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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/* Mailbox configuration:
28 * mailbox 60 - 63 - Rx FIFO mailboxes
29 * mailbox 56 - 59 - Tx FIFO mailboxes
30 * non-FIFO mailboxes are not used
31 */
32#define RCAR_CAN_N_MBX 64 /* Number of mailboxes in non-FIFO mode */
33#define RCAR_CAN_RX_FIFO_MBX 60 /* Mailbox - window to Rx FIFO */
34#define RCAR_CAN_TX_FIFO_MBX 56 /* Mailbox - window to Tx FIFO */
35#define RCAR_CAN_FIFO_DEPTH 4
36
37/* Mailbox registers structure */
38struct rcar_can_mbox_regs {
39 u32 id; /* IDE and RTR bits, SID and EID */
40 u8 stub; /* Not used */
41 u8 dlc; /* Data Length Code - bits [0..3] */
42 u8 data[8]; /* Data Bytes */
43 u8 tsh; /* Time Stamp Higher Byte */
44 u8 tsl; /* Time Stamp Lower Byte */
45};
46
47struct rcar_can_regs {
48 struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */
49 u32 mkr_2_9[8]; /* Mask Registers 2-9 */
50 u32 fidcr[2]; /* FIFO Received ID Compare Register */
51 u32 mkivlr1; /* Mask Invalid Register 1 */
52 u32 mier1; /* Mailbox Interrupt Enable Register 1 */
53 u32 mkr_0_1[2]; /* Mask Registers 0-1 */
54 u32 mkivlr0; /* Mask Invalid Register 0*/
55 u32 mier0; /* Mailbox Interrupt Enable Register 0 */
56 u8 pad_440[0x3c0];
57 u8 mctl[64]; /* Message Control Registers */
58 u16 ctlr; /* Control Register */
59 u16 str; /* Status register */
60 u8 bcr[3]; /* Bit Configuration Register */
61 u8 clkr; /* Clock Select Register */
62 u8 rfcr; /* Receive FIFO Control Register */
63 u8 rfpcr; /* Receive FIFO Pointer Control Register */
64 u8 tfcr; /* Transmit FIFO Control Register */
65 u8 tfpcr; /* Transmit FIFO Pointer Control Register */
66 u8 eier; /* Error Interrupt Enable Register */
67 u8 eifr; /* Error Interrupt Factor Judge Register */
68 u8 recr; /* Receive Error Count Register */
69 u8 tecr; /* Transmit Error Count Register */
70 u8 ecsr; /* Error Code Store Register */
71 u8 cssr; /* Channel Search Support Register */
72 u8 mssr; /* Mailbox Search Status Register */
73 u8 msmr; /* Mailbox Search Mode Register */
74 u16 tsr; /* Time Stamp Register */
75 u8 afsr; /* Acceptance Filter Support Register */
76 u8 pad_857;
77 u8 tcr; /* Test Control Register */
78 u8 pad_859[7];
79 u8 ier; /* Interrupt Enable Register */
80 u8 isr; /* Interrupt Status Register */
81 u8 pad_862;
82 u8 mbsmr; /* Mailbox Search Mask Register */
83};
84
85struct rcar_can_priv {
86 struct can_priv can; /* Must be the first member! */
87 struct net_device *ndev;
88 struct napi_struct napi;
89 struct rcar_can_regs __iomem *regs;
90 struct clk *clk;
91 struct clk *can_clk;
92 u8 tx_dlc[RCAR_CAN_FIFO_DEPTH];
93 u32 tx_head;
94 u32 tx_tail;
95 u8 clock_select;
96 u8 ier;
97};
98
99static const struct can_bittiming_const rcar_can_bittiming_const = {
100 .name = RCAR_CAN_DRV_NAME,
101 .tseg1_min = 4,
102 .tseg1_max = 16,
103 .tseg2_min = 2,
104 .tseg2_max = 8,
105 .sjw_max = 4,
106 .brp_min = 1,
107 .brp_max = 1024,
108 .brp_inc = 1,
109};
110
111/* Control Register bits */
112#define RCAR_CAN_CTLR_BOM (3 << 11) /* Bus-Off Recovery Mode Bits */
113#define RCAR_CAN_CTLR_BOM_ENT (1 << 11) /* Entry to halt mode */
114 /* at bus-off entry */
115#define RCAR_CAN_CTLR_SLPM (1 << 10)
116#define RCAR_CAN_CTLR_CANM (3 << 8) /* Operating Mode Select Bit */
117#define RCAR_CAN_CTLR_CANM_HALT (1 << 9)
118#define RCAR_CAN_CTLR_CANM_RESET (1 << 8)
119#define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8)
120#define RCAR_CAN_CTLR_MLM (1 << 3) /* Message Lost Mode Select */
121#define RCAR_CAN_CTLR_IDFM (3 << 1) /* ID Format Mode Select Bits */
122#define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */
123#define RCAR_CAN_CTLR_MBM (1 << 0) /* Mailbox Mode select */
124
125/* Status Register bits */
126#define RCAR_CAN_STR_RSTST (1 << 8) /* Reset Status Bit */
127
128/* FIFO Received ID Compare Registers 0 and 1 bits */
129#define RCAR_CAN_FIDCR_IDE (1 << 31) /* ID Extension Bit */
130#define RCAR_CAN_FIDCR_RTR (1 << 30) /* Remote Transmission Request Bit */
131
132/* Receive FIFO Control Register bits */
133#define RCAR_CAN_RFCR_RFEST (1 << 7) /* Receive FIFO Empty Status Flag */
134#define RCAR_CAN_RFCR_RFE (1 << 0) /* Receive FIFO Enable */
135
136/* Transmit FIFO Control Register bits */
137#define RCAR_CAN_TFCR_TFUST (7 << 1) /* Transmit FIFO Unsent Message */
138 /* Number Status Bits */
139#define RCAR_CAN_TFCR_TFUST_SHIFT 1 /* Offset of Transmit FIFO Unsent */
140 /* Message Number Status Bits */
141#define RCAR_CAN_TFCR_TFE (1 << 0) /* Transmit FIFO Enable */
142
143#define RCAR_CAN_N_RX_MKREGS1 2 /* Number of mask registers */
144 /* for Rx mailboxes 0-31 */
145#define RCAR_CAN_N_RX_MKREGS2 8
146
147/* Bit Configuration Register settings */
148#define RCAR_CAN_BCR_TSEG1(x) (((x) & 0x0f) << 20)
149#define RCAR_CAN_BCR_BPR(x) (((x) & 0x3ff) << 8)
150#define RCAR_CAN_BCR_SJW(x) (((x) & 0x3) << 4)
151#define RCAR_CAN_BCR_TSEG2(x) ((x) & 0x07)
152
153/* Mailbox and Mask Registers bits */
154#define RCAR_CAN_IDE (1 << 31)
155#define RCAR_CAN_RTR (1 << 30)
156#define RCAR_CAN_SID_SHIFT 18
157
158/* Mailbox Interrupt Enable Register 1 bits */
159#define RCAR_CAN_MIER1_RXFIE (1 << 28) /* Receive FIFO Interrupt Enable */
160#define RCAR_CAN_MIER1_TXFIE (1 << 24) /* Transmit FIFO Interrupt Enable */
161
162/* Interrupt Enable Register bits */
163#define RCAR_CAN_IER_ERSIE (1 << 5) /* Error (ERS) Interrupt Enable Bit */
164#define RCAR_CAN_IER_RXFIE (1 << 4) /* Reception FIFO Interrupt */
165 /* Enable Bit */
166#define RCAR_CAN_IER_TXFIE (1 << 3) /* Transmission FIFO Interrupt */
167 /* Enable Bit */
168/* Interrupt Status Register bits */
169#define RCAR_CAN_ISR_ERSF (1 << 5) /* Error (ERS) Interrupt Status Bit */
170#define RCAR_CAN_ISR_RXFF (1 << 4) /* Reception FIFO Interrupt */
171 /* Status Bit */
172#define RCAR_CAN_ISR_TXFF (1 << 3) /* Transmission FIFO Interrupt */
173 /* Status Bit */
174
175/* Error Interrupt Enable Register bits */
176#define RCAR_CAN_EIER_BLIE (1 << 7) /* Bus Lock Interrupt Enable */
177#define RCAR_CAN_EIER_OLIE (1 << 6) /* Overload Frame Transmit */
178 /* Interrupt Enable */
179#define RCAR_CAN_EIER_ORIE (1 << 5) /* Receive Overrun Interrupt Enable */
180#define RCAR_CAN_EIER_BORIE (1 << 4) /* Bus-Off Recovery Interrupt Enable */
181#define RCAR_CAN_EIER_BOEIE (1 << 3) /* Bus-Off Entry Interrupt Enable */
182#define RCAR_CAN_EIER_EPIE (1 << 2) /* Error Passive Interrupt Enable */
183#define RCAR_CAN_EIER_EWIE (1 << 1) /* Error Warning Interrupt Enable */
184#define RCAR_CAN_EIER_BEIE (1 << 0) /* Bus Error Interrupt Enable */
185
186/* Error Interrupt Factor Judge Register bits */
187#define RCAR_CAN_EIFR_BLIF (1 << 7) /* Bus Lock Detect Flag */
188#define RCAR_CAN_EIFR_OLIF (1 << 6) /* Overload Frame Transmission */
189 /* Detect Flag */
190#define RCAR_CAN_EIFR_ORIF (1 << 5) /* Receive Overrun Detect Flag */
191#define RCAR_CAN_EIFR_BORIF (1 << 4) /* Bus-Off Recovery Detect Flag */
192#define RCAR_CAN_EIFR_BOEIF (1 << 3) /* Bus-Off Entry Detect Flag */
193#define RCAR_CAN_EIFR_EPIF (1 << 2) /* Error Passive Detect Flag */
194#define RCAR_CAN_EIFR_EWIF (1 << 1) /* Error Warning Detect Flag */
195#define RCAR_CAN_EIFR_BEIF (1 << 0) /* Bus Error Detect Flag */
196
197/* Error Code Store Register bits */
198#define RCAR_CAN_ECSR_EDPM (1 << 7) /* Error Display Mode Select Bit */
199#define RCAR_CAN_ECSR_ADEF (1 << 6) /* ACK Delimiter Error Flag */
200#define RCAR_CAN_ECSR_BE0F (1 << 5) /* Bit Error (dominant) Flag */
201#define RCAR_CAN_ECSR_BE1F (1 << 4) /* Bit Error (recessive) Flag */
202#define RCAR_CAN_ECSR_CEF (1 << 3) /* CRC Error Flag */
203#define RCAR_CAN_ECSR_AEF (1 << 2) /* ACK Error Flag */
204#define RCAR_CAN_ECSR_FEF (1 << 1) /* Form Error Flag */
205#define RCAR_CAN_ECSR_SEF (1 << 0) /* Stuff Error Flag */
206
207#define RCAR_CAN_NAPI_WEIGHT 4
208#define MAX_STR_READS 0x100
209
210static void tx_failure_cleanup(struct net_device *ndev)
211{
212 int i;
213
214 for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
215 can_free_echo_skb(ndev, i);
216}
217
218static void rcar_can_error(struct net_device *ndev)
219{
220 struct rcar_can_priv *priv = netdev_priv(ndev);
221 struct net_device_stats *stats = &ndev->stats;
222 struct can_frame *cf;
223 struct sk_buff *skb;
224 u8 eifr, txerr = 0, rxerr = 0;
225
226 /* Propagate the error condition to the CAN stack */
227 skb = alloc_can_err_skb(ndev, &cf);
228
229 eifr = readb(&priv->regs->eifr);
230 if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) {
231 txerr = readb(&priv->regs->tecr);
232 rxerr = readb(&priv->regs->recr);
233 if (skb) {
234 cf->can_id |= CAN_ERR_CRTL;
235 cf->data[6] = txerr;
236 cf->data[7] = rxerr;
237 }
238 }
239 if (eifr & RCAR_CAN_EIFR_BEIF) {
240 int rx_errors = 0, tx_errors = 0;
241 u8 ecsr;
242
243 netdev_dbg(priv->ndev, "Bus error interrupt:\n");
244 if (skb)
245 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
246
247 ecsr = readb(&priv->regs->ecsr);
248 if (ecsr & RCAR_CAN_ECSR_ADEF) {
249 netdev_dbg(priv->ndev, "ACK Delimiter Error\n");
250 tx_errors++;
251 writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr);
252 if (skb)
253 cf->data[3] = CAN_ERR_PROT_LOC_ACK_DEL;
254 }
255 if (ecsr & RCAR_CAN_ECSR_BE0F) {
256 netdev_dbg(priv->ndev, "Bit Error (dominant)\n");
257 tx_errors++;
258 writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr);
259 if (skb)
260 cf->data[2] |= CAN_ERR_PROT_BIT0;
261 }
262 if (ecsr & RCAR_CAN_ECSR_BE1F) {
263 netdev_dbg(priv->ndev, "Bit Error (recessive)\n");
264 tx_errors++;
265 writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr);
266 if (skb)
267 cf->data[2] |= CAN_ERR_PROT_BIT1;
268 }
269 if (ecsr & RCAR_CAN_ECSR_CEF) {
270 netdev_dbg(priv->ndev, "CRC Error\n");
271 rx_errors++;
272 writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr);
273 if (skb)
274 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
275 }
276 if (ecsr & RCAR_CAN_ECSR_AEF) {
277 netdev_dbg(priv->ndev, "ACK Error\n");
278 tx_errors++;
279 writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr);
280 if (skb) {
281 cf->can_id |= CAN_ERR_ACK;
282 cf->data[3] = CAN_ERR_PROT_LOC_ACK;
283 }
284 }
285 if (ecsr & RCAR_CAN_ECSR_FEF) {
286 netdev_dbg(priv->ndev, "Form Error\n");
287 rx_errors++;
288 writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr);
289 if (skb)
290 cf->data[2] |= CAN_ERR_PROT_FORM;
291 }
292 if (ecsr & RCAR_CAN_ECSR_SEF) {
293 netdev_dbg(priv->ndev, "Stuff Error\n");
294 rx_errors++;
295 writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr);
296 if (skb)
297 cf->data[2] |= CAN_ERR_PROT_STUFF;
298 }
299
300 priv->can.can_stats.bus_error++;
301 ndev->stats.rx_errors += rx_errors;
302 ndev->stats.tx_errors += tx_errors;
303 writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr);
304 }
305 if (eifr & RCAR_CAN_EIFR_EWIF) {
306 netdev_dbg(priv->ndev, "Error warning interrupt\n");
307 priv->can.state = CAN_STATE_ERROR_WARNING;
308 priv->can.can_stats.error_warning++;
309 /* Clear interrupt condition */
310 writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr);
311 if (skb)
312 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
313 CAN_ERR_CRTL_RX_WARNING;
314 }
315 if (eifr & RCAR_CAN_EIFR_EPIF) {
316 netdev_dbg(priv->ndev, "Error passive interrupt\n");
317 priv->can.state = CAN_STATE_ERROR_PASSIVE;
318 priv->can.can_stats.error_passive++;
319 /* Clear interrupt condition */
320 writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr);
321 if (skb)
322 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
323 CAN_ERR_CRTL_RX_PASSIVE;
324 }
325 if (eifr & RCAR_CAN_EIFR_BOEIF) {
326 netdev_dbg(priv->ndev, "Bus-off entry interrupt\n");
327 tx_failure_cleanup(ndev);
328 priv->ier = RCAR_CAN_IER_ERSIE;
329 writeb(priv->ier, &priv->regs->ier);
330 priv->can.state = CAN_STATE_BUS_OFF;
331 /* Clear interrupt condition */
332 writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr);
333 priv->can.can_stats.bus_off++;
334 can_bus_off(ndev);
335 if (skb)
336 cf->can_id |= CAN_ERR_BUSOFF;
337 }
338 if (eifr & RCAR_CAN_EIFR_ORIF) {
339 netdev_dbg(priv->ndev, "Receive overrun error interrupt\n");
340 ndev->stats.rx_over_errors++;
341 ndev->stats.rx_errors++;
342 writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr);
343 if (skb) {
344 cf->can_id |= CAN_ERR_CRTL;
345 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
346 }
347 }
348 if (eifr & RCAR_CAN_EIFR_OLIF) {
349 netdev_dbg(priv->ndev,
350 "Overload Frame Transmission error interrupt\n");
351 ndev->stats.rx_over_errors++;
352 ndev->stats.rx_errors++;
353 writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr);
354 if (skb) {
355 cf->can_id |= CAN_ERR_PROT;
356 cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
357 }
358 }
359
360 if (skb) {
361 stats->rx_packets++;
362 stats->rx_bytes += cf->can_dlc;
363 netif_rx(skb);
364 }
365}
366
367static void rcar_can_tx_done(struct net_device *ndev)
368{
369 struct rcar_can_priv *priv = netdev_priv(ndev);
370 struct net_device_stats *stats = &ndev->stats;
371 u8 isr;
372
373 while (1) {
374 u8 unsent = readb(&priv->regs->tfcr);
375
376 unsent = (unsent & RCAR_CAN_TFCR_TFUST) >>
377 RCAR_CAN_TFCR_TFUST_SHIFT;
378 if (priv->tx_head - priv->tx_tail <= unsent)
379 break;
380 stats->tx_packets++;
381 stats->tx_bytes += priv->tx_dlc[priv->tx_tail %
382 RCAR_CAN_FIFO_DEPTH];
383 priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0;
384 can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH);
385 priv->tx_tail++;
386 netif_wake_queue(ndev);
387 }
388 /* Clear interrupt */
389 isr = readb(&priv->regs->isr);
390 writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr);
391 can_led_event(ndev, CAN_LED_EVENT_TX);
392}
393
394static irqreturn_t rcar_can_interrupt(int irq, void *dev_id)
395{
396 struct net_device *ndev = dev_id;
397 struct rcar_can_priv *priv = netdev_priv(ndev);
398 u8 isr;
399
400 isr = readb(&priv->regs->isr);
401 if (!(isr & priv->ier))
402 return IRQ_NONE;
403
404 if (isr & RCAR_CAN_ISR_ERSF)
405 rcar_can_error(ndev);
406
407 if (isr & RCAR_CAN_ISR_TXFF)
408 rcar_can_tx_done(ndev);
409
410 if (isr & RCAR_CAN_ISR_RXFF) {
411 if (napi_schedule_prep(&priv->napi)) {
412 /* Disable Rx FIFO interrupts */
413 priv->ier &= ~RCAR_CAN_IER_RXFIE;
414 writeb(priv->ier, &priv->regs->ier);
415 __napi_schedule(&priv->napi);
416 }
417 }
418
419 return IRQ_HANDLED;
420}
421
422static void rcar_can_set_bittiming(struct net_device *dev)
423{
424 struct rcar_can_priv *priv = netdev_priv(dev);
425 struct can_bittiming *bt = &priv->can.bittiming;
426 u32 bcr;
427
428 bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) |
429 RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) |
430 RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1);
431 /* Don't overwrite CLKR with 32-bit BCR access; CLKR has 8-bit access.
432 * All the registers are big-endian but they get byte-swapped on 32-bit
433 * read/write (but not on 8-bit, contrary to the manuals)...
434 */
435 writel((bcr << 8) | priv->clock_select, &priv->regs->bcr);
436}
437
438static void rcar_can_start(struct net_device *ndev)
439{
440 struct rcar_can_priv *priv = netdev_priv(ndev);
441 u16 ctlr;
442 int i;
443
444 /* Set controller to known mode:
445 * - FIFO mailbox mode
446 * - accept all messages
447 * - overrun mode
448 * CAN is in sleep mode after MCU hardware or software reset.
449 */
450 ctlr = readw(&priv->regs->ctlr);
451 ctlr &= ~RCAR_CAN_CTLR_SLPM;
452 writew(ctlr, &priv->regs->ctlr);
453 /* Go to reset mode */
454 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
455 writew(ctlr, &priv->regs->ctlr);
456 for (i = 0; i < MAX_STR_READS; i++) {
457 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
458 break;
459 }
460 rcar_can_set_bittiming(ndev);
461 ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */
462 ctlr |= RCAR_CAN_CTLR_BOM_ENT; /* Entry to halt mode automatically */
463 /* at bus-off */
464 ctlr |= RCAR_CAN_CTLR_MBM; /* Select FIFO mailbox mode */
465 ctlr |= RCAR_CAN_CTLR_MLM; /* Overrun mode */
466 writew(ctlr, &priv->regs->ctlr);
467
468 /* Accept all SID and EID */
469 writel(0, &priv->regs->mkr_2_9[6]);
470 writel(0, &priv->regs->mkr_2_9[7]);
471 /* In FIFO mailbox mode, write "0" to bits 24 to 31 */
472 writel(0, &priv->regs->mkivlr1);
473 /* Accept all frames */
474 writel(0, &priv->regs->fidcr[0]);
475 writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]);
476 /* Enable and configure FIFO mailbox interrupts */
477 writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1);
478
479 priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE |
480 RCAR_CAN_IER_TXFIE;
481 writeb(priv->ier, &priv->regs->ier);
482
483 /* Accumulate error codes */
484 writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr);
485 /* Enable error interrupts */
486 writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE |
487 (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ?
488 RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE |
489 RCAR_CAN_EIER_OLIE, &priv->regs->eier);
490 priv->can.state = CAN_STATE_ERROR_ACTIVE;
491
492 /* Go to operation mode */
493 writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr);
494 for (i = 0; i < MAX_STR_READS; i++) {
495 if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST))
496 break;
497 }
498 /* Enable Rx and Tx FIFO */
499 writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr);
500 writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr);
501}
502
503static int rcar_can_open(struct net_device *ndev)
504{
505 struct rcar_can_priv *priv = netdev_priv(ndev);
506 int err;
507
508 err = clk_prepare_enable(priv->clk);
509 if (err) {
510 netdev_err(ndev,
511 "failed to enable peripheral clock, error %d\n",
512 err);
513 goto out;
514 }
515 err = clk_prepare_enable(priv->can_clk);
516 if (err) {
517 netdev_err(ndev, "failed to enable CAN clock, error %d\n",
518 err);
519 goto out_clock;
520 }
521 err = open_candev(ndev);
522 if (err) {
523 netdev_err(ndev, "open_candev() failed, error %d\n", err);
524 goto out_can_clock;
525 }
526 napi_enable(&priv->napi);
527 err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev);
528 if (err) {
529 netdev_err(ndev, "request_irq(%d) failed, error %d\n",
530 ndev->irq, err);
531 goto out_close;
532 }
533 can_led_event(ndev, CAN_LED_EVENT_OPEN);
534 rcar_can_start(ndev);
535 netif_start_queue(ndev);
536 return 0;
537out_close:
538 napi_disable(&priv->napi);
539 close_candev(ndev);
540out_can_clock:
541 clk_disable_unprepare(priv->can_clk);
542out_clock:
543 clk_disable_unprepare(priv->clk);
544out:
545 return err;
546}
547
548static void rcar_can_stop(struct net_device *ndev)
549{
550 struct rcar_can_priv *priv = netdev_priv(ndev);
551 u16 ctlr;
552 int i;
553
554 /* Go to (force) reset mode */
555 ctlr = readw(&priv->regs->ctlr);
556 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
557 writew(ctlr, &priv->regs->ctlr);
558 for (i = 0; i < MAX_STR_READS; i++) {
559 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
560 break;
561 }
562 writel(0, &priv->regs->mier0);
563 writel(0, &priv->regs->mier1);
564 writeb(0, &priv->regs->ier);
565 writeb(0, &priv->regs->eier);
566 /* Go to sleep mode */
567 ctlr |= RCAR_CAN_CTLR_SLPM;
568 writew(ctlr, &priv->regs->ctlr);
569 priv->can.state = CAN_STATE_STOPPED;
570}
571
572static int rcar_can_close(struct net_device *ndev)
573{
574 struct rcar_can_priv *priv = netdev_priv(ndev);
575
576 netif_stop_queue(ndev);
577 rcar_can_stop(ndev);
578 free_irq(ndev->irq, ndev);
579 napi_disable(&priv->napi);
580 clk_disable_unprepare(priv->can_clk);
581 clk_disable_unprepare(priv->clk);
582 close_candev(ndev);
583 can_led_event(ndev, CAN_LED_EVENT_STOP);
584 return 0;
585}
586
587static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
588 struct net_device *ndev)
589{
590 struct rcar_can_priv *priv = netdev_priv(ndev);
591 struct can_frame *cf = (struct can_frame *)skb->data;
592 u32 data, i;
593
594 if (can_dropped_invalid_skb(ndev, skb))
595 return NETDEV_TX_OK;
596
597 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
598 data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE;
599 else /* Standard frame format */
600 data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT;
601
602 if (cf->can_id & CAN_RTR_FLAG) { /* Remote transmission request */
603 data |= RCAR_CAN_RTR;
604 } else {
605 for (i = 0; i < cf->can_dlc; i++)
606 writeb(cf->data[i],
607 &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]);
608 }
609
610 writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id);
611
612 writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
613
614 priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->can_dlc;
615 can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH);
616 priv->tx_head++;
617 /* Start Tx: write 0xff to the TFPCR register to increment
618 * the CPU-side pointer for the transmit FIFO to the next
619 * mailbox location
620 */
621 writeb(0xff, &priv->regs->tfpcr);
622 /* Stop the queue if we've filled all FIFO entries */
623 if (priv->tx_head - priv->tx_tail >= RCAR_CAN_FIFO_DEPTH)
624 netif_stop_queue(ndev);
625
626 return NETDEV_TX_OK;
627}
628
629static const struct net_device_ops rcar_can_netdev_ops = {
630 .ndo_open = rcar_can_open,
631 .ndo_stop = rcar_can_close,
632 .ndo_start_xmit = rcar_can_start_xmit,
633 .ndo_change_mtu = can_change_mtu,
634};
635
636static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
637{
638 struct net_device_stats *stats = &priv->ndev->stats;
639 struct can_frame *cf;
640 struct sk_buff *skb;
641 u32 data;
642 u8 dlc;
643
644 skb = alloc_can_skb(priv->ndev, &cf);
645 if (!skb) {
646 stats->rx_dropped++;
647 return;
648 }
649
650 data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id);
651 if (data & RCAR_CAN_IDE)
652 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
653 else
654 cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK;
655
656 dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc);
657 cf->can_dlc = get_can_dlc(dlc);
658 if (data & RCAR_CAN_RTR) {
659 cf->can_id |= CAN_RTR_FLAG;
660 } else {
661 for (dlc = 0; dlc < cf->can_dlc; dlc++)
662 cf->data[dlc] =
663 readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
664 }
665
666 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
667
668 stats->rx_bytes += cf->can_dlc;
669 stats->rx_packets++;
670 netif_receive_skb(skb);
671}
672
673static int rcar_can_rx_poll(struct napi_struct *napi, int quota)
674{
675 struct rcar_can_priv *priv = container_of(napi,
676 struct rcar_can_priv, napi);
677 int num_pkts;
678
679 for (num_pkts = 0; num_pkts < quota; num_pkts++) {
680 u8 rfcr, isr;
681
682 isr = readb(&priv->regs->isr);
683 /* Clear interrupt bit */
684 if (isr & RCAR_CAN_ISR_RXFF)
685 writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr);
686 rfcr = readb(&priv->regs->rfcr);
687 if (rfcr & RCAR_CAN_RFCR_RFEST)
688 break;
689 rcar_can_rx_pkt(priv);
690 /* Write 0xff to the RFPCR register to increment
691 * the CPU-side pointer for the receive FIFO
692 * to the next mailbox location
693 */
694 writeb(0xff, &priv->regs->rfpcr);
695 }
696 /* All packets processed */
697 if (num_pkts < quota) {
698 napi_complete(napi);
699 priv->ier |= RCAR_CAN_IER_RXFIE;
700 writeb(priv->ier, &priv->regs->ier);
701 }
702 return num_pkts;
703}
704
705static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
706{
707 switch (mode) {
708 case CAN_MODE_START:
709 rcar_can_start(ndev);
710 netif_wake_queue(ndev);
711 return 0;
712 default:
713 return -EOPNOTSUPP;
714 }
715}
716
717static int rcar_can_get_berr_counter(const struct net_device *dev,
718 struct can_berr_counter *bec)
719{
720 struct rcar_can_priv *priv = netdev_priv(dev);
721 int err;
722
723 err = clk_prepare_enable(priv->clk);
724 if (err)
725 return err;
726 bec->txerr = readb(&priv->regs->tecr);
727 bec->rxerr = readb(&priv->regs->recr);
728 clk_disable_unprepare(priv->clk);
729 return 0;
730}
731
732static const char * const clock_names[] = {
733 [CLKR_CLKP1] = "clkp1",
734 [CLKR_CLKP2] = "clkp2",
735 [CLKR_CLKEXT] = "can_clk",
736};
737
738static int rcar_can_probe(struct platform_device *pdev)
739{
740 struct rcar_can_platform_data *pdata;
741 struct rcar_can_priv *priv;
742 struct net_device *ndev;
743 struct resource *mem;
744 void __iomem *addr;
745 u32 clock_select = CLKR_CLKP1;
746 int err = -ENODEV;
747 int irq;
748
749 if (pdev->dev.of_node) {
750 of_property_read_u32(pdev->dev.of_node,
751 "renesas,can-clock-select", &clock_select);
752 } else {
753 pdata = dev_get_platdata(&pdev->dev);
754 if (!pdata) {
755 dev_err(&pdev->dev, "No platform data provided!\n");
756 goto fail;
757 }
758 clock_select = pdata->clock_select;
759 }
760
761 irq = platform_get_irq(pdev, 0);
762 if (irq < 0) {
763 dev_err(&pdev->dev, "No IRQ resource\n");
764 err = irq;
765 goto fail;
766 }
767
768 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
769 addr = devm_ioremap_resource(&pdev->dev, mem);
770 if (IS_ERR(addr)) {
771 err = PTR_ERR(addr);
772 goto fail;
773 }
774
775 ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH);
776 if (!ndev) {
777 dev_err(&pdev->dev, "alloc_candev() failed\n");
778 err = -ENOMEM;
779 goto fail;
780 }
781
782 priv = netdev_priv(ndev);
783
784 priv->clk = devm_clk_get(&pdev->dev, "clkp1");
785 if (IS_ERR(priv->clk)) {
786 err = PTR_ERR(priv->clk);
787 dev_err(&pdev->dev, "cannot get peripheral clock, error %d\n",
788 err);
789 goto fail_clk;
790 }
791
792 if (clock_select >= ARRAY_SIZE(clock_names)) {
793 err = -EINVAL;
794 dev_err(&pdev->dev, "invalid CAN clock selected\n");
795 goto fail_clk;
796 }
797 priv->can_clk = devm_clk_get(&pdev->dev, clock_names[clock_select]);
798 if (IS_ERR(priv->can_clk)) {
799 err = PTR_ERR(priv->can_clk);
800 dev_err(&pdev->dev, "cannot get CAN clock, error %d\n", err);
801 goto fail_clk;
802 }
803
804 ndev->netdev_ops = &rcar_can_netdev_ops;
805 ndev->irq = irq;
806 ndev->flags |= IFF_ECHO;
807 priv->ndev = ndev;
808 priv->regs = addr;
809 priv->clock_select = clock_select;
810 priv->can.clock.freq = clk_get_rate(priv->can_clk);
811 priv->can.bittiming_const = &rcar_can_bittiming_const;
812 priv->can.do_set_mode = rcar_can_do_set_mode;
813 priv->can.do_get_berr_counter = rcar_can_get_berr_counter;
814 priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
815 platform_set_drvdata(pdev, ndev);
816 SET_NETDEV_DEV(ndev, &pdev->dev);
817
818 netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll,
819 RCAR_CAN_NAPI_WEIGHT);
820 err = register_candev(ndev);
821 if (err) {
822 dev_err(&pdev->dev, "register_candev() failed, error %d\n",
823 err);
824 goto fail_candev;
825 }
826
827 devm_can_led_init(ndev);
828
829 dev_info(&pdev->dev, "device registered (regs @ %p, IRQ%d)\n",
830 priv->regs, ndev->irq);
831
832 return 0;
833fail_candev:
834 netif_napi_del(&priv->napi);
835fail_clk:
836 free_candev(ndev);
837fail:
838 return err;
839}
840
841static int rcar_can_remove(struct platform_device *pdev)
842{
843 struct net_device *ndev = platform_get_drvdata(pdev);
844 struct rcar_can_priv *priv = netdev_priv(ndev);
845
846 unregister_candev(ndev);
847 netif_napi_del(&priv->napi);
848 free_candev(ndev);
849 return 0;
850}
851
852static int __maybe_unused rcar_can_suspend(struct device *dev)
853{
854 struct net_device *ndev = dev_get_drvdata(dev);
855 struct rcar_can_priv *priv = netdev_priv(ndev);
856 u16 ctlr;
857
858 if (netif_running(ndev)) {
859 netif_stop_queue(ndev);
860 netif_device_detach(ndev);
861 }
862 ctlr = readw(&priv->regs->ctlr);
863 ctlr |= RCAR_CAN_CTLR_CANM_HALT;
864 writew(ctlr, &priv->regs->ctlr);
865 ctlr |= RCAR_CAN_CTLR_SLPM;
866 writew(ctlr, &priv->regs->ctlr);
867 priv->can.state = CAN_STATE_SLEEPING;
868
869 clk_disable(priv->clk);
870 return 0;
871}
872
873static int __maybe_unused rcar_can_resume(struct device *dev)
874{
875 struct net_device *ndev = dev_get_drvdata(dev);
876 struct rcar_can_priv *priv = netdev_priv(ndev);
877 u16 ctlr;
878 int err;
879
880 err = clk_enable(priv->clk);
881 if (err) {
882 netdev_err(ndev, "clk_enable() failed, error %d\n", err);
883 return err;
884 }
885
886 ctlr = readw(&priv->regs->ctlr);
887 ctlr &= ~RCAR_CAN_CTLR_SLPM;
888 writew(ctlr, &priv->regs->ctlr);
889 ctlr &= ~RCAR_CAN_CTLR_CANM;
890 writew(ctlr, &priv->regs->ctlr);
891 priv->can.state = CAN_STATE_ERROR_ACTIVE;
892
893 if (netif_running(ndev)) {
894 netif_device_attach(ndev);
895 netif_start_queue(ndev);
896 }
897 return 0;
898}
899
900static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
901
902static const struct of_device_id rcar_can_of_table[] __maybe_unused = {
903 { .compatible = "renesas,can-r8a7778" },
904 { .compatible = "renesas,can-r8a7779" },
905 { .compatible = "renesas,can-r8a7790" },
906 { .compatible = "renesas,can-r8a7791" },
907 { .compatible = "renesas,rcar-gen1-can" },
908 { .compatible = "renesas,rcar-gen2-can" },
909 { .compatible = "renesas,rcar-gen3-can" },
910 { }
911};
912MODULE_DEVICE_TABLE(of, rcar_can_of_table);
913
914static struct platform_driver rcar_can_driver = {
915 .driver = {
916 .name = RCAR_CAN_DRV_NAME,
917 .of_match_table = of_match_ptr(rcar_can_of_table),
918 .pm = &rcar_can_pm_ops,
919 },
920 .probe = rcar_can_probe,
921 .remove = rcar_can_remove,
922};
923
924module_platform_driver(rcar_can_driver);
925
926MODULE_AUTHOR("Cogent Embedded, Inc.");
927MODULE_LICENSE("GPL");
928MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC");
929MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);