1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // flexcan.c - FLEXCAN CAN controller driver
4 //
5 // Copyright (c) 2005-2006 Varma Electronics Oy
6 // Copyright (c) 2009 Sascha Hauer, Pengutronix
7 // Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
8 // Copyright (c) 2014 David Jander, Protonic Holland
9 //
10 // Based on code originally by Andrey Volkov <avolkov@varma-el.com>
11 
12 #include <linux/netdevice.h>
13 #include <linux/can.h>
14 #include <linux/can/dev.h>
15 #include <linux/can/error.h>
16 #include <linux/can/led.h>
17 #include <linux/can/rx-offload.h>
18 #include <linux/clk.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/io.h>
22 #include <linux/mfd/syscon.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/regulator/consumer.h>
29 #include <linux/regmap.h>
30 
31 #define DRV_NAME			"flexcan"
32 
33 /* 8 for RX fifo and 2 error handling */
34 #define FLEXCAN_NAPI_WEIGHT		(8 + 2)
35 
36 /* FLEXCAN module configuration register (CANMCR) bits */
37 #define FLEXCAN_MCR_MDIS		BIT(31)
38 #define FLEXCAN_MCR_FRZ			BIT(30)
39 #define FLEXCAN_MCR_FEN			BIT(29)
40 #define FLEXCAN_MCR_HALT		BIT(28)
41 #define FLEXCAN_MCR_NOT_RDY		BIT(27)
42 #define FLEXCAN_MCR_WAK_MSK		BIT(26)
43 #define FLEXCAN_MCR_SOFTRST		BIT(25)
44 #define FLEXCAN_MCR_FRZ_ACK		BIT(24)
45 #define FLEXCAN_MCR_SUPV		BIT(23)
46 #define FLEXCAN_MCR_SLF_WAK		BIT(22)
47 #define FLEXCAN_MCR_WRN_EN		BIT(21)
48 #define FLEXCAN_MCR_LPM_ACK		BIT(20)
49 #define FLEXCAN_MCR_WAK_SRC		BIT(19)
50 #define FLEXCAN_MCR_DOZE		BIT(18)
51 #define FLEXCAN_MCR_SRX_DIS		BIT(17)
52 #define FLEXCAN_MCR_IRMQ		BIT(16)
53 #define FLEXCAN_MCR_LPRIO_EN		BIT(13)
54 #define FLEXCAN_MCR_AEN			BIT(12)
55 /* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
56 #define FLEXCAN_MCR_MAXMB(x)		((x) & 0x7f)
57 #define FLEXCAN_MCR_IDAM_A		(0x0 << 8)
58 #define FLEXCAN_MCR_IDAM_B		(0x1 << 8)
59 #define FLEXCAN_MCR_IDAM_C		(0x2 << 8)
60 #define FLEXCAN_MCR_IDAM_D		(0x3 << 8)
61 
62 /* FLEXCAN control register (CANCTRL) bits */
63 #define FLEXCAN_CTRL_PRESDIV(x)		(((x) & 0xff) << 24)
64 #define FLEXCAN_CTRL_RJW(x)		(((x) & 0x03) << 22)
65 #define FLEXCAN_CTRL_PSEG1(x)		(((x) & 0x07) << 19)
66 #define FLEXCAN_CTRL_PSEG2(x)		(((x) & 0x07) << 16)
67 #define FLEXCAN_CTRL_BOFF_MSK		BIT(15)
68 #define FLEXCAN_CTRL_ERR_MSK		BIT(14)
69 #define FLEXCAN_CTRL_CLK_SRC		BIT(13)
70 #define FLEXCAN_CTRL_LPB		BIT(12)
71 #define FLEXCAN_CTRL_TWRN_MSK		BIT(11)
72 #define FLEXCAN_CTRL_RWRN_MSK		BIT(10)
73 #define FLEXCAN_CTRL_SMP		BIT(7)
74 #define FLEXCAN_CTRL_BOFF_REC		BIT(6)
75 #define FLEXCAN_CTRL_TSYN		BIT(5)
76 #define FLEXCAN_CTRL_LBUF		BIT(4)
77 #define FLEXCAN_CTRL_LOM		BIT(3)
78 #define FLEXCAN_CTRL_PROPSEG(x)		((x) & 0x07)
79 #define FLEXCAN_CTRL_ERR_BUS		(FLEXCAN_CTRL_ERR_MSK)
80 #define FLEXCAN_CTRL_ERR_STATE \
81 	(FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
82 	 FLEXCAN_CTRL_BOFF_MSK)
83 #define FLEXCAN_CTRL_ERR_ALL \
84 	(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
85 
86 /* FLEXCAN control register 2 (CTRL2) bits */
87 #define FLEXCAN_CTRL2_ECRWRE		BIT(29)
88 #define FLEXCAN_CTRL2_WRMFRZ		BIT(28)
89 #define FLEXCAN_CTRL2_RFFN(x)		(((x) & 0x0f) << 24)
90 #define FLEXCAN_CTRL2_TASD(x)		(((x) & 0x1f) << 19)
91 #define FLEXCAN_CTRL2_MRP		BIT(18)
92 #define FLEXCAN_CTRL2_RRS		BIT(17)
93 #define FLEXCAN_CTRL2_EACEN		BIT(16)
94 
95 /* FLEXCAN memory error control register (MECR) bits */
96 #define FLEXCAN_MECR_ECRWRDIS		BIT(31)
97 #define FLEXCAN_MECR_HANCEI_MSK		BIT(19)
98 #define FLEXCAN_MECR_FANCEI_MSK		BIT(18)
99 #define FLEXCAN_MECR_CEI_MSK		BIT(16)
100 #define FLEXCAN_MECR_HAERRIE		BIT(15)
101 #define FLEXCAN_MECR_FAERRIE		BIT(14)
102 #define FLEXCAN_MECR_EXTERRIE		BIT(13)
103 #define FLEXCAN_MECR_RERRDIS		BIT(9)
104 #define FLEXCAN_MECR_ECCDIS		BIT(8)
105 #define FLEXCAN_MECR_NCEFAFRZ		BIT(7)
106 
107 /* FLEXCAN error and status register (ESR) bits */
108 #define FLEXCAN_ESR_TWRN_INT		BIT(17)
109 #define FLEXCAN_ESR_RWRN_INT		BIT(16)
110 #define FLEXCAN_ESR_BIT1_ERR		BIT(15)
111 #define FLEXCAN_ESR_BIT0_ERR		BIT(14)
112 #define FLEXCAN_ESR_ACK_ERR		BIT(13)
113 #define FLEXCAN_ESR_CRC_ERR		BIT(12)
114 #define FLEXCAN_ESR_FRM_ERR		BIT(11)
115 #define FLEXCAN_ESR_STF_ERR		BIT(10)
116 #define FLEXCAN_ESR_TX_WRN		BIT(9)
117 #define FLEXCAN_ESR_RX_WRN		BIT(8)
118 #define FLEXCAN_ESR_IDLE		BIT(7)
119 #define FLEXCAN_ESR_TXRX		BIT(6)
120 #define FLEXCAN_EST_FLT_CONF_SHIFT	(4)
121 #define FLEXCAN_ESR_FLT_CONF_MASK	(0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
122 #define FLEXCAN_ESR_FLT_CONF_ACTIVE	(0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
123 #define FLEXCAN_ESR_FLT_CONF_PASSIVE	(0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
124 #define FLEXCAN_ESR_BOFF_INT		BIT(2)
125 #define FLEXCAN_ESR_ERR_INT		BIT(1)
126 #define FLEXCAN_ESR_WAK_INT		BIT(0)
127 #define FLEXCAN_ESR_ERR_BUS \
128 	(FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
129 	 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
130 	 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
131 #define FLEXCAN_ESR_ERR_STATE \
132 	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
133 #define FLEXCAN_ESR_ERR_ALL \
134 	(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
135 #define FLEXCAN_ESR_ALL_INT \
136 	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
137 	 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT | \
138 	 FLEXCAN_ESR_WAK_INT)
139 
140 /* FLEXCAN interrupt flag register (IFLAG) bits */
141 /* Errata ERR005829 step7: Reserve first valid MB */
142 #define FLEXCAN_TX_MB_RESERVED_OFF_FIFO		8
143 #define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP	0
144 #define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST	(FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP + 1)
145 #define FLEXCAN_IFLAG_MB(x)		BIT((x) & 0x1f)
146 #define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW	BIT(7)
147 #define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
148 #define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
149 
150 /* FLEXCAN message buffers */
151 #define FLEXCAN_MB_CODE_MASK		(0xf << 24)
152 #define FLEXCAN_MB_CODE_RX_BUSY_BIT	(0x1 << 24)
153 #define FLEXCAN_MB_CODE_RX_INACTIVE	(0x0 << 24)
154 #define FLEXCAN_MB_CODE_RX_EMPTY	(0x4 << 24)
155 #define FLEXCAN_MB_CODE_RX_FULL		(0x2 << 24)
156 #define FLEXCAN_MB_CODE_RX_OVERRUN	(0x6 << 24)
157 #define FLEXCAN_MB_CODE_RX_RANSWER	(0xa << 24)
158 
159 #define FLEXCAN_MB_CODE_TX_INACTIVE	(0x8 << 24)
160 #define FLEXCAN_MB_CODE_TX_ABORT	(0x9 << 24)
161 #define FLEXCAN_MB_CODE_TX_DATA		(0xc << 24)
162 #define FLEXCAN_MB_CODE_TX_TANSWER	(0xe << 24)
163 
164 #define FLEXCAN_MB_CNT_SRR		BIT(22)
165 #define FLEXCAN_MB_CNT_IDE		BIT(21)
166 #define FLEXCAN_MB_CNT_RTR		BIT(20)
167 #define FLEXCAN_MB_CNT_LENGTH(x)	(((x) & 0xf) << 16)
168 #define FLEXCAN_MB_CNT_TIMESTAMP(x)	((x) & 0xffff)
169 
170 #define FLEXCAN_TIMEOUT_US		(250)
171 
172 /* FLEXCAN hardware feature flags
173  *
174  * Below is some version info we got:
175  *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT IRQ Err Memory err RTR re-
176  *                                Filter? connected?  Passive detection  ception in MB
177  *   MX25  FlexCAN2  03.00.00.00     no        no        no       no        no
178  *   MX28  FlexCAN2  03.00.04.00    yes       yes        no       no        no
179  *   MX35  FlexCAN2  03.00.00.00     no        no        no       no        no
180  *   MX53  FlexCAN2  03.00.00.00    yes        no        no       no        no
181  *   MX6s  FlexCAN3  10.00.12.00    yes       yes        no       no       yes
182  *   VF610 FlexCAN3  ?               no       yes        no      yes       yes?
183  * LS1021A FlexCAN2  03.00.04.00     no       yes        no       no       yes
184  *
185  * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
186  */
187 #define FLEXCAN_QUIRK_BROKEN_WERR_STATE	BIT(1) /* [TR]WRN_INT not connected */
188 #define FLEXCAN_QUIRK_DISABLE_RXFG	BIT(2) /* Disable RX FIFO Global mask */
189 #define FLEXCAN_QUIRK_ENABLE_EACEN_RRS	BIT(3) /* Enable EACEN and RRS bit in ctrl2 */
190 #define FLEXCAN_QUIRK_DISABLE_MECR	BIT(4) /* Disable Memory error detection */
191 #define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP	BIT(5) /* Use timestamp based offloading */
192 #define FLEXCAN_QUIRK_BROKEN_PERR_STATE	BIT(6) /* No interrupt for error passive */
193 #define FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN	BIT(7) /* default to BE register access */
194 #define FLEXCAN_QUIRK_SETUP_STOP_MODE		BIT(8) /* Setup stop mode to support wakeup */
195 
196 /* Structure of the message buffer */
197 struct flexcan_mb {
198 	u32 can_ctrl;
199 	u32 can_id;
200 	u32 data[];
201 };
202 
203 /* Structure of the hardware registers */
204 struct flexcan_regs {
205 	u32 mcr;		/* 0x00 */
206 	u32 ctrl;		/* 0x04 */
207 	u32 timer;		/* 0x08 */
208 	u32 _reserved1;		/* 0x0c */
209 	u32 rxgmask;		/* 0x10 */
210 	u32 rx14mask;		/* 0x14 */
211 	u32 rx15mask;		/* 0x18 */
212 	u32 ecr;		/* 0x1c */
213 	u32 esr;		/* 0x20 */
214 	u32 imask2;		/* 0x24 */
215 	u32 imask1;		/* 0x28 */
216 	u32 iflag2;		/* 0x2c */
217 	u32 iflag1;		/* 0x30 */
218 	union {			/* 0x34 */
219 		u32 gfwr_mx28;	/* MX28, MX53 */
220 		u32 ctrl2;	/* MX6, VF610 */
221 	};
222 	u32 esr2;		/* 0x38 */
223 	u32 imeur;		/* 0x3c */
224 	u32 lrfr;		/* 0x40 */
225 	u32 crcr;		/* 0x44 */
226 	u32 rxfgmask;		/* 0x48 */
227 	u32 rxfir;		/* 0x4c */
228 	u32 _reserved3[12];	/* 0x50 */
229 	u8 mb[2][512];		/* 0x80 */
230 	/* FIFO-mode:
231 	 *			MB
232 	 * 0x080...0x08f	0	RX message buffer
233 	 * 0x090...0x0df	1-5	reserverd
234 	 * 0x0e0...0x0ff	6-7	8 entry ID table
235 	 *				(mx25, mx28, mx35, mx53)
236 	 * 0x0e0...0x2df	6-7..37	8..128 entry ID table
237 	 *				size conf'ed via ctrl2::RFFN
238 	 *				(mx6, vf610)
239 	 */
240 	u32 _reserved4[256];	/* 0x480 */
241 	u32 rximr[64];		/* 0x880 */
242 	u32 _reserved5[24];	/* 0x980 */
243 	u32 gfwr_mx6;		/* 0x9e0 - MX6 */
244 	u32 _reserved6[63];	/* 0x9e4 */
245 	u32 mecr;		/* 0xae0 */
246 	u32 erriar;		/* 0xae4 */
247 	u32 erridpr;		/* 0xae8 */
248 	u32 errippr;		/* 0xaec */
249 	u32 rerrar;		/* 0xaf0 */
250 	u32 rerrdr;		/* 0xaf4 */
251 	u32 rerrsynr;		/* 0xaf8 */
252 	u32 errsr;		/* 0xafc */
253 };
254 
255 struct flexcan_devtype_data {
256 	u32 quirks;		/* quirks needed for different IP cores */
257 };
258 
259 struct flexcan_stop_mode {
260 	struct regmap *gpr;
261 	u8 req_gpr;
262 	u8 req_bit;
263 	u8 ack_gpr;
264 	u8 ack_bit;
265 };
266 
267 struct flexcan_priv {
268 	struct can_priv can;
269 	struct can_rx_offload offload;
270 	struct device *dev;
271 
272 	struct flexcan_regs __iomem *regs;
273 	struct flexcan_mb __iomem *tx_mb;
274 	struct flexcan_mb __iomem *tx_mb_reserved;
275 	u8 tx_mb_idx;
276 	u8 mb_count;
277 	u8 mb_size;
278 	u8 clk_src;	/* clock source of CAN Protocol Engine */
279 
280 	u32 reg_ctrl_default;
281 	u32 reg_imask1_default;
282 	u32 reg_imask2_default;
283 
284 	struct clk *clk_ipg;
285 	struct clk *clk_per;
286 	const struct flexcan_devtype_data *devtype_data;
287 	struct regulator *reg_xceiver;
288 	struct flexcan_stop_mode stm;
289 
290 	/* Read and Write APIs */
291 	u32 (*read)(void __iomem *addr);
292 	void (*write)(u32 val, void __iomem *addr);
293 };
294 
295 static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
296 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
297 		FLEXCAN_QUIRK_BROKEN_PERR_STATE |
298 		FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN,
299 };
300 
301 static const struct flexcan_devtype_data fsl_imx25_devtype_data = {
302 	.quirks = FLEXCAN_QUIRK_BROKEN_WERR_STATE |
303 		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
304 };
305 
306 static const struct flexcan_devtype_data fsl_imx28_devtype_data = {
307 	.quirks = FLEXCAN_QUIRK_BROKEN_PERR_STATE,
308 };
309 
310 static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
311 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
312 		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
313 		FLEXCAN_QUIRK_SETUP_STOP_MODE,
314 };
315 
316 static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
317 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
318 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP |
319 		FLEXCAN_QUIRK_BROKEN_PERR_STATE,
320 };
321 
322 static const struct flexcan_devtype_data fsl_ls1021a_r2_devtype_data = {
323 	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
324 		FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_BROKEN_PERR_STATE |
325 		FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
326 };
327 
328 static const struct can_bittiming_const flexcan_bittiming_const = {
329 	.name = DRV_NAME,
330 	.tseg1_min = 4,
331 	.tseg1_max = 16,
332 	.tseg2_min = 2,
333 	.tseg2_max = 8,
334 	.sjw_max = 4,
335 	.brp_min = 1,
336 	.brp_max = 256,
337 	.brp_inc = 1,
338 };
339 
340 /* FlexCAN module is essentially modelled as a little-endian IP in most
341  * SoCs, i.e the registers as well as the message buffer areas are
342  * implemented in a little-endian fashion.
343  *
344  * However there are some SoCs (e.g. LS1021A) which implement the FlexCAN
345  * module in a big-endian fashion (i.e the registers as well as the
346  * message buffer areas are implemented in a big-endian way).
347  *
348  * In addition, the FlexCAN module can be found on SoCs having ARM or
349  * PPC cores. So, we need to abstract off the register read/write
350  * functions, ensuring that these cater to all the combinations of module
351  * endianness and underlying CPU endianness.
352  */
flexcan_read_be(void __iomem * addr)353 static inline u32 flexcan_read_be(void __iomem *addr)
354 {
355 	return ioread32be(addr);
356 }
357 
flexcan_write_be(u32 val,void __iomem * addr)358 static inline void flexcan_write_be(u32 val, void __iomem *addr)
359 {
360 	iowrite32be(val, addr);
361 }
362 
flexcan_read_le(void __iomem * addr)363 static inline u32 flexcan_read_le(void __iomem *addr)
364 {
365 	return ioread32(addr);
366 }
367 
flexcan_write_le(u32 val,void __iomem * addr)368 static inline void flexcan_write_le(u32 val, void __iomem *addr)
369 {
370 	iowrite32(val, addr);
371 }
372 
flexcan_get_mb(const struct flexcan_priv * priv,u8 mb_index)373 static struct flexcan_mb __iomem *flexcan_get_mb(const struct flexcan_priv *priv,
374 						 u8 mb_index)
375 {
376 	u8 bank_size;
377 	bool bank;
378 
379 	if (WARN_ON(mb_index >= priv->mb_count))
380 		return NULL;
381 
382 	bank_size = sizeof(priv->regs->mb[0]) / priv->mb_size;
383 
384 	bank = mb_index >= bank_size;
385 	if (bank)
386 		mb_index -= bank_size;
387 
388 	return (struct flexcan_mb __iomem *)
389 		(&priv->regs->mb[bank][priv->mb_size * mb_index]);
390 }
391 
flexcan_enable_wakeup_irq(struct flexcan_priv * priv,bool enable)392 static void flexcan_enable_wakeup_irq(struct flexcan_priv *priv, bool enable)
393 {
394 	struct flexcan_regs __iomem *regs = priv->regs;
395 	u32 reg_mcr;
396 
397 	reg_mcr = priv->read(&regs->mcr);
398 
399 	if (enable)
400 		reg_mcr |= FLEXCAN_MCR_WAK_MSK;
401 	else
402 		reg_mcr &= ~FLEXCAN_MCR_WAK_MSK;
403 
404 	priv->write(reg_mcr, &regs->mcr);
405 }
406 
flexcan_enter_stop_mode(struct flexcan_priv * priv)407 static inline int flexcan_enter_stop_mode(struct flexcan_priv *priv)
408 {
409 	struct flexcan_regs __iomem *regs = priv->regs;
410 	unsigned int ackval;
411 	u32 reg_mcr;
412 
413 	reg_mcr = priv->read(&regs->mcr);
414 	reg_mcr |= FLEXCAN_MCR_SLF_WAK;
415 	priv->write(reg_mcr, &regs->mcr);
416 
417 	/* enable stop request */
418 	regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
419 			   1 << priv->stm.req_bit, 1 << priv->stm.req_bit);
420 
421 	/* get stop acknowledgment */
422 	if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr,
423 				     ackval, ackval & (1 << priv->stm.ack_bit),
424 				     0, FLEXCAN_TIMEOUT_US))
425 		return -ETIMEDOUT;
426 
427 	return 0;
428 }
429 
flexcan_exit_stop_mode(struct flexcan_priv * priv)430 static inline int flexcan_exit_stop_mode(struct flexcan_priv *priv)
431 {
432 	struct flexcan_regs __iomem *regs = priv->regs;
433 	unsigned int ackval;
434 	u32 reg_mcr;
435 
436 	/* remove stop request */
437 	regmap_update_bits(priv->stm.gpr, priv->stm.req_gpr,
438 			   1 << priv->stm.req_bit, 0);
439 
440 	/* get stop acknowledgment */
441 	if (regmap_read_poll_timeout(priv->stm.gpr, priv->stm.ack_gpr,
442 				     ackval, !(ackval & (1 << priv->stm.ack_bit)),
443 				     0, FLEXCAN_TIMEOUT_US))
444 		return -ETIMEDOUT;
445 
446 	reg_mcr = priv->read(&regs->mcr);
447 	reg_mcr &= ~FLEXCAN_MCR_SLF_WAK;
448 	priv->write(reg_mcr, &regs->mcr);
449 
450 	return 0;
451 }
452 
flexcan_error_irq_enable(const struct flexcan_priv * priv)453 static inline void flexcan_error_irq_enable(const struct flexcan_priv *priv)
454 {
455 	struct flexcan_regs __iomem *regs = priv->regs;
456 	u32 reg_ctrl = (priv->reg_ctrl_default | FLEXCAN_CTRL_ERR_MSK);
457 
458 	priv->write(reg_ctrl, &regs->ctrl);
459 }
460 
flexcan_error_irq_disable(const struct flexcan_priv * priv)461 static inline void flexcan_error_irq_disable(const struct flexcan_priv *priv)
462 {
463 	struct flexcan_regs __iomem *regs = priv->regs;
464 	u32 reg_ctrl = (priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_MSK);
465 
466 	priv->write(reg_ctrl, &regs->ctrl);
467 }
468 
flexcan_clks_enable(const struct flexcan_priv * priv)469 static int flexcan_clks_enable(const struct flexcan_priv *priv)
470 {
471 	int err;
472 
473 	err = clk_prepare_enable(priv->clk_ipg);
474 	if (err)
475 		return err;
476 
477 	err = clk_prepare_enable(priv->clk_per);
478 	if (err)
479 		clk_disable_unprepare(priv->clk_ipg);
480 
481 	return err;
482 }
483 
flexcan_clks_disable(const struct flexcan_priv * priv)484 static void flexcan_clks_disable(const struct flexcan_priv *priv)
485 {
486 	clk_disable_unprepare(priv->clk_per);
487 	clk_disable_unprepare(priv->clk_ipg);
488 }
489 
flexcan_transceiver_enable(const struct flexcan_priv * priv)490 static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
491 {
492 	if (!priv->reg_xceiver)
493 		return 0;
494 
495 	return regulator_enable(priv->reg_xceiver);
496 }
497 
flexcan_transceiver_disable(const struct flexcan_priv * priv)498 static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
499 {
500 	if (!priv->reg_xceiver)
501 		return 0;
502 
503 	return regulator_disable(priv->reg_xceiver);
504 }
505 
flexcan_chip_enable(struct flexcan_priv * priv)506 static int flexcan_chip_enable(struct flexcan_priv *priv)
507 {
508 	struct flexcan_regs __iomem *regs = priv->regs;
509 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
510 	u32 reg;
511 
512 	reg = priv->read(&regs->mcr);
513 	reg &= ~FLEXCAN_MCR_MDIS;
514 	priv->write(reg, &regs->mcr);
515 
516 	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
517 		udelay(10);
518 
519 	if (priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
520 		return -ETIMEDOUT;
521 
522 	return 0;
523 }
524 
flexcan_chip_disable(struct flexcan_priv * priv)525 static int flexcan_chip_disable(struct flexcan_priv *priv)
526 {
527 	struct flexcan_regs __iomem *regs = priv->regs;
528 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
529 	u32 reg;
530 
531 	reg = priv->read(&regs->mcr);
532 	reg |= FLEXCAN_MCR_MDIS;
533 	priv->write(reg, &regs->mcr);
534 
535 	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
536 		udelay(10);
537 
538 	if (!(priv->read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
539 		return -ETIMEDOUT;
540 
541 	return 0;
542 }
543 
flexcan_chip_freeze(struct flexcan_priv * priv)544 static int flexcan_chip_freeze(struct flexcan_priv *priv)
545 {
546 	struct flexcan_regs __iomem *regs = priv->regs;
547 	unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
548 	u32 reg;
549 
550 	reg = priv->read(&regs->mcr);
551 	reg |= FLEXCAN_MCR_HALT;
552 	priv->write(reg, &regs->mcr);
553 
554 	while (timeout-- && !(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
555 		udelay(100);
556 
557 	if (!(priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
558 		return -ETIMEDOUT;
559 
560 	return 0;
561 }
562 
flexcan_chip_unfreeze(struct flexcan_priv * priv)563 static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
564 {
565 	struct flexcan_regs __iomem *regs = priv->regs;
566 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
567 	u32 reg;
568 
569 	reg = priv->read(&regs->mcr);
570 	reg &= ~FLEXCAN_MCR_HALT;
571 	priv->write(reg, &regs->mcr);
572 
573 	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
574 		udelay(10);
575 
576 	if (priv->read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
577 		return -ETIMEDOUT;
578 
579 	return 0;
580 }
581 
flexcan_chip_softreset(struct flexcan_priv * priv)582 static int flexcan_chip_softreset(struct flexcan_priv *priv)
583 {
584 	struct flexcan_regs __iomem *regs = priv->regs;
585 	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
586 
587 	priv->write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
588 	while (timeout-- && (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
589 		udelay(10);
590 
591 	if (priv->read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
592 		return -ETIMEDOUT;
593 
594 	return 0;
595 }
596 
__flexcan_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)597 static int __flexcan_get_berr_counter(const struct net_device *dev,
598 				      struct can_berr_counter *bec)
599 {
600 	const struct flexcan_priv *priv = netdev_priv(dev);
601 	struct flexcan_regs __iomem *regs = priv->regs;
602 	u32 reg = priv->read(&regs->ecr);
603 
604 	bec->txerr = (reg >> 0) & 0xff;
605 	bec->rxerr = (reg >> 8) & 0xff;
606 
607 	return 0;
608 }
609 
flexcan_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)610 static int flexcan_get_berr_counter(const struct net_device *dev,
611 				    struct can_berr_counter *bec)
612 {
613 	const struct flexcan_priv *priv = netdev_priv(dev);
614 	int err;
615 
616 	err = pm_runtime_get_sync(priv->dev);
617 	if (err < 0)
618 		return err;
619 
620 	err = __flexcan_get_berr_counter(dev, bec);
621 
622 	pm_runtime_put(priv->dev);
623 
624 	return err;
625 }
626 
flexcan_start_xmit(struct sk_buff * skb,struct net_device * dev)627 static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
628 {
629 	const struct flexcan_priv *priv = netdev_priv(dev);
630 	struct can_frame *cf = (struct can_frame *)skb->data;
631 	u32 can_id;
632 	u32 data;
633 	u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | (cf->can_dlc << 16);
634 	int i;
635 
636 	if (can_dropped_invalid_skb(dev, skb))
637 		return NETDEV_TX_OK;
638 
639 	netif_stop_queue(dev);
640 
641 	if (cf->can_id & CAN_EFF_FLAG) {
642 		can_id = cf->can_id & CAN_EFF_MASK;
643 		ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
644 	} else {
645 		can_id = (cf->can_id & CAN_SFF_MASK) << 18;
646 	}
647 
648 	if (cf->can_id & CAN_RTR_FLAG)
649 		ctrl |= FLEXCAN_MB_CNT_RTR;
650 
651 	for (i = 0; i < cf->can_dlc; i += sizeof(u32)) {
652 		data = be32_to_cpup((__be32 *)&cf->data[i]);
653 		priv->write(data, &priv->tx_mb->data[i / sizeof(u32)]);
654 	}
655 
656 	can_put_echo_skb(skb, dev, 0);
657 
658 	priv->write(can_id, &priv->tx_mb->can_id);
659 	priv->write(ctrl, &priv->tx_mb->can_ctrl);
660 
661 	/* Errata ERR005829 step8:
662 	 * Write twice INACTIVE(0x8) code to first MB.
663 	 */
664 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
665 		    &priv->tx_mb_reserved->can_ctrl);
666 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
667 		    &priv->tx_mb_reserved->can_ctrl);
668 
669 	return NETDEV_TX_OK;
670 }
671 
flexcan_irq_bus_err(struct net_device * dev,u32 reg_esr)672 static void flexcan_irq_bus_err(struct net_device *dev, u32 reg_esr)
673 {
674 	struct flexcan_priv *priv = netdev_priv(dev);
675 	struct flexcan_regs __iomem *regs = priv->regs;
676 	struct sk_buff *skb;
677 	struct can_frame *cf;
678 	bool rx_errors = false, tx_errors = false;
679 	u32 timestamp;
680 	int err;
681 
682 	timestamp = priv->read(&regs->timer) << 16;
683 
684 	skb = alloc_can_err_skb(dev, &cf);
685 	if (unlikely(!skb))
686 		return;
687 
688 	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
689 
690 	if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
691 		netdev_dbg(dev, "BIT1_ERR irq\n");
692 		cf->data[2] |= CAN_ERR_PROT_BIT1;
693 		tx_errors = true;
694 	}
695 	if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
696 		netdev_dbg(dev, "BIT0_ERR irq\n");
697 		cf->data[2] |= CAN_ERR_PROT_BIT0;
698 		tx_errors = true;
699 	}
700 	if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
701 		netdev_dbg(dev, "ACK_ERR irq\n");
702 		cf->can_id |= CAN_ERR_ACK;
703 		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
704 		tx_errors = true;
705 	}
706 	if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
707 		netdev_dbg(dev, "CRC_ERR irq\n");
708 		cf->data[2] |= CAN_ERR_PROT_BIT;
709 		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
710 		rx_errors = true;
711 	}
712 	if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
713 		netdev_dbg(dev, "FRM_ERR irq\n");
714 		cf->data[2] |= CAN_ERR_PROT_FORM;
715 		rx_errors = true;
716 	}
717 	if (reg_esr & FLEXCAN_ESR_STF_ERR) {
718 		netdev_dbg(dev, "STF_ERR irq\n");
719 		cf->data[2] |= CAN_ERR_PROT_STUFF;
720 		rx_errors = true;
721 	}
722 
723 	priv->can.can_stats.bus_error++;
724 	if (rx_errors)
725 		dev->stats.rx_errors++;
726 	if (tx_errors)
727 		dev->stats.tx_errors++;
728 
729 	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
730 	if (err)
731 		dev->stats.rx_fifo_errors++;
732 }
733 
flexcan_irq_state(struct net_device * dev,u32 reg_esr)734 static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
735 {
736 	struct flexcan_priv *priv = netdev_priv(dev);
737 	struct flexcan_regs __iomem *regs = priv->regs;
738 	struct sk_buff *skb;
739 	struct can_frame *cf;
740 	enum can_state new_state, rx_state, tx_state;
741 	int flt;
742 	struct can_berr_counter bec;
743 	u32 timestamp;
744 	int err;
745 
746 	timestamp = priv->read(&regs->timer) << 16;
747 
748 	flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
749 	if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
750 		tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
751 			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
752 		rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
753 			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
754 		new_state = max(tx_state, rx_state);
755 	} else {
756 		__flexcan_get_berr_counter(dev, &bec);
757 		new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
758 			CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
759 		rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
760 		tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
761 	}
762 
763 	/* state hasn't changed */
764 	if (likely(new_state == priv->can.state))
765 		return;
766 
767 	skb = alloc_can_err_skb(dev, &cf);
768 	if (unlikely(!skb))
769 		return;
770 
771 	can_change_state(dev, cf, tx_state, rx_state);
772 
773 	if (unlikely(new_state == CAN_STATE_BUS_OFF))
774 		can_bus_off(dev);
775 
776 	err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp);
777 	if (err)
778 		dev->stats.rx_fifo_errors++;
779 }
780 
rx_offload_to_priv(struct can_rx_offload * offload)781 static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *offload)
782 {
783 	return container_of(offload, struct flexcan_priv, offload);
784 }
785 
flexcan_mailbox_read(struct can_rx_offload * offload,struct can_frame * cf,u32 * timestamp,unsigned int n)786 static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
787 					 struct can_frame *cf,
788 					 u32 *timestamp, unsigned int n)
789 {
790 	struct flexcan_priv *priv = rx_offload_to_priv(offload);
791 	struct flexcan_regs __iomem *regs = priv->regs;
792 	struct flexcan_mb __iomem *mb;
793 	u32 reg_ctrl, reg_id, reg_iflag1;
794 	int i;
795 
796 	mb = flexcan_get_mb(priv, n);
797 
798 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
799 		u32 code;
800 
801 		do {
802 			reg_ctrl = priv->read(&mb->can_ctrl);
803 		} while (reg_ctrl & FLEXCAN_MB_CODE_RX_BUSY_BIT);
804 
805 		/* is this MB empty? */
806 		code = reg_ctrl & FLEXCAN_MB_CODE_MASK;
807 		if ((code != FLEXCAN_MB_CODE_RX_FULL) &&
808 		    (code != FLEXCAN_MB_CODE_RX_OVERRUN))
809 			return 0;
810 
811 		if (code == FLEXCAN_MB_CODE_RX_OVERRUN) {
812 			/* This MB was overrun, we lost data */
813 			offload->dev->stats.rx_over_errors++;
814 			offload->dev->stats.rx_errors++;
815 		}
816 	} else {
817 		reg_iflag1 = priv->read(&regs->iflag1);
818 		if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
819 			return 0;
820 
821 		reg_ctrl = priv->read(&mb->can_ctrl);
822 	}
823 
824 	/* increase timstamp to full 32 bit */
825 	*timestamp = reg_ctrl << 16;
826 
827 	reg_id = priv->read(&mb->can_id);
828 	if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
829 		cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
830 	else
831 		cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
832 
833 	if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
834 		cf->can_id |= CAN_RTR_FLAG;
835 	cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
836 
837 	for (i = 0; i < cf->can_dlc; i += sizeof(u32)) {
838 		__be32 data = cpu_to_be32(priv->read(&mb->data[i / sizeof(u32)]));
839 		*(__be32 *)(cf->data + i) = data;
840 	}
841 
842 	/* mark as read */
843 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
844 		/* Clear IRQ */
845 		if (n < 32)
846 			priv->write(BIT(n), &regs->iflag1);
847 		else
848 			priv->write(BIT(n - 32), &regs->iflag2);
849 	} else {
850 		priv->write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
851 	}
852 
853 	/* Read the Free Running Timer. It is optional but recommended
854 	 * to unlock Mailbox as soon as possible and make it available
855 	 * for reception.
856 	 */
857 	priv->read(&regs->timer);
858 
859 	return 1;
860 }
861 
862 
flexcan_read_reg_iflag_rx(struct flexcan_priv * priv)863 static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
864 {
865 	struct flexcan_regs __iomem *regs = priv->regs;
866 	u32 iflag1, iflag2;
867 
868 	iflag2 = priv->read(&regs->iflag2) & priv->reg_imask2_default &
869 		~FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
870 	iflag1 = priv->read(&regs->iflag1) & priv->reg_imask1_default;
871 
872 	return (u64)iflag2 << 32 | iflag1;
873 }
874 
flexcan_irq(int irq,void * dev_id)875 static irqreturn_t flexcan_irq(int irq, void *dev_id)
876 {
877 	struct net_device *dev = dev_id;
878 	struct net_device_stats *stats = &dev->stats;
879 	struct flexcan_priv *priv = netdev_priv(dev);
880 	struct flexcan_regs __iomem *regs = priv->regs;
881 	irqreturn_t handled = IRQ_NONE;
882 	u32 reg_iflag2, reg_esr;
883 	enum can_state last_state = priv->can.state;
884 
885 	/* reception interrupt */
886 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
887 		u64 reg_iflag;
888 		int ret;
889 
890 		while ((reg_iflag = flexcan_read_reg_iflag_rx(priv))) {
891 			handled = IRQ_HANDLED;
892 			ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
893 								   reg_iflag);
894 			if (!ret)
895 				break;
896 		}
897 	} else {
898 		u32 reg_iflag1;
899 
900 		reg_iflag1 = priv->read(&regs->iflag1);
901 		if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
902 			handled = IRQ_HANDLED;
903 			can_rx_offload_irq_offload_fifo(&priv->offload);
904 		}
905 
906 		/* FIFO overflow interrupt */
907 		if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
908 			handled = IRQ_HANDLED;
909 			priv->write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW,
910 				    &regs->iflag1);
911 			dev->stats.rx_over_errors++;
912 			dev->stats.rx_errors++;
913 		}
914 	}
915 
916 	reg_iflag2 = priv->read(&regs->iflag2);
917 
918 	/* transmission complete interrupt */
919 	if (reg_iflag2 & FLEXCAN_IFLAG_MB(priv->tx_mb_idx)) {
920 		u32 reg_ctrl = priv->read(&priv->tx_mb->can_ctrl);
921 
922 		handled = IRQ_HANDLED;
923 		stats->tx_bytes += can_rx_offload_get_echo_skb(&priv->offload,
924 							       0, reg_ctrl << 16);
925 		stats->tx_packets++;
926 		can_led_event(dev, CAN_LED_EVENT_TX);
927 
928 		/* after sending a RTR frame MB is in RX mode */
929 		priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
930 			    &priv->tx_mb->can_ctrl);
931 		priv->write(FLEXCAN_IFLAG_MB(priv->tx_mb_idx), &regs->iflag2);
932 		netif_wake_queue(dev);
933 	}
934 
935 	reg_esr = priv->read(&regs->esr);
936 
937 	/* ACK all bus error and state change IRQ sources */
938 	if (reg_esr & FLEXCAN_ESR_ALL_INT) {
939 		handled = IRQ_HANDLED;
940 		priv->write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
941 	}
942 
943 	/* state change interrupt or broken error state quirk fix is enabled */
944 	if ((reg_esr & FLEXCAN_ESR_ERR_STATE) ||
945 	    (priv->devtype_data->quirks & (FLEXCAN_QUIRK_BROKEN_WERR_STATE |
946 					   FLEXCAN_QUIRK_BROKEN_PERR_STATE)))
947 		flexcan_irq_state(dev, reg_esr);
948 
949 	/* bus error IRQ - handle if bus error reporting is activated */
950 	if ((reg_esr & FLEXCAN_ESR_ERR_BUS) &&
951 	    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
952 		flexcan_irq_bus_err(dev, reg_esr);
953 
954 	/* availability of error interrupt among state transitions in case
955 	 * bus error reporting is de-activated and
956 	 * FLEXCAN_QUIRK_BROKEN_PERR_STATE is enabled:
957 	 *  +--------------------------------------------------------------+
958 	 *  | +----------------------------------------------+ [stopped /  |
959 	 *  | |                                              |  sleeping] -+
960 	 *  +-+-> active <-> warning <-> passive -> bus off -+
961 	 *        ___________^^^^^^^^^^^^_______________________________
962 	 *        disabled(1)  enabled             disabled
963 	 *
964 	 * (1): enabled if FLEXCAN_QUIRK_BROKEN_WERR_STATE is enabled
965 	 */
966 	if ((last_state != priv->can.state) &&
967 	    (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_PERR_STATE) &&
968 	    !(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
969 		switch (priv->can.state) {
970 		case CAN_STATE_ERROR_ACTIVE:
971 			if (priv->devtype_data->quirks &
972 			    FLEXCAN_QUIRK_BROKEN_WERR_STATE)
973 				flexcan_error_irq_enable(priv);
974 			else
975 				flexcan_error_irq_disable(priv);
976 			break;
977 
978 		case CAN_STATE_ERROR_WARNING:
979 			flexcan_error_irq_enable(priv);
980 			break;
981 
982 		case CAN_STATE_ERROR_PASSIVE:
983 		case CAN_STATE_BUS_OFF:
984 			flexcan_error_irq_disable(priv);
985 			break;
986 
987 		default:
988 			break;
989 		}
990 	}
991 
992 	return handled;
993 }
994 
flexcan_set_bittiming(struct net_device * dev)995 static void flexcan_set_bittiming(struct net_device *dev)
996 {
997 	const struct flexcan_priv *priv = netdev_priv(dev);
998 	const struct can_bittiming *bt = &priv->can.bittiming;
999 	struct flexcan_regs __iomem *regs = priv->regs;
1000 	u32 reg;
1001 
1002 	reg = priv->read(&regs->ctrl);
1003 	reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
1004 		 FLEXCAN_CTRL_RJW(0x3) |
1005 		 FLEXCAN_CTRL_PSEG1(0x7) |
1006 		 FLEXCAN_CTRL_PSEG2(0x7) |
1007 		 FLEXCAN_CTRL_PROPSEG(0x7) |
1008 		 FLEXCAN_CTRL_LPB |
1009 		 FLEXCAN_CTRL_SMP |
1010 		 FLEXCAN_CTRL_LOM);
1011 
1012 	reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
1013 		FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
1014 		FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
1015 		FLEXCAN_CTRL_RJW(bt->sjw - 1) |
1016 		FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
1017 
1018 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
1019 		reg |= FLEXCAN_CTRL_LPB;
1020 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1021 		reg |= FLEXCAN_CTRL_LOM;
1022 	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
1023 		reg |= FLEXCAN_CTRL_SMP;
1024 
1025 	netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
1026 	priv->write(reg, &regs->ctrl);
1027 
1028 	/* print chip status */
1029 	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
1030 		   priv->read(&regs->mcr), priv->read(&regs->ctrl));
1031 }
1032 
1033 /* flexcan_chip_start
1034  *
1035  * this functions is entered with clocks enabled
1036  *
1037  */
flexcan_chip_start(struct net_device * dev)1038 static int flexcan_chip_start(struct net_device *dev)
1039 {
1040 	struct flexcan_priv *priv = netdev_priv(dev);
1041 	struct flexcan_regs __iomem *regs = priv->regs;
1042 	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
1043 	int err, i;
1044 	struct flexcan_mb __iomem *mb;
1045 
1046 	/* enable module */
1047 	err = flexcan_chip_enable(priv);
1048 	if (err)
1049 		return err;
1050 
1051 	/* soft reset */
1052 	err = flexcan_chip_softreset(priv);
1053 	if (err)
1054 		goto out_chip_disable;
1055 
1056 	flexcan_set_bittiming(dev);
1057 
1058 	/* MCR
1059 	 *
1060 	 * enable freeze
1061 	 * halt now
1062 	 * only supervisor access
1063 	 * enable warning int
1064 	 * enable individual RX masking
1065 	 * choose format C
1066 	 * set max mailbox number
1067 	 */
1068 	reg_mcr = priv->read(&regs->mcr);
1069 	reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
1070 	reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV |
1071 		FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IRMQ | FLEXCAN_MCR_IDAM_C |
1072 		FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
1073 
1074 	/* MCR
1075 	 *
1076 	 * FIFO:
1077 	 * - disable for timestamp mode
1078 	 * - enable for FIFO mode
1079 	 */
1080 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
1081 		reg_mcr &= ~FLEXCAN_MCR_FEN;
1082 	else
1083 		reg_mcr |= FLEXCAN_MCR_FEN;
1084 
1085 	/* MCR
1086 	 *
1087 	 * NOTE: In loopback mode, the CAN_MCR[SRXDIS] cannot be
1088 	 *       asserted because this will impede the self reception
1089 	 *       of a transmitted message. This is not documented in
1090 	 *       earlier versions of flexcan block guide.
1091 	 *
1092 	 * Self Reception:
1093 	 * - enable Self Reception for loopback mode
1094 	 *   (by clearing "Self Reception Disable" bit)
1095 	 * - disable for normal operation
1096 	 */
1097 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
1098 		reg_mcr &= ~FLEXCAN_MCR_SRX_DIS;
1099 	else
1100 		reg_mcr |= FLEXCAN_MCR_SRX_DIS;
1101 
1102 	netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
1103 	priv->write(reg_mcr, &regs->mcr);
1104 
1105 	/* CTRL
1106 	 *
1107 	 * disable timer sync feature
1108 	 *
1109 	 * disable auto busoff recovery
1110 	 * transmit lowest buffer first
1111 	 *
1112 	 * enable tx and rx warning interrupt
1113 	 * enable bus off interrupt
1114 	 * (== FLEXCAN_CTRL_ERR_STATE)
1115 	 */
1116 	reg_ctrl = priv->read(&regs->ctrl);
1117 	reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
1118 	reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
1119 		FLEXCAN_CTRL_ERR_STATE;
1120 
1121 	/* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
1122 	 * on most Flexcan cores, too. Otherwise we don't get
1123 	 * any error warning or passive interrupts.
1124 	 */
1125 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_WERR_STATE ||
1126 	    priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
1127 		reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
1128 	else
1129 		reg_ctrl &= ~FLEXCAN_CTRL_ERR_MSK;
1130 
1131 	/* save for later use */
1132 	priv->reg_ctrl_default = reg_ctrl;
1133 	/* leave interrupts disabled for now */
1134 	reg_ctrl &= ~FLEXCAN_CTRL_ERR_ALL;
1135 	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
1136 	priv->write(reg_ctrl, &regs->ctrl);
1137 
1138 	if ((priv->devtype_data->quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
1139 		reg_ctrl2 = priv->read(&regs->ctrl2);
1140 		reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
1141 		priv->write(reg_ctrl2, &regs->ctrl2);
1142 	}
1143 
1144 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
1145 		for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++) {
1146 			mb = flexcan_get_mb(priv, i);
1147 			priv->write(FLEXCAN_MB_CODE_RX_EMPTY,
1148 				    &mb->can_ctrl);
1149 		}
1150 	} else {
1151 		/* clear and invalidate unused mailboxes first */
1152 		for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < priv->mb_count; i++) {
1153 			mb = flexcan_get_mb(priv, i);
1154 			priv->write(FLEXCAN_MB_CODE_RX_INACTIVE,
1155 				    &mb->can_ctrl);
1156 		}
1157 	}
1158 
1159 	/* Errata ERR005829: mark first TX mailbox as INACTIVE */
1160 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
1161 		    &priv->tx_mb_reserved->can_ctrl);
1162 
1163 	/* mark TX mailbox as INACTIVE */
1164 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
1165 		    &priv->tx_mb->can_ctrl);
1166 
1167 	/* acceptance mask/acceptance code (accept everything) */
1168 	priv->write(0x0, &regs->rxgmask);
1169 	priv->write(0x0, &regs->rx14mask);
1170 	priv->write(0x0, &regs->rx15mask);
1171 
1172 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
1173 		priv->write(0x0, &regs->rxfgmask);
1174 
1175 	/* clear acceptance filters */
1176 	for (i = 0; i < priv->mb_count; i++)
1177 		priv->write(0, &regs->rximr[i]);
1178 
1179 	/* On Vybrid, disable memory error detection interrupts
1180 	 * and freeze mode.
1181 	 * This also works around errata e5295 which generates
1182 	 * false positive memory errors and put the device in
1183 	 * freeze mode.
1184 	 */
1185 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
1186 		/* Follow the protocol as described in "Detection
1187 		 * and Correction of Memory Errors" to write to
1188 		 * MECR register
1189 		 */
1190 		reg_ctrl2 = priv->read(&regs->ctrl2);
1191 		reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE;
1192 		priv->write(reg_ctrl2, &regs->ctrl2);
1193 
1194 		reg_mecr = priv->read(&regs->mecr);
1195 		reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
1196 		priv->write(reg_mecr, &regs->mecr);
1197 		reg_mecr |= FLEXCAN_MECR_ECCDIS;
1198 		reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
1199 			      FLEXCAN_MECR_FANCEI_MSK);
1200 		priv->write(reg_mecr, &regs->mecr);
1201 	}
1202 
1203 	err = flexcan_transceiver_enable(priv);
1204 	if (err)
1205 		goto out_chip_disable;
1206 
1207 	/* synchronize with the can bus */
1208 	err = flexcan_chip_unfreeze(priv);
1209 	if (err)
1210 		goto out_transceiver_disable;
1211 
1212 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1213 
1214 	/* enable interrupts atomically */
1215 	disable_irq(dev->irq);
1216 	priv->write(priv->reg_ctrl_default, &regs->ctrl);
1217 	priv->write(priv->reg_imask1_default, &regs->imask1);
1218 	priv->write(priv->reg_imask2_default, &regs->imask2);
1219 	enable_irq(dev->irq);
1220 
1221 	/* print chip status */
1222 	netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
1223 		   priv->read(&regs->mcr), priv->read(&regs->ctrl));
1224 
1225 	return 0;
1226 
1227  out_transceiver_disable:
1228 	flexcan_transceiver_disable(priv);
1229  out_chip_disable:
1230 	flexcan_chip_disable(priv);
1231 	return err;
1232 }
1233 
1234 /* flexcan_chip_stop
1235  *
1236  * this functions is entered with clocks enabled
1237  */
flexcan_chip_stop(struct net_device * dev)1238 static void flexcan_chip_stop(struct net_device *dev)
1239 {
1240 	struct flexcan_priv *priv = netdev_priv(dev);
1241 	struct flexcan_regs __iomem *regs = priv->regs;
1242 
1243 	/* freeze + disable module */
1244 	flexcan_chip_freeze(priv);
1245 	flexcan_chip_disable(priv);
1246 
1247 	/* Disable all interrupts */
1248 	priv->write(0, &regs->imask2);
1249 	priv->write(0, &regs->imask1);
1250 	priv->write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
1251 		    &regs->ctrl);
1252 
1253 	flexcan_transceiver_disable(priv);
1254 	priv->can.state = CAN_STATE_STOPPED;
1255 }
1256 
flexcan_open(struct net_device * dev)1257 static int flexcan_open(struct net_device *dev)
1258 {
1259 	struct flexcan_priv *priv = netdev_priv(dev);
1260 	int err;
1261 
1262 	err = pm_runtime_get_sync(priv->dev);
1263 	if (err < 0)
1264 		return err;
1265 
1266 	err = open_candev(dev);
1267 	if (err)
1268 		goto out_runtime_put;
1269 
1270 	err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
1271 	if (err)
1272 		goto out_close;
1273 
1274 	priv->mb_size = sizeof(struct flexcan_mb) + CAN_MAX_DLEN;
1275 	priv->mb_count = (sizeof(priv->regs->mb[0]) / priv->mb_size) +
1276 			 (sizeof(priv->regs->mb[1]) / priv->mb_size);
1277 
1278 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
1279 		priv->tx_mb_reserved =
1280 			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP);
1281 	else
1282 		priv->tx_mb_reserved =
1283 			flexcan_get_mb(priv, FLEXCAN_TX_MB_RESERVED_OFF_FIFO);
1284 	priv->tx_mb_idx = priv->mb_count - 1;
1285 	priv->tx_mb = flexcan_get_mb(priv, priv->tx_mb_idx);
1286 
1287 	priv->reg_imask1_default = 0;
1288 	priv->reg_imask2_default = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
1289 
1290 	priv->offload.mailbox_read = flexcan_mailbox_read;
1291 
1292 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
1293 		u64 imask;
1294 
1295 		priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
1296 		priv->offload.mb_last = priv->mb_count - 2;
1297 
1298 		imask = GENMASK_ULL(priv->offload.mb_last,
1299 				    priv->offload.mb_first);
1300 		priv->reg_imask1_default |= imask;
1301 		priv->reg_imask2_default |= imask >> 32;
1302 
1303 		err = can_rx_offload_add_timestamp(dev, &priv->offload);
1304 	} else {
1305 		priv->reg_imask1_default |= FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
1306 			FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
1307 		err = can_rx_offload_add_fifo(dev, &priv->offload,
1308 					      FLEXCAN_NAPI_WEIGHT);
1309 	}
1310 	if (err)
1311 		goto out_free_irq;
1312 
1313 	/* start chip and queuing */
1314 	err = flexcan_chip_start(dev);
1315 	if (err)
1316 		goto out_offload_del;
1317 
1318 	can_led_event(dev, CAN_LED_EVENT_OPEN);
1319 
1320 	can_rx_offload_enable(&priv->offload);
1321 	netif_start_queue(dev);
1322 
1323 	return 0;
1324 
1325  out_offload_del:
1326 	can_rx_offload_del(&priv->offload);
1327  out_free_irq:
1328 	free_irq(dev->irq, dev);
1329  out_close:
1330 	close_candev(dev);
1331  out_runtime_put:
1332 	pm_runtime_put(priv->dev);
1333 
1334 	return err;
1335 }
1336 
flexcan_close(struct net_device * dev)1337 static int flexcan_close(struct net_device *dev)
1338 {
1339 	struct flexcan_priv *priv = netdev_priv(dev);
1340 
1341 	netif_stop_queue(dev);
1342 	can_rx_offload_disable(&priv->offload);
1343 	flexcan_chip_stop(dev);
1344 
1345 	can_rx_offload_del(&priv->offload);
1346 	free_irq(dev->irq, dev);
1347 
1348 	close_candev(dev);
1349 	pm_runtime_put(priv->dev);
1350 
1351 	can_led_event(dev, CAN_LED_EVENT_STOP);
1352 
1353 	return 0;
1354 }
1355 
flexcan_set_mode(struct net_device * dev,enum can_mode mode)1356 static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
1357 {
1358 	int err;
1359 
1360 	switch (mode) {
1361 	case CAN_MODE_START:
1362 		err = flexcan_chip_start(dev);
1363 		if (err)
1364 			return err;
1365 
1366 		netif_wake_queue(dev);
1367 		break;
1368 
1369 	default:
1370 		return -EOPNOTSUPP;
1371 	}
1372 
1373 	return 0;
1374 }
1375 
1376 static const struct net_device_ops flexcan_netdev_ops = {
1377 	.ndo_open	= flexcan_open,
1378 	.ndo_stop	= flexcan_close,
1379 	.ndo_start_xmit	= flexcan_start_xmit,
1380 	.ndo_change_mtu = can_change_mtu,
1381 };
1382 
register_flexcandev(struct net_device * dev)1383 static int register_flexcandev(struct net_device *dev)
1384 {
1385 	struct flexcan_priv *priv = netdev_priv(dev);
1386 	struct flexcan_regs __iomem *regs = priv->regs;
1387 	u32 reg, err;
1388 
1389 	err = flexcan_clks_enable(priv);
1390 	if (err)
1391 		return err;
1392 
1393 	/* select "bus clock", chip must be disabled */
1394 	err = flexcan_chip_disable(priv);
1395 	if (err)
1396 		goto out_clks_disable;
1397 
1398 	reg = priv->read(&regs->ctrl);
1399 	if (priv->clk_src)
1400 		reg |= FLEXCAN_CTRL_CLK_SRC;
1401 	else
1402 		reg &= ~FLEXCAN_CTRL_CLK_SRC;
1403 	priv->write(reg, &regs->ctrl);
1404 
1405 	err = flexcan_chip_enable(priv);
1406 	if (err)
1407 		goto out_chip_disable;
1408 
1409 	/* set freeze, halt and activate FIFO, restrict register access */
1410 	reg = priv->read(&regs->mcr);
1411 	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
1412 		FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
1413 	priv->write(reg, &regs->mcr);
1414 
1415 	/* Currently we only support newer versions of this core
1416 	 * featuring a RX hardware FIFO (although this driver doesn't
1417 	 * make use of it on some cores). Older cores, found on some
1418 	 * Coldfire derivates are not tested.
1419 	 */
1420 	reg = priv->read(&regs->mcr);
1421 	if (!(reg & FLEXCAN_MCR_FEN)) {
1422 		netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
1423 		err = -ENODEV;
1424 		goto out_chip_disable;
1425 	}
1426 
1427 	err = register_candev(dev);
1428 	if (err)
1429 		goto out_chip_disable;
1430 
1431 	/* Disable core and let pm_runtime_put() disable the clocks.
1432 	 * If CONFIG_PM is not enabled, the clocks will stay powered.
1433 	 */
1434 	flexcan_chip_disable(priv);
1435 	pm_runtime_put(priv->dev);
1436 
1437 	return 0;
1438 
1439  out_chip_disable:
1440 	flexcan_chip_disable(priv);
1441  out_clks_disable:
1442 	flexcan_clks_disable(priv);
1443 	return err;
1444 }
1445 
unregister_flexcandev(struct net_device * dev)1446 static void unregister_flexcandev(struct net_device *dev)
1447 {
1448 	unregister_candev(dev);
1449 }
1450 
flexcan_setup_stop_mode(struct platform_device * pdev)1451 static int flexcan_setup_stop_mode(struct platform_device *pdev)
1452 {
1453 	struct net_device *dev = platform_get_drvdata(pdev);
1454 	struct device_node *np = pdev->dev.of_node;
1455 	struct device_node *gpr_np;
1456 	struct flexcan_priv *priv;
1457 	phandle phandle;
1458 	u32 out_val[5];
1459 	int ret;
1460 
1461 	if (!np)
1462 		return -EINVAL;
1463 
1464 	/* stop mode property format is:
1465 	 * <&gpr req_gpr req_bit ack_gpr ack_bit>.
1466 	 */
1467 	ret = of_property_read_u32_array(np, "fsl,stop-mode", out_val,
1468 					 ARRAY_SIZE(out_val));
1469 	if (ret) {
1470 		dev_dbg(&pdev->dev, "no stop-mode property\n");
1471 		return ret;
1472 	}
1473 	phandle = *out_val;
1474 
1475 	gpr_np = of_find_node_by_phandle(phandle);
1476 	if (!gpr_np) {
1477 		dev_dbg(&pdev->dev, "could not find gpr node by phandle\n");
1478 		return -ENODEV;
1479 	}
1480 
1481 	priv = netdev_priv(dev);
1482 	priv->stm.gpr = syscon_node_to_regmap(gpr_np);
1483 	if (IS_ERR(priv->stm.gpr)) {
1484 		dev_dbg(&pdev->dev, "could not find gpr regmap\n");
1485 		ret = PTR_ERR(priv->stm.gpr);
1486 		goto out_put_node;
1487 	}
1488 
1489 	priv->stm.req_gpr = out_val[1];
1490 	priv->stm.req_bit = out_val[2];
1491 	priv->stm.ack_gpr = out_val[3];
1492 	priv->stm.ack_bit = out_val[4];
1493 
1494 	dev_dbg(&pdev->dev,
1495 		"gpr %s req_gpr=0x02%x req_bit=%u ack_gpr=0x02%x ack_bit=%u\n",
1496 		gpr_np->full_name, priv->stm.req_gpr, priv->stm.req_bit,
1497 		priv->stm.ack_gpr, priv->stm.ack_bit);
1498 
1499 	device_set_wakeup_capable(&pdev->dev, true);
1500 
1501 	if (of_property_read_bool(np, "wakeup-source"))
1502 		device_set_wakeup_enable(&pdev->dev, true);
1503 
1504 	return 0;
1505 
1506 out_put_node:
1507 	of_node_put(gpr_np);
1508 	return ret;
1509 }
1510 
1511 static const struct of_device_id flexcan_of_match[] = {
1512 	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
1513 	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
1514 	{ .compatible = "fsl,imx53-flexcan", .data = &fsl_imx25_devtype_data, },
1515 	{ .compatible = "fsl,imx35-flexcan", .data = &fsl_imx25_devtype_data, },
1516 	{ .compatible = "fsl,imx25-flexcan", .data = &fsl_imx25_devtype_data, },
1517 	{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
1518 	{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
1519 	{ .compatible = "fsl,ls1021ar2-flexcan", .data = &fsl_ls1021a_r2_devtype_data, },
1520 	{ /* sentinel */ },
1521 };
1522 MODULE_DEVICE_TABLE(of, flexcan_of_match);
1523 
1524 static const struct platform_device_id flexcan_id_table[] = {
1525 	{ .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
1526 	{ /* sentinel */ },
1527 };
1528 MODULE_DEVICE_TABLE(platform, flexcan_id_table);
1529 
flexcan_probe(struct platform_device * pdev)1530 static int flexcan_probe(struct platform_device *pdev)
1531 {
1532 	const struct of_device_id *of_id;
1533 	const struct flexcan_devtype_data *devtype_data;
1534 	struct net_device *dev;
1535 	struct flexcan_priv *priv;
1536 	struct regulator *reg_xceiver;
1537 	struct resource *mem;
1538 	struct clk *clk_ipg = NULL, *clk_per = NULL;
1539 	struct flexcan_regs __iomem *regs;
1540 	int err, irq;
1541 	u8 clk_src = 1;
1542 	u32 clock_freq = 0;
1543 
1544 	reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
1545 	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
1546 		return -EPROBE_DEFER;
1547 	else if (IS_ERR(reg_xceiver))
1548 		reg_xceiver = NULL;
1549 
1550 	if (pdev->dev.of_node) {
1551 		of_property_read_u32(pdev->dev.of_node,
1552 				     "clock-frequency", &clock_freq);
1553 		of_property_read_u8(pdev->dev.of_node,
1554 				    "fsl,clk-source", &clk_src);
1555 	}
1556 
1557 	if (!clock_freq) {
1558 		clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1559 		if (IS_ERR(clk_ipg)) {
1560 			dev_err(&pdev->dev, "no ipg clock defined\n");
1561 			return PTR_ERR(clk_ipg);
1562 		}
1563 
1564 		clk_per = devm_clk_get(&pdev->dev, "per");
1565 		if (IS_ERR(clk_per)) {
1566 			dev_err(&pdev->dev, "no per clock defined\n");
1567 			return PTR_ERR(clk_per);
1568 		}
1569 		clock_freq = clk_get_rate(clk_per);
1570 	}
1571 
1572 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1573 	irq = platform_get_irq(pdev, 0);
1574 	if (irq <= 0)
1575 		return -ENODEV;
1576 
1577 	regs = devm_ioremap_resource(&pdev->dev, mem);
1578 	if (IS_ERR(regs))
1579 		return PTR_ERR(regs);
1580 
1581 	of_id = of_match_device(flexcan_of_match, &pdev->dev);
1582 	if (of_id) {
1583 		devtype_data = of_id->data;
1584 	} else if (platform_get_device_id(pdev)->driver_data) {
1585 		devtype_data = (struct flexcan_devtype_data *)
1586 			platform_get_device_id(pdev)->driver_data;
1587 	} else {
1588 		return -ENODEV;
1589 	}
1590 
1591 	dev = alloc_candev(sizeof(struct flexcan_priv), 1);
1592 	if (!dev)
1593 		return -ENOMEM;
1594 
1595 	platform_set_drvdata(pdev, dev);
1596 	SET_NETDEV_DEV(dev, &pdev->dev);
1597 
1598 	dev->netdev_ops = &flexcan_netdev_ops;
1599 	dev->irq = irq;
1600 	dev->flags |= IFF_ECHO;
1601 
1602 	priv = netdev_priv(dev);
1603 
1604 	if (of_property_read_bool(pdev->dev.of_node, "big-endian") ||
1605 	    devtype_data->quirks & FLEXCAN_QUIRK_DEFAULT_BIG_ENDIAN) {
1606 		priv->read = flexcan_read_be;
1607 		priv->write = flexcan_write_be;
1608 	} else {
1609 		priv->read = flexcan_read_le;
1610 		priv->write = flexcan_write_le;
1611 	}
1612 
1613 	priv->dev = &pdev->dev;
1614 	priv->can.clock.freq = clock_freq;
1615 	priv->can.bittiming_const = &flexcan_bittiming_const;
1616 	priv->can.do_set_mode = flexcan_set_mode;
1617 	priv->can.do_get_berr_counter = flexcan_get_berr_counter;
1618 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1619 		CAN_CTRLMODE_LISTENONLY	| CAN_CTRLMODE_3_SAMPLES |
1620 		CAN_CTRLMODE_BERR_REPORTING;
1621 	priv->regs = regs;
1622 	priv->clk_ipg = clk_ipg;
1623 	priv->clk_per = clk_per;
1624 	priv->clk_src = clk_src;
1625 	priv->devtype_data = devtype_data;
1626 	priv->reg_xceiver = reg_xceiver;
1627 
1628 	pm_runtime_get_noresume(&pdev->dev);
1629 	pm_runtime_set_active(&pdev->dev);
1630 	pm_runtime_enable(&pdev->dev);
1631 
1632 	err = register_flexcandev(dev);
1633 	if (err) {
1634 		dev_err(&pdev->dev, "registering netdev failed\n");
1635 		goto failed_register;
1636 	}
1637 
1638 	devm_can_led_init(dev);
1639 
1640 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_SETUP_STOP_MODE) {
1641 		err = flexcan_setup_stop_mode(pdev);
1642 		if (err)
1643 			dev_dbg(&pdev->dev, "failed to setup stop-mode\n");
1644 	}
1645 
1646 	return 0;
1647 
1648  failed_register:
1649 	free_candev(dev);
1650 	return err;
1651 }
1652 
flexcan_remove(struct platform_device * pdev)1653 static int flexcan_remove(struct platform_device *pdev)
1654 {
1655 	struct net_device *dev = platform_get_drvdata(pdev);
1656 
1657 	unregister_flexcandev(dev);
1658 	pm_runtime_disable(&pdev->dev);
1659 	free_candev(dev);
1660 
1661 	return 0;
1662 }
1663 
flexcan_suspend(struct device * device)1664 static int __maybe_unused flexcan_suspend(struct device *device)
1665 {
1666 	struct net_device *dev = dev_get_drvdata(device);
1667 	struct flexcan_priv *priv = netdev_priv(dev);
1668 	int err = 0;
1669 
1670 	if (netif_running(dev)) {
1671 		/* if wakeup is enabled, enter stop mode
1672 		 * else enter disabled mode.
1673 		 */
1674 		if (device_may_wakeup(device)) {
1675 			enable_irq_wake(dev->irq);
1676 			err = flexcan_enter_stop_mode(priv);
1677 			if (err)
1678 				return err;
1679 		} else {
1680 			err = flexcan_chip_disable(priv);
1681 			if (err)
1682 				return err;
1683 
1684 			err = pm_runtime_force_suspend(device);
1685 		}
1686 		netif_stop_queue(dev);
1687 		netif_device_detach(dev);
1688 	}
1689 	priv->can.state = CAN_STATE_SLEEPING;
1690 
1691 	return err;
1692 }
1693 
flexcan_resume(struct device * device)1694 static int __maybe_unused flexcan_resume(struct device *device)
1695 {
1696 	struct net_device *dev = dev_get_drvdata(device);
1697 	struct flexcan_priv *priv = netdev_priv(dev);
1698 	int err = 0;
1699 
1700 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1701 	if (netif_running(dev)) {
1702 		netif_device_attach(dev);
1703 		netif_start_queue(dev);
1704 		if (device_may_wakeup(device)) {
1705 			disable_irq_wake(dev->irq);
1706 		} else {
1707 			err = pm_runtime_force_resume(device);
1708 			if (err)
1709 				return err;
1710 
1711 			err = flexcan_chip_enable(priv);
1712 		}
1713 	}
1714 
1715 	return err;
1716 }
1717 
flexcan_runtime_suspend(struct device * device)1718 static int __maybe_unused flexcan_runtime_suspend(struct device *device)
1719 {
1720 	struct net_device *dev = dev_get_drvdata(device);
1721 	struct flexcan_priv *priv = netdev_priv(dev);
1722 
1723 	flexcan_clks_disable(priv);
1724 
1725 	return 0;
1726 }
1727 
flexcan_runtime_resume(struct device * device)1728 static int __maybe_unused flexcan_runtime_resume(struct device *device)
1729 {
1730 	struct net_device *dev = dev_get_drvdata(device);
1731 	struct flexcan_priv *priv = netdev_priv(dev);
1732 
1733 	return flexcan_clks_enable(priv);
1734 }
1735 
flexcan_noirq_suspend(struct device * device)1736 static int __maybe_unused flexcan_noirq_suspend(struct device *device)
1737 {
1738 	struct net_device *dev = dev_get_drvdata(device);
1739 	struct flexcan_priv *priv = netdev_priv(dev);
1740 
1741 	if (netif_running(dev) && device_may_wakeup(device))
1742 		flexcan_enable_wakeup_irq(priv, true);
1743 
1744 	return 0;
1745 }
1746 
flexcan_noirq_resume(struct device * device)1747 static int __maybe_unused flexcan_noirq_resume(struct device *device)
1748 {
1749 	struct net_device *dev = dev_get_drvdata(device);
1750 	struct flexcan_priv *priv = netdev_priv(dev);
1751 	int err;
1752 
1753 	if (netif_running(dev) && device_may_wakeup(device)) {
1754 		flexcan_enable_wakeup_irq(priv, false);
1755 		err = flexcan_exit_stop_mode(priv);
1756 		if (err)
1757 			return err;
1758 	}
1759 
1760 	return 0;
1761 }
1762 
1763 static const struct dev_pm_ops flexcan_pm_ops = {
1764 	SET_SYSTEM_SLEEP_PM_OPS(flexcan_suspend, flexcan_resume)
1765 	SET_RUNTIME_PM_OPS(flexcan_runtime_suspend, flexcan_runtime_resume, NULL)
1766 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(flexcan_noirq_suspend, flexcan_noirq_resume)
1767 };
1768 
1769 static struct platform_driver flexcan_driver = {
1770 	.driver = {
1771 		.name = DRV_NAME,
1772 		.pm = &flexcan_pm_ops,
1773 		.of_match_table = flexcan_of_match,
1774 	},
1775 	.probe = flexcan_probe,
1776 	.remove = flexcan_remove,
1777 	.id_table = flexcan_id_table,
1778 };
1779 
1780 module_platform_driver(flexcan_driver);
1781 
1782 MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1783 	      "Marc Kleine-Budde <kernel@pengutronix.de>");
1784 MODULE_LICENSE("GPL v2");
1785 MODULE_DESCRIPTION("CAN port driver for flexcan based chip");
1786