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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 1999 - 2010 Intel Corporation.
4  * Copyright (C) 2010 LAPIS SEMICONDUCTOR CO., LTD.
5  */
6 
7 #include <linux/interrupt.h>
8 #include <linux/delay.h>
9 #include <linux/io.h>
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/pci.h>
13 #include <linux/kernel.h>
14 #include <linux/types.h>
15 #include <linux/errno.h>
16 #include <linux/netdevice.h>
17 #include <linux/skbuff.h>
18 #include <linux/can.h>
19 #include <linux/can/dev.h>
20 #include <linux/can/error.h>
21 
22 #define PCH_CTRL_INIT		BIT(0) /* The INIT bit of CANCONT register. */
23 #define PCH_CTRL_IE		BIT(1) /* The IE bit of CAN control register */
24 #define PCH_CTRL_IE_SIE_EIE	(BIT(3) | BIT(2) | BIT(1))
25 #define PCH_CTRL_CCE		BIT(6)
26 #define PCH_CTRL_OPT		BIT(7) /* The OPT bit of CANCONT register. */
27 #define PCH_OPT_SILENT		BIT(3) /* The Silent bit of CANOPT reg. */
28 #define PCH_OPT_LBACK		BIT(4) /* The LoopBack bit of CANOPT reg. */
29 
30 #define PCH_CMASK_RX_TX_SET	0x00f3
31 #define PCH_CMASK_RX_TX_GET	0x0073
32 #define PCH_CMASK_ALL		0xff
33 #define PCH_CMASK_NEWDAT	BIT(2)
34 #define PCH_CMASK_CLRINTPND	BIT(3)
35 #define PCH_CMASK_CTRL		BIT(4)
36 #define PCH_CMASK_ARB		BIT(5)
37 #define PCH_CMASK_MASK		BIT(6)
38 #define PCH_CMASK_RDWR		BIT(7)
39 #define PCH_IF_MCONT_NEWDAT	BIT(15)
40 #define PCH_IF_MCONT_MSGLOST	BIT(14)
41 #define PCH_IF_MCONT_INTPND	BIT(13)
42 #define PCH_IF_MCONT_UMASK	BIT(12)
43 #define PCH_IF_MCONT_TXIE	BIT(11)
44 #define PCH_IF_MCONT_RXIE	BIT(10)
45 #define PCH_IF_MCONT_RMTEN	BIT(9)
46 #define PCH_IF_MCONT_TXRQXT	BIT(8)
47 #define PCH_IF_MCONT_EOB	BIT(7)
48 #define PCH_IF_MCONT_DLC	(BIT(0) | BIT(1) | BIT(2) | BIT(3))
49 #define PCH_MASK2_MDIR_MXTD	(BIT(14) | BIT(15))
50 #define PCH_ID2_DIR		BIT(13)
51 #define PCH_ID2_XTD		BIT(14)
52 #define PCH_ID_MSGVAL		BIT(15)
53 #define PCH_IF_CREQ_BUSY	BIT(15)
54 
55 #define PCH_STATUS_INT		0x8000
56 #define PCH_RP			0x00008000
57 #define PCH_REC			0x00007f00
58 #define PCH_TEC			0x000000ff
59 
60 #define PCH_TX_OK		BIT(3)
61 #define PCH_RX_OK		BIT(4)
62 #define PCH_EPASSIV		BIT(5)
63 #define PCH_EWARN		BIT(6)
64 #define PCH_BUS_OFF		BIT(7)
65 
66 /* bit position of certain controller bits. */
67 #define PCH_BIT_BRP_SHIFT	0
68 #define PCH_BIT_SJW_SHIFT	6
69 #define PCH_BIT_TSEG1_SHIFT	8
70 #define PCH_BIT_TSEG2_SHIFT	12
71 #define PCH_BIT_BRPE_BRPE_SHIFT	6
72 
73 #define PCH_MSK_BITT_BRP	0x3f
74 #define PCH_MSK_BRPE_BRPE	0x3c0
75 #define PCH_MSK_CTRL_IE_SIE_EIE	0x07
76 #define PCH_COUNTER_LIMIT	10
77 
78 #define PCH_CAN_CLK		50000000	/* 50MHz */
79 
80 /*
81  * Define the number of message object.
82  * PCH CAN communications are done via Message RAM.
83  * The Message RAM consists of 32 message objects.
84  */
85 #define PCH_RX_OBJ_NUM		26
86 #define PCH_TX_OBJ_NUM		6
87 #define PCH_RX_OBJ_START	1
88 #define PCH_RX_OBJ_END		PCH_RX_OBJ_NUM
89 #define PCH_TX_OBJ_START	(PCH_RX_OBJ_END + 1)
90 #define PCH_TX_OBJ_END		(PCH_RX_OBJ_NUM + PCH_TX_OBJ_NUM)
91 
92 #define PCH_FIFO_THRESH		16
93 
94 /* TxRqst2 show status of MsgObjNo.17~32 */
95 #define PCH_TREQ2_TX_MASK	(((1 << PCH_TX_OBJ_NUM) - 1) <<\
96 							(PCH_RX_OBJ_END - 16))
97 
98 enum pch_ifreg {
99 	PCH_RX_IFREG,
100 	PCH_TX_IFREG,
101 };
102 
103 enum pch_can_err {
104 	PCH_STUF_ERR = 1,
105 	PCH_FORM_ERR,
106 	PCH_ACK_ERR,
107 	PCH_BIT1_ERR,
108 	PCH_BIT0_ERR,
109 	PCH_CRC_ERR,
110 	PCH_LEC_ALL,
111 };
112 
113 enum pch_can_mode {
114 	PCH_CAN_ENABLE,
115 	PCH_CAN_DISABLE,
116 	PCH_CAN_ALL,
117 	PCH_CAN_NONE,
118 	PCH_CAN_STOP,
119 	PCH_CAN_RUN,
120 };
121 
122 struct pch_can_if_regs {
123 	u32 creq;
124 	u32 cmask;
125 	u32 mask1;
126 	u32 mask2;
127 	u32 id1;
128 	u32 id2;
129 	u32 mcont;
130 	u32 data[4];
131 	u32 rsv[13];
132 };
133 
134 struct pch_can_regs {
135 	u32 cont;
136 	u32 stat;
137 	u32 errc;
138 	u32 bitt;
139 	u32 intr;
140 	u32 opt;
141 	u32 brpe;
142 	u32 reserve;
143 	struct pch_can_if_regs ifregs[2]; /* [0]=if1  [1]=if2 */
144 	u32 reserve1[8];
145 	u32 treq1;
146 	u32 treq2;
147 	u32 reserve2[6];
148 	u32 data1;
149 	u32 data2;
150 	u32 reserve3[6];
151 	u32 canipend1;
152 	u32 canipend2;
153 	u32 reserve4[6];
154 	u32 canmval1;
155 	u32 canmval2;
156 	u32 reserve5[37];
157 	u32 srst;
158 };
159 
160 struct pch_can_priv {
161 	struct can_priv can;
162 	struct pci_dev *dev;
163 	u32 tx_enable[PCH_TX_OBJ_END];
164 	u32 rx_enable[PCH_TX_OBJ_END];
165 	u32 rx_link[PCH_TX_OBJ_END];
166 	u32 int_enables;
167 	struct net_device *ndev;
168 	struct pch_can_regs __iomem *regs;
169 	struct napi_struct napi;
170 	int tx_obj;	/* Point next Tx Obj index */
171 	int use_msi;
172 };
173 
174 static const struct can_bittiming_const pch_can_bittiming_const = {
175 	.name = KBUILD_MODNAME,
176 	.tseg1_min = 2,
177 	.tseg1_max = 16,
178 	.tseg2_min = 1,
179 	.tseg2_max = 8,
180 	.sjw_max = 4,
181 	.brp_min = 1,
182 	.brp_max = 1024, /* 6bit + extended 4bit */
183 	.brp_inc = 1,
184 };
185 
186 static const struct pci_device_id pch_pci_tbl[] = {
187 	{PCI_VENDOR_ID_INTEL, 0x8818, PCI_ANY_ID, PCI_ANY_ID,},
188 	{0,}
189 };
190 MODULE_DEVICE_TABLE(pci, pch_pci_tbl);
191 
pch_can_bit_set(void __iomem * addr,u32 mask)192 static inline void pch_can_bit_set(void __iomem *addr, u32 mask)
193 {
194 	iowrite32(ioread32(addr) | mask, addr);
195 }
196 
pch_can_bit_clear(void __iomem * addr,u32 mask)197 static inline void pch_can_bit_clear(void __iomem *addr, u32 mask)
198 {
199 	iowrite32(ioread32(addr) & ~mask, addr);
200 }
201 
pch_can_set_run_mode(struct pch_can_priv * priv,enum pch_can_mode mode)202 static void pch_can_set_run_mode(struct pch_can_priv *priv,
203 				 enum pch_can_mode mode)
204 {
205 	switch (mode) {
206 	case PCH_CAN_RUN:
207 		pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_INIT);
208 		break;
209 
210 	case PCH_CAN_STOP:
211 		pch_can_bit_set(&priv->regs->cont, PCH_CTRL_INIT);
212 		break;
213 
214 	default:
215 		netdev_err(priv->ndev, "%s -> Invalid Mode.\n", __func__);
216 		break;
217 	}
218 }
219 
pch_can_set_optmode(struct pch_can_priv * priv)220 static void pch_can_set_optmode(struct pch_can_priv *priv)
221 {
222 	u32 reg_val = ioread32(&priv->regs->opt);
223 
224 	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
225 		reg_val |= PCH_OPT_SILENT;
226 
227 	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
228 		reg_val |= PCH_OPT_LBACK;
229 
230 	pch_can_bit_set(&priv->regs->cont, PCH_CTRL_OPT);
231 	iowrite32(reg_val, &priv->regs->opt);
232 }
233 
pch_can_rw_msg_obj(void __iomem * creq_addr,u32 num)234 static void pch_can_rw_msg_obj(void __iomem *creq_addr, u32 num)
235 {
236 	int counter = PCH_COUNTER_LIMIT;
237 	u32 ifx_creq;
238 
239 	iowrite32(num, creq_addr);
240 	while (counter) {
241 		ifx_creq = ioread32(creq_addr) & PCH_IF_CREQ_BUSY;
242 		if (!ifx_creq)
243 			break;
244 		counter--;
245 		udelay(1);
246 	}
247 	if (!counter)
248 		pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
249 }
250 
pch_can_set_int_enables(struct pch_can_priv * priv,enum pch_can_mode interrupt_no)251 static void pch_can_set_int_enables(struct pch_can_priv *priv,
252 				    enum pch_can_mode interrupt_no)
253 {
254 	switch (interrupt_no) {
255 	case PCH_CAN_DISABLE:
256 		pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE);
257 		break;
258 
259 	case PCH_CAN_ALL:
260 		pch_can_bit_set(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
261 		break;
262 
263 	case PCH_CAN_NONE:
264 		pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
265 		break;
266 
267 	default:
268 		netdev_err(priv->ndev, "Invalid interrupt number.\n");
269 		break;
270 	}
271 }
272 
pch_can_set_rxtx(struct pch_can_priv * priv,u32 buff_num,int set,enum pch_ifreg dir)273 static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
274 			     int set, enum pch_ifreg dir)
275 {
276 	u32 ie;
277 
278 	if (dir)
279 		ie = PCH_IF_MCONT_TXIE;
280 	else
281 		ie = PCH_IF_MCONT_RXIE;
282 
283 	/* Reading the Msg buffer from Message RAM to IF1/2 registers. */
284 	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
285 	pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
286 
287 	/* Setting the IF1/2MASK1 register to access MsgVal and RxIE bits */
288 	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_ARB | PCH_CMASK_CTRL,
289 		  &priv->regs->ifregs[dir].cmask);
290 
291 	if (set) {
292 		/* Setting the MsgVal and RxIE/TxIE bits */
293 		pch_can_bit_set(&priv->regs->ifregs[dir].mcont, ie);
294 		pch_can_bit_set(&priv->regs->ifregs[dir].id2, PCH_ID_MSGVAL);
295 	} else {
296 		/* Clearing the MsgVal and RxIE/TxIE bits */
297 		pch_can_bit_clear(&priv->regs->ifregs[dir].mcont, ie);
298 		pch_can_bit_clear(&priv->regs->ifregs[dir].id2, PCH_ID_MSGVAL);
299 	}
300 
301 	pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
302 }
303 
pch_can_set_rx_all(struct pch_can_priv * priv,int set)304 static void pch_can_set_rx_all(struct pch_can_priv *priv, int set)
305 {
306 	int i;
307 
308 	/* Traversing to obtain the object configured as receivers. */
309 	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++)
310 		pch_can_set_rxtx(priv, i, set, PCH_RX_IFREG);
311 }
312 
pch_can_set_tx_all(struct pch_can_priv * priv,int set)313 static void pch_can_set_tx_all(struct pch_can_priv *priv, int set)
314 {
315 	int i;
316 
317 	/* Traversing to obtain the object configured as transmit object. */
318 	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
319 		pch_can_set_rxtx(priv, i, set, PCH_TX_IFREG);
320 }
321 
pch_can_int_pending(struct pch_can_priv * priv)322 static u32 pch_can_int_pending(struct pch_can_priv *priv)
323 {
324 	return ioread32(&priv->regs->intr) & 0xffff;
325 }
326 
pch_can_clear_if_buffers(struct pch_can_priv * priv)327 static void pch_can_clear_if_buffers(struct pch_can_priv *priv)
328 {
329 	int i; /* Msg Obj ID (1~32) */
330 
331 	for (i = PCH_RX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
332 		iowrite32(PCH_CMASK_RX_TX_SET, &priv->regs->ifregs[0].cmask);
333 		iowrite32(0xffff, &priv->regs->ifregs[0].mask1);
334 		iowrite32(0xffff, &priv->regs->ifregs[0].mask2);
335 		iowrite32(0x0, &priv->regs->ifregs[0].id1);
336 		iowrite32(0x0, &priv->regs->ifregs[0].id2);
337 		iowrite32(0x0, &priv->regs->ifregs[0].mcont);
338 		iowrite32(0x0, &priv->regs->ifregs[0].data[0]);
339 		iowrite32(0x0, &priv->regs->ifregs[0].data[1]);
340 		iowrite32(0x0, &priv->regs->ifregs[0].data[2]);
341 		iowrite32(0x0, &priv->regs->ifregs[0].data[3]);
342 		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK |
343 			  PCH_CMASK_ARB | PCH_CMASK_CTRL,
344 			  &priv->regs->ifregs[0].cmask);
345 		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
346 	}
347 }
348 
pch_can_config_rx_tx_buffers(struct pch_can_priv * priv)349 static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
350 {
351 	int i;
352 
353 	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
354 		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
355 		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
356 
357 		iowrite32(0x0, &priv->regs->ifregs[0].id1);
358 		iowrite32(0x0, &priv->regs->ifregs[0].id2);
359 
360 		pch_can_bit_set(&priv->regs->ifregs[0].mcont,
361 				PCH_IF_MCONT_UMASK);
362 
363 		/* In case FIFO mode, Last EoB of Rx Obj must be 1 */
364 		if (i == PCH_RX_OBJ_END)
365 			pch_can_bit_set(&priv->regs->ifregs[0].mcont,
366 					PCH_IF_MCONT_EOB);
367 		else
368 			pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
369 					  PCH_IF_MCONT_EOB);
370 
371 		iowrite32(0, &priv->regs->ifregs[0].mask1);
372 		pch_can_bit_clear(&priv->regs->ifregs[0].mask2,
373 				  0x1fff | PCH_MASK2_MDIR_MXTD);
374 
375 		/* Setting CMASK for writing */
376 		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK | PCH_CMASK_ARB |
377 			  PCH_CMASK_CTRL, &priv->regs->ifregs[0].cmask);
378 
379 		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
380 	}
381 
382 	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
383 		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask);
384 		pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, i);
385 
386 		/* Resetting DIR bit for reception */
387 		iowrite32(0x0, &priv->regs->ifregs[1].id1);
388 		iowrite32(PCH_ID2_DIR, &priv->regs->ifregs[1].id2);
389 
390 		/* Setting EOB bit for transmitter */
391 		iowrite32(PCH_IF_MCONT_EOB | PCH_IF_MCONT_UMASK,
392 			  &priv->regs->ifregs[1].mcont);
393 
394 		iowrite32(0, &priv->regs->ifregs[1].mask1);
395 		pch_can_bit_clear(&priv->regs->ifregs[1].mask2, 0x1fff);
396 
397 		/* Setting CMASK for writing */
398 		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK | PCH_CMASK_ARB |
399 			  PCH_CMASK_CTRL, &priv->regs->ifregs[1].cmask);
400 
401 		pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, i);
402 	}
403 }
404 
pch_can_init(struct pch_can_priv * priv)405 static void pch_can_init(struct pch_can_priv *priv)
406 {
407 	/* Stopping the Can device. */
408 	pch_can_set_run_mode(priv, PCH_CAN_STOP);
409 
410 	/* Clearing all the message object buffers. */
411 	pch_can_clear_if_buffers(priv);
412 
413 	/* Configuring the respective message object as either rx/tx object. */
414 	pch_can_config_rx_tx_buffers(priv);
415 
416 	/* Enabling the interrupts. */
417 	pch_can_set_int_enables(priv, PCH_CAN_ALL);
418 }
419 
pch_can_release(struct pch_can_priv * priv)420 static void pch_can_release(struct pch_can_priv *priv)
421 {
422 	/* Stooping the CAN device. */
423 	pch_can_set_run_mode(priv, PCH_CAN_STOP);
424 
425 	/* Disabling the interrupts. */
426 	pch_can_set_int_enables(priv, PCH_CAN_NONE);
427 
428 	/* Disabling all the receive object. */
429 	pch_can_set_rx_all(priv, 0);
430 
431 	/* Disabling all the transmit object. */
432 	pch_can_set_tx_all(priv, 0);
433 }
434 
435 /* This function clears interrupt(s) from the CAN device. */
pch_can_int_clr(struct pch_can_priv * priv,u32 mask)436 static void pch_can_int_clr(struct pch_can_priv *priv, u32 mask)
437 {
438 	/* Clear interrupt for transmit object */
439 	if ((mask >= PCH_RX_OBJ_START) && (mask <= PCH_RX_OBJ_END)) {
440 		/* Setting CMASK for clearing the reception interrupts. */
441 		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL | PCH_CMASK_ARB,
442 			  &priv->regs->ifregs[0].cmask);
443 
444 		/* Clearing the Dir bit. */
445 		pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);
446 
447 		/* Clearing NewDat & IntPnd */
448 		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
449 				  PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND);
450 
451 		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, mask);
452 	} else if ((mask >= PCH_TX_OBJ_START) && (mask <= PCH_TX_OBJ_END)) {
453 		/*
454 		 * Setting CMASK for clearing interrupts for frame transmission.
455 		 */
456 		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL | PCH_CMASK_ARB,
457 			  &priv->regs->ifregs[1].cmask);
458 
459 		/* Resetting the ID registers. */
460 		pch_can_bit_set(&priv->regs->ifregs[1].id2,
461 			       PCH_ID2_DIR | (0x7ff << 2));
462 		iowrite32(0x0, &priv->regs->ifregs[1].id1);
463 
464 		/* Clearing NewDat, TxRqst & IntPnd */
465 		pch_can_bit_clear(&priv->regs->ifregs[1].mcont,
466 				  PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND |
467 				  PCH_IF_MCONT_TXRQXT);
468 		pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, mask);
469 	}
470 }
471 
pch_can_reset(struct pch_can_priv * priv)472 static void pch_can_reset(struct pch_can_priv *priv)
473 {
474 	/* write to sw reset register */
475 	iowrite32(1, &priv->regs->srst);
476 	iowrite32(0, &priv->regs->srst);
477 }
478 
pch_can_error(struct net_device * ndev,u32 status)479 static void pch_can_error(struct net_device *ndev, u32 status)
480 {
481 	struct sk_buff *skb;
482 	struct pch_can_priv *priv = netdev_priv(ndev);
483 	struct can_frame *cf;
484 	u32 errc, lec;
485 	struct net_device_stats *stats = &(priv->ndev->stats);
486 	enum can_state state = priv->can.state;
487 
488 	skb = alloc_can_err_skb(ndev, &cf);
489 	if (!skb)
490 		return;
491 
492 	errc = ioread32(&priv->regs->errc);
493 	if (status & PCH_BUS_OFF) {
494 		pch_can_set_tx_all(priv, 0);
495 		pch_can_set_rx_all(priv, 0);
496 		state = CAN_STATE_BUS_OFF;
497 		cf->can_id |= CAN_ERR_BUSOFF;
498 		priv->can.can_stats.bus_off++;
499 		can_bus_off(ndev);
500 	} else {
501 		cf->data[6] = errc & PCH_TEC;
502 		cf->data[7] = (errc & PCH_REC) >> 8;
503 	}
504 
505 	/* Warning interrupt. */
506 	if (status & PCH_EWARN) {
507 		state = CAN_STATE_ERROR_WARNING;
508 		priv->can.can_stats.error_warning++;
509 		cf->can_id |= CAN_ERR_CRTL;
510 		if (((errc & PCH_REC) >> 8) > 96)
511 			cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
512 		if ((errc & PCH_TEC) > 96)
513 			cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
514 		netdev_dbg(ndev,
515 			"%s -> Error Counter is more than 96.\n", __func__);
516 	}
517 	/* Error passive interrupt. */
518 	if (status & PCH_EPASSIV) {
519 		priv->can.can_stats.error_passive++;
520 		state = CAN_STATE_ERROR_PASSIVE;
521 		cf->can_id |= CAN_ERR_CRTL;
522 		if (errc & PCH_RP)
523 			cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
524 		if ((errc & PCH_TEC) > 127)
525 			cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
526 		netdev_dbg(ndev,
527 			"%s -> CAN controller is ERROR PASSIVE .\n", __func__);
528 	}
529 
530 	lec = status & PCH_LEC_ALL;
531 	switch (lec) {
532 	case PCH_STUF_ERR:
533 		cf->data[2] |= CAN_ERR_PROT_STUFF;
534 		priv->can.can_stats.bus_error++;
535 		stats->rx_errors++;
536 		break;
537 	case PCH_FORM_ERR:
538 		cf->data[2] |= CAN_ERR_PROT_FORM;
539 		priv->can.can_stats.bus_error++;
540 		stats->rx_errors++;
541 		break;
542 	case PCH_ACK_ERR:
543 		cf->can_id |= CAN_ERR_ACK;
544 		priv->can.can_stats.bus_error++;
545 		stats->rx_errors++;
546 		break;
547 	case PCH_BIT1_ERR:
548 	case PCH_BIT0_ERR:
549 		cf->data[2] |= CAN_ERR_PROT_BIT;
550 		priv->can.can_stats.bus_error++;
551 		stats->rx_errors++;
552 		break;
553 	case PCH_CRC_ERR:
554 		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
555 		priv->can.can_stats.bus_error++;
556 		stats->rx_errors++;
557 		break;
558 	case PCH_LEC_ALL: /* Written by CPU. No error status */
559 		break;
560 	}
561 
562 	priv->can.state = state;
563 	netif_receive_skb(skb);
564 
565 	stats->rx_packets++;
566 	stats->rx_bytes += cf->can_dlc;
567 }
568 
pch_can_interrupt(int irq,void * dev_id)569 static irqreturn_t pch_can_interrupt(int irq, void *dev_id)
570 {
571 	struct net_device *ndev = (struct net_device *)dev_id;
572 	struct pch_can_priv *priv = netdev_priv(ndev);
573 
574 	if (!pch_can_int_pending(priv))
575 		return IRQ_NONE;
576 
577 	pch_can_set_int_enables(priv, PCH_CAN_NONE);
578 	napi_schedule(&priv->napi);
579 	return IRQ_HANDLED;
580 }
581 
pch_fifo_thresh(struct pch_can_priv * priv,int obj_id)582 static void pch_fifo_thresh(struct pch_can_priv *priv, int obj_id)
583 {
584 	if (obj_id < PCH_FIFO_THRESH) {
585 		iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL |
586 			  PCH_CMASK_ARB, &priv->regs->ifregs[0].cmask);
587 
588 		/* Clearing the Dir bit. */
589 		pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);
590 
591 		/* Clearing NewDat & IntPnd */
592 		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
593 				  PCH_IF_MCONT_INTPND);
594 		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_id);
595 	} else if (obj_id > PCH_FIFO_THRESH) {
596 		pch_can_int_clr(priv, obj_id);
597 	} else if (obj_id == PCH_FIFO_THRESH) {
598 		int cnt;
599 		for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
600 			pch_can_int_clr(priv, cnt + 1);
601 	}
602 }
603 
pch_can_rx_msg_lost(struct net_device * ndev,int obj_id)604 static void pch_can_rx_msg_lost(struct net_device *ndev, int obj_id)
605 {
606 	struct pch_can_priv *priv = netdev_priv(ndev);
607 	struct net_device_stats *stats = &(priv->ndev->stats);
608 	struct sk_buff *skb;
609 	struct can_frame *cf;
610 
611 	netdev_dbg(priv->ndev, "Msg Obj is overwritten.\n");
612 	pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
613 			  PCH_IF_MCONT_MSGLOST);
614 	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
615 		  &priv->regs->ifregs[0].cmask);
616 	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_id);
617 
618 	skb = alloc_can_err_skb(ndev, &cf);
619 	if (!skb)
620 		return;
621 
622 	cf->can_id |= CAN_ERR_CRTL;
623 	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
624 	stats->rx_over_errors++;
625 	stats->rx_errors++;
626 
627 	netif_receive_skb(skb);
628 }
629 
pch_can_rx_normal(struct net_device * ndev,u32 obj_num,int quota)630 static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
631 {
632 	u32 reg;
633 	canid_t id;
634 	int rcv_pkts = 0;
635 	struct sk_buff *skb;
636 	struct can_frame *cf;
637 	struct pch_can_priv *priv = netdev_priv(ndev);
638 	struct net_device_stats *stats = &(priv->ndev->stats);
639 	int i;
640 	u32 id2;
641 	u16 data_reg;
642 
643 	do {
644 		/* Reading the message object from the Message RAM */
645 		iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
646 		pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_num);
647 
648 		/* Reading the MCONT register. */
649 		reg = ioread32(&priv->regs->ifregs[0].mcont);
650 
651 		if (reg & PCH_IF_MCONT_EOB)
652 			break;
653 
654 		/* If MsgLost bit set. */
655 		if (reg & PCH_IF_MCONT_MSGLOST) {
656 			pch_can_rx_msg_lost(ndev, obj_num);
657 			rcv_pkts++;
658 			quota--;
659 			obj_num++;
660 			continue;
661 		} else if (!(reg & PCH_IF_MCONT_NEWDAT)) {
662 			obj_num++;
663 			continue;
664 		}
665 
666 		skb = alloc_can_skb(priv->ndev, &cf);
667 		if (!skb) {
668 			netdev_err(ndev, "alloc_can_skb Failed\n");
669 			return rcv_pkts;
670 		}
671 
672 		/* Get Received data */
673 		id2 = ioread32(&priv->regs->ifregs[0].id2);
674 		if (id2 & PCH_ID2_XTD) {
675 			id = (ioread32(&priv->regs->ifregs[0].id1) & 0xffff);
676 			id |= (((id2) & 0x1fff) << 16);
677 			cf->can_id = id | CAN_EFF_FLAG;
678 		} else {
679 			id = (id2 >> 2) & CAN_SFF_MASK;
680 			cf->can_id = id;
681 		}
682 
683 		if (id2 & PCH_ID2_DIR)
684 			cf->can_id |= CAN_RTR_FLAG;
685 
686 		cf->can_dlc = get_can_dlc((ioread32(&priv->regs->
687 						    ifregs[0].mcont)) & 0xF);
688 
689 		for (i = 0; i < cf->can_dlc; i += 2) {
690 			data_reg = ioread16(&priv->regs->ifregs[0].data[i / 2]);
691 			cf->data[i] = data_reg;
692 			cf->data[i + 1] = data_reg >> 8;
693 		}
694 
695 		rcv_pkts++;
696 		stats->rx_packets++;
697 		quota--;
698 		stats->rx_bytes += cf->can_dlc;
699 		netif_receive_skb(skb);
700 
701 		pch_fifo_thresh(priv, obj_num);
702 		obj_num++;
703 	} while (quota > 0);
704 
705 	return rcv_pkts;
706 }
707 
pch_can_tx_complete(struct net_device * ndev,u32 int_stat)708 static void pch_can_tx_complete(struct net_device *ndev, u32 int_stat)
709 {
710 	struct pch_can_priv *priv = netdev_priv(ndev);
711 	struct net_device_stats *stats = &(priv->ndev->stats);
712 	u32 dlc;
713 
714 	can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1);
715 	iowrite32(PCH_CMASK_RX_TX_GET | PCH_CMASK_CLRINTPND,
716 		  &priv->regs->ifregs[1].cmask);
717 	pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, int_stat);
718 	dlc = get_can_dlc(ioread32(&priv->regs->ifregs[1].mcont) &
719 			  PCH_IF_MCONT_DLC);
720 	stats->tx_bytes += dlc;
721 	stats->tx_packets++;
722 	if (int_stat == PCH_TX_OBJ_END)
723 		netif_wake_queue(ndev);
724 }
725 
pch_can_poll(struct napi_struct * napi,int quota)726 static int pch_can_poll(struct napi_struct *napi, int quota)
727 {
728 	struct net_device *ndev = napi->dev;
729 	struct pch_can_priv *priv = netdev_priv(ndev);
730 	u32 int_stat;
731 	u32 reg_stat;
732 	int quota_save = quota;
733 
734 	int_stat = pch_can_int_pending(priv);
735 	if (!int_stat)
736 		goto end;
737 
738 	if (int_stat == PCH_STATUS_INT) {
739 		reg_stat = ioread32(&priv->regs->stat);
740 
741 		if ((reg_stat & (PCH_BUS_OFF | PCH_LEC_ALL)) &&
742 		   ((reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL)) {
743 			pch_can_error(ndev, reg_stat);
744 			quota--;
745 		}
746 
747 		if (reg_stat & (PCH_TX_OK | PCH_RX_OK))
748 			pch_can_bit_clear(&priv->regs->stat,
749 					  reg_stat & (PCH_TX_OK | PCH_RX_OK));
750 
751 		int_stat = pch_can_int_pending(priv);
752 	}
753 
754 	if (quota == 0)
755 		goto end;
756 
757 	if ((int_stat >= PCH_RX_OBJ_START) && (int_stat <= PCH_RX_OBJ_END)) {
758 		quota -= pch_can_rx_normal(ndev, int_stat, quota);
759 	} else if ((int_stat >= PCH_TX_OBJ_START) &&
760 		   (int_stat <= PCH_TX_OBJ_END)) {
761 		/* Handle transmission interrupt */
762 		pch_can_tx_complete(ndev, int_stat);
763 	}
764 
765 end:
766 	napi_complete(napi);
767 	pch_can_set_int_enables(priv, PCH_CAN_ALL);
768 
769 	return quota_save - quota;
770 }
771 
pch_set_bittiming(struct net_device * ndev)772 static int pch_set_bittiming(struct net_device *ndev)
773 {
774 	struct pch_can_priv *priv = netdev_priv(ndev);
775 	const struct can_bittiming *bt = &priv->can.bittiming;
776 	u32 canbit;
777 	u32 bepe;
778 
779 	/* Setting the CCE bit for accessing the Can Timing register. */
780 	pch_can_bit_set(&priv->regs->cont, PCH_CTRL_CCE);
781 
782 	canbit = (bt->brp - 1) & PCH_MSK_BITT_BRP;
783 	canbit |= (bt->sjw - 1) << PCH_BIT_SJW_SHIFT;
784 	canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << PCH_BIT_TSEG1_SHIFT;
785 	canbit |= (bt->phase_seg2 - 1) << PCH_BIT_TSEG2_SHIFT;
786 	bepe = ((bt->brp - 1) & PCH_MSK_BRPE_BRPE) >> PCH_BIT_BRPE_BRPE_SHIFT;
787 	iowrite32(canbit, &priv->regs->bitt);
788 	iowrite32(bepe, &priv->regs->brpe);
789 	pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_CCE);
790 
791 	return 0;
792 }
793 
pch_can_start(struct net_device * ndev)794 static void pch_can_start(struct net_device *ndev)
795 {
796 	struct pch_can_priv *priv = netdev_priv(ndev);
797 
798 	if (priv->can.state != CAN_STATE_STOPPED)
799 		pch_can_reset(priv);
800 
801 	pch_set_bittiming(ndev);
802 	pch_can_set_optmode(priv);
803 
804 	pch_can_set_tx_all(priv, 1);
805 	pch_can_set_rx_all(priv, 1);
806 
807 	/* Setting the CAN to run mode. */
808 	pch_can_set_run_mode(priv, PCH_CAN_RUN);
809 
810 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
811 
812 	return;
813 }
814 
pch_can_do_set_mode(struct net_device * ndev,enum can_mode mode)815 static int pch_can_do_set_mode(struct net_device *ndev, enum can_mode mode)
816 {
817 	int ret = 0;
818 
819 	switch (mode) {
820 	case CAN_MODE_START:
821 		pch_can_start(ndev);
822 		netif_wake_queue(ndev);
823 		break;
824 	default:
825 		ret = -EOPNOTSUPP;
826 		break;
827 	}
828 
829 	return ret;
830 }
831 
pch_can_open(struct net_device * ndev)832 static int pch_can_open(struct net_device *ndev)
833 {
834 	struct pch_can_priv *priv = netdev_priv(ndev);
835 	int retval;
836 
837 	/* Registering the interrupt. */
838 	retval = request_irq(priv->dev->irq, pch_can_interrupt, IRQF_SHARED,
839 			     ndev->name, ndev);
840 	if (retval) {
841 		netdev_err(ndev, "request_irq failed.\n");
842 		goto req_irq_err;
843 	}
844 
845 	/* Open common can device */
846 	retval = open_candev(ndev);
847 	if (retval) {
848 		netdev_err(ndev, "open_candev() failed %d\n", retval);
849 		goto err_open_candev;
850 	}
851 
852 	pch_can_init(priv);
853 	pch_can_start(ndev);
854 	napi_enable(&priv->napi);
855 	netif_start_queue(ndev);
856 
857 	return 0;
858 
859 err_open_candev:
860 	free_irq(priv->dev->irq, ndev);
861 req_irq_err:
862 	pch_can_release(priv);
863 
864 	return retval;
865 }
866 
pch_close(struct net_device * ndev)867 static int pch_close(struct net_device *ndev)
868 {
869 	struct pch_can_priv *priv = netdev_priv(ndev);
870 
871 	netif_stop_queue(ndev);
872 	napi_disable(&priv->napi);
873 	pch_can_release(priv);
874 	free_irq(priv->dev->irq, ndev);
875 	close_candev(ndev);
876 	priv->can.state = CAN_STATE_STOPPED;
877 	return 0;
878 }
879 
pch_xmit(struct sk_buff * skb,struct net_device * ndev)880 static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
881 {
882 	struct pch_can_priv *priv = netdev_priv(ndev);
883 	struct can_frame *cf = (struct can_frame *)skb->data;
884 	int tx_obj_no;
885 	int i;
886 	u32 id2;
887 
888 	if (can_dropped_invalid_skb(ndev, skb))
889 		return NETDEV_TX_OK;
890 
891 	tx_obj_no = priv->tx_obj;
892 	if (priv->tx_obj == PCH_TX_OBJ_END) {
893 		if (ioread32(&priv->regs->treq2) & PCH_TREQ2_TX_MASK)
894 			netif_stop_queue(ndev);
895 
896 		priv->tx_obj = PCH_TX_OBJ_START;
897 	} else {
898 		priv->tx_obj++;
899 	}
900 
901 	/* Setting the CMASK register. */
902 	pch_can_bit_set(&priv->regs->ifregs[1].cmask, PCH_CMASK_ALL);
903 
904 	/* If ID extended is set. */
905 	if (cf->can_id & CAN_EFF_FLAG) {
906 		iowrite32(cf->can_id & 0xffff, &priv->regs->ifregs[1].id1);
907 		id2 = ((cf->can_id >> 16) & 0x1fff) | PCH_ID2_XTD;
908 	} else {
909 		iowrite32(0, &priv->regs->ifregs[1].id1);
910 		id2 = (cf->can_id & CAN_SFF_MASK) << 2;
911 	}
912 
913 	id2 |= PCH_ID_MSGVAL;
914 
915 	/* If remote frame has to be transmitted.. */
916 	if (!(cf->can_id & CAN_RTR_FLAG))
917 		id2 |= PCH_ID2_DIR;
918 
919 	iowrite32(id2, &priv->regs->ifregs[1].id2);
920 
921 	/* Copy data to register */
922 	for (i = 0; i < cf->can_dlc; i += 2) {
923 		iowrite16(cf->data[i] | (cf->data[i + 1] << 8),
924 			  &priv->regs->ifregs[1].data[i / 2]);
925 	}
926 
927 	can_put_echo_skb(skb, ndev, tx_obj_no - PCH_RX_OBJ_END - 1);
928 
929 	/* Set the size of the data. Update if2_mcont */
930 	iowrite32(cf->can_dlc | PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_TXRQXT |
931 		  PCH_IF_MCONT_TXIE, &priv->regs->ifregs[1].mcont);
932 
933 	pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);
934 
935 	return NETDEV_TX_OK;
936 }
937 
938 static const struct net_device_ops pch_can_netdev_ops = {
939 	.ndo_open		= pch_can_open,
940 	.ndo_stop		= pch_close,
941 	.ndo_start_xmit		= pch_xmit,
942 	.ndo_change_mtu		= can_change_mtu,
943 };
944 
pch_can_remove(struct pci_dev * pdev)945 static void pch_can_remove(struct pci_dev *pdev)
946 {
947 	struct net_device *ndev = pci_get_drvdata(pdev);
948 	struct pch_can_priv *priv = netdev_priv(ndev);
949 
950 	unregister_candev(priv->ndev);
951 	if (priv->use_msi)
952 		pci_disable_msi(priv->dev);
953 	pci_release_regions(pdev);
954 	pci_disable_device(pdev);
955 	pch_can_reset(priv);
956 	pci_iounmap(pdev, priv->regs);
957 	free_candev(priv->ndev);
958 }
959 
pch_can_set_int_custom(struct pch_can_priv * priv)960 static void __maybe_unused pch_can_set_int_custom(struct pch_can_priv *priv)
961 {
962 	/* Clearing the IE, SIE and EIE bits of Can control register. */
963 	pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
964 
965 	/* Appropriately setting them. */
966 	pch_can_bit_set(&priv->regs->cont,
967 			((priv->int_enables & PCH_MSK_CTRL_IE_SIE_EIE) << 1));
968 }
969 
970 /* This function retrieves interrupt enabled for the CAN device. */
pch_can_get_int_enables(struct pch_can_priv * priv)971 static u32 __maybe_unused pch_can_get_int_enables(struct pch_can_priv *priv)
972 {
973 	/* Obtaining the status of IE, SIE and EIE interrupt bits. */
974 	return (ioread32(&priv->regs->cont) & PCH_CTRL_IE_SIE_EIE) >> 1;
975 }
976 
pch_can_get_rxtx_ir(struct pch_can_priv * priv,u32 buff_num,enum pch_ifreg dir)977 static u32 __maybe_unused pch_can_get_rxtx_ir(struct pch_can_priv *priv,
978 					      u32 buff_num, enum pch_ifreg dir)
979 {
980 	u32 ie, enable;
981 
982 	if (dir)
983 		ie = PCH_IF_MCONT_RXIE;
984 	else
985 		ie = PCH_IF_MCONT_TXIE;
986 
987 	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
988 	pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
989 
990 	if (((ioread32(&priv->regs->ifregs[dir].id2)) & PCH_ID_MSGVAL) &&
991 			((ioread32(&priv->regs->ifregs[dir].mcont)) & ie))
992 		enable = 1;
993 	else
994 		enable = 0;
995 
996 	return enable;
997 }
998 
pch_can_set_rx_buffer_link(struct pch_can_priv * priv,u32 buffer_num,int set)999 static void __maybe_unused pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
1000 						      u32 buffer_num, int set)
1001 {
1002 	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
1003 	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
1004 	iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
1005 		  &priv->regs->ifregs[0].cmask);
1006 	if (set)
1007 		pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
1008 				  PCH_IF_MCONT_EOB);
1009 	else
1010 		pch_can_bit_set(&priv->regs->ifregs[0].mcont, PCH_IF_MCONT_EOB);
1011 
1012 	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
1013 }
1014 
pch_can_get_rx_buffer_link(struct pch_can_priv * priv,u32 buffer_num)1015 static u32 __maybe_unused pch_can_get_rx_buffer_link(struct pch_can_priv *priv,
1016 						     u32 buffer_num)
1017 {
1018 	u32 link;
1019 
1020 	iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
1021 	pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
1022 
1023 	if (ioread32(&priv->regs->ifregs[0].mcont) & PCH_IF_MCONT_EOB)
1024 		link = 0;
1025 	else
1026 		link = 1;
1027 	return link;
1028 }
1029 
pch_can_get_buffer_status(struct pch_can_priv * priv)1030 static int __maybe_unused pch_can_get_buffer_status(struct pch_can_priv *priv)
1031 {
1032 	return (ioread32(&priv->regs->treq1) & 0xffff) |
1033 	       (ioread32(&priv->regs->treq2) << 16);
1034 }
1035 
pch_can_suspend(struct device * dev_d)1036 static int __maybe_unused pch_can_suspend(struct device *dev_d)
1037 {
1038 	int i;
1039 	u32 buf_stat;	/* Variable for reading the transmit buffer status. */
1040 	int counter = PCH_COUNTER_LIMIT;
1041 
1042 	struct net_device *dev = dev_get_drvdata(dev_d);
1043 	struct pch_can_priv *priv = netdev_priv(dev);
1044 
1045 	/* Stop the CAN controller */
1046 	pch_can_set_run_mode(priv, PCH_CAN_STOP);
1047 
1048 	/* Indicate that we are aboutto/in suspend */
1049 	priv->can.state = CAN_STATE_STOPPED;
1050 
1051 	/* Waiting for all transmission to complete. */
1052 	while (counter) {
1053 		buf_stat = pch_can_get_buffer_status(priv);
1054 		if (!buf_stat)
1055 			break;
1056 		counter--;
1057 		udelay(1);
1058 	}
1059 	if (!counter)
1060 		dev_err(dev_d, "%s -> Transmission time out.\n", __func__);
1061 
1062 	/* Save interrupt configuration and then disable them */
1063 	priv->int_enables = pch_can_get_int_enables(priv);
1064 	pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
1065 
1066 	/* Save Tx buffer enable state */
1067 	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
1068 		priv->tx_enable[i - 1] = pch_can_get_rxtx_ir(priv, i,
1069 							     PCH_TX_IFREG);
1070 
1071 	/* Disable all Transmit buffers */
1072 	pch_can_set_tx_all(priv, 0);
1073 
1074 	/* Save Rx buffer enable state */
1075 	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
1076 		priv->rx_enable[i - 1] = pch_can_get_rxtx_ir(priv, i,
1077 							     PCH_RX_IFREG);
1078 		priv->rx_link[i - 1] = pch_can_get_rx_buffer_link(priv, i);
1079 	}
1080 
1081 	/* Disable all Receive buffers */
1082 	pch_can_set_rx_all(priv, 0);
1083 
1084 	return 0;
1085 }
1086 
pch_can_resume(struct device * dev_d)1087 static int __maybe_unused pch_can_resume(struct device *dev_d)
1088 {
1089 	int i;
1090 	struct net_device *dev = dev_get_drvdata(dev_d);
1091 	struct pch_can_priv *priv = netdev_priv(dev);
1092 
1093 	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1094 
1095 	/* Disabling all interrupts. */
1096 	pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
1097 
1098 	/* Setting the CAN device in Stop Mode. */
1099 	pch_can_set_run_mode(priv, PCH_CAN_STOP);
1100 
1101 	/* Configuring the transmit and receive buffers. */
1102 	pch_can_config_rx_tx_buffers(priv);
1103 
1104 	/* Restore the CAN state */
1105 	pch_set_bittiming(dev);
1106 
1107 	/* Listen/Active */
1108 	pch_can_set_optmode(priv);
1109 
1110 	/* Enabling the transmit buffer. */
1111 	for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
1112 		pch_can_set_rxtx(priv, i, priv->tx_enable[i - 1], PCH_TX_IFREG);
1113 
1114 	/* Configuring the receive buffer and enabling them. */
1115 	for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
1116 		/* Restore buffer link */
1117 		pch_can_set_rx_buffer_link(priv, i, priv->rx_link[i - 1]);
1118 
1119 		/* Restore buffer enables */
1120 		pch_can_set_rxtx(priv, i, priv->rx_enable[i - 1], PCH_RX_IFREG);
1121 	}
1122 
1123 	/* Enable CAN Interrupts */
1124 	pch_can_set_int_custom(priv);
1125 
1126 	/* Restore Run Mode */
1127 	pch_can_set_run_mode(priv, PCH_CAN_RUN);
1128 
1129 	return 0;
1130 }
1131 
pch_can_get_berr_counter(const struct net_device * dev,struct can_berr_counter * bec)1132 static int pch_can_get_berr_counter(const struct net_device *dev,
1133 				    struct can_berr_counter *bec)
1134 {
1135 	struct pch_can_priv *priv = netdev_priv(dev);
1136 	u32 errc = ioread32(&priv->regs->errc);
1137 
1138 	bec->txerr = errc & PCH_TEC;
1139 	bec->rxerr = (errc & PCH_REC) >> 8;
1140 
1141 	return 0;
1142 }
1143 
pch_can_probe(struct pci_dev * pdev,const struct pci_device_id * id)1144 static int pch_can_probe(struct pci_dev *pdev,
1145 				   const struct pci_device_id *id)
1146 {
1147 	struct net_device *ndev;
1148 	struct pch_can_priv *priv;
1149 	int rc;
1150 	void __iomem *addr;
1151 
1152 	rc = pci_enable_device(pdev);
1153 	if (rc) {
1154 		dev_err(&pdev->dev, "Failed pci_enable_device %d\n", rc);
1155 		goto probe_exit_endev;
1156 	}
1157 
1158 	rc = pci_request_regions(pdev, KBUILD_MODNAME);
1159 	if (rc) {
1160 		dev_err(&pdev->dev, "Failed pci_request_regions %d\n", rc);
1161 		goto probe_exit_pcireq;
1162 	}
1163 
1164 	addr = pci_iomap(pdev, 1, 0);
1165 	if (!addr) {
1166 		rc = -EIO;
1167 		dev_err(&pdev->dev, "Failed pci_iomap\n");
1168 		goto probe_exit_ipmap;
1169 	}
1170 
1171 	ndev = alloc_candev(sizeof(struct pch_can_priv), PCH_TX_OBJ_END);
1172 	if (!ndev) {
1173 		rc = -ENOMEM;
1174 		dev_err(&pdev->dev, "Failed alloc_candev\n");
1175 		goto probe_exit_alloc_candev;
1176 	}
1177 
1178 	priv = netdev_priv(ndev);
1179 	priv->ndev = ndev;
1180 	priv->regs = addr;
1181 	priv->dev = pdev;
1182 	priv->can.bittiming_const = &pch_can_bittiming_const;
1183 	priv->can.do_set_mode = pch_can_do_set_mode;
1184 	priv->can.do_get_berr_counter = pch_can_get_berr_counter;
1185 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
1186 				       CAN_CTRLMODE_LOOPBACK;
1187 	priv->tx_obj = PCH_TX_OBJ_START; /* Point head of Tx Obj */
1188 
1189 	ndev->irq = pdev->irq;
1190 	ndev->flags |= IFF_ECHO;
1191 
1192 	pci_set_drvdata(pdev, ndev);
1193 	SET_NETDEV_DEV(ndev, &pdev->dev);
1194 	ndev->netdev_ops = &pch_can_netdev_ops;
1195 	priv->can.clock.freq = PCH_CAN_CLK; /* Hz */
1196 
1197 	netif_napi_add(ndev, &priv->napi, pch_can_poll, PCH_RX_OBJ_END);
1198 
1199 	rc = pci_enable_msi(priv->dev);
1200 	if (rc) {
1201 		netdev_err(ndev, "PCH CAN opened without MSI\n");
1202 		priv->use_msi = 0;
1203 	} else {
1204 		netdev_err(ndev, "PCH CAN opened with MSI\n");
1205 		pci_set_master(pdev);
1206 		priv->use_msi = 1;
1207 	}
1208 
1209 	rc = register_candev(ndev);
1210 	if (rc) {
1211 		dev_err(&pdev->dev, "Failed register_candev %d\n", rc);
1212 		goto probe_exit_reg_candev;
1213 	}
1214 
1215 	return 0;
1216 
1217 probe_exit_reg_candev:
1218 	if (priv->use_msi)
1219 		pci_disable_msi(priv->dev);
1220 	free_candev(ndev);
1221 probe_exit_alloc_candev:
1222 	pci_iounmap(pdev, addr);
1223 probe_exit_ipmap:
1224 	pci_release_regions(pdev);
1225 probe_exit_pcireq:
1226 	pci_disable_device(pdev);
1227 probe_exit_endev:
1228 	return rc;
1229 }
1230 
1231 static SIMPLE_DEV_PM_OPS(pch_can_pm_ops,
1232 			 pch_can_suspend,
1233 			 pch_can_resume);
1234 
1235 static struct pci_driver pch_can_pci_driver = {
1236 	.name = "pch_can",
1237 	.id_table = pch_pci_tbl,
1238 	.probe = pch_can_probe,
1239 	.remove = pch_can_remove,
1240 	.driver.pm = &pch_can_pm_ops,
1241 };
1242 
1243 module_pci_driver(pch_can_pci_driver);
1244 
1245 MODULE_DESCRIPTION("Intel EG20T PCH CAN(Controller Area Network) Driver");
1246 MODULE_LICENSE("GPL v2");
1247 MODULE_VERSION("0.94");
1248