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authorSergei Shtylyov <sergei.shtylyov@cogentembedded.com>2014-05-16 16:03:54 -0400
committerMarc Kleine-Budde <mkl@pengutronix.de>2014-05-19 03:38:23 -0400
commitfd1159318e55e901cf269de90163b19fd62938cb (patch)
treeb4135b3757011dc93efa5d2ccaf24efd78eee89f
parenta9c692099e2c6f85d2213be75095593311074ce1 (diff)
can: add Renesas R-Car CAN driver
Add support for the CAN controller found in Renesas R-Car SoCs. Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat
-rw-r--r--drivers/net/can/Kconfig10
-rw-r--r--drivers/net/can/Makefile1
-rw-r--r--drivers/net/can/rcar_can.c876
-rw-r--r--include/linux/can/platform/rcar_can.h17
4 files changed, 904 insertions, 0 deletions
diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index ac67afa7735c..714b18790caf 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -119,6 +119,16 @@ config CAN_GRCAN
119 endian syntheses of the cores would need some modifications on 119 endian syntheses of the cores would need some modifications on
120 the hardware level to work. 120 the hardware level to work.
121 121
122config CAN_RCAR
123 tristate "Renesas R-Car CAN controller"
124 depends on ARM
125 ---help---
126 Say Y here if you want to use CAN controller found on Renesas R-Car
127 SoCs.
128
129 To compile this driver as a module, choose M here: the module will
130 be called rcar_can.
131
122source "drivers/net/can/mscan/Kconfig" 132source "drivers/net/can/mscan/Kconfig"
123 133
124source "drivers/net/can/sja1000/Kconfig" 134source "drivers/net/can/sja1000/Kconfig"
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index c42058868b0f..90f538c73f8c 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -25,5 +25,6 @@ obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o
25obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o 25obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o
26obj-$(CONFIG_PCH_CAN) += pch_can.o 26obj-$(CONFIG_PCH_CAN) += pch_can.o
27obj-$(CONFIG_CAN_GRCAN) += grcan.o 27obj-$(CONFIG_CAN_GRCAN) += grcan.o
28obj-$(CONFIG_CAN_RCAR) += rcar_can.o
28 29
29ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG 30ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/rcar_can.c b/drivers/net/can/rcar_can.c
new file mode 100644
index 000000000000..5268d216ecfa
--- /dev/null
+++ b/drivers/net/can/rcar_can.c
@@ -0,0 +1,876 @@
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
24#define RCAR_CAN_DRV_NAME "rcar_can"
25
26/* Mailbox configuration:
27 * mailbox 60 - 63 - Rx FIFO mailboxes
28 * mailbox 56 - 59 - Tx FIFO mailboxes
29 * non-FIFO mailboxes are not used
30 */
31#define RCAR_CAN_N_MBX 64 /* Number of mailboxes in non-FIFO mode */
32#define RCAR_CAN_RX_FIFO_MBX 60 /* Mailbox - window to Rx FIFO */
33#define RCAR_CAN_TX_FIFO_MBX 56 /* Mailbox - window to Tx FIFO */
34#define RCAR_CAN_FIFO_DEPTH 4
35
36/* Mailbox registers structure */
37struct rcar_can_mbox_regs {
38 u32 id; /* IDE and RTR bits, SID and EID */
39 u8 stub; /* Not used */
40 u8 dlc; /* Data Length Code - bits [0..3] */
41 u8 data[8]; /* Data Bytes */
42 u8 tsh; /* Time Stamp Higher Byte */
43 u8 tsl; /* Time Stamp Lower Byte */
44};
45
46struct rcar_can_regs {
47 struct rcar_can_mbox_regs mb[RCAR_CAN_N_MBX]; /* Mailbox registers */
48 u32 mkr_2_9[8]; /* Mask Registers 2-9 */
49 u32 fidcr[2]; /* FIFO Received ID Compare Register */
50 u32 mkivlr1; /* Mask Invalid Register 1 */
51 u32 mier1; /* Mailbox Interrupt Enable Register 1 */
52 u32 mkr_0_1[2]; /* Mask Registers 0-1 */
53 u32 mkivlr0; /* Mask Invalid Register 0*/
54 u32 mier0; /* Mailbox Interrupt Enable Register 0 */
55 u8 pad_440[0x3c0];
56 u8 mctl[64]; /* Message Control Registers */
57 u16 ctlr; /* Control Register */
58 u16 str; /* Status register */
59 u8 bcr[3]; /* Bit Configuration Register */
60 u8 clkr; /* Clock Select Register */
61 u8 rfcr; /* Receive FIFO Control Register */
62 u8 rfpcr; /* Receive FIFO Pointer Control Register */
63 u8 tfcr; /* Transmit FIFO Control Register */
64 u8 tfpcr; /* Transmit FIFO Pointer Control Register */
65 u8 eier; /* Error Interrupt Enable Register */
66 u8 eifr; /* Error Interrupt Factor Judge Register */
67 u8 recr; /* Receive Error Count Register */
68 u8 tecr; /* Transmit Error Count Register */
69 u8 ecsr; /* Error Code Store Register */
70 u8 cssr; /* Channel Search Support Register */
71 u8 mssr; /* Mailbox Search Status Register */
72 u8 msmr; /* Mailbox Search Mode Register */
73 u16 tsr; /* Time Stamp Register */
74 u8 afsr; /* Acceptance Filter Support Register */
75 u8 pad_857;
76 u8 tcr; /* Test Control Register */
77 u8 pad_859[7];
78 u8 ier; /* Interrupt Enable Register */
79 u8 isr; /* Interrupt Status Register */
80 u8 pad_862;
81 u8 mbsmr; /* Mailbox Search Mask Register */
82};
83
84struct rcar_can_priv {
85 struct can_priv can; /* Must be the first member! */
86 struct net_device *ndev;
87 struct napi_struct napi;
88 struct rcar_can_regs __iomem *regs;
89 struct clk *clk;
90 u8 tx_dlc[RCAR_CAN_FIFO_DEPTH];
91 u32 tx_head;
92 u32 tx_tail;
93 u8 clock_select;
94 u8 ier;
95};
96
97static const struct can_bittiming_const rcar_can_bittiming_const = {
98 .name = RCAR_CAN_DRV_NAME,
99 .tseg1_min = 4,
100 .tseg1_max = 16,
101 .tseg2_min = 2,
102 .tseg2_max = 8,
103 .sjw_max = 4,
104 .brp_min = 1,
105 .brp_max = 1024,
106 .brp_inc = 1,
107};
108
109/* Control Register bits */
110#define RCAR_CAN_CTLR_BOM (3 << 11) /* Bus-Off Recovery Mode Bits */
111#define RCAR_CAN_CTLR_BOM_ENT (1 << 11) /* Entry to halt mode */
112 /* at bus-off entry */
113#define RCAR_CAN_CTLR_SLPM (1 << 10)
114#define RCAR_CAN_CTLR_CANM (3 << 8) /* Operating Mode Select Bit */
115#define RCAR_CAN_CTLR_CANM_HALT (1 << 9)
116#define RCAR_CAN_CTLR_CANM_RESET (1 << 8)
117#define RCAR_CAN_CTLR_CANM_FORCE_RESET (3 << 8)
118#define RCAR_CAN_CTLR_MLM (1 << 3) /* Message Lost Mode Select */
119#define RCAR_CAN_CTLR_IDFM (3 << 1) /* ID Format Mode Select Bits */
120#define RCAR_CAN_CTLR_IDFM_MIXED (1 << 2) /* Mixed ID mode */
121#define RCAR_CAN_CTLR_MBM (1 << 0) /* Mailbox Mode select */
122
123/* Status Register bits */
124#define RCAR_CAN_STR_RSTST (1 << 8) /* Reset Status Bit */
125
126/* FIFO Received ID Compare Registers 0 and 1 bits */
127#define RCAR_CAN_FIDCR_IDE (1 << 31) /* ID Extension Bit */
128#define RCAR_CAN_FIDCR_RTR (1 << 30) /* Remote Transmission Request Bit */
129
130/* Receive FIFO Control Register bits */
131#define RCAR_CAN_RFCR_RFEST (1 << 7) /* Receive FIFO Empty Status Flag */
132#define RCAR_CAN_RFCR_RFE (1 << 0) /* Receive FIFO Enable */
133
134/* Transmit FIFO Control Register bits */
135#define RCAR_CAN_TFCR_TFUST (7 << 1) /* Transmit FIFO Unsent Message */
136 /* Number Status Bits */
137#define RCAR_CAN_TFCR_TFUST_SHIFT 1 /* Offset of Transmit FIFO Unsent */
138 /* Message Number Status Bits */
139#define RCAR_CAN_TFCR_TFE (1 << 0) /* Transmit FIFO Enable */
140
141#define RCAR_CAN_N_RX_MKREGS1 2 /* Number of mask registers */
142 /* for Rx mailboxes 0-31 */
143#define RCAR_CAN_N_RX_MKREGS2 8
144
145/* Bit Configuration Register settings */
146#define RCAR_CAN_BCR_TSEG1(x) (((x) & 0x0f) << 20)
147#define RCAR_CAN_BCR_BPR(x) (((x) & 0x3ff) << 8)
148#define RCAR_CAN_BCR_SJW(x) (((x) & 0x3) << 4)
149#define RCAR_CAN_BCR_TSEG2(x) ((x) & 0x07)
150
151/* Mailbox and Mask Registers bits */
152#define RCAR_CAN_IDE (1 << 31)
153#define RCAR_CAN_RTR (1 << 30)
154#define RCAR_CAN_SID_SHIFT 18
155
156/* Mailbox Interrupt Enable Register 1 bits */
157#define RCAR_CAN_MIER1_RXFIE (1 << 28) /* Receive FIFO Interrupt Enable */
158#define RCAR_CAN_MIER1_TXFIE (1 << 24) /* Transmit FIFO Interrupt Enable */
159
160/* Interrupt Enable Register bits */
161#define RCAR_CAN_IER_ERSIE (1 << 5) /* Error (ERS) Interrupt Enable Bit */
162#define RCAR_CAN_IER_RXFIE (1 << 4) /* Reception FIFO Interrupt */
163 /* Enable Bit */
164#define RCAR_CAN_IER_TXFIE (1 << 3) /* Transmission FIFO Interrupt */
165 /* Enable Bit */
166/* Interrupt Status Register bits */
167#define RCAR_CAN_ISR_ERSF (1 << 5) /* Error (ERS) Interrupt Status Bit */
168#define RCAR_CAN_ISR_RXFF (1 << 4) /* Reception FIFO Interrupt */
169 /* Status Bit */
170#define RCAR_CAN_ISR_TXFF (1 << 3) /* Transmission FIFO Interrupt */
171 /* Status Bit */
172
173/* Error Interrupt Enable Register bits */
174#define RCAR_CAN_EIER_BLIE (1 << 7) /* Bus Lock Interrupt Enable */
175#define RCAR_CAN_EIER_OLIE (1 << 6) /* Overload Frame Transmit */
176 /* Interrupt Enable */
177#define RCAR_CAN_EIER_ORIE (1 << 5) /* Receive Overrun Interrupt Enable */
178#define RCAR_CAN_EIER_BORIE (1 << 4) /* Bus-Off Recovery Interrupt Enable */
179#define RCAR_CAN_EIER_BOEIE (1 << 3) /* Bus-Off Entry Interrupt Enable */
180#define RCAR_CAN_EIER_EPIE (1 << 2) /* Error Passive Interrupt Enable */
181#define RCAR_CAN_EIER_EWIE (1 << 1) /* Error Warning Interrupt Enable */
182#define RCAR_CAN_EIER_BEIE (1 << 0) /* Bus Error Interrupt Enable */
183
184/* Error Interrupt Factor Judge Register bits */
185#define RCAR_CAN_EIFR_BLIF (1 << 7) /* Bus Lock Detect Flag */
186#define RCAR_CAN_EIFR_OLIF (1 << 6) /* Overload Frame Transmission */
187 /* Detect Flag */
188#define RCAR_CAN_EIFR_ORIF (1 << 5) /* Receive Overrun Detect Flag */
189#define RCAR_CAN_EIFR_BORIF (1 << 4) /* Bus-Off Recovery Detect Flag */
190#define RCAR_CAN_EIFR_BOEIF (1 << 3) /* Bus-Off Entry Detect Flag */
191#define RCAR_CAN_EIFR_EPIF (1 << 2) /* Error Passive Detect Flag */
192#define RCAR_CAN_EIFR_EWIF (1 << 1) /* Error Warning Detect Flag */
193#define RCAR_CAN_EIFR_BEIF (1 << 0) /* Bus Error Detect Flag */
194
195/* Error Code Store Register bits */
196#define RCAR_CAN_ECSR_EDPM (1 << 7) /* Error Display Mode Select Bit */
197#define RCAR_CAN_ECSR_ADEF (1 << 6) /* ACK Delimiter Error Flag */
198#define RCAR_CAN_ECSR_BE0F (1 << 5) /* Bit Error (dominant) Flag */
199#define RCAR_CAN_ECSR_BE1F (1 << 4) /* Bit Error (recessive) Flag */
200#define RCAR_CAN_ECSR_CEF (1 << 3) /* CRC Error Flag */
201#define RCAR_CAN_ECSR_AEF (1 << 2) /* ACK Error Flag */
202#define RCAR_CAN_ECSR_FEF (1 << 1) /* Form Error Flag */
203#define RCAR_CAN_ECSR_SEF (1 << 0) /* Stuff Error Flag */
204
205#define RCAR_CAN_NAPI_WEIGHT 4
206#define MAX_STR_READS 0x100
207
208static void tx_failure_cleanup(struct net_device *ndev)
209{
210 int i;
211
212 for (i = 0; i < RCAR_CAN_FIFO_DEPTH; i++)
213 can_free_echo_skb(ndev, i);
214}
215
216static void rcar_can_error(struct net_device *ndev)
217{
218 struct rcar_can_priv *priv = netdev_priv(ndev);
219 struct net_device_stats *stats = &ndev->stats;
220 struct can_frame *cf;
221 struct sk_buff *skb;
222 u8 eifr, txerr = 0, rxerr = 0;
223
224 /* Propagate the error condition to the CAN stack */
225 skb = alloc_can_err_skb(ndev, &cf);
226
227 eifr = readb(&priv->regs->eifr);
228 if (eifr & (RCAR_CAN_EIFR_EWIF | RCAR_CAN_EIFR_EPIF)) {
229 txerr = readb(&priv->regs->tecr);
230 rxerr = readb(&priv->regs->recr);
231 if (skb) {
232 cf->can_id |= CAN_ERR_CRTL;
233 cf->data[6] = txerr;
234 cf->data[7] = rxerr;
235 }
236 }
237 if (eifr & RCAR_CAN_EIFR_BEIF) {
238 int rx_errors = 0, tx_errors = 0;
239 u8 ecsr;
240
241 netdev_dbg(priv->ndev, "Bus error interrupt:\n");
242 if (skb) {
243 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT;
244 cf->data[2] = CAN_ERR_PROT_UNSPEC;
245 }
246 ecsr = readb(&priv->regs->ecsr);
247 if (ecsr & RCAR_CAN_ECSR_ADEF) {
248 netdev_dbg(priv->ndev, "ACK Delimiter Error\n");
249 tx_errors++;
250 writeb(~RCAR_CAN_ECSR_ADEF, &priv->regs->ecsr);
251 if (skb)
252 cf->data[3] |= CAN_ERR_PROT_LOC_ACK_DEL;
253 }
254 if (ecsr & RCAR_CAN_ECSR_BE0F) {
255 netdev_dbg(priv->ndev, "Bit Error (dominant)\n");
256 tx_errors++;
257 writeb(~RCAR_CAN_ECSR_BE0F, &priv->regs->ecsr);
258 if (skb)
259 cf->data[2] |= CAN_ERR_PROT_BIT0;
260 }
261 if (ecsr & RCAR_CAN_ECSR_BE1F) {
262 netdev_dbg(priv->ndev, "Bit Error (recessive)\n");
263 tx_errors++;
264 writeb(~RCAR_CAN_ECSR_BE1F, &priv->regs->ecsr);
265 if (skb)
266 cf->data[2] |= CAN_ERR_PROT_BIT1;
267 }
268 if (ecsr & RCAR_CAN_ECSR_CEF) {
269 netdev_dbg(priv->ndev, "CRC Error\n");
270 rx_errors++;
271 writeb(~RCAR_CAN_ECSR_CEF, &priv->regs->ecsr);
272 if (skb)
273 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
274 }
275 if (ecsr & RCAR_CAN_ECSR_AEF) {
276 netdev_dbg(priv->ndev, "ACK Error\n");
277 tx_errors++;
278 writeb(~RCAR_CAN_ECSR_AEF, &priv->regs->ecsr);
279 if (skb) {
280 cf->can_id |= CAN_ERR_ACK;
281 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
282 }
283 }
284 if (ecsr & RCAR_CAN_ECSR_FEF) {
285 netdev_dbg(priv->ndev, "Form Error\n");
286 rx_errors++;
287 writeb(~RCAR_CAN_ECSR_FEF, &priv->regs->ecsr);
288 if (skb)
289 cf->data[2] |= CAN_ERR_PROT_FORM;
290 }
291 if (ecsr & RCAR_CAN_ECSR_SEF) {
292 netdev_dbg(priv->ndev, "Stuff Error\n");
293 rx_errors++;
294 writeb(~RCAR_CAN_ECSR_SEF, &priv->regs->ecsr);
295 if (skb)
296 cf->data[2] |= CAN_ERR_PROT_STUFF;
297 }
298
299 priv->can.can_stats.bus_error++;
300 ndev->stats.rx_errors += rx_errors;
301 ndev->stats.tx_errors += tx_errors;
302 writeb(~RCAR_CAN_EIFR_BEIF, &priv->regs->eifr);
303 }
304 if (eifr & RCAR_CAN_EIFR_EWIF) {
305 netdev_dbg(priv->ndev, "Error warning interrupt\n");
306 priv->can.state = CAN_STATE_ERROR_WARNING;
307 priv->can.can_stats.error_warning++;
308 /* Clear interrupt condition */
309 writeb(~RCAR_CAN_EIFR_EWIF, &priv->regs->eifr);
310 if (skb)
311 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_WARNING :
312 CAN_ERR_CRTL_RX_WARNING;
313 }
314 if (eifr & RCAR_CAN_EIFR_EPIF) {
315 netdev_dbg(priv->ndev, "Error passive interrupt\n");
316 priv->can.state = CAN_STATE_ERROR_PASSIVE;
317 priv->can.can_stats.error_passive++;
318 /* Clear interrupt condition */
319 writeb(~RCAR_CAN_EIFR_EPIF, &priv->regs->eifr);
320 if (skb)
321 cf->data[1] = txerr > rxerr ? CAN_ERR_CRTL_TX_PASSIVE :
322 CAN_ERR_CRTL_RX_PASSIVE;
323 }
324 if (eifr & RCAR_CAN_EIFR_BOEIF) {
325 netdev_dbg(priv->ndev, "Bus-off entry interrupt\n");
326 tx_failure_cleanup(ndev);
327 priv->ier = RCAR_CAN_IER_ERSIE;
328 writeb(priv->ier, &priv->regs->ier);
329 priv->can.state = CAN_STATE_BUS_OFF;
330 /* Clear interrupt condition */
331 writeb(~RCAR_CAN_EIFR_BOEIF, &priv->regs->eifr);
332 can_bus_off(ndev);
333 if (skb)
334 cf->can_id |= CAN_ERR_BUSOFF;
335 }
336 if (eifr & RCAR_CAN_EIFR_ORIF) {
337 netdev_dbg(priv->ndev, "Receive overrun error interrupt\n");
338 ndev->stats.rx_over_errors++;
339 ndev->stats.rx_errors++;
340 writeb(~RCAR_CAN_EIFR_ORIF, &priv->regs->eifr);
341 if (skb) {
342 cf->can_id |= CAN_ERR_CRTL;
343 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
344 }
345 }
346 if (eifr & RCAR_CAN_EIFR_OLIF) {
347 netdev_dbg(priv->ndev,
348 "Overload Frame Transmission error interrupt\n");
349 ndev->stats.rx_over_errors++;
350 ndev->stats.rx_errors++;
351 writeb(~RCAR_CAN_EIFR_OLIF, &priv->regs->eifr);
352 if (skb) {
353 cf->can_id |= CAN_ERR_PROT;
354 cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
355 }
356 }
357
358 if (skb) {
359 stats->rx_packets++;
360 stats->rx_bytes += cf->can_dlc;
361 netif_rx(skb);
362 }
363}
364
365static void rcar_can_tx_done(struct net_device *ndev)
366{
367 struct rcar_can_priv *priv = netdev_priv(ndev);
368 struct net_device_stats *stats = &ndev->stats;
369 u8 isr;
370
371 while (1) {
372 u8 unsent = readb(&priv->regs->tfcr);
373
374 unsent = (unsent & RCAR_CAN_TFCR_TFUST) >>
375 RCAR_CAN_TFCR_TFUST_SHIFT;
376 if (priv->tx_head - priv->tx_tail <= unsent)
377 break;
378 stats->tx_packets++;
379 stats->tx_bytes += priv->tx_dlc[priv->tx_tail %
380 RCAR_CAN_FIFO_DEPTH];
381 priv->tx_dlc[priv->tx_tail % RCAR_CAN_FIFO_DEPTH] = 0;
382 can_get_echo_skb(ndev, priv->tx_tail % RCAR_CAN_FIFO_DEPTH);
383 priv->tx_tail++;
384 netif_wake_queue(ndev);
385 }
386 /* Clear interrupt */
387 isr = readb(&priv->regs->isr);
388 writeb(isr & ~RCAR_CAN_ISR_TXFF, &priv->regs->isr);
389 can_led_event(ndev, CAN_LED_EVENT_TX);
390}
391
392static irqreturn_t rcar_can_interrupt(int irq, void *dev_id)
393{
394 struct net_device *ndev = dev_id;
395 struct rcar_can_priv *priv = netdev_priv(ndev);
396 u8 isr;
397
398 isr = readb(&priv->regs->isr);
399 if (!(isr & priv->ier))
400 return IRQ_NONE;
401
402 if (isr & RCAR_CAN_ISR_ERSF)
403 rcar_can_error(ndev);
404
405 if (isr & RCAR_CAN_ISR_TXFF)
406 rcar_can_tx_done(ndev);
407
408 if (isr & RCAR_CAN_ISR_RXFF) {
409 if (napi_schedule_prep(&priv->napi)) {
410 /* Disable Rx FIFO interrupts */
411 priv->ier &= ~RCAR_CAN_IER_RXFIE;
412 writeb(priv->ier, &priv->regs->ier);
413 __napi_schedule(&priv->napi);
414 }
415 }
416
417 return IRQ_HANDLED;
418}
419
420static void rcar_can_set_bittiming(struct net_device *dev)
421{
422 struct rcar_can_priv *priv = netdev_priv(dev);
423 struct can_bittiming *bt = &priv->can.bittiming;
424 u32 bcr;
425
426 bcr = RCAR_CAN_BCR_TSEG1(bt->phase_seg1 + bt->prop_seg - 1) |
427 RCAR_CAN_BCR_BPR(bt->brp - 1) | RCAR_CAN_BCR_SJW(bt->sjw - 1) |
428 RCAR_CAN_BCR_TSEG2(bt->phase_seg2 - 1);
429 /* Don't overwrite CLKR with 32-bit BCR access; CLKR has 8-bit access.
430 * All the registers are big-endian but they get byte-swapped on 32-bit
431 * read/write (but not on 8-bit, contrary to the manuals)...
432 */
433 writel((bcr << 8) | priv->clock_select, &priv->regs->bcr);
434}
435
436static void rcar_can_start(struct net_device *ndev)
437{
438 struct rcar_can_priv *priv = netdev_priv(ndev);
439 u16 ctlr;
440 int i;
441
442 /* Set controller to known mode:
443 * - FIFO mailbox mode
444 * - accept all messages
445 * - overrun mode
446 * CAN is in sleep mode after MCU hardware or software reset.
447 */
448 ctlr = readw(&priv->regs->ctlr);
449 ctlr &= ~RCAR_CAN_CTLR_SLPM;
450 writew(ctlr, &priv->regs->ctlr);
451 /* Go to reset mode */
452 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
453 writew(ctlr, &priv->regs->ctlr);
454 for (i = 0; i < MAX_STR_READS; i++) {
455 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
456 break;
457 }
458 rcar_can_set_bittiming(ndev);
459 ctlr |= RCAR_CAN_CTLR_IDFM_MIXED; /* Select mixed ID mode */
460 ctlr |= RCAR_CAN_CTLR_BOM_ENT; /* Entry to halt mode automatically */
461 /* at bus-off */
462 ctlr |= RCAR_CAN_CTLR_MBM; /* Select FIFO mailbox mode */
463 ctlr |= RCAR_CAN_CTLR_MLM; /* Overrun mode */
464 writew(ctlr, &priv->regs->ctlr);
465
466 /* Accept all SID and EID */
467 writel(0, &priv->regs->mkr_2_9[6]);
468 writel(0, &priv->regs->mkr_2_9[7]);
469 /* In FIFO mailbox mode, write "0" to bits 24 to 31 */
470 writel(0, &priv->regs->mkivlr1);
471 /* Accept all frames */
472 writel(0, &priv->regs->fidcr[0]);
473 writel(RCAR_CAN_FIDCR_IDE | RCAR_CAN_FIDCR_RTR, &priv->regs->fidcr[1]);
474 /* Enable and configure FIFO mailbox interrupts */
475 writel(RCAR_CAN_MIER1_RXFIE | RCAR_CAN_MIER1_TXFIE, &priv->regs->mier1);
476
477 priv->ier = RCAR_CAN_IER_ERSIE | RCAR_CAN_IER_RXFIE |
478 RCAR_CAN_IER_TXFIE;
479 writeb(priv->ier, &priv->regs->ier);
480
481 /* Accumulate error codes */
482 writeb(RCAR_CAN_ECSR_EDPM, &priv->regs->ecsr);
483 /* Enable error interrupts */
484 writeb(RCAR_CAN_EIER_EWIE | RCAR_CAN_EIER_EPIE | RCAR_CAN_EIER_BOEIE |
485 (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING ?
486 RCAR_CAN_EIER_BEIE : 0) | RCAR_CAN_EIER_ORIE |
487 RCAR_CAN_EIER_OLIE, &priv->regs->eier);
488 priv->can.state = CAN_STATE_ERROR_ACTIVE;
489
490 /* Go to operation mode */
491 writew(ctlr & ~RCAR_CAN_CTLR_CANM, &priv->regs->ctlr);
492 for (i = 0; i < MAX_STR_READS; i++) {
493 if (!(readw(&priv->regs->str) & RCAR_CAN_STR_RSTST))
494 break;
495 }
496 /* Enable Rx and Tx FIFO */
497 writeb(RCAR_CAN_RFCR_RFE, &priv->regs->rfcr);
498 writeb(RCAR_CAN_TFCR_TFE, &priv->regs->tfcr);
499}
500
501static int rcar_can_open(struct net_device *ndev)
502{
503 struct rcar_can_priv *priv = netdev_priv(ndev);
504 int err;
505
506 err = clk_prepare_enable(priv->clk);
507 if (err) {
508 netdev_err(ndev, "clk_prepare_enable() failed, error %d\n",
509 err);
510 goto out;
511 }
512 err = open_candev(ndev);
513 if (err) {
514 netdev_err(ndev, "open_candev() failed, error %d\n", err);
515 goto out_clock;
516 }
517 napi_enable(&priv->napi);
518 err = request_irq(ndev->irq, rcar_can_interrupt, 0, ndev->name, ndev);
519 if (err) {
520 netdev_err(ndev, "error requesting interrupt %x\n", ndev->irq);
521 goto out_close;
522 }
523 can_led_event(ndev, CAN_LED_EVENT_OPEN);
524 rcar_can_start(ndev);
525 netif_start_queue(ndev);
526 return 0;
527out_close:
528 napi_disable(&priv->napi);
529 close_candev(ndev);
530out_clock:
531 clk_disable_unprepare(priv->clk);
532out:
533 return err;
534}
535
536static void rcar_can_stop(struct net_device *ndev)
537{
538 struct rcar_can_priv *priv = netdev_priv(ndev);
539 u16 ctlr;
540 int i;
541
542 /* Go to (force) reset mode */
543 ctlr = readw(&priv->regs->ctlr);
544 ctlr |= RCAR_CAN_CTLR_CANM_FORCE_RESET;
545 writew(ctlr, &priv->regs->ctlr);
546 for (i = 0; i < MAX_STR_READS; i++) {
547 if (readw(&priv->regs->str) & RCAR_CAN_STR_RSTST)
548 break;
549 }
550 writel(0, &priv->regs->mier0);
551 writel(0, &priv->regs->mier1);
552 writeb(0, &priv->regs->ier);
553 writeb(0, &priv->regs->eier);
554 /* Go to sleep mode */
555 ctlr |= RCAR_CAN_CTLR_SLPM;
556 writew(ctlr, &priv->regs->ctlr);
557 priv->can.state = CAN_STATE_STOPPED;
558}
559
560static int rcar_can_close(struct net_device *ndev)
561{
562 struct rcar_can_priv *priv = netdev_priv(ndev);
563
564 netif_stop_queue(ndev);
565 rcar_can_stop(ndev);
566 free_irq(ndev->irq, ndev);
567 napi_disable(&priv->napi);
568 clk_disable_unprepare(priv->clk);
569 close_candev(ndev);
570 can_led_event(ndev, CAN_LED_EVENT_STOP);
571 return 0;
572}
573
574static netdev_tx_t rcar_can_start_xmit(struct sk_buff *skb,
575 struct net_device *ndev)
576{
577 struct rcar_can_priv *priv = netdev_priv(ndev);
578 struct can_frame *cf = (struct can_frame *)skb->data;
579 u32 data, i;
580
581 if (can_dropped_invalid_skb(ndev, skb))
582 return NETDEV_TX_OK;
583
584 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */
585 data = (cf->can_id & CAN_EFF_MASK) | RCAR_CAN_IDE;
586 else /* Standard frame format */
587 data = (cf->can_id & CAN_SFF_MASK) << RCAR_CAN_SID_SHIFT;
588
589 if (cf->can_id & CAN_RTR_FLAG) { /* Remote transmission request */
590 data |= RCAR_CAN_RTR;
591 } else {
592 for (i = 0; i < cf->can_dlc; i++)
593 writeb(cf->data[i],
594 &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].data[i]);
595 }
596
597 writel(data, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].id);
598
599 writeb(cf->can_dlc, &priv->regs->mb[RCAR_CAN_TX_FIFO_MBX].dlc);
600
601 priv->tx_dlc[priv->tx_head % RCAR_CAN_FIFO_DEPTH] = cf->can_dlc;
602 can_put_echo_skb(skb, ndev, priv->tx_head % RCAR_CAN_FIFO_DEPTH);
603 priv->tx_head++;
604 /* Start Tx: write 0xff to the TFPCR register to increment
605 * the CPU-side pointer for the transmit FIFO to the next
606 * mailbox location
607 */
608 writeb(0xff, &priv->regs->tfpcr);
609 /* Stop the queue if we've filled all FIFO entries */
610 if (priv->tx_head - priv->tx_tail >= RCAR_CAN_FIFO_DEPTH)
611 netif_stop_queue(ndev);
612
613 return NETDEV_TX_OK;
614}
615
616static const struct net_device_ops rcar_can_netdev_ops = {
617 .ndo_open = rcar_can_open,
618 .ndo_stop = rcar_can_close,
619 .ndo_start_xmit = rcar_can_start_xmit,
620};
621
622static void rcar_can_rx_pkt(struct rcar_can_priv *priv)
623{
624 struct net_device_stats *stats = &priv->ndev->stats;
625 struct can_frame *cf;
626 struct sk_buff *skb;
627 u32 data;
628 u8 dlc;
629
630 skb = alloc_can_skb(priv->ndev, &cf);
631 if (!skb) {
632 stats->rx_dropped++;
633 return;
634 }
635
636 data = readl(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].id);
637 if (data & RCAR_CAN_IDE)
638 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG;
639 else
640 cf->can_id = (data >> RCAR_CAN_SID_SHIFT) & CAN_SFF_MASK;
641
642 dlc = readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].dlc);
643 cf->can_dlc = get_can_dlc(dlc);
644 if (data & RCAR_CAN_RTR) {
645 cf->can_id |= CAN_RTR_FLAG;
646 } else {
647 for (dlc = 0; dlc < cf->can_dlc; dlc++)
648 cf->data[dlc] =
649 readb(&priv->regs->mb[RCAR_CAN_RX_FIFO_MBX].data[dlc]);
650 }
651
652 can_led_event(priv->ndev, CAN_LED_EVENT_RX);
653
654 stats->rx_bytes += cf->can_dlc;
655 stats->rx_packets++;
656 netif_receive_skb(skb);
657}
658
659static int rcar_can_rx_poll(struct napi_struct *napi, int quota)
660{
661 struct rcar_can_priv *priv = container_of(napi,
662 struct rcar_can_priv, napi);
663 int num_pkts;
664
665 for (num_pkts = 0; num_pkts < quota; num_pkts++) {
666 u8 rfcr, isr;
667
668 isr = readb(&priv->regs->isr);
669 /* Clear interrupt bit */
670 if (isr & RCAR_CAN_ISR_RXFF)
671 writeb(isr & ~RCAR_CAN_ISR_RXFF, &priv->regs->isr);
672 rfcr = readb(&priv->regs->rfcr);
673 if (rfcr & RCAR_CAN_RFCR_RFEST)
674 break;
675 rcar_can_rx_pkt(priv);
676 /* Write 0xff to the RFPCR register to increment
677 * the CPU-side pointer for the receive FIFO
678 * to the next mailbox location
679 */
680 writeb(0xff, &priv->regs->rfpcr);
681 }
682 /* All packets processed */
683 if (num_pkts < quota) {
684 napi_complete(napi);
685 priv->ier |= RCAR_CAN_IER_RXFIE;
686 writeb(priv->ier, &priv->regs->ier);
687 }
688 return num_pkts;
689}
690
691static int rcar_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
692{
693 switch (mode) {
694 case CAN_MODE_START:
695 rcar_can_start(ndev);
696 netif_wake_queue(ndev);
697 return 0;
698 default:
699 return -EOPNOTSUPP;
700 }
701}
702
703static int rcar_can_get_berr_counter(const struct net_device *dev,
704 struct can_berr_counter *bec)
705{
706 struct rcar_can_priv *priv = netdev_priv(dev);
707 int err;
708
709 err = clk_prepare_enable(priv->clk);
710 if (err)
711 return err;
712 bec->txerr = readb(&priv->regs->tecr);
713 bec->rxerr = readb(&priv->regs->recr);
714 clk_disable_unprepare(priv->clk);
715 return 0;
716}
717
718static int rcar_can_probe(struct platform_device *pdev)
719{
720 struct rcar_can_platform_data *pdata;
721 struct rcar_can_priv *priv;
722 struct net_device *ndev;
723 struct resource *mem;
724 void __iomem *addr;
725 int err = -ENODEV;
726 int irq;
727
728 pdata = dev_get_platdata(&pdev->dev);
729 if (!pdata) {
730 dev_err(&pdev->dev, "No platform data provided!\n");
731 goto fail;
732 }
733
734 irq = platform_get_irq(pdev, 0);
735 if (!irq) {
736 dev_err(&pdev->dev, "No IRQ resource\n");
737 goto fail;
738 }
739
740 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
741 addr = devm_ioremap_resource(&pdev->dev, mem);
742 if (IS_ERR(addr)) {
743 err = PTR_ERR(addr);
744 goto fail;
745 }
746
747 ndev = alloc_candev(sizeof(struct rcar_can_priv), RCAR_CAN_FIFO_DEPTH);
748 if (!ndev) {
749 dev_err(&pdev->dev, "alloc_candev() failed\n");
750 err = -ENOMEM;
751 goto fail;
752 }
753
754 priv = netdev_priv(ndev);
755
756 priv->clk = devm_clk_get(&pdev->dev, NULL);
757 if (IS_ERR(priv->clk)) {
758 err = PTR_ERR(priv->clk);
759 dev_err(&pdev->dev, "cannot get clock: %d\n", err);
760 goto fail_clk;
761 }
762
763 ndev->netdev_ops = &rcar_can_netdev_ops;
764 ndev->irq = irq;
765 ndev->flags |= IFF_ECHO;
766 priv->ndev = ndev;
767 priv->regs = addr;
768 priv->clock_select = pdata->clock_select;
769 priv->can.clock.freq = clk_get_rate(priv->clk);
770 priv->can.bittiming_const = &rcar_can_bittiming_const;
771 priv->can.do_set_mode = rcar_can_do_set_mode;
772 priv->can.do_get_berr_counter = rcar_can_get_berr_counter;
773 priv->can.ctrlmode_supported = CAN_CTRLMODE_BERR_REPORTING;
774 platform_set_drvdata(pdev, ndev);
775 SET_NETDEV_DEV(ndev, &pdev->dev);
776
777 netif_napi_add(ndev, &priv->napi, rcar_can_rx_poll,
778 RCAR_CAN_NAPI_WEIGHT);
779 err = register_candev(ndev);
780 if (err) {
781 dev_err(&pdev->dev, "register_candev() failed, error %d\n",
782 err);
783 goto fail_candev;
784 }
785
786 devm_can_led_init(ndev);
787
788 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n",
789 priv->regs, ndev->irq);
790
791 return 0;
792fail_candev:
793 netif_napi_del(&priv->napi);
794fail_clk:
795 free_candev(ndev);
796fail:
797 return err;
798}
799
800static int rcar_can_remove(struct platform_device *pdev)
801{
802 struct net_device *ndev = platform_get_drvdata(pdev);
803 struct rcar_can_priv *priv = netdev_priv(ndev);
804
805 unregister_candev(ndev);
806 netif_napi_del(&priv->napi);
807 free_candev(ndev);
808 return 0;
809}
810
811static int __maybe_unused rcar_can_suspend(struct device *dev)
812{
813 struct net_device *ndev = dev_get_drvdata(dev);
814 struct rcar_can_priv *priv = netdev_priv(ndev);
815 u16 ctlr;
816
817 if (netif_running(ndev)) {
818 netif_stop_queue(ndev);
819 netif_device_detach(ndev);
820 }
821 ctlr = readw(&priv->regs->ctlr);
822 ctlr |= RCAR_CAN_CTLR_CANM_HALT;
823 writew(ctlr, &priv->regs->ctlr);
824 ctlr |= RCAR_CAN_CTLR_SLPM;
825 writew(ctlr, &priv->regs->ctlr);
826 priv->can.state = CAN_STATE_SLEEPING;
827
828 clk_disable(priv->clk);
829 return 0;
830}
831
832static int __maybe_unused rcar_can_resume(struct device *dev)
833{
834 struct net_device *ndev = dev_get_drvdata(dev);
835 struct rcar_can_priv *priv = netdev_priv(ndev);
836 u16 ctlr;
837 int err;
838
839 err = clk_enable(priv->clk);
840 if (err) {
841 netdev_err(ndev, "clk_enable() failed, error %d\n", err);
842 return err;
843 }
844
845 ctlr = readw(&priv->regs->ctlr);
846 ctlr &= ~RCAR_CAN_CTLR_SLPM;
847 writew(ctlr, &priv->regs->ctlr);
848 ctlr &= ~RCAR_CAN_CTLR_CANM;
849 writew(ctlr, &priv->regs->ctlr);
850 priv->can.state = CAN_STATE_ERROR_ACTIVE;
851
852 if (netif_running(ndev)) {
853 netif_device_attach(ndev);
854 netif_start_queue(ndev);
855 }
856 return 0;
857}
858
859static SIMPLE_DEV_PM_OPS(rcar_can_pm_ops, rcar_can_suspend, rcar_can_resume);
860
861static struct platform_driver rcar_can_driver = {
862 .driver = {
863 .name = RCAR_CAN_DRV_NAME,
864 .owner = THIS_MODULE,
865 .pm = &rcar_can_pm_ops,
866 },
867 .probe = rcar_can_probe,
868 .remove = rcar_can_remove,
869};
870
871module_platform_driver(rcar_can_driver);
872
873MODULE_AUTHOR("Cogent Embedded, Inc.");
874MODULE_LICENSE("GPL");
875MODULE_DESCRIPTION("CAN driver for Renesas R-Car SoC");
876MODULE_ALIAS("platform:" RCAR_CAN_DRV_NAME);
diff --git a/include/linux/can/platform/rcar_can.h b/include/linux/can/platform/rcar_can.h
new file mode 100644
index 000000000000..0f4a2f3df504
--- /dev/null
+++ b/include/linux/can/platform/rcar_can.h
@@ -0,0 +1,17 @@
1#ifndef _CAN_PLATFORM_RCAR_CAN_H_
2#define _CAN_PLATFORM_RCAR_CAN_H_
3
4#include <linux/types.h>
5
6/* Clock Select Register settings */
7enum CLKR {
8 CLKR_CLKP1 = 0, /* Peripheral clock (clkp1) */
9 CLKR_CLKP2 = 1, /* Peripheral clock (clkp2) */
10 CLKR_CLKEXT = 3 /* Externally input clock */
11};
12
13struct rcar_can_platform_data {
14 enum CLKR clock_select; /* Clock source select */
15};
16
17#endif /* !_CAN_PLATFORM_RCAR_CAN_H_ */
generated by cgit v1.2.2 (git 2.25.0) at 2025-01-18 02:27:48 -0500