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authorMarc Kleine-Budde <mkl@pengutronix.de>2009-07-29 04:20:10 -0400
committerMarc Kleine-Budde <mkl@pengutronix.de>2010-07-22 12:06:25 -0400
commite955cead031177b083fbf18d04a03c06e330a439 (patch)
treef0507320407f63913a806eabe7230760e6b661ab /drivers/net/can
parent4cfa580e7eebb8694b875d2caff3b989ada2efac (diff)
CAN: Add Flexcan CAN controller driver
This core is found on some Freescale SoCs and also some Coldfire SoCs. Support for Coldfire is missing though at the moment as they have an older revision of the core which does not have RX FIFO support. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/Kconfig9
-rw-r--r--drivers/net/can/Makefile1
-rw-r--r--drivers/net/can/flexcan.c1030
3 files changed, 1040 insertions, 0 deletions
diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index 2c5227c02fa0..9d9e45394433 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -73,6 +73,15 @@ config CAN_JANZ_ICAN3
73 This driver can also be built as a module. If so, the module will be 73 This driver can also be built as a module. If so, the module will be
74 called janz-ican3.ko. 74 called janz-ican3.ko.
75 75
76config HAVE_CAN_FLEXCAN
77 bool
78
79config CAN_FLEXCAN
80 tristate "Support for Freescale FLEXCAN based chips"
81 depends on CAN_DEV && HAVE_CAN_FLEXCAN
82 ---help---
83 Say Y here if you want to support for Freescale FlexCAN.
84
76source "drivers/net/can/mscan/Kconfig" 85source "drivers/net/can/mscan/Kconfig"
77 86
78source "drivers/net/can/sja1000/Kconfig" 87source "drivers/net/can/sja1000/Kconfig"
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index 9047cd066fea..00575373bbd0 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -16,5 +16,6 @@ obj-$(CONFIG_CAN_TI_HECC) += ti_hecc.o
16obj-$(CONFIG_CAN_MCP251X) += mcp251x.o 16obj-$(CONFIG_CAN_MCP251X) += mcp251x.o
17obj-$(CONFIG_CAN_BFIN) += bfin_can.o 17obj-$(CONFIG_CAN_BFIN) += bfin_can.o
18obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o 18obj-$(CONFIG_CAN_JANZ_ICAN3) += janz-ican3.o
19obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o
19 20
20ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG 21ccflags-$(CONFIG_CAN_DEBUG_DEVICES) := -DDEBUG
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
new file mode 100644
index 000000000000..ef443a090ba7
--- /dev/null
+++ b/drivers/net/can/flexcan.c
@@ -0,0 +1,1030 @@
1/*
2 * flexcan.c - FLEXCAN CAN controller driver
3 *
4 * Copyright (c) 2005-2006 Varma Electronics Oy
5 * Copyright (c) 2009 Sascha Hauer, Pengutronix
6 * Copyright (c) 2010 Marc Kleine-Budde, Pengutronix
7 *
8 * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
9 *
10 * LICENCE:
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License as
13 * published by the Free Software Foundation version 2.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 */
21
22#include <linux/netdevice.h>
23#include <linux/can.h>
24#include <linux/can/dev.h>
25#include <linux/can/error.h>
26#include <linux/can/platform/flexcan.h>
27#include <linux/clk.h>
28#include <linux/delay.h>
29#include <linux/if_arp.h>
30#include <linux/if_ether.h>
31#include <linux/interrupt.h>
32#include <linux/io.h>
33#include <linux/kernel.h>
34#include <linux/list.h>
35#include <linux/module.h>
36#include <linux/platform_device.h>
37
38#include <mach/clock.h>
39
40#define DRV_NAME "flexcan"
41
42/* 8 for RX fifo and 2 error handling */
43#define FLEXCAN_NAPI_WEIGHT (8 + 2)
44
45/* FLEXCAN module configuration register (CANMCR) bits */
46#define FLEXCAN_MCR_MDIS BIT(31)
47#define FLEXCAN_MCR_FRZ BIT(30)
48#define FLEXCAN_MCR_FEN BIT(29)
49#define FLEXCAN_MCR_HALT BIT(28)
50#define FLEXCAN_MCR_NOT_RDY BIT(27)
51#define FLEXCAN_MCR_WAK_MSK BIT(26)
52#define FLEXCAN_MCR_SOFTRST BIT(25)
53#define FLEXCAN_MCR_FRZ_ACK BIT(24)
54#define FLEXCAN_MCR_SUPV BIT(23)
55#define FLEXCAN_MCR_SLF_WAK BIT(22)
56#define FLEXCAN_MCR_WRN_EN BIT(21)
57#define FLEXCAN_MCR_LPM_ACK BIT(20)
58#define FLEXCAN_MCR_WAK_SRC BIT(19)
59#define FLEXCAN_MCR_DOZE BIT(18)
60#define FLEXCAN_MCR_SRX_DIS BIT(17)
61#define FLEXCAN_MCR_BCC BIT(16)
62#define FLEXCAN_MCR_LPRIO_EN BIT(13)
63#define FLEXCAN_MCR_AEN BIT(12)
64#define FLEXCAN_MCR_MAXMB(x) ((x) & 0xf)
65#define FLEXCAN_MCR_IDAM_A (0 << 8)
66#define FLEXCAN_MCR_IDAM_B (1 << 8)
67#define FLEXCAN_MCR_IDAM_C (2 << 8)
68#define FLEXCAN_MCR_IDAM_D (3 << 8)
69
70/* FLEXCAN control register (CANCTRL) bits */
71#define FLEXCAN_CTRL_PRESDIV(x) (((x) & 0xff) << 24)
72#define FLEXCAN_CTRL_RJW(x) (((x) & 0x03) << 22)
73#define FLEXCAN_CTRL_PSEG1(x) (((x) & 0x07) << 19)
74#define FLEXCAN_CTRL_PSEG2(x) (((x) & 0x07) << 16)
75#define FLEXCAN_CTRL_BOFF_MSK BIT(15)
76#define FLEXCAN_CTRL_ERR_MSK BIT(14)
77#define FLEXCAN_CTRL_CLK_SRC BIT(13)
78#define FLEXCAN_CTRL_LPB BIT(12)
79#define FLEXCAN_CTRL_TWRN_MSK BIT(11)
80#define FLEXCAN_CTRL_RWRN_MSK BIT(10)
81#define FLEXCAN_CTRL_SMP BIT(7)
82#define FLEXCAN_CTRL_BOFF_REC BIT(6)
83#define FLEXCAN_CTRL_TSYN BIT(5)
84#define FLEXCAN_CTRL_LBUF BIT(4)
85#define FLEXCAN_CTRL_LOM BIT(3)
86#define FLEXCAN_CTRL_PROPSEG(x) ((x) & 0x07)
87#define FLEXCAN_CTRL_ERR_BUS (FLEXCAN_CTRL_ERR_MSK)
88#define FLEXCAN_CTRL_ERR_STATE \
89 (FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
90 FLEXCAN_CTRL_BOFF_MSK)
91#define FLEXCAN_CTRL_ERR_ALL \
92 (FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
93
94/* FLEXCAN error and status register (ESR) bits */
95#define FLEXCAN_ESR_TWRN_INT BIT(17)
96#define FLEXCAN_ESR_RWRN_INT BIT(16)
97#define FLEXCAN_ESR_BIT1_ERR BIT(15)
98#define FLEXCAN_ESR_BIT0_ERR BIT(14)
99#define FLEXCAN_ESR_ACK_ERR BIT(13)
100#define FLEXCAN_ESR_CRC_ERR BIT(12)
101#define FLEXCAN_ESR_FRM_ERR BIT(11)
102#define FLEXCAN_ESR_STF_ERR BIT(10)
103#define FLEXCAN_ESR_TX_WRN BIT(9)
104#define FLEXCAN_ESR_RX_WRN BIT(8)
105#define FLEXCAN_ESR_IDLE BIT(7)
106#define FLEXCAN_ESR_TXRX BIT(6)
107#define FLEXCAN_EST_FLT_CONF_SHIFT (4)
108#define FLEXCAN_ESR_FLT_CONF_MASK (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
109#define FLEXCAN_ESR_FLT_CONF_ACTIVE (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
110#define FLEXCAN_ESR_FLT_CONF_PASSIVE (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
111#define FLEXCAN_ESR_BOFF_INT BIT(2)
112#define FLEXCAN_ESR_ERR_INT BIT(1)
113#define FLEXCAN_ESR_WAK_INT BIT(0)
114#define FLEXCAN_ESR_ERR_BUS \
115 (FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
116 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
117 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
118#define FLEXCAN_ESR_ERR_STATE \
119 (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
120#define FLEXCAN_ESR_ERR_ALL \
121 (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
122
123/* FLEXCAN interrupt flag register (IFLAG) bits */
124#define FLEXCAN_TX_BUF_ID 8
125#define FLEXCAN_IFLAG_BUF(x) BIT(x)
126#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW BIT(7)
127#define FLEXCAN_IFLAG_RX_FIFO_WARN BIT(6)
128#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
129#define FLEXCAN_IFLAG_DEFAULT \
130 (FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \
131 FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID))
132
133/* FLEXCAN message buffers */
134#define FLEXCAN_MB_CNT_CODE(x) (((x) & 0xf) << 24)
135#define FLEXCAN_MB_CNT_SRR BIT(22)
136#define FLEXCAN_MB_CNT_IDE BIT(21)
137#define FLEXCAN_MB_CNT_RTR BIT(20)
138#define FLEXCAN_MB_CNT_LENGTH(x) (((x) & 0xf) << 16)
139#define FLEXCAN_MB_CNT_TIMESTAMP(x) ((x) & 0xffff)
140
141#define FLEXCAN_MB_CODE_MASK (0xf0ffffff)
142
143/* Structure of the message buffer */
144struct flexcan_mb {
145 u32 can_ctrl;
146 u32 can_id;
147 u32 data[2];
148};
149
150/* Structure of the hardware registers */
151struct flexcan_regs {
152 u32 mcr; /* 0x00 */
153 u32 ctrl; /* 0x04 */
154 u32 timer; /* 0x08 */
155 u32 _reserved1; /* 0x0c */
156 u32 rxgmask; /* 0x10 */
157 u32 rx14mask; /* 0x14 */
158 u32 rx15mask; /* 0x18 */
159 u32 ecr; /* 0x1c */
160 u32 esr; /* 0x20 */
161 u32 imask2; /* 0x24 */
162 u32 imask1; /* 0x28 */
163 u32 iflag2; /* 0x2c */
164 u32 iflag1; /* 0x30 */
165 u32 _reserved2[19];
166 struct flexcan_mb cantxfg[64];
167};
168
169struct flexcan_priv {
170 struct can_priv can;
171 struct net_device *dev;
172 struct napi_struct napi;
173
174 void __iomem *base;
175 u32 reg_esr;
176 u32 reg_ctrl_default;
177
178 struct clk *clk;
179 struct flexcan_platform_data *pdata;
180};
181
182static struct can_bittiming_const flexcan_bittiming_const = {
183 .name = DRV_NAME,
184 .tseg1_min = 4,
185 .tseg1_max = 16,
186 .tseg2_min = 2,
187 .tseg2_max = 8,
188 .sjw_max = 4,
189 .brp_min = 1,
190 .brp_max = 256,
191 .brp_inc = 1,
192};
193
194/*
195 * Swtich transceiver on or off
196 */
197static void flexcan_transceiver_switch(const struct flexcan_priv *priv, int on)
198{
199 if (priv->pdata && priv->pdata->transceiver_switch)
200 priv->pdata->transceiver_switch(on);
201}
202
203static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
204 u32 reg_esr)
205{
206 return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
207 (reg_esr & FLEXCAN_ESR_ERR_BUS);
208}
209
210static inline void flexcan_chip_enable(struct flexcan_priv *priv)
211{
212 struct flexcan_regs __iomem *regs = priv->base;
213 u32 reg;
214
215 reg = readl(&regs->mcr);
216 reg &= ~FLEXCAN_MCR_MDIS;
217 writel(reg, &regs->mcr);
218
219 udelay(10);
220}
221
222static inline void flexcan_chip_disable(struct flexcan_priv *priv)
223{
224 struct flexcan_regs __iomem *regs = priv->base;
225 u32 reg;
226
227 reg = readl(&regs->mcr);
228 reg |= FLEXCAN_MCR_MDIS;
229 writel(reg, &regs->mcr);
230}
231
232static int flexcan_get_berr_counter(const struct net_device *dev,
233 struct can_berr_counter *bec)
234{
235 const struct flexcan_priv *priv = netdev_priv(dev);
236 struct flexcan_regs __iomem *regs = priv->base;
237 u32 reg = readl(&regs->ecr);
238
239 bec->txerr = (reg >> 0) & 0xff;
240 bec->rxerr = (reg >> 8) & 0xff;
241
242 return 0;
243}
244
245static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
246{
247 const struct flexcan_priv *priv = netdev_priv(dev);
248 struct net_device_stats *stats = &dev->stats;
249 struct flexcan_regs __iomem *regs = priv->base;
250 struct can_frame *cf = (struct can_frame *)skb->data;
251 u32 can_id;
252 u32 ctrl = FLEXCAN_MB_CNT_CODE(0xc) | (cf->can_dlc << 16);
253
254 if (can_dropped_invalid_skb(dev, skb))
255 return NETDEV_TX_OK;
256
257 netif_stop_queue(dev);
258
259 if (cf->can_id & CAN_EFF_FLAG) {
260 can_id = cf->can_id & CAN_EFF_MASK;
261 ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
262 } else {
263 can_id = (cf->can_id & CAN_SFF_MASK) << 18;
264 }
265
266 if (cf->can_id & CAN_RTR_FLAG)
267 ctrl |= FLEXCAN_MB_CNT_RTR;
268
269 if (cf->can_dlc > 0) {
270 u32 data = be32_to_cpup((__be32 *)&cf->data[0]);
271 writel(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[0]);
272 }
273 if (cf->can_dlc > 3) {
274 u32 data = be32_to_cpup((__be32 *)&cf->data[4]);
275 writel(data, &regs->cantxfg[FLEXCAN_TX_BUF_ID].data[1]);
276 }
277
278 writel(can_id, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_id);
279 writel(ctrl, &regs->cantxfg[FLEXCAN_TX_BUF_ID].can_ctrl);
280
281 kfree_skb(skb);
282
283 /* tx_packets is incremented in flexcan_irq */
284 stats->tx_bytes += cf->can_dlc;
285
286 return NETDEV_TX_OK;
287}
288
289static void do_bus_err(struct net_device *dev,
290 struct can_frame *cf, u32 reg_esr)
291{
292 struct flexcan_priv *priv = netdev_priv(dev);
293 int rx_errors = 0, tx_errors = 0;
294
295 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
296
297 if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
298 dev_dbg(dev->dev.parent, "BIT1_ERR irq\n");
299 cf->data[2] |= CAN_ERR_PROT_BIT1;
300 tx_errors = 1;
301 }
302 if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
303 dev_dbg(dev->dev.parent, "BIT0_ERR irq\n");
304 cf->data[2] |= CAN_ERR_PROT_BIT0;
305 tx_errors = 1;
306 }
307 if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
308 dev_dbg(dev->dev.parent, "ACK_ERR irq\n");
309 cf->can_id |= CAN_ERR_ACK;
310 cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
311 tx_errors = 1;
312 }
313 if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
314 dev_dbg(dev->dev.parent, "CRC_ERR irq\n");
315 cf->data[2] |= CAN_ERR_PROT_BIT;
316 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
317 rx_errors = 1;
318 }
319 if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
320 dev_dbg(dev->dev.parent, "FRM_ERR irq\n");
321 cf->data[2] |= CAN_ERR_PROT_FORM;
322 rx_errors = 1;
323 }
324 if (reg_esr & FLEXCAN_ESR_STF_ERR) {
325 dev_dbg(dev->dev.parent, "STF_ERR irq\n");
326 cf->data[2] |= CAN_ERR_PROT_STUFF;
327 rx_errors = 1;
328 }
329
330 priv->can.can_stats.bus_error++;
331 if (rx_errors)
332 dev->stats.rx_errors++;
333 if (tx_errors)
334 dev->stats.tx_errors++;
335}
336
337static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
338{
339 struct sk_buff *skb;
340 struct can_frame *cf;
341
342 skb = alloc_can_err_skb(dev, &cf);
343 if (unlikely(!skb))
344 return 0;
345
346 do_bus_err(dev, cf, reg_esr);
347 netif_receive_skb(skb);
348
349 dev->stats.rx_packets++;
350 dev->stats.rx_bytes += cf->can_dlc;
351
352 return 1;
353}
354
355static void do_state(struct net_device *dev,
356 struct can_frame *cf, enum can_state new_state)
357{
358 struct flexcan_priv *priv = netdev_priv(dev);
359 struct can_berr_counter bec;
360
361 flexcan_get_berr_counter(dev, &bec);
362
363 switch (priv->can.state) {
364 case CAN_STATE_ERROR_ACTIVE:
365 /*
366 * from: ERROR_ACTIVE
367 * to : ERROR_WARNING, ERROR_PASSIVE, BUS_OFF
368 * => : there was a warning int
369 */
370 if (new_state >= CAN_STATE_ERROR_WARNING &&
371 new_state <= CAN_STATE_BUS_OFF) {
372 dev_dbg(dev->dev.parent, "Error Warning IRQ\n");
373 priv->can.can_stats.error_warning++;
374
375 cf->can_id |= CAN_ERR_CRTL;
376 cf->data[1] = (bec.txerr > bec.rxerr) ?
377 CAN_ERR_CRTL_TX_WARNING :
378 CAN_ERR_CRTL_RX_WARNING;
379 }
380 case CAN_STATE_ERROR_WARNING: /* fallthrough */
381 /*
382 * from: ERROR_ACTIVE, ERROR_WARNING
383 * to : ERROR_PASSIVE, BUS_OFF
384 * => : error passive int
385 */
386 if (new_state >= CAN_STATE_ERROR_PASSIVE &&
387 new_state <= CAN_STATE_BUS_OFF) {
388 dev_dbg(dev->dev.parent, "Error Passive IRQ\n");
389 priv->can.can_stats.error_passive++;
390
391 cf->can_id |= CAN_ERR_CRTL;
392 cf->data[1] = (bec.txerr > bec.rxerr) ?
393 CAN_ERR_CRTL_TX_PASSIVE :
394 CAN_ERR_CRTL_RX_PASSIVE;
395 }
396 break;
397 case CAN_STATE_BUS_OFF:
398 dev_err(dev->dev.parent,
399 "BUG! hardware recovered automatically from BUS_OFF\n");
400 break;
401 default:
402 break;
403 }
404
405 /* process state changes depending on the new state */
406 switch (new_state) {
407 case CAN_STATE_ERROR_ACTIVE:
408 dev_dbg(dev->dev.parent, "Error Active\n");
409 cf->can_id |= CAN_ERR_PROT;
410 cf->data[2] = CAN_ERR_PROT_ACTIVE;
411 break;
412 case CAN_STATE_BUS_OFF:
413 cf->can_id |= CAN_ERR_BUSOFF;
414 can_bus_off(dev);
415 break;
416 default:
417 break;
418 }
419}
420
421static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
422{
423 struct flexcan_priv *priv = netdev_priv(dev);
424 struct sk_buff *skb;
425 struct can_frame *cf;
426 enum can_state new_state;
427 int flt;
428
429 flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
430 if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
431 if (likely(!(reg_esr & (FLEXCAN_ESR_TX_WRN |
432 FLEXCAN_ESR_RX_WRN))))
433 new_state = CAN_STATE_ERROR_ACTIVE;
434 else
435 new_state = CAN_STATE_ERROR_WARNING;
436 } else if (unlikely(flt == FLEXCAN_ESR_FLT_CONF_PASSIVE))
437 new_state = CAN_STATE_ERROR_PASSIVE;
438 else
439 new_state = CAN_STATE_BUS_OFF;
440
441 /* state hasn't changed */
442 if (likely(new_state == priv->can.state))
443 return 0;
444
445 skb = alloc_can_err_skb(dev, &cf);
446 if (unlikely(!skb))
447 return 0;
448
449 do_state(dev, cf, new_state);
450 priv->can.state = new_state;
451 netif_receive_skb(skb);
452
453 dev->stats.rx_packets++;
454 dev->stats.rx_bytes += cf->can_dlc;
455
456 return 1;
457}
458
459static void flexcan_read_fifo(const struct net_device *dev,
460 struct can_frame *cf)
461{
462 const struct flexcan_priv *priv = netdev_priv(dev);
463 struct flexcan_regs __iomem *regs = priv->base;
464 struct flexcan_mb __iomem *mb = &regs->cantxfg[0];
465 u32 reg_ctrl, reg_id;
466
467 reg_ctrl = readl(&mb->can_ctrl);
468 reg_id = readl(&mb->can_id);
469 if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
470 cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
471 else
472 cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
473
474 if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
475 cf->can_id |= CAN_RTR_FLAG;
476 cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
477
478 *(__be32 *)(cf->data + 0) = cpu_to_be32(readl(&mb->data[0]));
479 *(__be32 *)(cf->data + 4) = cpu_to_be32(readl(&mb->data[1]));
480
481 /* mark as read */
482 writel(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
483 readl(&regs->timer);
484}
485
486static int flexcan_read_frame(struct net_device *dev)
487{
488 struct net_device_stats *stats = &dev->stats;
489 struct can_frame *cf;
490 struct sk_buff *skb;
491
492 skb = alloc_can_skb(dev, &cf);
493 if (unlikely(!skb)) {
494 stats->rx_dropped++;
495 return 0;
496 }
497
498 flexcan_read_fifo(dev, cf);
499 netif_receive_skb(skb);
500
501 stats->rx_packets++;
502 stats->rx_bytes += cf->can_dlc;
503
504 return 1;
505}
506
507static int flexcan_poll(struct napi_struct *napi, int quota)
508{
509 struct net_device *dev = napi->dev;
510 const struct flexcan_priv *priv = netdev_priv(dev);
511 struct flexcan_regs __iomem *regs = priv->base;
512 u32 reg_iflag1, reg_esr;
513 int work_done = 0;
514
515 /*
516 * The error bits are cleared on read,
517 * use saved value from irq handler.
518 */
519 reg_esr = readl(&regs->esr) | priv->reg_esr;
520
521 /* handle state changes */
522 work_done += flexcan_poll_state(dev, reg_esr);
523
524 /* handle RX-FIFO */
525 reg_iflag1 = readl(&regs->iflag1);
526 while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
527 work_done < quota) {
528 work_done += flexcan_read_frame(dev);
529 reg_iflag1 = readl(&regs->iflag1);
530 }
531
532 /* report bus errors */
533 if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
534 work_done += flexcan_poll_bus_err(dev, reg_esr);
535
536 if (work_done < quota) {
537 napi_complete(napi);
538 /* enable IRQs */
539 writel(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
540 writel(priv->reg_ctrl_default, &regs->ctrl);
541 }
542
543 return work_done;
544}
545
546static irqreturn_t flexcan_irq(int irq, void *dev_id)
547{
548 struct net_device *dev = dev_id;
549 struct net_device_stats *stats = &dev->stats;
550 struct flexcan_priv *priv = netdev_priv(dev);
551 struct flexcan_regs __iomem *regs = priv->base;
552 u32 reg_iflag1, reg_esr;
553
554 reg_iflag1 = readl(&regs->iflag1);
555 reg_esr = readl(&regs->esr);
556 writel(FLEXCAN_ESR_ERR_INT, &regs->esr); /* ACK err IRQ */
557
558 /*
559 * schedule NAPI in case of:
560 * - rx IRQ
561 * - state change IRQ
562 * - bus error IRQ and bus error reporting is activated
563 */
564 if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
565 (reg_esr & FLEXCAN_ESR_ERR_STATE) ||
566 flexcan_has_and_handle_berr(priv, reg_esr)) {
567 /*
568 * The error bits are cleared on read,
569 * save them for later use.
570 */
571 priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
572 writel(FLEXCAN_IFLAG_DEFAULT & ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE,
573 &regs->imask1);
574 writel(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
575 &regs->ctrl);
576 napi_schedule(&priv->napi);
577 }
578
579 /* FIFO overflow */
580 if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
581 writel(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
582 dev->stats.rx_over_errors++;
583 dev->stats.rx_errors++;
584 }
585
586 /* transmission complete interrupt */
587 if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
588 /* tx_bytes is incremented in flexcan_start_xmit */
589 stats->tx_packets++;
590 writel((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
591 netif_wake_queue(dev);
592 }
593
594 return IRQ_HANDLED;
595}
596
597static void flexcan_set_bittiming(struct net_device *dev)
598{
599 const struct flexcan_priv *priv = netdev_priv(dev);
600 const struct can_bittiming *bt = &priv->can.bittiming;
601 struct flexcan_regs __iomem *regs = priv->base;
602 u32 reg;
603
604 reg = readl(&regs->ctrl);
605 reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
606 FLEXCAN_CTRL_RJW(0x3) |
607 FLEXCAN_CTRL_PSEG1(0x7) |
608 FLEXCAN_CTRL_PSEG2(0x7) |
609 FLEXCAN_CTRL_PROPSEG(0x7) |
610 FLEXCAN_CTRL_LPB |
611 FLEXCAN_CTRL_SMP |
612 FLEXCAN_CTRL_LOM);
613
614 reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
615 FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
616 FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
617 FLEXCAN_CTRL_RJW(bt->sjw - 1) |
618 FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
619
620 if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
621 reg |= FLEXCAN_CTRL_LPB;
622 if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
623 reg |= FLEXCAN_CTRL_LOM;
624 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
625 reg |= FLEXCAN_CTRL_SMP;
626
627 dev_info(dev->dev.parent, "writing ctrl=0x%08x\n", reg);
628 writel(reg, &regs->ctrl);
629
630 /* print chip status */
631 dev_dbg(dev->dev.parent, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
632 readl(&regs->mcr), readl(&regs->ctrl));
633}
634
635/*
636 * flexcan_chip_start
637 *
638 * this functions is entered with clocks enabled
639 *
640 */
641static int flexcan_chip_start(struct net_device *dev)
642{
643 struct flexcan_priv *priv = netdev_priv(dev);
644 struct flexcan_regs __iomem *regs = priv->base;
645 unsigned int i;
646 int err;
647 u32 reg_mcr, reg_ctrl;
648
649 /* enable module */
650 flexcan_chip_enable(priv);
651
652 /* soft reset */
653 writel(FLEXCAN_MCR_SOFTRST, &regs->mcr);
654 udelay(10);
655
656 reg_mcr = readl(&regs->mcr);
657 if (reg_mcr & FLEXCAN_MCR_SOFTRST) {
658 dev_err(dev->dev.parent,
659 "Failed to softreset can module (mcr=0x%08x)\n",
660 reg_mcr);
661 err = -ENODEV;
662 goto out;
663 }
664
665 flexcan_set_bittiming(dev);
666
667 /*
668 * MCR
669 *
670 * enable freeze
671 * enable fifo
672 * halt now
673 * only supervisor access
674 * enable warning int
675 * choose format C
676 *
677 */
678 reg_mcr = readl(&regs->mcr);
679 reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
680 FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN |
681 FLEXCAN_MCR_IDAM_C;
682 dev_dbg(dev->dev.parent, "%s: writing mcr=0x%08x", __func__, reg_mcr);
683 writel(reg_mcr, &regs->mcr);
684
685 /*
686 * CTRL
687 *
688 * disable timer sync feature
689 *
690 * disable auto busoff recovery
691 * transmit lowest buffer first
692 *
693 * enable tx and rx warning interrupt
694 * enable bus off interrupt
695 * (== FLEXCAN_CTRL_ERR_STATE)
696 *
697 * _note_: we enable the "error interrupt"
698 * (FLEXCAN_CTRL_ERR_MSK), too. Otherwise we don't get any
699 * warning or bus passive interrupts.
700 */
701 reg_ctrl = readl(&regs->ctrl);
702 reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
703 reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
704 FLEXCAN_CTRL_ERR_STATE | FLEXCAN_CTRL_ERR_MSK;
705
706 /* save for later use */
707 priv->reg_ctrl_default = reg_ctrl;
708 dev_dbg(dev->dev.parent, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
709 writel(reg_ctrl, &regs->ctrl);
710
711 for (i = 0; i < ARRAY_SIZE(regs->cantxfg); i++) {
712 writel(0, &regs->cantxfg[i].can_ctrl);
713 writel(0, &regs->cantxfg[i].can_id);
714 writel(0, &regs->cantxfg[i].data[0]);
715 writel(0, &regs->cantxfg[i].data[1]);
716
717 /* put MB into rx queue */
718 writel(FLEXCAN_MB_CNT_CODE(0x4), &regs->cantxfg[i].can_ctrl);
719 }
720
721 /* acceptance mask/acceptance code (accept everything) */
722 writel(0x0, &regs->rxgmask);
723 writel(0x0, &regs->rx14mask);
724 writel(0x0, &regs->rx15mask);
725
726 flexcan_transceiver_switch(priv, 1);
727
728 /* synchronize with the can bus */
729 reg_mcr = readl(&regs->mcr);
730 reg_mcr &= ~FLEXCAN_MCR_HALT;
731 writel(reg_mcr, &regs->mcr);
732
733 priv->can.state = CAN_STATE_ERROR_ACTIVE;
734
735 /* enable FIFO interrupts */
736 writel(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
737
738 /* print chip status */
739 dev_dbg(dev->dev.parent, "%s: reading mcr=0x%08x ctrl=0x%08x\n",
740 __func__, readl(&regs->mcr), readl(&regs->ctrl));
741
742 return 0;
743
744 out:
745 flexcan_chip_disable(priv);
746 return err;
747}
748
749/*
750 * flexcan_chip_stop
751 *
752 * this functions is entered with clocks enabled
753 *
754 */
755static void flexcan_chip_stop(struct net_device *dev)
756{
757 struct flexcan_priv *priv = netdev_priv(dev);
758 struct flexcan_regs __iomem *regs = priv->base;
759 u32 reg;
760
761 /* Disable all interrupts */
762 writel(0, &regs->imask1);
763
764 /* Disable + halt module */
765 reg = readl(&regs->mcr);
766 reg |= FLEXCAN_MCR_MDIS | FLEXCAN_MCR_HALT;
767 writel(reg, &regs->mcr);
768
769 flexcan_transceiver_switch(priv, 0);
770 priv->can.state = CAN_STATE_STOPPED;
771
772 return;
773}
774
775static int flexcan_open(struct net_device *dev)
776{
777 struct flexcan_priv *priv = netdev_priv(dev);
778 int err;
779
780 clk_enable(priv->clk);
781
782 err = open_candev(dev);
783 if (err)
784 goto out;
785
786 err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
787 if (err)
788 goto out_close;
789
790 /* start chip and queuing */
791 err = flexcan_chip_start(dev);
792 if (err)
793 goto out_close;
794 napi_enable(&priv->napi);
795 netif_start_queue(dev);
796
797 return 0;
798
799 out_close:
800 close_candev(dev);
801 out:
802 clk_disable(priv->clk);
803
804 return err;
805}
806
807static int flexcan_close(struct net_device *dev)
808{
809 struct flexcan_priv *priv = netdev_priv(dev);
810
811 netif_stop_queue(dev);
812 napi_disable(&priv->napi);
813 flexcan_chip_stop(dev);
814
815 free_irq(dev->irq, dev);
816 clk_disable(priv->clk);
817
818 close_candev(dev);
819
820 return 0;
821}
822
823static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
824{
825 int err;
826
827 switch (mode) {
828 case CAN_MODE_START:
829 err = flexcan_chip_start(dev);
830 if (err)
831 return err;
832
833 netif_wake_queue(dev);
834 break;
835
836 default:
837 return -EOPNOTSUPP;
838 }
839
840 return 0;
841}
842
843static const struct net_device_ops flexcan_netdev_ops = {
844 .ndo_open = flexcan_open,
845 .ndo_stop = flexcan_close,
846 .ndo_start_xmit = flexcan_start_xmit,
847};
848
849static int __devinit register_flexcandev(struct net_device *dev)
850{
851 struct flexcan_priv *priv = netdev_priv(dev);
852 struct flexcan_regs __iomem *regs = priv->base;
853 u32 reg, err;
854
855 clk_enable(priv->clk);
856
857 /* select "bus clock", chip must be disabled */
858 flexcan_chip_disable(priv);
859 reg = readl(&regs->ctrl);
860 reg |= FLEXCAN_CTRL_CLK_SRC;
861 writel(reg, &regs->ctrl);
862
863 flexcan_chip_enable(priv);
864
865 /* set freeze, halt and activate FIFO, restrict register access */
866 reg = readl(&regs->mcr);
867 reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
868 FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
869 writel(reg, &regs->mcr);
870
871 /*
872 * Currently we only support newer versions of this core
873 * featuring a RX FIFO. Older cores found on some Coldfire
874 * derivates are not yet supported.
875 */
876 reg = readl(&regs->mcr);
877 if (!(reg & FLEXCAN_MCR_FEN)) {
878 dev_err(dev->dev.parent,
879 "Could not enable RX FIFO, unsupported core\n");
880 err = -ENODEV;
881 goto out;
882 }
883
884 err = register_candev(dev);
885
886 out:
887 /* disable core and turn off clocks */
888 flexcan_chip_disable(priv);
889 clk_disable(priv->clk);
890
891 return err;
892}
893
894static void __devexit unregister_flexcandev(struct net_device *dev)
895{
896 unregister_candev(dev);
897}
898
899static int __devinit flexcan_probe(struct platform_device *pdev)
900{
901 struct net_device *dev;
902 struct flexcan_priv *priv;
903 struct resource *mem;
904 struct clk *clk;
905 void __iomem *base;
906 resource_size_t mem_size;
907 int err, irq;
908
909 clk = clk_get(&pdev->dev, NULL);
910 if (IS_ERR(clk)) {
911 dev_err(&pdev->dev, "no clock defined\n");
912 err = PTR_ERR(clk);
913 goto failed_clock;
914 }
915
916 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
917 irq = platform_get_irq(pdev, 0);
918 if (!mem || irq <= 0) {
919 err = -ENODEV;
920 goto failed_get;
921 }
922
923 mem_size = resource_size(mem);
924 if (!request_mem_region(mem->start, mem_size, pdev->name)) {
925 err = -EBUSY;
926 goto failed_req;
927 }
928
929 base = ioremap(mem->start, mem_size);
930 if (!base) {
931 err = -ENOMEM;
932 goto failed_map;
933 }
934
935 dev = alloc_candev(sizeof(struct flexcan_priv), 0);
936 if (!dev) {
937 err = -ENOMEM;
938 goto failed_alloc;
939 }
940
941 dev->netdev_ops = &flexcan_netdev_ops;
942 dev->irq = irq;
943 dev->flags |= IFF_ECHO; /* we support local echo in hardware */
944
945 priv = netdev_priv(dev);
946 priv->can.clock.freq = clk_get_rate(clk);
947 priv->can.bittiming_const = &flexcan_bittiming_const;
948 priv->can.do_set_mode = flexcan_set_mode;
949 priv->can.do_get_berr_counter = flexcan_get_berr_counter;
950 priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
951 CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
952 CAN_CTRLMODE_BERR_REPORTING;
953 priv->base = base;
954 priv->dev = dev;
955 priv->clk = clk;
956 priv->pdata = pdev->dev.platform_data;
957
958 netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
959
960 dev_set_drvdata(&pdev->dev, dev);
961 SET_NETDEV_DEV(dev, &pdev->dev);
962
963 err = register_flexcandev(dev);
964 if (err) {
965 dev_err(&pdev->dev, "registering netdev failed\n");
966 goto failed_register;
967 }
968
969 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
970 priv->base, dev->irq);
971
972 return 0;
973
974 failed_register:
975 free_candev(dev);
976 failed_alloc:
977 iounmap(base);
978 failed_map:
979 release_mem_region(mem->start, mem_size);
980 failed_req:
981 clk_put(clk);
982 failed_get:
983 failed_clock:
984 return err;
985}
986
987static int __devexit flexcan_remove(struct platform_device *pdev)
988{
989 struct net_device *dev = platform_get_drvdata(pdev);
990 struct flexcan_priv *priv = netdev_priv(dev);
991 struct resource *mem;
992
993 unregister_flexcandev(dev);
994 platform_set_drvdata(pdev, NULL);
995 free_candev(dev);
996 iounmap(priv->base);
997
998 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
999 release_mem_region(mem->start, resource_size(mem));
1000
1001 clk_put(priv->clk);
1002
1003 return 0;
1004}
1005
1006static struct platform_driver flexcan_driver = {
1007 .driver.name = DRV_NAME,
1008 .probe = flexcan_probe,
1009 .remove = __devexit_p(flexcan_remove),
1010};
1011
1012static int __init flexcan_init(void)
1013{
1014 pr_info("%s netdevice driver\n", DRV_NAME);
1015 return platform_driver_register(&flexcan_driver);
1016}
1017
1018static void __exit flexcan_exit(void)
1019{
1020 platform_driver_unregister(&flexcan_driver);
1021 pr_info("%s: driver removed\n", DRV_NAME);
1022}
1023
1024module_init(flexcan_init);
1025module_exit(flexcan_exit);
1026
1027MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1028 "Marc Kleine-Budde <kernel@pengutronix.de>");
1029MODULE_LICENSE("GPL v2");
1030MODULE_DESCRIPTION("CAN port driver for flexcan based chip");
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-01 23:48:39 -0500