bittiming(struct net_device *dev)
426 {
427 struct rcar_can_priv *priv = netdev_priv(dev);
428 struct can_bittiming *bt = &priv->can.bittiming;
429 u32 bcr;
430
431 bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) |
432 RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) |
433 RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1);
434 /* Don't overwrite CLKR with 32-bit BCR access; CLKR has 8-bit access.
435 * All the registers are big-endian but they get byte-swapped on 32-bit
436 * read/write (but not on 8-bit, contrary to the manuals)...
437 */
438 writel((bcr << 8) | priv->clock_select, &priv->regs->bcr);
439 }
440
rcar_can_start(struct net_device * ndev)441 static void rcar_can_start(struct net_device *ndev)
442 {
443 struct rcar_can_priv *priv = netdev_priv(ndev);
444 u16 ctlr;
445 int i;
446
447 /* Set controller to known mode:
448 * - FIFO mailbox mode
449 * - accept all messages
450 * - overrun mode
451 * CAN is in sleep mode after MCU hardware or software reset.
452 */
453 ctlr = readw(&priv->regs->ctlr);
454 ctlr &= ~RCAR_CAN_CTLR_SLPM;
455 writew(ctlr, &priv->regs->ctlr);
456 /* Go to reset mode */
457 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
458 writew(ctlr, &priv->regs->ctlr);
459 for (i = 0; i < MAX_STR_READS; i++) {
460 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
461 break;
462 }
463 rcar_can_set_bittiming(ndev);
464 ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */
465 ctlr |= RCAR_CAN_CTLR_BOM_ENT; /* Entry to halt mode automatically */
466 /* at bus-off */
467 ctlr |= RCAR_CAN_CTLR_MBM; /* Select FIFO mailbox mode */
468 ctlr |= RCAR_CAN_CTLR_MLM; /* Overrun mode */
469 writew(ctlr, &priv->regs->ctlr);
470
471 /* Accept all SID and EID */
472 writel(0, &priv->regs->mkr_2_9[6]);
473 writel(0, &priv->regs->mkr_2_9[7]);
474 /* In FIFO mailbox mode, write "0" to bits 24 to 31 */
475 writel(0, &priv->regs->mkivlr1);
476 /* Accept all frames */
477 writel(0, &priv->regs->fidcr[0]);
478 writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]);
479 /* Enable and configure FIFO mailbox interrupts */
480 writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1);
481
482 priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE |
483 RCAR_CAN_IER_TXFIE;
484 writeb(priv->ier, &priv->regs->ier);
485
486 /* Accumulate error codes */
487 writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr);
488 /* Enable error interrupts */
489 writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE |
490 (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ?
491 RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE |
492 RCAR_CAN_EIER_OLIE, &priv->regs->eier);
493 priv->can.state = CAN_STATE_ERROR_ACTIVE;
494
495 /* Go to operation mode */
496 writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr);
497 for (i = 0; i < MAX_STR_READS; i++) {
498 if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST))
499 break;
500 }
501 /* Enable Rx and Tx FIFO */
502 writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr);
503 writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr);
504 }
505
rcar_can_open(struct net_device * ndev)506 static int rcar_can_open(struct net_device *ndev)
507 {
508 struct rcar_can_priv *priv = netdev_priv(ndev);
509 int err;
510
511 err = clk_prepare_enable(priv->clk);
512 if (err) {
513 netdev_err(ndev,
514 "failed to enable peripheral clock, error %d\n",
515 err);
516 goto out;
517 }
518 err = clk_prepare_enable(priv->can_clk);
519 if (err) {
520 netdev_err(ndev, "failed to enable CAN clock, error %d\n",
521 err);
522 goto out_clock;
523 }
524 err = open_candev(ndev);
525 if (err) {
526 netdev_err(ndev, "open_candev() failed, error %d\n", err);
527 goto out_can_clock;
528 }
529 napi_enable(&priv->napi);
530 err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev);
531 if (err) {
532 netdev_err(ndev, "request_irq(%d) failed, error %d\n",
533 ndev->irq, err);
534 goto out_close;
535 }
536 can_led_event(ndev, CAN_LED_EVENT_OPEN);
537 rcar_can_start(ndev);
538 netif_start_queue(ndev);
539 return 0;
540 out_close:
541 napi_disable(&priv->napi);
542 close_candev(ndev);
543 out_can_clock:
544 clk_disable_unprepare(priv->can_clk);
545 out_clock:
546 clk_disable_unprepare(priv->clk);
547 out:
548 return err;
549 }
550
rcar_can_stop(struct net_device * ndev)551 static void rcar_can_stop(struct net_device *ndev)
552 {
553 struct rcar_can_priv *priv = netdev_priv(ndev);
554 u16 ctlr;
555 int i;
556
557 /* Go to (force) reset mode */
558 ctlr = readw(&priv->regs->ctlr);
559 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
560 writew(ctlr, &priv->regs->ctlr);
561 for (i = 0; i < MAX_STR_READS; i++) {
562 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
563 break;
564 }
565 writel(0, &priv->regs->mier0);
566 writel(0, &priv->regs->mier1);
567 writeb(0, &priv->regs->ier);
568 writeb(0, &priv->regs->eier);
569 /* Go to sleep mode */
570 ctlr |= RCAR_CAN_CTLR_SLPM;
571 writew(ctlr, &priv->regs->ctlr);
572 priv->can.state = CAN_STATE_STOPPED;
573 }
574
rcar_can_close(struct net_device * ndev)575 static int rcar_can_close(struct net_device *ndev)
576 {
577 struct rcar_can_priv *priv = netdev_priv(ndev);
578
579 netif_stop_queue(ndev);
580 rcar_can_stop(ndev);
581 free_irq(ndev->irq, ndev);
582 napi_disable(&priv->napi);
583 clk_disable_unprepare(priv->can_clk);
584 clk_disable_unprepare(priv->clk);
585 close_candev(ndev);
586 can_led_event(ndev, CAN_LED_EVENT_STOP);
587 return 0;
588 }
589
rcar_can_start_xmit(struct sk_buff * skb,struct net_device * ndev)590 static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
591 struct net_device *ndev)
592 {
593 struct rcar_can_priv *priv = netdev_priv(ndev);
594 struct can_frame *cf = (struct can_frame *)skb->data;
595 u32 data, i;
596
597 if (can_dropped_invalid_skb(ndev, skb))
598 return NETDEV_TX_OK;
599
600 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
601 data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE;
602 else /* Standard frame format */
603 data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT;
604
605 if (cf->can_id & CAN_RTR_FLAG) { /* Remote transmission request */
606 data |= RCAR_CAN_RTR;
607 } else {
608 for (i = 0; i < cf->can_dlc; i++)
609 writeb(cf->data[i],
610 &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]);
611 }
612
613 writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id);
614
615 writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
616
617 priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->can_dlc;
618 can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH);
619 priv->tx_head++;
620 /* Start Tx: write 0xff to the TFPCR register to increment
621 * the CPU-side pointer for the transmit FIFO to the next
622 * mailbox location
623 */
624 writeb(0xff, &priv->regs->tfpcr);
625 /* Stop the queue if we've filled all FIFO entries */
626 if (priv->tx_head - priv->tx_tail >= RCAR_CAN_FIFO_DEPTH)
627 netif_stop_queue(ndev);
628
629 return NETDEV_TX_OK;
630 }
631
632 static const struct net_device_ops rcar_can_netdev_ops = {
633 .ndo_open = rcar_can_open,
634 .ndo_stop = rcar_can_close,
635 .ndo_start_xmit = rcar_can_start_xmit,
636 .ndo_change_mtu = can_change_mtu,
637 };
638
rcar_can_rx_pkt(struct rcar_can_priv * priv)639 static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
640 {
641 struct net_device_stats *stats = &priv->ndev->stats;
642 struct can_frame *cf;
643 struct sk_buff *skb;
644 u32 data;
645 u8 dlc;
646
647 skb = alloc_can_skb(priv->ndev, &cf);
648 if (!skb) {
649 stats->rx_dropped++;
650 return;
651 }
652
653 data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id);
654 if (data & RCAR_CAN_IDE)
655 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
656 else
657 cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK;
658
659 dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc);
660 cf->can_dlc = get_can_dlc(dlc);
661 if (data & RCAR_CAN_RTR) {
662 cf->can_id |= CAN_RTR_FLAG;
663 } else {
664 for (dlc = 0; dlc < cf->can_dlc; dlc++)
665 cf->data[dlc] =
666 readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
667 }
668
669 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
670
671 stats->rx_bytes += cf->can_dlc;
672 stats->rx_packets++;
673 netif_receive_skb(skb);
674 }
675
rcar_can_rx_poll(struct napi_struct * napi,int quota)676 static int rcar_can_rx_poll(struct napi_struct *napi, int quota)
677 {
678 struct rcar_can_priv *priv = container_of(napi,
679 struct rcar_can_priv, napi);
680 int num_pkts;
681
682 for (num_pkts = 0; num_pkts < quota; num_pkts++) {
683 u8 rfcr, isr;
684
685 isr = readb(&priv->regs->isr);
686 /* Clear interrupt bit */
687 if (isr & RCAR_CAN_ISR_RXFF)
688 writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr);
689 rfcr = readb(&priv->regs->rfcr);
690 if (rfcr & RCAR_CAN_RFCR_RFEST)
691 break;
692 rcar_can_rx_pkt(priv);
693 /* Write 0xff to the RFPCR register to increment
694 * the CPU-side pointer for the receive FIFO
695 * to the next mailbox location
696 */
697 writeb(0xff, &priv->regs->rfpcr);
698 }
699 /* All packets processed */
700 if (num_pkts < quota) {
701 napi_complete(napi);
702 priv->ier |= RCAR_CAN_IER_RXFIE;
703 writeb(priv->ier, &priv->regs->ier);
704 }
705 return num_pkts;
706 }
707
rcar_can_do_set_mode(struct net_device * ndev,enum can_mode mode)708 static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
709 {
710 switch (mode) {
711 case CAN_MODE_START:
712 rcar_can_start(ndev);
713 netif_wake_queue(ndev);
714 return 0;
715 default:
716 return -EOPNOTSUPP;
717 }
718 }
719
rcar_can_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)720 static int rcar_can_get_berr_counter(const struct net_device *dev,
721 struct can_berr_counter *bec)
722 {
723 struct rcar_can_priv *priv = netdev_priv(dev);
724 int err;
725
726 err = clk_prepare_enable(priv->clk);
727 if (err)
728 return err;
729 bec->txerr = readb(&priv->regs->tecr);
730 bec->rxerr = readb(&priv->regs->recr);
731 clk_disable_unprepare(priv->clk);
732 return 0;
733 }
734
735 static const char * const clock_names[] = {
736 [CLKR_CLKP1] = "clkp1",
737 [CLKR_CLKP2] = "clkp2",
738 [CLKR_CLKEXT] = "can_clk",
739 };
740
rcar_can_probe(struct platform_device * pdev)741 static int rcar_can_probe(struct platform_device *pdev)
742 {
743 struct rcar_can_platform_data *pdata;
744 struct rcar_can_priv *priv;
745 struct net_device *ndev;
746 struct resource *mem;
747 void __iomem *addr;
748 u32 clock_select = CLKR_CLKP1;
749 int err = -ENODEV;
750 int irq;
751
752 if (pdev->dev.of_node) {
753 of_property_read_u32(pdev->dev.of_node,
754 "renesas,can-clock-select", &clock_select);
755 } else {
756 pdata = dev_get_platdata(&pdev->dev);
757 if (!pdata) {
758 dev_err(&pdev->dev, "No platform data provided!\n");
759 goto fail;
760 }
761 clock_select = pdata->clock_select;
762 }
763
764 irq = platform_get_irq(pdev, 0);
765 if (irq < 0) {
766 dev_err(&pdev->dev, "No IRQ resource\n");
767 err = irq;
768 goto fail;
769 }
770
771 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
772 addr = devm_ioremap_resource(&pdev->dev, mem);
773 if (IS_ERR(addr)) {
774 err = PTR_ERR(addr);
775 goto fail;
776 }
777
778 ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH);
779 if (!ndev) {
780 dev_err(&pdev->dev, "alloc_candev() failed\n");
781 err = -ENOMEM;
782 goto fail;
783 }
784
785 priv = netdev_priv(ndev);
786
787 priv->clk = devm_clk_get(&pdev->dev, "clkp1");
788 if (IS_ERR(priv->clk)) {
789 err = PTR_ERR(priv->clk);
790 dev_err(&pdev->dev, "cannot get peripheral clock, error %d\n",
791 err);
792 goto fail_clk;
793 }
794
795 if (!(BIT(clock_select) & RCAR_SUPPORTED_CLOCKS)) {
796 err = -EINVAL;
797 dev_err(&pdev->dev, "invalid CAN clock selected\n");
798 goto fail_clk;
799 }
800 priv->can_clk = devm_clk_get(&pdev->dev, clock_names[clock_select]);
801 if (IS_ERR(priv->can_clk)) {
802 err = PTR_ERR(priv->can_clk);
803 dev_err(&pdev->dev, "cannot get CAN clock, error %d\n", err);
804 goto fail_clk;
805 }
806
807 ndev->netdev_ops = &rcar_can_netdev_ops;
808 ndev->irq = irq;
809 ndev->flags |= IFF_ECHO;
810 priv->ndev = ndev;
811 priv->regs = addr;
812 priv->clock_select = clock_select;
813 priv->can.clock.freq = clk_get_rate(priv->can_clk);
814 priv->can.bittiming_const = &rcar_can_bittiming_const;
815 priv->can.do_set_mode = rcar_can_do_set_mode;
816 priv->can.do_get_berr_counter = rcar_can_get_berr_counter;
817 priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
818 platform_set_drvdata(pdev, ndev);
819 SET_NETDEV_DEV(ndev, &pdev->dev);
820
821 netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll,
822 RCAR_CAN_NAPI_WEIGHT);
823 err = register_candev(ndev);
824 if (err) {
825 dev_err(&pdev->dev, "register_candev() failed, error %d\n",
826 err);
827 goto fail_candev;
828 }
829
830 devm_can_led_init(ndev);
831
832 dev_info(&pdev->dev, "device registered (regs @ %p, IRQ%d)\n",
833 priv->regs, ndev->irq);
834
835 return 0;
836 fail_candev:
837 netif_napi_del(&priv->napi);
838 fail_clk:
839 free_candev(ndev);
840 fail:
841 return err;
842 }
843
rcar_can_remove(struct platform_device * pdev)844 static int rcar_can_remove(struct platform_device *pdev)
845 {
846 struct net_device *ndev = platform_get_drvdata(pdev);
847 struct rcar_can_priv *priv = netdev_priv(ndev);
848
849 unregister_candev(ndev);
850 netif_napi_del(&priv->napi);
851 free_candev(ndev);
852 return 0;
853 }
854
rcar_can_suspend(struct device * dev)855 static int __maybe_unused rcar_can_suspend(struct device *dev)
856 {
857 struct net_device *ndev = dev_get_drvdata(dev);
858 struct rcar_can_priv *priv = netdev_priv(ndev);
859 u16 ctlr;
860
861 if (!netif_running(ndev))
862 return 0;
863
864 netif_stop_queue(ndev);
865 netif_device_detach(ndev);
866
867 ctlr = readw(&priv->regs->ctlr);
868 ctlr |= RCAR_CAN_CTLR_CANM_HALT;
869 writew(ctlr, &priv->regs->ctlr);
870 ctlr |= RCAR_CAN_CTLR_SLPM;
871 writew(ctlr, &priv->regs->ctlr);
872 priv->can.state = CAN_STATE_SLEEPING;
873
874 clk_disable(priv->clk);
875 return 0;
876 }
877
rcar_can_resume(struct device * dev)878 static int __maybe_unused rcar_can_resume(struct device *dev)
879 {
880 struct net_device *ndev = dev_get_drvdata(dev);
881 struct rcar_can_priv *priv = netdev_priv(ndev);
882 u16 ctlr;
883 int err;
884
885 if (!netif_running(ndev))
886 return 0;
887
888 err = clk_enable(priv->clk);
889 if (err) {
890 netdev_err(ndev, "clk_enable() failed, error %d\n", err);
891 return err;
892 }
893
894 ctlr = readw(&priv->regs->ctlr);
895 ctlr &= ~RCAR_CAN_CTLR_SLPM;
896 writew(ctlr, &priv->regs->ctlr);
897 ctlr &= ~RCAR_CAN_CTLR_CANM;
898 writew(ctlr, &priv->regs->ctlr);
899 priv->can.state = CAN_STATE_ERROR_ACTIVE;
900
901 netif_device_attach(ndev);
902 netif_start_queue(ndev);
903
904 return 0;
905 }
906
907 static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
908
909 static const struct of_device_id rcar_can_of_table[] __maybe_unused = {
910 { .compatible = "renesas,can-r8a7778" },
911 { .compatible = "renesas,can-r8a7779" },
912 { .compatible = "renesas,can-r8a7790" },
913 { .compatible = "renesas,can-r8a7791" },
914 { }
915 };
916 MODULE_DEVICE_TABLE(of, rcar_can_of_table);
917
918 static struct platform_driver rcar_can_driver = {
919 .driver = {
920 .name = RCAR_CAN_DRV_NAME,
921 .of_match_table = of_match_ptr(rcar_can_of_table),
922 .pm = &rcar_can_pm_ops,
923 },
924 .probe = rcar_can_probe,
925 .remove = rcar_can_remove,
926 };
927
928 module_platform_driver(rcar_can_driver);
929
930 MODULE_AUTHOR("Cogent Embedded, Inc.");
931 MODULE_LICENSE("GPL");
932 MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC");
933 MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);
934