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1 /*
2  * CAN bus driver for Bosch M_CAN controller
3  *
4  * Copyright (C) 2014 Freescale Semiconductor, Inc.
5  *	Dong Aisheng <b29396@freescale.com>
6  *
7  * Bosch M_CAN user manual can be obtained from:
8  * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
9  * mcan_users_manual_v302.pdf
10  *
11  * This file is licensed under the terms of the GNU General Public
12  * License version 2. This program is licensed "as is" without any
13  * warranty of any kind, whether express or implied.
14  */
15 
16 #include <linux/clk.h>
17 #include <linux/delay.h>
18 #include <linux/interrupt.h>
19 #include <linux/io.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/netdevice.h>
23 #include <linux/of.h>
24 #include <linux/of_device.h>
25 #include <linux/platform_device.h>
26 #include <linux/iopoll.h>
27 #include <linux/can/dev.h>
28 #include <linux/pinctrl/consumer.h>
29 
30 /* napi related */
31 #define M_CAN_NAPI_WEIGHT	64
32 
33 /* message ram configuration data length */
34 #define MRAM_CFG_LEN	8
35 
36 /* registers definition */
37 enum m_can_reg {
38 	M_CAN_CREL	= 0x0,
39 	M_CAN_ENDN	= 0x4,
40 	M_CAN_CUST	= 0x8,
41 	M_CAN_DBTP	= 0xc,
42 	M_CAN_TEST	= 0x10,
43 	M_CAN_RWD	= 0x14,
44 	M_CAN_CCCR	= 0x18,
45 	M_CAN_NBTP	= 0x1c,
46 	M_CAN_TSCC	= 0x20,
47 	M_CAN_TSCV	= 0x24,
48 	M_CAN_TOCC	= 0x28,
49 	M_CAN_TOCV	= 0x2c,
50 	M_CAN_ECR	= 0x40,
51 	M_CAN_PSR	= 0x44,
52 /* TDCR Register only available for version >=3.1.x */
53 	M_CAN_TDCR	= 0x48,
54 	M_CAN_IR	= 0x50,
55 	M_CAN_IE	= 0x54,
56 	M_CAN_ILS	= 0x58,
57 	M_CAN_ILE	= 0x5c,
58 	M_CAN_GFC	= 0x80,
59 	M_CAN_SIDFC	= 0x84,
60 	M_CAN_XIDFC	= 0x88,
61 	M_CAN_XIDAM	= 0x90,
62 	M_CAN_HPMS	= 0x94,
63 	M_CAN_NDAT1	= 0x98,
64 	M_CAN_NDAT2	= 0x9c,
65 	M_CAN_RXF0C	= 0xa0,
66 	M_CAN_RXF0S	= 0xa4,
67 	M_CAN_RXF0A	= 0xa8,
68 	M_CAN_RXBC	= 0xac,
69 	M_CAN_RXF1C	= 0xb0,
70 	M_CAN_RXF1S	= 0xb4,
71 	M_CAN_RXF1A	= 0xb8,
72 	M_CAN_RXESC	= 0xbc,
73 	M_CAN_TXBC	= 0xc0,
74 	M_CAN_TXFQS	= 0xc4,
75 	M_CAN_TXESC	= 0xc8,
76 	M_CAN_TXBRP	= 0xcc,
77 	M_CAN_TXBAR	= 0xd0,
78 	M_CAN_TXBCR	= 0xd4,
79 	M_CAN_TXBTO	= 0xd8,
80 	M_CAN_TXBCF	= 0xdc,
81 	M_CAN_TXBTIE	= 0xe0,
82 	M_CAN_TXBCIE	= 0xe4,
83 	M_CAN_TXEFC	= 0xf0,
84 	M_CAN_TXEFS	= 0xf4,
85 	M_CAN_TXEFA	= 0xf8,
86 };
87 
88 /* m_can lec values */
89 enum m_can_lec_type {
90 	LEC_NO_ERROR = 0,
91 	LEC_STUFF_ERROR,
92 	LEC_FORM_ERROR,
93 	LEC_ACK_ERROR,
94 	LEC_BIT1_ERROR,
95 	LEC_BIT0_ERROR,
96 	LEC_CRC_ERROR,
97 	LEC_UNUSED,
98 };
99 
100 enum m_can_mram_cfg {
101 	MRAM_SIDF = 0,
102 	MRAM_XIDF,
103 	MRAM_RXF0,
104 	MRAM_RXF1,
105 	MRAM_RXB,
106 	MRAM_TXE,
107 	MRAM_TXB,
108 	MRAM_CFG_NUM,
109 };
110 
111 /* Core Release Register (CREL) */
112 #define CREL_REL_SHIFT		28
113 #define CREL_REL_MASK		(0xF << CREL_REL_SHIFT)
114 #define CREL_STEP_SHIFT		24
115 #define CREL_STEP_MASK		(0xF << CREL_STEP_SHIFT)
116 #define CREL_SUBSTEP_SHIFT	20
117 #define CREL_SUBSTEP_MASK	(0xF << CREL_SUBSTEP_SHIFT)
118 
119 /* Data Bit Timing & Prescaler Register (DBTP) */
120 #define DBTP_TDC		BIT(23)
121 #define DBTP_DBRP_SHIFT		16
122 #define DBTP_DBRP_MASK		(0x1f << DBTP_DBRP_SHIFT)
123 #define DBTP_DTSEG1_SHIFT	8
124 #define DBTP_DTSEG1_MASK	(0x1f << DBTP_DTSEG1_SHIFT)
125 #define DBTP_DTSEG2_SHIFT	4
126 #define DBTP_DTSEG2_MASK	(0xf << DBTP_DTSEG2_SHIFT)
127 #define DBTP_DSJW_SHIFT		0
128 #define DBTP_DSJW_MASK		(0xf << DBTP_DSJW_SHIFT)
129 
130 /* Test Register (TEST) */
131 #define TEST_LBCK		BIT(4)
132 
133 /* CC Control Register(CCCR) */
134 #define CCCR_CMR_MASK		0x3
135 #define CCCR_CMR_SHIFT		10
136 #define CCCR_CMR_CANFD		0x1
137 #define CCCR_CMR_CANFD_BRS	0x2
138 #define CCCR_CMR_CAN		0x3
139 #define CCCR_CME_MASK		0x3
140 #define CCCR_CME_SHIFT		8
141 #define CCCR_CME_CAN		0
142 #define CCCR_CME_CANFD		0x1
143 #define CCCR_CME_CANFD_BRS	0x2
144 #define CCCR_TXP		BIT(14)
145 #define CCCR_TEST		BIT(7)
146 #define CCCR_MON		BIT(5)
147 #define CCCR_CSR		BIT(4)
148 #define CCCR_CSA		BIT(3)
149 #define CCCR_ASM		BIT(2)
150 #define CCCR_CCE		BIT(1)
151 #define CCCR_INIT		BIT(0)
152 #define CCCR_CANFD		0x10
153 /* for version >=3.1.x */
154 #define CCCR_EFBI		BIT(13)
155 #define CCCR_PXHD		BIT(12)
156 #define CCCR_BRSE		BIT(9)
157 #define CCCR_FDOE		BIT(8)
158 /* only for version >=3.2.x */
159 #define CCCR_NISO		BIT(15)
160 
161 /* Nominal Bit Timing & Prescaler Register (NBTP) */
162 #define NBTP_NSJW_SHIFT		25
163 #define NBTP_NSJW_MASK		(0x7f << NBTP_NSJW_SHIFT)
164 #define NBTP_NBRP_SHIFT		16
165 #define NBTP_NBRP_MASK		(0x1ff << NBTP_NBRP_SHIFT)
166 #define NBTP_NTSEG1_SHIFT	8
167 #define NBTP_NTSEG1_MASK	(0xff << NBTP_NTSEG1_SHIFT)
168 #define NBTP_NTSEG2_SHIFT	0
169 #define NBTP_NTSEG2_MASK	(0x7f << NBTP_NTSEG2_SHIFT)
170 
171 /* Error Counter Register(ECR) */
172 #define ECR_RP			BIT(15)
173 #define ECR_REC_SHIFT		8
174 #define ECR_REC_MASK		(0x7f << ECR_REC_SHIFT)
175 #define ECR_TEC_SHIFT		0
176 #define ECR_TEC_MASK		0xff
177 
178 /* Protocol Status Register(PSR) */
179 #define PSR_BO		BIT(7)
180 #define PSR_EW		BIT(6)
181 #define PSR_EP		BIT(5)
182 #define PSR_LEC_MASK	0x7
183 
184 /* Interrupt Register(IR) */
185 #define IR_ALL_INT	0xffffffff
186 
187 /* Renamed bits for versions > 3.1.x */
188 #define IR_ARA		BIT(29)
189 #define IR_PED		BIT(28)
190 #define IR_PEA		BIT(27)
191 
192 /* Bits for version 3.0.x */
193 #define IR_STE		BIT(31)
194 #define IR_FOE		BIT(30)
195 #define IR_ACKE		BIT(29)
196 #define IR_BE		BIT(28)
197 #define IR_CRCE		BIT(27)
198 #define IR_WDI		BIT(26)
199 #define IR_BO		BIT(25)
200 #define IR_EW		BIT(24)
201 #define IR_EP		BIT(23)
202 #define IR_ELO		BIT(22)
203 #define IR_BEU		BIT(21)
204 #define IR_BEC		BIT(20)
205 #define IR_DRX		BIT(19)
206 #define IR_TOO		BIT(18)
207 #define IR_MRAF		BIT(17)
208 #define IR_TSW		BIT(16)
209 #define IR_TEFL		BIT(15)
210 #define IR_TEFF		BIT(14)
211 #define IR_TEFW		BIT(13)
212 #define IR_TEFN		BIT(12)
213 #define IR_TFE		BIT(11)
214 #define IR_TCF		BIT(10)
215 #define IR_TC		BIT(9)
216 #define IR_HPM		BIT(8)
217 #define IR_RF1L		BIT(7)
218 #define IR_RF1F		BIT(6)
219 #define IR_RF1W		BIT(5)
220 #define IR_RF1N		BIT(4)
221 #define IR_RF0L		BIT(3)
222 #define IR_RF0F		BIT(2)
223 #define IR_RF0W		BIT(1)
224 #define IR_RF0N		BIT(0)
225 #define IR_ERR_STATE	(IR_BO | IR_EW | IR_EP)
226 
227 /* Interrupts for version 3.0.x */
228 #define IR_ERR_LEC_30X	(IR_STE	| IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
229 #define IR_ERR_BUS_30X	(IR_ERR_LEC_30X | IR_WDI | IR_ELO | IR_BEU | \
230 			 IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \
231 			 IR_RF1L | IR_RF0L)
232 #define IR_ERR_ALL_30X	(IR_ERR_STATE | IR_ERR_BUS_30X)
233 /* Interrupts for version >= 3.1.x */
234 #define IR_ERR_LEC_31X	(IR_PED | IR_PEA)
235 #define IR_ERR_BUS_31X      (IR_ERR_LEC_31X | IR_WDI | IR_ELO | IR_BEU | \
236 			 IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \
237 			 IR_RF1L | IR_RF0L)
238 #define IR_ERR_ALL_31X	(IR_ERR_STATE | IR_ERR_BUS_31X)
239 
240 /* Interrupt Line Select (ILS) */
241 #define ILS_ALL_INT0	0x0
242 #define ILS_ALL_INT1	0xFFFFFFFF
243 
244 /* Interrupt Line Enable (ILE) */
245 #define ILE_EINT1	BIT(1)
246 #define ILE_EINT0	BIT(0)
247 
248 /* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
249 #define RXFC_FWM_SHIFT	24
250 #define RXFC_FWM_MASK	(0x7f << RXFC_FWM_SHIFT)
251 #define RXFC_FS_SHIFT	16
252 #define RXFC_FS_MASK	(0x7f << RXFC_FS_SHIFT)
253 
254 /* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
255 #define RXFS_RFL	BIT(25)
256 #define RXFS_FF		BIT(24)
257 #define RXFS_FPI_SHIFT	16
258 #define RXFS_FPI_MASK	0x3f0000
259 #define RXFS_FGI_SHIFT	8
260 #define RXFS_FGI_MASK	0x3f00
261 #define RXFS_FFL_MASK	0x7f
262 
263 /* Rx Buffer / FIFO Element Size Configuration (RXESC) */
264 #define M_CAN_RXESC_8BYTES	0x0
265 #define M_CAN_RXESC_64BYTES	0x777
266 
267 /* Tx Buffer Configuration(TXBC) */
268 #define TXBC_NDTB_SHIFT		16
269 #define TXBC_NDTB_MASK		(0x3f << TXBC_NDTB_SHIFT)
270 #define TXBC_TFQS_SHIFT		24
271 #define TXBC_TFQS_MASK		(0x3f << TXBC_TFQS_SHIFT)
272 
273 /* Tx FIFO/Queue Status (TXFQS) */
274 #define TXFQS_TFQF		BIT(21)
275 #define TXFQS_TFQPI_SHIFT	16
276 #define TXFQS_TFQPI_MASK	(0x1f << TXFQS_TFQPI_SHIFT)
277 #define TXFQS_TFGI_SHIFT	8
278 #define TXFQS_TFGI_MASK		(0x1f << TXFQS_TFGI_SHIFT)
279 #define TXFQS_TFFL_SHIFT	0
280 #define TXFQS_TFFL_MASK		(0x3f << TXFQS_TFFL_SHIFT)
281 
282 /* Tx Buffer Element Size Configuration(TXESC) */
283 #define TXESC_TBDS_8BYTES	0x0
284 #define TXESC_TBDS_64BYTES	0x7
285 
286 /* Tx Event FIFO Configuration (TXEFC) */
287 #define TXEFC_EFS_SHIFT		16
288 #define TXEFC_EFS_MASK		(0x3f << TXEFC_EFS_SHIFT)
289 
290 /* Tx Event FIFO Status (TXEFS) */
291 #define TXEFS_TEFL		BIT(25)
292 #define TXEFS_EFF		BIT(24)
293 #define TXEFS_EFGI_SHIFT	8
294 #define	TXEFS_EFGI_MASK		(0x1f << TXEFS_EFGI_SHIFT)
295 #define TXEFS_EFFL_SHIFT	0
296 #define TXEFS_EFFL_MASK		(0x3f << TXEFS_EFFL_SHIFT)
297 
298 /* Tx Event FIFO Acknowledge (TXEFA) */
299 #define TXEFA_EFAI_SHIFT	0
300 #define TXEFA_EFAI_MASK		(0x1f << TXEFA_EFAI_SHIFT)
301 
302 /* Message RAM Configuration (in bytes) */
303 #define SIDF_ELEMENT_SIZE	4
304 #define XIDF_ELEMENT_SIZE	8
305 #define RXF0_ELEMENT_SIZE	72
306 #define RXF1_ELEMENT_SIZE	72
307 #define RXB_ELEMENT_SIZE	72
308 #define TXE_ELEMENT_SIZE	8
309 #define TXB_ELEMENT_SIZE	72
310 
311 /* Message RAM Elements */
312 #define M_CAN_FIFO_ID		0x0
313 #define M_CAN_FIFO_DLC		0x4
314 #define M_CAN_FIFO_DATA(n)	(0x8 + ((n) << 2))
315 
316 /* Rx Buffer Element */
317 /* R0 */
318 #define RX_BUF_ESI		BIT(31)
319 #define RX_BUF_XTD		BIT(30)
320 #define RX_BUF_RTR		BIT(29)
321 /* R1 */
322 #define RX_BUF_ANMF		BIT(31)
323 #define RX_BUF_FDF		BIT(21)
324 #define RX_BUF_BRS		BIT(20)
325 
326 /* Tx Buffer Element */
327 /* T0 */
328 #define TX_BUF_ESI		BIT(31)
329 #define TX_BUF_XTD		BIT(30)
330 #define TX_BUF_RTR		BIT(29)
331 /* T1 */
332 #define TX_BUF_EFC		BIT(23)
333 #define TX_BUF_FDF		BIT(21)
334 #define TX_BUF_BRS		BIT(20)
335 #define TX_BUF_MM_SHIFT		24
336 #define TX_BUF_MM_MASK		(0xff << TX_BUF_MM_SHIFT)
337 
338 /* Tx event FIFO Element */
339 /* E1 */
340 #define TX_EVENT_MM_SHIFT	TX_BUF_MM_SHIFT
341 #define TX_EVENT_MM_MASK	(0xff << TX_EVENT_MM_SHIFT)
342 
343 /* address offset and element number for each FIFO/Buffer in the Message RAM */
344 struct mram_cfg {
345 	u16 off;
346 	u8  num;
347 };
348 
349 /* m_can private data structure */
350 struct m_can_priv {
351 	struct can_priv can;	/* must be the first member */
352 	struct napi_struct napi;
353 	struct net_device *dev;
354 	struct device *device;
355 	struct clk *hclk;
356 	struct clk *cclk;
357 	void __iomem *base;
358 	u32 irqstatus;
359 	int version;
360 
361 	/* message ram configuration */
362 	void __iomem *mram_base;
363 	struct mram_cfg mcfg[MRAM_CFG_NUM];
364 };
365 
m_can_read(const struct m_can_priv * priv,enum m_can_reg reg)366 static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg)
367 {
368 	return readl(priv->base + reg);
369 }
370 
m_can_write(const struct m_can_priv * priv,enum m_can_reg reg,u32 val)371 static inline void m_can_write(const struct m_can_priv *priv,
372 			       enum m_can_reg reg, u32 val)
373 {
374 	writel(val, priv->base + reg);
375 }
376 
m_can_fifo_read(const struct m_can_priv * priv,u32 fgi,unsigned int offset)377 static inline u32 m_can_fifo_read(const struct m_can_priv *priv,
378 				  u32 fgi, unsigned int offset)
379 {
380 	return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off +
381 		     fgi * RXF0_ELEMENT_SIZE + offset);
382 }
383 
m_can_fifo_write(const struct m_can_priv * priv,u32 fpi,unsigned int offset,u32 val)384 static inline void m_can_fifo_write(const struct m_can_priv *priv,
385 				    u32 fpi, unsigned int offset, u32 val)
386 {
387 	writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off +
388 	       fpi * TXB_ELEMENT_SIZE + offset);
389 }
390 
m_can_txe_fifo_read(const struct m_can_priv * priv,u32 fgi,u32 offset)391 static inline u32 m_can_txe_fifo_read(const struct m_can_priv *priv,
392 				      u32 fgi,
393 				      u32 offset) {
394 	return readl(priv->mram_base + priv->mcfg[MRAM_TXE].off +
395 			fgi * TXE_ELEMENT_SIZE + offset);
396 }
397 
m_can_tx_fifo_full(const struct m_can_priv * priv)398 static inline bool m_can_tx_fifo_full(const struct m_can_priv *priv)
399 {
400 		return !!(m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQF);
401 }
402 
m_can_config_endisable(const struct m_can_priv * priv,bool enable)403 static inline void m_can_config_endisable(const struct m_can_priv *priv,
404 					  bool enable)
405 {
406 	u32 cccr = m_can_read(priv, M_CAN_CCCR);
407 	u32 timeout = 10;
408 	u32 val = 0;
409 
410 	if (enable) {
411 		/* enable m_can configuration */
412 		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
413 		udelay(5);
414 		/* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
415 		m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
416 	} else {
417 		m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
418 	}
419 
420 	/* there's a delay for module initialization */
421 	if (enable)
422 		val = CCCR_INIT | CCCR_CCE;
423 
424 	while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
425 		if (timeout == 0) {
426 			netdev_warn(priv->dev, "Failed to init module\n");
427 			return;
428 		}
429 		timeout--;
430 		udelay(1);
431 	}
432 }
433 
m_can_enable_all_interrupts(const struct m_can_priv * priv)434 static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv)
435 {
436 	/* Only interrupt line 0 is used in this driver */
437 	m_can_write(priv, M_CAN_ILE, ILE_EINT0);
438 }
439 
m_can_disable_all_interrupts(const struct m_can_priv * priv)440 static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
441 {
442 	m_can_write(priv, M_CAN_ILE, 0x0);
443 }
444 
m_can_read_fifo(struct net_device * dev,u32 rxfs)445 static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
446 {
447 	struct net_device_stats *stats = &dev->stats;
448 	struct m_can_priv *priv = netdev_priv(dev);
449 	struct canfd_frame *cf;
450 	struct sk_buff *skb;
451 	u32 id, fgi, dlc;
452 	int i;
453 
454 	/* calculate the fifo get index for where to read data */
455 	fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_SHIFT;
456 	dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
457 	if (dlc & RX_BUF_FDF)
458 		skb = alloc_canfd_skb(dev, &cf);
459 	else
460 		skb = alloc_can_skb(dev, (struct can_frame **)&cf);
461 	if (!skb) {
462 		stats->rx_dropped++;
463 		return;
464 	}
465 
466 	if (dlc & RX_BUF_FDF)
467 		cf->len = can_dlc2len((dlc >> 16) & 0x0F);
468 	else
469 		cf->len = get_can_dlc((dlc >> 16) & 0x0F);
470 
471 	id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID);
472 	if (id & RX_BUF_XTD)
473 		cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
474 	else
475 		cf->can_id = (id >> 18) & CAN_SFF_MASK;
476 
477 	if (id & RX_BUF_ESI) {
478 		cf->flags |= CANFD_ESI;
479 		netdev_dbg(dev, "ESI Error\n");
480 	}
481 
482 	if (!(dlc & RX_BUF_FDF) && (id & RX_BUF_RTR)) {
483 		cf->can_id |= CAN_RTR_FLAG;
484 	} else {
485 		if (dlc & RX_BUF_BRS)
486 			cf->flags |= CANFD_BRS;
487 
488 		for (i = 0; i < cf->len; i += 4)
489 			*(u32 *)(cf->data + i) =
490 				m_can_fifo_read(priv, fgi,
491 						M_CAN_FIFO_DATA(i / 4));
492 	}
493 
494 	/* acknowledge rx fifo 0 */
495 	m_can_write(priv, M_CAN_RXF0A, fgi);
496 
497 	stats->rx_packets++;
498 	stats->rx_bytes += cf->len;
499 
500 	netif_receive_skb(skb);
501 }
502 
m_can_do_rx_poll(struct net_device * dev,int quota)503 static int m_can_do_rx_poll(struct net_device *dev, int quota)
504 {
505 	struct m_can_priv *priv = netdev_priv(dev);
506 	u32 pkts = 0;
507 	u32 rxfs;
508 
509 	rxfs = m_can_read(priv, M_CAN_RXF0S);
510 	if (!(rxfs & RXFS_FFL_MASK)) {
511 		netdev_dbg(dev, "no messages in fifo0\n");
512 		return 0;
513 	}
514 
515 	while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
516 		if (rxfs & RXFS_RFL)
517 			netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
518 
519 		m_can_read_fifo(dev, rxfs);
520 
521 		quota--;
522 		pkts++;
523 		rxfs = m_can_read(priv, M_CAN_RXF0S);
524 	}
525 
526 	if (pkts)
527 		can_led_event(dev, CAN_LED_EVENT_RX);
528 
529 	return pkts;
530 }
531 
m_can_handle_lost_msg(struct net_device * dev)532 static int m_can_handle_lost_msg(struct net_device *dev)
533 {
534 	struct net_device_stats *stats = &dev->stats;
535 	struct sk_buff *skb;
536 	struct can_frame *frame;
537 
538 	netdev_err(dev, "msg lost in rxf0\n");
539 
540 	stats->rx_errors++;
541 	stats->rx_over_errors++;
542 
543 	skb = alloc_can_err_skb(dev, &frame);
544 	if (unlikely(!skb))
545 		return 0;
546 
547 	frame->can_id |= CAN_ERR_CRTL;
548 	frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
549 
550 	netif_receive_skb(skb);
551 
552 	return 1;
553 }
554 
m_can_handle_lec_err(struct net_device * dev,enum m_can_lec_type lec_type)555 static int m_can_handle_lec_err(struct net_device *dev,
556 				enum m_can_lec_type lec_type)
557 {
558 	struct m_can_priv *priv = netdev_priv(dev);
559 	struct net_device_stats *stats = &dev->stats;
560 	struct can_frame *cf;
561 	struct sk_buff *skb;
562 
563 	priv->can.can_stats.bus_error++;
564 	stats->rx_errors++;
565 
566 	/* propagate the error condition to the CAN stack */
567 	skb = alloc_can_err_skb(dev, &cf);
568 	if (unlikely(!skb))
569 		return 0;
570 
571 	/* check for 'last error code' which tells us the
572 	 * type of the last error to occur on the CAN bus
573 	 */
574 	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
575 
576 	switch (lec_type) {
577 	case LEC_STUFF_ERROR:
578 		netdev_dbg(dev, "stuff error\n");
579 		cf->data[2] |= CAN_ERR_PROT_STUFF;
580 		break;
581 	case LEC_FORM_ERROR:
582 		netdev_dbg(dev, "form error\n");
583 		cf->data[2] |= CAN_ERR_PROT_FORM;
584 		break;
585 	case LEC_ACK_ERROR:
586 		netdev_dbg(dev, "ack error\n");
587 		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
588 		break;
589 	case LEC_BIT1_ERROR:
590 		netdev_dbg(dev, "bit1 error\n");
591 		cf->data[2] |= CAN_ERR_PROT_BIT1;
592 		break;
593 	case LEC_BIT0_ERROR:
594 		netdev_dbg(dev, "bit0 error\n");
595 		cf->data[2] |= CAN_ERR_PROT_BIT0;
596 		break;
597 	case LEC_CRC_ERROR:
598 		netdev_dbg(dev, "CRC error\n");
599 		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
600 		break;
601 	default:
602 		break;
603 	}
604 
605 	stats->rx_packets++;
606 	stats->rx_bytes += cf->can_dlc;
607 	netif_receive_skb(skb);
608 
609 	return 1;
610 }
611 
__m_can_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)612 static int __m_can_get_berr_counter(const struct net_device *dev,
613 				    struct can_berr_counter *bec)
614 {
615 	struct m_can_priv *priv = netdev_priv(dev);
616 	unsigned int ecr;
617 
618 	ecr = m_can_read(priv, M_CAN_ECR);
619 	bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
620 	bec->txerr = (ecr & ECR_TEC_MASK) >> ECR_TEC_SHIFT;
621 
622 	return 0;
623 }
624 
m_can_clk_start(struct m_can_priv * priv)625 static int m_can_clk_start(struct m_can_priv *priv)
626 {
627 	int err;
628 
629 	err = clk_prepare_enable(priv->hclk);
630 	if (err)
631 		return err;
632 
633 	err = clk_prepare_enable(priv->cclk);
634 	if (err)
635 		clk_disable_unprepare(priv->hclk);
636 
637 	return err;
638 }
639 
m_can_clk_stop(struct m_can_priv * priv)640 static void m_can_clk_stop(struct m_can_priv *priv)
641 {
642 	clk_disable_unprepare(priv->cclk);
643 	clk_disable_unprepare(priv->hclk);
644 }
645 
m_can_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)646 static int m_can_get_berr_counter(const struct net_device *dev,
647 				  struct can_berr_counter *bec)
648 {
649 	struct m_can_priv *priv = netdev_priv(dev);
650 	int err;
651 
652 	err = m_can_clk_start(priv);
653 	if (err)
654 		return err;
655 
656 	__m_can_get_berr_counter(dev, bec);
657 
658 	m_can_clk_stop(priv);
659 
660 	return 0;
661 }
662 
m_can_handle_state_change(struct net_device * dev,enum can_state new_state)663 static int m_can_handle_state_change(struct net_device *dev,
664 				     enum can_state new_state)
665 {
666 	struct m_can_priv *priv = netdev_priv(dev);
667 	struct net_device_stats *stats = &dev->stats;
668 	struct can_frame *cf;
669 	struct sk_buff *skb;
670 	struct can_berr_counter bec;
671 	unsigned int ecr;
672 
673 	switch (new_state) {
674 	case CAN_STATE_ERROR_ACTIVE:
675 		/* error warning state */
676 		priv->can.can_stats.error_warning++;
677 		priv->can.state = CAN_STATE_ERROR_WARNING;
678 		break;
679 	case CAN_STATE_ERROR_PASSIVE:
680 		/* error passive state */
681 		priv->can.can_stats.error_passive++;
682 		priv->can.state = CAN_STATE_ERROR_PASSIVE;
683 		break;
684 	case CAN_STATE_BUS_OFF:
685 		/* bus-off state */
686 		priv->can.state = CAN_STATE_BUS_OFF;
687 		m_can_disable_all_interrupts(priv);
688 		priv->can.can_stats.bus_off++;
689 		can_bus_off(dev);
690 		break;
691 	default:
692 		break;
693 	}
694 
695 	/* propagate the error condition to the CAN stack */
696 	skb = alloc_can_err_skb(dev, &cf);
697 	if (unlikely(!skb))
698 		return 0;
699 
700 	__m_can_get_berr_counter(dev, &bec);
701 
702 	switch (new_state) {
703 	case CAN_STATE_ERROR_ACTIVE:
704 		/* error warning state */
705 		cf->can_id |= CAN_ERR_CRTL;
706 		cf->data[1] = (bec.txerr > bec.rxerr) ?
707 			CAN_ERR_CRTL_TX_WARNING :
708 			CAN_ERR_CRTL_RX_WARNING;
709 		cf->data[6] = bec.txerr;
710 		cf->data[7] = bec.rxerr;
711 		break;
712 	case CAN_STATE_ERROR_PASSIVE:
713 		/* error passive state */
714 		cf->can_id |= CAN_ERR_CRTL;
715 		ecr = m_can_read(priv, M_CAN_ECR);
716 		if (ecr & ECR_RP)
717 			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
718 		if (bec.txerr > 127)
719 			cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
720 		cf->data[6] = bec.txerr;
721 		cf->data[7] = bec.rxerr;
722 		break;
723 	case CAN_STATE_BUS_OFF:
724 		/* bus-off state */
725 		cf->can_id |= CAN_ERR_BUSOFF;
726 		break;
727 	default:
728 		break;
729 	}
730 
731 	stats->rx_packets++;
732 	stats->rx_bytes += cf->can_dlc;
733 	netif_receive_skb(skb);
734 
735 	return 1;
736 }
737 
m_can_handle_state_errors(struct net_device * dev,u32 psr)738 static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
739 {
740 	struct m_can_priv *priv = netdev_priv(dev);
741 	int work_done = 0;
742 
743 	if ((psr & PSR_EW) &&
744 	    (priv->can.state != CAN_STATE_ERROR_WARNING)) {
745 		netdev_dbg(dev, "entered error warning state\n");
746 		work_done += m_can_handle_state_change(dev,
747 						       CAN_STATE_ERROR_WARNING);
748 	}
749 
750 	if ((psr & PSR_EP) &&
751 	    (priv->can.state != CAN_STATE_ERROR_PASSIVE)) {
752 		netdev_dbg(dev, "entered error passive state\n");
753 		work_done += m_can_handle_state_change(dev,
754 						       CAN_STATE_ERROR_PASSIVE);
755 	}
756 
757 	if ((psr & PSR_BO) &&
758 	    (priv->can.state != CAN_STATE_BUS_OFF)) {
759 		netdev_dbg(dev, "entered error bus off state\n");
760 		work_done += m_can_handle_state_change(dev,
761 						       CAN_STATE_BUS_OFF);
762 	}
763 
764 	return work_done;
765 }
766 
m_can_handle_other_err(struct net_device * dev,u32 irqstatus)767 static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
768 {
769 	if (irqstatus & IR_WDI)
770 		netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
771 	if (irqstatus & IR_ELO)
772 		netdev_err(dev, "Error Logging Overflow\n");
773 	if (irqstatus & IR_BEU)
774 		netdev_err(dev, "Bit Error Uncorrected\n");
775 	if (irqstatus & IR_BEC)
776 		netdev_err(dev, "Bit Error Corrected\n");
777 	if (irqstatus & IR_TOO)
778 		netdev_err(dev, "Timeout reached\n");
779 	if (irqstatus & IR_MRAF)
780 		netdev_err(dev, "Message RAM access failure occurred\n");
781 }
782 
is_lec_err(u32 psr)783 static inline bool is_lec_err(u32 psr)
784 {
785 	psr &= LEC_UNUSED;
786 
787 	return psr && (psr != LEC_UNUSED);
788 }
789 
m_can_handle_bus_errors(struct net_device * dev,u32 irqstatus,u32 psr)790 static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
791 				   u32 psr)
792 {
793 	struct m_can_priv *priv = netdev_priv(dev);
794 	int work_done = 0;
795 
796 	if (irqstatus & IR_RF0L)
797 		work_done += m_can_handle_lost_msg(dev);
798 
799 	/* handle lec errors on the bus */
800 	if ((priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
801 	    is_lec_err(psr))
802 		work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED);
803 
804 	/* other unproccessed error interrupts */
805 	m_can_handle_other_err(dev, irqstatus);
806 
807 	return work_done;
808 }
809 
m_can_poll(struct napi_struct * napi,int quota)810 static int m_can_poll(struct napi_struct *napi, int quota)
811 {
812 	struct net_device *dev = napi->dev;
813 	struct m_can_priv *priv = netdev_priv(dev);
814 	int work_done = 0;
815 	u32 irqstatus, psr;
816 
817 	irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR);
818 	if (!irqstatus)
819 		goto end;
820 
821 	/* Errata workaround for issue "Needless activation of MRAF irq"
822 	 * During frame reception while the MCAN is in Error Passive state
823 	 * and the Receive Error Counter has the value MCAN_ECR.REC = 127,
824 	 * it may happen that MCAN_IR.MRAF is set although there was no
825 	 * Message RAM access failure.
826 	 * If MCAN_IR.MRAF is enabled, an interrupt to the Host CPU is generated
827 	 * The Message RAM Access Failure interrupt routine needs to check
828 	 * whether MCAN_ECR.RP = ’1’ and MCAN_ECR.REC = 127.
829 	 * In this case, reset MCAN_IR.MRAF. No further action is required.
830 	 */
831 	if ((priv->version <= 31) && (irqstatus & IR_MRAF) &&
832 	    (m_can_read(priv, M_CAN_ECR) & ECR_RP)) {
833 		struct can_berr_counter bec;
834 
835 		__m_can_get_berr_counter(dev, &bec);
836 		if (bec.rxerr == 127) {
837 			m_can_write(priv, M_CAN_IR, IR_MRAF);
838 			irqstatus &= ~IR_MRAF;
839 		}
840 	}
841 
842 	psr = m_can_read(priv, M_CAN_PSR);
843 	if (irqstatus & IR_ERR_STATE)
844 		work_done += m_can_handle_state_errors(dev, psr);
845 
846 	if (irqstatus & IR_ERR_BUS_30X)
847 		work_done += m_can_handle_bus_errors(dev, irqstatus, psr);
848 
849 	if (irqstatus & IR_RF0N)
850 		work_done += m_can_do_rx_poll(dev, (quota - work_done));
851 
852 	if (work_done < quota) {
853 		napi_complete_done(napi, work_done);
854 		m_can_enable_all_interrupts(priv);
855 	}
856 
857 end:
858 	return work_done;
859 }
860 
m_can_echo_tx_event(struct net_device * dev)861 static void m_can_echo_tx_event(struct net_device *dev)
862 {
863 	u32 txe_count = 0;
864 	u32 m_can_txefs;
865 	u32 fgi = 0;
866 	int i = 0;
867 	unsigned int msg_mark;
868 
869 	struct m_can_priv *priv = netdev_priv(dev);
870 	struct net_device_stats *stats = &dev->stats;
871 
872 	/* read tx event fifo status */
873 	m_can_txefs = m_can_read(priv, M_CAN_TXEFS);
874 
875 	/* Get Tx Event fifo element count */
876 	txe_count = (m_can_txefs & TXEFS_EFFL_MASK)
877 			>> TXEFS_EFFL_SHIFT;
878 
879 	/* Get and process all sent elements */
880 	for (i = 0; i < txe_count; i++) {
881 		/* retrieve get index */
882 		fgi = (m_can_read(priv, M_CAN_TXEFS) & TXEFS_EFGI_MASK)
883 			>> TXEFS_EFGI_SHIFT;
884 
885 		/* get message marker */
886 		msg_mark = (m_can_txe_fifo_read(priv, fgi, 4) &
887 			    TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
888 
889 		/* ack txe element */
890 		m_can_write(priv, M_CAN_TXEFA, (TXEFA_EFAI_MASK &
891 						(fgi << TXEFA_EFAI_SHIFT)));
892 
893 		/* update stats */
894 		stats->tx_bytes += can_get_echo_skb(dev, msg_mark);
895 		stats->tx_packets++;
896 	}
897 }
898 
m_can_isr(int irq,void * dev_id)899 static irqreturn_t m_can_isr(int irq, void *dev_id)
900 {
901 	struct net_device *dev = (struct net_device *)dev_id;
902 	struct m_can_priv *priv = netdev_priv(dev);
903 	struct net_device_stats *stats = &dev->stats;
904 	u32 ir;
905 
906 	ir = m_can_read(priv, M_CAN_IR);
907 	if (!ir)
908 		return IRQ_NONE;
909 
910 	/* ACK all irqs */
911 	if (ir & IR_ALL_INT)
912 		m_can_write(priv, M_CAN_IR, ir);
913 
914 	/* schedule NAPI in case of
915 	 * - rx IRQ
916 	 * - state change IRQ
917 	 * - bus error IRQ and bus error reporting
918 	 */
919 	if ((ir & IR_RF0N) || (ir & IR_ERR_ALL_30X)) {
920 		priv->irqstatus = ir;
921 		m_can_disable_all_interrupts(priv);
922 		napi_schedule(&priv->napi);
923 	}
924 
925 	if (priv->version == 30) {
926 		if (ir & IR_TC) {
927 			/* Transmission Complete Interrupt*/
928 			stats->tx_bytes += can_get_echo_skb(dev, 0);
929 			stats->tx_packets++;
930 			can_led_event(dev, CAN_LED_EVENT_TX);
931 			netif_wake_queue(dev);
932 		}
933 	} else  {
934 		if (ir & IR_TEFN) {
935 			/* New TX FIFO Element arrived */
936 			m_can_echo_tx_event(dev);
937 			can_led_event(dev, CAN_LED_EVENT_TX);
938 			if (netif_queue_stopped(dev) &&
939 			    !m_can_tx_fifo_full(priv))
940 				netif_wake_queue(dev);
941 		}
942 	}
943 
944 	return IRQ_HANDLED;
945 }
946 
947 static const struct can_bittiming_const m_can_bittiming_const_30X = {
948 	.name = KBUILD_MODNAME,
949 	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
950 	.tseg1_max = 64,
951 	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
952 	.tseg2_max = 16,
953 	.sjw_max = 16,
954 	.brp_min = 1,
955 	.brp_max = 1024,
956 	.brp_inc = 1,
957 };
958 
959 static const struct can_bittiming_const m_can_data_bittiming_const_30X = {
960 	.name = KBUILD_MODNAME,
961 	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
962 	.tseg1_max = 16,
963 	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
964 	.tseg2_max = 8,
965 	.sjw_max = 4,
966 	.brp_min = 1,
967 	.brp_max = 32,
968 	.brp_inc = 1,
969 };
970 
971 static const struct can_bittiming_const m_can_bittiming_const_31X = {
972 	.name = KBUILD_MODNAME,
973 	.tseg1_min = 2,		/* Time segment 1 = prop_seg + phase_seg1 */
974 	.tseg1_max = 256,
975 	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
976 	.tseg2_max = 128,
977 	.sjw_max = 128,
978 	.brp_min = 1,
979 	.brp_max = 512,
980 	.brp_inc = 1,
981 };
982 
983 static const struct can_bittiming_const m_can_data_bittiming_const_31X = {
984 	.name = KBUILD_MODNAME,
985 	.tseg1_min = 1,		/* Time segment 1 = prop_seg + phase_seg1 */
986 	.tseg1_max = 32,
987 	.tseg2_min = 1,		/* Time segment 2 = phase_seg2 */
988 	.tseg2_max = 16,
989 	.sjw_max = 16,
990 	.brp_min = 1,
991 	.brp_max = 32,
992 	.brp_inc = 1,
993 };
994 
m_can_set_bittiming(struct net_device * dev)995 static int m_can_set_bittiming(struct net_device *dev)
996 {
997 	struct m_can_priv *priv = netdev_priv(dev);
998 	const struct can_bittiming *bt = &priv->can.bittiming;
999 	const struct can_bittiming *dbt = &priv->can.data_bittiming;
1000 	u16 brp, sjw, tseg1, tseg2;
1001 	u32 reg_btp;
1002 
1003 	brp = bt->brp - 1;
1004 	sjw = bt->sjw - 1;
1005 	tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
1006 	tseg2 = bt->phase_seg2 - 1;
1007 	reg_btp = (brp << NBTP_NBRP_SHIFT) | (sjw << NBTP_NSJW_SHIFT) |
1008 		(tseg1 << NBTP_NTSEG1_SHIFT) | (tseg2 << NBTP_NTSEG2_SHIFT);
1009 	m_can_write(priv, M_CAN_NBTP, reg_btp);
1010 
1011 	if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1012 		brp = dbt->brp - 1;
1013 		sjw = dbt->sjw - 1;
1014 		tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
1015 		tseg2 = dbt->phase_seg2 - 1;
1016 		reg_btp = (brp << DBTP_DBRP_SHIFT) | (sjw << DBTP_DSJW_SHIFT) |
1017 			(tseg1 << DBTP_DTSEG1_SHIFT) |
1018 			(tseg2 << DBTP_DTSEG2_SHIFT);
1019 		m_can_write(priv, M_CAN_DBTP, reg_btp);
1020 	}
1021 
1022 	return 0;
1023 }
1024 
1025 /* Configure M_CAN chip:
1026  * - set rx buffer/fifo element size
1027  * - configure rx fifo
1028  * - accept non-matching frame into fifo 0
1029  * - configure tx buffer
1030  *		- >= v3.1.x: TX FIFO is used
1031  * - configure mode
1032  * - setup bittiming
1033  */
m_can_chip_config(struct net_device * dev)1034 static void m_can_chip_config(struct net_device *dev)
1035 {
1036 	struct m_can_priv *priv = netdev_priv(dev);
1037 	u32 cccr, test;
1038 
1039 	m_can_config_endisable(priv, true);
1040 
1041 	/* RX Buffer/FIFO Element Size 64 bytes data field */
1042 	m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
1043 
1044 	/* Accept Non-matching Frames Into FIFO 0 */
1045 	m_can_write(priv, M_CAN_GFC, 0x0);
1046 
1047 	if (priv->version == 30) {
1048 		/* only support one Tx Buffer currently */
1049 		m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_SHIFT) |
1050 				priv->mcfg[MRAM_TXB].off);
1051 	} else {
1052 		/* TX FIFO is used for newer IP Core versions */
1053 		m_can_write(priv, M_CAN_TXBC,
1054 			    (priv->mcfg[MRAM_TXB].num << TXBC_TFQS_SHIFT) |
1055 			    (priv->mcfg[MRAM_TXB].off));
1056 	}
1057 
1058 	/* support 64 bytes payload */
1059 	m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES);
1060 
1061 	/* TX Event FIFO */
1062 	if (priv->version == 30) {
1063 		m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_SHIFT) |
1064 				priv->mcfg[MRAM_TXE].off);
1065 	} else {
1066 		/* Full TX Event FIFO is used */
1067 		m_can_write(priv, M_CAN_TXEFC,
1068 			    ((priv->mcfg[MRAM_TXE].num << TXEFC_EFS_SHIFT)
1069 			     & TXEFC_EFS_MASK) |
1070 			    priv->mcfg[MRAM_TXE].off);
1071 	}
1072 
1073 	/* rx fifo configuration, blocking mode, fifo size 1 */
1074 	m_can_write(priv, M_CAN_RXF0C,
1075 		    (priv->mcfg[MRAM_RXF0].num << RXFC_FS_SHIFT) |
1076 		     priv->mcfg[MRAM_RXF0].off);
1077 
1078 	m_can_write(priv, M_CAN_RXF1C,
1079 		    (priv->mcfg[MRAM_RXF1].num << RXFC_FS_SHIFT) |
1080 		     priv->mcfg[MRAM_RXF1].off);
1081 
1082 	cccr = m_can_read(priv, M_CAN_CCCR);
1083 	test = m_can_read(priv, M_CAN_TEST);
1084 	test &= ~TEST_LBCK;
1085 	if (priv->version == 30) {
1086 	/* Version 3.0.x */
1087 
1088 		cccr &= ~(CCCR_TEST | CCCR_MON |
1089 			(CCCR_CMR_MASK << CCCR_CMR_SHIFT) |
1090 			(CCCR_CME_MASK << CCCR_CME_SHIFT));
1091 
1092 		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
1093 			cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
1094 
1095 	} else {
1096 	/* Version 3.1.x or 3.2.x */
1097 		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |
1098 			  CCCR_NISO);
1099 
1100 		/* Only 3.2.x has NISO Bit implemented */
1101 		if (priv->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
1102 			cccr |= CCCR_NISO;
1103 
1104 		if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
1105 			cccr |= (CCCR_BRSE | CCCR_FDOE);
1106 	}
1107 
1108 	/* Loopback Mode */
1109 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
1110 		cccr |= CCCR_TEST | CCCR_MON;
1111 		test |= TEST_LBCK;
1112 	}
1113 
1114 	/* Enable Monitoring (all versions) */
1115 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1116 		cccr |= CCCR_MON;
1117 
1118 	/* Write config */
1119 	m_can_write(priv, M_CAN_CCCR, cccr);
1120 	m_can_write(priv, M_CAN_TEST, test);
1121 
1122 	/* Enable interrupts */
1123 	m_can_write(priv, M_CAN_IR, IR_ALL_INT);
1124 	if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
1125 		if (priv->version == 30)
1126 			m_can_write(priv, M_CAN_IE, IR_ALL_INT &
1127 				    ~(IR_ERR_LEC_30X));
1128 		else
1129 			m_can_write(priv, M_CAN_IE, IR_ALL_INT &
1130 				    ~(IR_ERR_LEC_31X));
1131 	else
1132 		m_can_write(priv, M_CAN_IE, IR_ALL_INT);
1133 
1134 	/* route all interrupts to INT0 */
1135 	m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0);
1136 
1137 	/* set bittiming params */
1138 	m_can_set_bittiming(dev);
1139 
1140 	m_can_config_endisable(priv, false);
1141 }
1142 
m_can_start(struct net_device * dev)1143 static void m_can_start(struct net_device *dev)
1144 {
1145 	struct m_can_priv *priv = netdev_priv(dev);
1146 
1147 	/* basic m_can configuration */
1148 	m_can_chip_config(dev);
1149 
1150 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1151 
1152 	m_can_enable_all_interrupts(priv);
1153 }
1154 
m_can_set_mode(struct net_device * dev,enum can_mode mode)1155 static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
1156 {
1157 	switch (mode) {
1158 	case CAN_MODE_START:
1159 		m_can_start(dev);
1160 		netif_wake_queue(dev);
1161 		break;
1162 	default:
1163 		return -EOPNOTSUPP;
1164 	}
1165 
1166 	return 0;
1167 }
1168 
free_m_can_dev(struct net_device * dev)1169 static void free_m_can_dev(struct net_device *dev)
1170 {
1171 	free_candev(dev);
1172 }
1173 
1174 /* Checks core release number of M_CAN
1175  * returns 0 if an unsupported device is detected
1176  * else it returns the release and step coded as:
1177  * return value = 10 * <release> + 1 * <step>
1178  */
m_can_check_core_release(void __iomem * m_can_base)1179 static int m_can_check_core_release(void __iomem *m_can_base)
1180 {
1181 	u32 crel_reg;
1182 	u8 rel;
1183 	u8 step;
1184 	int res;
1185 	struct m_can_priv temp_priv = {
1186 		.base = m_can_base
1187 	};
1188 
1189 	/* Read Core Release Version and split into version number
1190 	 * Example: Version 3.2.1 => rel = 3; step = 2; substep = 1;
1191 	 */
1192 	crel_reg = m_can_read(&temp_priv, M_CAN_CREL);
1193 	rel = (u8)((crel_reg & CREL_REL_MASK) >> CREL_REL_SHIFT);
1194 	step = (u8)((crel_reg & CREL_STEP_MASK) >> CREL_STEP_SHIFT);
1195 
1196 	if (rel == 3) {
1197 		/* M_CAN v3.x.y: create return value */
1198 		res = 30 + step;
1199 	} else {
1200 		/* Unsupported M_CAN version */
1201 		res = 0;
1202 	}
1203 
1204 	return res;
1205 }
1206 
1207 /* Selectable Non ISO support only in version 3.2.x
1208  * This function checks if the bit is writable.
1209  */
m_can_niso_supported(const struct m_can_priv * priv)1210 static bool m_can_niso_supported(const struct m_can_priv *priv)
1211 {
1212 	u32 cccr_reg, cccr_poll;
1213 	int niso_timeout;
1214 
1215 	m_can_config_endisable(priv, true);
1216 	cccr_reg = m_can_read(priv, M_CAN_CCCR);
1217 	cccr_reg |= CCCR_NISO;
1218 	m_can_write(priv, M_CAN_CCCR, cccr_reg);
1219 
1220 	niso_timeout = readl_poll_timeout((priv->base + M_CAN_CCCR), cccr_poll,
1221 					  (cccr_poll == cccr_reg), 0, 10);
1222 
1223 	/* Clear NISO */
1224 	cccr_reg &= ~(CCCR_NISO);
1225 	m_can_write(priv, M_CAN_CCCR, cccr_reg);
1226 
1227 	m_can_config_endisable(priv, false);
1228 
1229 	/* return false if time out (-ETIMEDOUT), else return true */
1230 	return !niso_timeout;
1231 }
1232 
alloc_m_can_dev(struct platform_device * pdev,void __iomem * addr,u32 tx_fifo_size)1233 static struct net_device *alloc_m_can_dev(struct platform_device *pdev,
1234 					  void __iomem *addr, u32 tx_fifo_size)
1235 {
1236 	struct net_device *dev;
1237 	struct m_can_priv *priv;
1238 	int m_can_version;
1239 	unsigned int echo_buffer_count;
1240 
1241 	m_can_version = m_can_check_core_release(addr);
1242 	/* return if unsupported version */
1243 	if (!m_can_version) {
1244 		dev = NULL;
1245 		goto return_dev;
1246 	}
1247 
1248 	/* If version < 3.1.x, then only one echo buffer is used */
1249 	echo_buffer_count = ((m_can_version == 30)
1250 				? 1U
1251 				: (unsigned int)tx_fifo_size);
1252 
1253 	dev = alloc_candev(sizeof(*priv), echo_buffer_count);
1254 	if (!dev) {
1255 		dev = NULL;
1256 		goto return_dev;
1257 	}
1258 	priv = netdev_priv(dev);
1259 	netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
1260 
1261 	/* Shared properties of all M_CAN versions */
1262 	priv->version = m_can_version;
1263 	priv->dev = dev;
1264 	priv->base = addr;
1265 	priv->can.do_set_mode = m_can_set_mode;
1266 	priv->can.do_get_berr_counter = m_can_get_berr_counter;
1267 
1268 	/* Set M_CAN supported operations */
1269 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1270 					CAN_CTRLMODE_LISTENONLY |
1271 					CAN_CTRLMODE_BERR_REPORTING |
1272 					CAN_CTRLMODE_FD;
1273 
1274 	/* Set properties depending on M_CAN version */
1275 	switch (priv->version) {
1276 	case 30:
1277 		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.x */
1278 		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1279 		priv->can.bittiming_const = &m_can_bittiming_const_30X;
1280 		priv->can.data_bittiming_const =
1281 				&m_can_data_bittiming_const_30X;
1282 		break;
1283 	case 31:
1284 		/* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.1.x */
1285 		can_set_static_ctrlmode(dev, CAN_CTRLMODE_FD_NON_ISO);
1286 		priv->can.bittiming_const = &m_can_bittiming_const_31X;
1287 		priv->can.data_bittiming_const =
1288 				&m_can_data_bittiming_const_31X;
1289 		break;
1290 	case 32:
1291 		priv->can.bittiming_const = &m_can_bittiming_const_31X;
1292 		priv->can.data_bittiming_const =
1293 				&m_can_data_bittiming_const_31X;
1294 		priv->can.ctrlmode_supported |= (m_can_niso_supported(priv)
1295 						? CAN_CTRLMODE_FD_NON_ISO
1296 						: 0);
1297 		break;
1298 	default:
1299 		/* Unsupported device: free candev */
1300 		free_m_can_dev(dev);
1301 		dev_err(&pdev->dev, "Unsupported version number: %2d",
1302 			priv->version);
1303 		dev = NULL;
1304 		break;
1305 	}
1306 
1307 return_dev:
1308 	return dev;
1309 }
1310 
m_can_open(struct net_device * dev)1311 static int m_can_open(struct net_device *dev)
1312 {
1313 	struct m_can_priv *priv = netdev_priv(dev);
1314 	int err;
1315 
1316 	err = m_can_clk_start(priv);
1317 	if (err)
1318 		return err;
1319 
1320 	/* open the can device */
1321 	err = open_candev(dev);
1322 	if (err) {
1323 		netdev_err(dev, "failed to open can device\n");
1324 		goto exit_disable_clks;
1325 	}
1326 
1327 	/* register interrupt handler */
1328 	err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
1329 			  dev);
1330 	if (err < 0) {
1331 		netdev_err(dev, "failed to request interrupt\n");
1332 		goto exit_irq_fail;
1333 	}
1334 
1335 	/* start the m_can controller */
1336 	m_can_start(dev);
1337 
1338 	can_led_event(dev, CAN_LED_EVENT_OPEN);
1339 	napi_enable(&priv->napi);
1340 	netif_start_queue(dev);
1341 
1342 	return 0;
1343 
1344 exit_irq_fail:
1345 	close_candev(dev);
1346 exit_disable_clks:
1347 	m_can_clk_stop(priv);
1348 	return err;
1349 }
1350 
m_can_stop(struct net_device * dev)1351 static void m_can_stop(struct net_device *dev)
1352 {
1353 	struct m_can_priv *priv = netdev_priv(dev);
1354 
1355 	/* disable all interrupts */
1356 	m_can_disable_all_interrupts(priv);
1357 
1358 	/* set the state as STOPPED */
1359 	priv->can.state = CAN_STATE_STOPPED;
1360 }
1361 
m_can_close(struct net_device * dev)1362 static int m_can_close(struct net_device *dev)
1363 {
1364 	struct m_can_priv *priv = netdev_priv(dev);
1365 
1366 	netif_stop_queue(dev);
1367 	napi_disable(&priv->napi);
1368 	m_can_stop(dev);
1369 	m_can_clk_stop(priv);
1370 	free_irq(dev->irq, dev);
1371 	close_candev(dev);
1372 	can_led_event(dev, CAN_LED_EVENT_STOP);
1373 
1374 	return 0;
1375 }
1376 
m_can_next_echo_skb_occupied(struct net_device * dev,int putidx)1377 static int m_can_next_echo_skb_occupied(struct net_device *dev, int putidx)
1378 {
1379 	struct m_can_priv *priv = netdev_priv(dev);
1380 	/*get wrap around for loopback skb index */
1381 	unsigned int wrap = priv->can.echo_skb_max;
1382 	int next_idx;
1383 
1384 	/* calculate next index */
1385 	next_idx = (++putidx >= wrap ? 0 : putidx);
1386 
1387 	/* check if occupied */
1388 	return !!priv->can.echo_skb[next_idx];
1389 }
1390 
m_can_start_xmit(struct sk_buff * skb,struct net_device * dev)1391 static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
1392 				    struct net_device *dev)
1393 {
1394 	struct m_can_priv *priv = netdev_priv(dev);
1395 	struct canfd_frame *cf = (struct canfd_frame *)skb->data;
1396 	u32 id, cccr, fdflags;
1397 	int i;
1398 	int putidx;
1399 
1400 	if (can_dropped_invalid_skb(dev, skb))
1401 		return NETDEV_TX_OK;
1402 
1403 	/* Generate ID field for TX buffer Element */
1404 	/* Common to all supported M_CAN versions */
1405 	if (cf->can_id & CAN_EFF_FLAG) {
1406 		id = cf->can_id & CAN_EFF_MASK;
1407 		id |= TX_BUF_XTD;
1408 	} else {
1409 		id = ((cf->can_id & CAN_SFF_MASK) << 18);
1410 	}
1411 
1412 	if (cf->can_id & CAN_RTR_FLAG)
1413 		id |= TX_BUF_RTR;
1414 
1415 	if (priv->version == 30) {
1416 		netif_stop_queue(dev);
1417 
1418 		/* message ram configuration */
1419 		m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
1420 		m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC,
1421 				 can_len2dlc(cf->len) << 16);
1422 
1423 		for (i = 0; i < cf->len; i += 4)
1424 			m_can_fifo_write(priv, 0,
1425 					 M_CAN_FIFO_DATA(i / 4),
1426 					 *(u32 *)(cf->data + i));
1427 
1428 		can_put_echo_skb(skb, dev, 0);
1429 
1430 		if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1431 			cccr = m_can_read(priv, M_CAN_CCCR);
1432 			cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
1433 			if (can_is_canfd_skb(skb)) {
1434 				if (cf->flags & CANFD_BRS)
1435 					cccr |= CCCR_CMR_CANFD_BRS <<
1436 						CCCR_CMR_SHIFT;
1437 				else
1438 					cccr |= CCCR_CMR_CANFD <<
1439 						CCCR_CMR_SHIFT;
1440 			} else {
1441 				cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
1442 			}
1443 			m_can_write(priv, M_CAN_CCCR, cccr);
1444 		}
1445 		m_can_write(priv, M_CAN_TXBTIE, 0x1);
1446 		m_can_write(priv, M_CAN_TXBAR, 0x1);
1447 		/* End of xmit function for version 3.0.x */
1448 	} else {
1449 		/* Transmit routine for version >= v3.1.x */
1450 
1451 		/* Check if FIFO full */
1452 		if (m_can_tx_fifo_full(priv)) {
1453 			/* This shouldn't happen */
1454 			netif_stop_queue(dev);
1455 			netdev_warn(dev,
1456 				    "TX queue active although FIFO is full.");
1457 			return NETDEV_TX_BUSY;
1458 		}
1459 
1460 		/* get put index for frame */
1461 		putidx = ((m_can_read(priv, M_CAN_TXFQS) & TXFQS_TFQPI_MASK)
1462 				  >> TXFQS_TFQPI_SHIFT);
1463 		/* Write ID Field to FIFO Element */
1464 		m_can_fifo_write(priv, putidx, M_CAN_FIFO_ID, id);
1465 
1466 		/* get CAN FD configuration of frame */
1467 		fdflags = 0;
1468 		if (can_is_canfd_skb(skb)) {
1469 			fdflags |= TX_BUF_FDF;
1470 			if (cf->flags & CANFD_BRS)
1471 				fdflags |= TX_BUF_BRS;
1472 		}
1473 
1474 		/* Construct DLC Field. Also contains CAN-FD configuration
1475 		 * use put index of fifo as message marker
1476 		 * it is used in TX interrupt for
1477 		 * sending the correct echo frame
1478 		 */
1479 		m_can_fifo_write(priv, putidx, M_CAN_FIFO_DLC,
1480 				 ((putidx << TX_BUF_MM_SHIFT) &
1481 				  TX_BUF_MM_MASK) |
1482 				 (can_len2dlc(cf->len) << 16) |
1483 				 fdflags | TX_BUF_EFC);
1484 
1485 		for (i = 0; i < cf->len; i += 4)
1486 			m_can_fifo_write(priv, putidx, M_CAN_FIFO_DATA(i / 4),
1487 					 *(u32 *)(cf->data + i));
1488 
1489 		/* Push loopback echo.
1490 		 * Will be looped back on TX interrupt based on message marker
1491 		 */
1492 		can_put_echo_skb(skb, dev, putidx);
1493 
1494 		/* Enable TX FIFO element to start transfer  */
1495 		m_can_write(priv, M_CAN_TXBAR, (1 << putidx));
1496 
1497 		/* stop network queue if fifo full */
1498 			if (m_can_tx_fifo_full(priv) ||
1499 			    m_can_next_echo_skb_occupied(dev, putidx))
1500 				netif_stop_queue(dev);
1501 	}
1502 
1503 	return NETDEV_TX_OK;
1504 }
1505 
1506 static const struct net_device_ops m_can_netdev_ops = {
1507 	.ndo_open = m_can_open,
1508 	.ndo_stop = m_can_close,
1509 	.ndo_start_xmit = m_can_start_xmit,
1510 	.ndo_change_mtu = can_change_mtu,
1511 };
1512 
register_m_can_dev(struct net_device * dev)1513 static int register_m_can_dev(struct net_device *dev)
1514 {
1515 	dev->flags |= IFF_ECHO;	/* we support local echo */
1516 	dev->netdev_ops = &m_can_netdev_ops;
1517 
1518 	return register_candev(dev);
1519 }
1520 
m_can_init_ram(struct m_can_priv * priv)1521 static void m_can_init_ram(struct m_can_priv *priv)
1522 {
1523 	int end, i, start;
1524 
1525 	/* initialize the entire Message RAM in use to avoid possible
1526 	 * ECC/parity checksum errors when reading an uninitialized buffer
1527 	 */
1528 	start = priv->mcfg[MRAM_SIDF].off;
1529 	end = priv->mcfg[MRAM_TXB].off +
1530 		priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
1531 	for (i = start; i < end; i += 4)
1532 		writel(0x0, priv->mram_base + i);
1533 }
1534 
m_can_of_parse_mram(struct m_can_priv * priv,const u32 * mram_config_vals)1535 static void m_can_of_parse_mram(struct m_can_priv *priv,
1536 				const u32 *mram_config_vals)
1537 {
1538 	priv->mcfg[MRAM_SIDF].off = mram_config_vals[0];
1539 	priv->mcfg[MRAM_SIDF].num = mram_config_vals[1];
1540 	priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +
1541 			priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
1542 	priv->mcfg[MRAM_XIDF].num = mram_config_vals[2];
1543 	priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +
1544 			priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
1545 	priv->mcfg[MRAM_RXF0].num = mram_config_vals[3] &
1546 			(RXFC_FS_MASK >> RXFC_FS_SHIFT);
1547 	priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +
1548 			priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
1549 	priv->mcfg[MRAM_RXF1].num = mram_config_vals[4] &
1550 			(RXFC_FS_MASK >> RXFC_FS_SHIFT);
1551 	priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +
1552 			priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
1553 	priv->mcfg[MRAM_RXB].num = mram_config_vals[5];
1554 	priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +
1555 			priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
1556 	priv->mcfg[MRAM_TXE].num = mram_config_vals[6];
1557 	priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +
1558 			priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
1559 	priv->mcfg[MRAM_TXB].num = mram_config_vals[7] &
1560 			(TXBC_NDTB_MASK >> TXBC_NDTB_SHIFT);
1561 
1562 	dev_dbg(priv->device,
1563 		"mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
1564 		priv->mram_base,
1565 		priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
1566 		priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
1567 		priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
1568 		priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num,
1569 		priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
1570 		priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
1571 		priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
1572 
1573 	m_can_init_ram(priv);
1574 }
1575 
m_can_plat_probe(struct platform_device * pdev)1576 static int m_can_plat_probe(struct platform_device *pdev)
1577 {
1578 	struct net_device *dev;
1579 	struct m_can_priv *priv;
1580 	struct resource *res;
1581 	void __iomem *addr;
1582 	void __iomem *mram_addr;
1583 	struct clk *hclk, *cclk;
1584 	int irq, ret;
1585 	struct device_node *np;
1586 	u32 mram_config_vals[MRAM_CFG_LEN];
1587 	u32 tx_fifo_size;
1588 
1589 	np = pdev->dev.of_node;
1590 
1591 	hclk = devm_clk_get(&pdev->dev, "hclk");
1592 	cclk = devm_clk_get(&pdev->dev, "cclk");
1593 
1594 	if (IS_ERR(hclk) || IS_ERR(cclk)) {
1595 		dev_err(&pdev->dev, "no clock found\n");
1596 		ret = -ENODEV;
1597 		goto failed_ret;
1598 	}
1599 
1600 	/* Enable clocks. Necessary to read Core Release in order to determine
1601 	 * M_CAN version
1602 	 */
1603 	ret = clk_prepare_enable(hclk);
1604 	if (ret)
1605 		goto disable_hclk_ret;
1606 
1607 	ret = clk_prepare_enable(cclk);
1608 	if (ret)
1609 		goto disable_cclk_ret;
1610 
1611 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
1612 	addr = devm_ioremap_resource(&pdev->dev, res);
1613 	irq = platform_get_irq_byname(pdev, "int0");
1614 
1615 	if (IS_ERR(addr) || irq < 0) {
1616 		ret = -EINVAL;
1617 		goto disable_cclk_ret;
1618 	}
1619 
1620 	/* message ram could be shared */
1621 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
1622 	if (!res) {
1623 		ret = -ENODEV;
1624 		goto disable_cclk_ret;
1625 	}
1626 
1627 	mram_addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
1628 	if (!mram_addr) {
1629 		ret = -ENOMEM;
1630 		goto disable_cclk_ret;
1631 	}
1632 
1633 	/* get message ram configuration */
1634 	ret = of_property_read_u32_array(np, "bosch,mram-cfg",
1635 					 mram_config_vals,
1636 					 sizeof(mram_config_vals) / 4);
1637 	if (ret) {
1638 		dev_err(&pdev->dev, "Could not get Message RAM configuration.");
1639 		goto disable_cclk_ret;
1640 	}
1641 
1642 	/* Get TX FIFO size
1643 	 * Defines the total amount of echo buffers for loopback
1644 	 */
1645 	tx_fifo_size = mram_config_vals[7];
1646 
1647 	/* allocate the m_can device */
1648 	dev = alloc_m_can_dev(pdev, addr, tx_fifo_size);
1649 	if (!dev) {
1650 		ret = -ENOMEM;
1651 		goto disable_cclk_ret;
1652 	}
1653 	priv = netdev_priv(dev);
1654 	dev->irq = irq;
1655 	priv->device = &pdev->dev;
1656 	priv->hclk = hclk;
1657 	priv->cclk = cclk;
1658 	priv->can.clock.freq = clk_get_rate(cclk);
1659 	priv->mram_base = mram_addr;
1660 
1661 	platform_set_drvdata(pdev, dev);
1662 	SET_NETDEV_DEV(dev, &pdev->dev);
1663 
1664 	ret = register_m_can_dev(dev);
1665 	if (ret) {
1666 		dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
1667 			KBUILD_MODNAME, ret);
1668 		goto failed_free_dev;
1669 	}
1670 
1671 	m_can_of_parse_mram(priv, mram_config_vals);
1672 
1673 	devm_can_led_init(dev);
1674 
1675 	dev_info(&pdev->dev, "%s device registered (irq=%d, version=%d)\n",
1676 		 KBUILD_MODNAME, dev->irq, priv->version);
1677 
1678 	/* Probe finished
1679 	 * Stop clocks. They will be reactivated once the M_CAN device is opened
1680 	 */
1681 
1682 	goto disable_cclk_ret;
1683 
1684 failed_free_dev:
1685 	free_m_can_dev(dev);
1686 disable_cclk_ret:
1687 	clk_disable_unprepare(cclk);
1688 disable_hclk_ret:
1689 	clk_disable_unprepare(hclk);
1690 failed_ret:
1691 	return ret;
1692 }
1693 
1694 /* TODO: runtime PM with power down or sleep mode  */
1695 
m_can_suspend(struct device * dev)1696 static __maybe_unused int m_can_suspend(struct device *dev)
1697 {
1698 	struct net_device *ndev = dev_get_drvdata(dev);
1699 	struct m_can_priv *priv = netdev_priv(ndev);
1700 
1701 	if (netif_running(ndev)) {
1702 		netif_stop_queue(ndev);
1703 		netif_device_detach(ndev);
1704 		m_can_stop(ndev);
1705 		m_can_clk_stop(priv);
1706 	}
1707 
1708 	pinctrl_pm_select_sleep_state(dev);
1709 
1710 	priv->can.state = CAN_STATE_SLEEPING;
1711 
1712 	return 0;
1713 }
1714 
m_can_resume(struct device * dev)1715 static __maybe_unused int m_can_resume(struct device *dev)
1716 {
1717 	struct net_device *ndev = dev_get_drvdata(dev);
1718 	struct m_can_priv *priv = netdev_priv(ndev);
1719 
1720 	pinctrl_pm_select_default_state(dev);
1721 
1722 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1723 
1724 	if (netif_running(ndev)) {
1725 		int ret;
1726 
1727 		ret = m_can_clk_start(priv);
1728 		if (ret)
1729 			return ret;
1730 
1731 		m_can_init_ram(priv);
1732 		m_can_start(ndev);
1733 		netif_device_attach(ndev);
1734 		netif_start_queue(ndev);
1735 	}
1736 
1737 	return 0;
1738 }
1739 
unregister_m_can_dev(struct net_device * dev)1740 static void unregister_m_can_dev(struct net_device *dev)
1741 {
1742 	unregister_candev(dev);
1743 }
1744 
m_can_plat_remove(struct platform_device * pdev)1745 static int m_can_plat_remove(struct platform_device *pdev)
1746 {
1747 	struct net_device *dev = platform_get_drvdata(pdev);
1748 
1749 	unregister_m_can_dev(dev);
1750 	platform_set_drvdata(pdev, NULL);
1751 
1752 	free_m_can_dev(dev);
1753 
1754 	return 0;
1755 }
1756 
1757 static const struct dev_pm_ops m_can_pmops = {
1758 	SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
1759 };
1760 
1761 static const struct of_device_id m_can_of_table[] = {
1762 	{ .compatible = "bosch,m_can", .data = NULL },
1763 	{ /* sentinel */ },
1764 };
1765 MODULE_DEVICE_TABLE(of, m_can_of_table);
1766 
1767 static struct platform_driver m_can_plat_driver = {
1768 	.driver = {
1769 		.name = KBUILD_MODNAME,
1770 		.of_match_table = m_can_of_table,
1771 		.pm     = &m_can_pmops,
1772 	},
1773 	.probe = m_can_plat_probe,
1774 	.remove = m_can_plat_remove,
1775 };
1776 
1777 module_platform_driver(m_can_plat_driver);
1778 
1779 MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
1780 MODULE_LICENSE("GPL v2");
1781 MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
1782