xref: /openbmc/linux/drivers/net/can/sja1000/peak_pci.c (revision ee8ec048)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
4  * Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
5  *
6  * Derived from the PCAN project file driver/src/pcan_pci.c:
7  *
8  * Copyright (C) 2001-2006  PEAK System-Technik GmbH
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/netdevice.h>
15 #include <linux/delay.h>
16 #include <linux/pci.h>
17 #include <linux/io.h>
18 #include <linux/i2c.h>
19 #include <linux/i2c-algo-bit.h>
20 #include <linux/can.h>
21 #include <linux/can/dev.h>
22 
23 #include "sja1000.h"
24 
25 MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>");
26 MODULE_DESCRIPTION("Socket-CAN driver for PEAK PCAN PCI family cards");
27 MODULE_LICENSE("GPL v2");
28 
29 #define DRV_NAME  "peak_pci"
30 
31 /* FPGA cards FW version registers */
32 #define PEAK_VER_REG1		0x40
33 #define PEAK_VER_REG2		0x44
34 
35 struct peak_pciec_card;
36 struct peak_pci_chan {
37 	void __iomem *cfg_base;		/* Common for all channels */
38 	struct net_device *prev_dev;	/* Chain of network devices */
39 	u16 icr_mask;			/* Interrupt mask for fast ack */
40 	struct peak_pciec_card *pciec_card;	/* only for PCIeC LEDs */
41 };
42 
43 #define PEAK_PCI_CAN_CLOCK	(16000000 / 2)
44 
45 #define PEAK_PCI_CDR		(CDR_CBP | CDR_CLKOUT_MASK)
46 #define PEAK_PCI_OCR		OCR_TX0_PUSHPULL
47 
48 /* Important PITA registers */
49 #define PITA_ICR		0x00	/* Interrupt control register */
50 #define PITA_GPIOICR		0x18	/* GPIO interface control register */
51 #define PITA_MISC		0x1C	/* Miscellaneous register */
52 
53 #define PEAK_PCI_CFG_SIZE	0x1000	/* Size of the config PCI bar */
54 #define PEAK_PCI_CHAN_SIZE	0x0400	/* Size used by the channel */
55 
56 #define PEAK_PCI_VENDOR_ID	0x001C	/* The PCI device and vendor IDs */
57 #define PEAK_PCI_DEVICE_ID	0x0001	/* for PCI/PCIe slot cards */
58 #define PEAK_PCIEC_DEVICE_ID	0x0002	/* for ExpressCard slot cards */
59 #define PEAK_PCIE_DEVICE_ID	0x0003	/* for nextgen PCIe slot cards */
60 #define PEAK_CPCI_DEVICE_ID	0x0004	/* for nextgen cPCI slot cards */
61 #define PEAK_MPCI_DEVICE_ID	0x0005	/* for nextgen miniPCI slot cards */
62 #define PEAK_PC_104P_DEVICE_ID	0x0006	/* PCAN-PC/104+ cards */
63 #define PEAK_PCI_104E_DEVICE_ID	0x0007	/* PCAN-PCI/104 Express cards */
64 #define PEAK_MPCIE_DEVICE_ID	0x0008	/* The miniPCIe slot cards */
65 #define PEAK_PCIE_OEM_ID	0x0009	/* PCAN-PCI Express OEM */
66 #define PEAK_PCIEC34_DEVICE_ID	0x000A	/* PCAN-PCI Express 34 (one channel) */
67 
68 #define PEAK_PCI_CHAN_MAX	4
69 
70 static const u16 peak_pci_icr_masks[PEAK_PCI_CHAN_MAX] = {
71 	0x02, 0x01, 0x40, 0x80
72 };
73 
74 static const struct pci_device_id peak_pci_tbl[] = {
75 	{
76 		PEAK_PCI_VENDOR_ID, PEAK_PCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
77 		.driver_data = (kernel_ulong_t)"PCAN-PCI",
78 	}, {
79 		PEAK_PCI_VENDOR_ID, PEAK_PCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
80 		.driver_data = (kernel_ulong_t)"PCAN-PCI Express",
81 	}, {
82 		PEAK_PCI_VENDOR_ID, PEAK_MPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
83 		.driver_data = (kernel_ulong_t)"PCAN-miniPCI",
84 	}, {
85 		PEAK_PCI_VENDOR_ID, PEAK_MPCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
86 		.driver_data = (kernel_ulong_t)"PCAN-miniPCIe",
87 	}, {
88 		PEAK_PCI_VENDOR_ID, PEAK_PC_104P_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
89 		.driver_data = (kernel_ulong_t)"PCAN-PC/104-Plus Quad",
90 	}, {
91 		PEAK_PCI_VENDOR_ID, PEAK_PCI_104E_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
92 		.driver_data = (kernel_ulong_t)"PCAN-PCI/104-Express",
93 	}, {
94 		PEAK_PCI_VENDOR_ID, PEAK_CPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
95 		.driver_data = (kernel_ulong_t)"PCAN-cPCI",
96 	}, {
97 		PEAK_PCI_VENDOR_ID, PEAK_PCIE_OEM_ID, PCI_ANY_ID, PCI_ANY_ID,
98 		.driver_data = (kernel_ulong_t)"PCAN-Chip PCIe",
99 	},
100 #ifdef CONFIG_CAN_PEAK_PCIEC
101 	{
102 		PEAK_PCI_VENDOR_ID, PEAK_PCIEC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
103 		.driver_data = (kernel_ulong_t)"PCAN-ExpressCard",
104 	}, {
105 		PEAK_PCI_VENDOR_ID, PEAK_PCIEC34_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,
106 		.driver_data = (kernel_ulong_t)"PCAN-ExpressCard 34",
107 	},
108 #endif
109 	{ /* sentinel */ }
110 };
111 
112 MODULE_DEVICE_TABLE(pci, peak_pci_tbl);
113 
114 #ifdef CONFIG_CAN_PEAK_PCIEC
115 /* PCAN-ExpressCard needs I2C bit-banging configuration option. */
116 
117 /* GPIOICR byte access offsets */
118 #define PITA_GPOUT		0x18	/* GPx output value */
119 #define PITA_GPIN		0x19	/* GPx input value */
120 #define PITA_GPOEN		0x1A	/* configure GPx as output pin */
121 
122 /* I2C GP bits */
123 #define PITA_GPIN_SCL		0x01	/* Serial Clock Line */
124 #define PITA_GPIN_SDA		0x04	/* Serial DAta line */
125 
126 #define PCA9553_1_SLAVEADDR	(0xC4 >> 1)
127 
128 /* PCA9553 LS0 fields values */
129 enum {
130 	PCA9553_LOW,
131 	PCA9553_HIGHZ,
132 	PCA9553_PWM0,
133 	PCA9553_PWM1
134 };
135 
136 /* LEDs control */
137 #define PCA9553_ON		PCA9553_LOW
138 #define PCA9553_OFF		PCA9553_HIGHZ
139 #define PCA9553_SLOW		PCA9553_PWM0
140 #define PCA9553_FAST		PCA9553_PWM1
141 
142 #define PCA9553_LED(c)		(1 << (c))
143 #define PCA9553_LED_STATE(s, c)	((s) << ((c) << 1))
144 
145 #define PCA9553_LED_ON(c)	PCA9553_LED_STATE(PCA9553_ON, c)
146 #define PCA9553_LED_OFF(c)	PCA9553_LED_STATE(PCA9553_OFF, c)
147 #define PCA9553_LED_SLOW(c)	PCA9553_LED_STATE(PCA9553_SLOW, c)
148 #define PCA9553_LED_FAST(c)	PCA9553_LED_STATE(PCA9553_FAST, c)
149 #define PCA9553_LED_MASK(c)	PCA9553_LED_STATE(0x03, c)
150 
151 #define PCA9553_LED_OFF_ALL	(PCA9553_LED_OFF(0) | PCA9553_LED_OFF(1))
152 
153 #define PCA9553_LS0_INIT	0x40 /* initial value (!= from 0x00) */
154 
155 struct peak_pciec_chan {
156 	struct net_device *netdev;
157 	unsigned long prev_rx_bytes;
158 	unsigned long prev_tx_bytes;
159 };
160 
161 struct peak_pciec_card {
162 	void __iomem *cfg_base;		/* Common for all channels */
163 	void __iomem *reg_base;		/* first channel base address */
164 	u8 led_cache;			/* leds state cache */
165 
166 	/* PCIExpressCard i2c data */
167 	struct i2c_algo_bit_data i2c_bit;
168 	struct i2c_adapter led_chip;
169 	struct delayed_work led_work;	/* led delayed work */
170 	int chan_count;
171 	struct peak_pciec_chan channel[PEAK_PCI_CHAN_MAX];
172 };
173 
174 /* "normal" pci register write callback is overloaded for leds control */
175 static void peak_pci_write_reg(const struct sja1000_priv *priv,
176 			       int port, u8 val);
177 
178 static inline void pita_set_scl_highz(struct peak_pciec_card *card)
179 {
180 	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SCL;
181 
182 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
183 }
184 
185 static inline void pita_set_sda_highz(struct peak_pciec_card *card)
186 {
187 	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SDA;
188 
189 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
190 }
191 
192 static void peak_pciec_init_pita_gpio(struct peak_pciec_card *card)
193 {
194 	/* raise SCL & SDA GPIOs to high-Z */
195 	pita_set_scl_highz(card);
196 	pita_set_sda_highz(card);
197 }
198 
199 static void pita_setsda(void *data, int state)
200 {
201 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
202 	u8 gp_out, gp_outen;
203 
204 	/* set output sda always to 0 */
205 	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SDA;
206 	writeb(gp_out, card->cfg_base + PITA_GPOUT);
207 
208 	/* control output sda with GPOEN */
209 	gp_outen = readb(card->cfg_base + PITA_GPOEN);
210 	if (state)
211 		gp_outen &= ~PITA_GPIN_SDA;
212 	else
213 		gp_outen |= PITA_GPIN_SDA;
214 
215 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
216 }
217 
218 static void pita_setscl(void *data, int state)
219 {
220 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
221 	u8 gp_out, gp_outen;
222 
223 	/* set output scl always to 0 */
224 	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SCL;
225 	writeb(gp_out, card->cfg_base + PITA_GPOUT);
226 
227 	/* control output scl with GPOEN */
228 	gp_outen = readb(card->cfg_base + PITA_GPOEN);
229 	if (state)
230 		gp_outen &= ~PITA_GPIN_SCL;
231 	else
232 		gp_outen |= PITA_GPIN_SCL;
233 
234 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
235 }
236 
237 static int pita_getsda(void *data)
238 {
239 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
240 
241 	/* set tristate */
242 	pita_set_sda_highz(card);
243 
244 	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SDA) ? 1 : 0;
245 }
246 
247 static int pita_getscl(void *data)
248 {
249 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
250 
251 	/* set tristate */
252 	pita_set_scl_highz(card);
253 
254 	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SCL) ? 1 : 0;
255 }
256 
257 /* write commands to the LED chip though the I2C-bus of the PCAN-PCIeC */
258 static int peak_pciec_write_pca9553(struct peak_pciec_card *card,
259 				    u8 offset, u8 data)
260 {
261 	u8 buffer[2] = {
262 		offset,
263 		data
264 	};
265 	struct i2c_msg msg = {
266 		.addr = PCA9553_1_SLAVEADDR,
267 		.len = 2,
268 		.buf = buffer,
269 	};
270 	int ret;
271 
272 	/* cache led mask */
273 	if (offset == 5 && data == card->led_cache)
274 		return 0;
275 
276 	ret = i2c_transfer(&card->led_chip, &msg, 1);
277 	if (ret < 0)
278 		return ret;
279 
280 	if (offset == 5)
281 		card->led_cache = data;
282 
283 	return 0;
284 }
285 
286 /* delayed work callback used to control the LEDs */
287 static void peak_pciec_led_work(struct work_struct *work)
288 {
289 	struct peak_pciec_card *card =
290 		container_of(work, struct peak_pciec_card, led_work.work);
291 	struct net_device *netdev;
292 	u8 new_led = card->led_cache;
293 	int i, up_count = 0;
294 
295 	/* first check what is to do */
296 	for (i = 0; i < card->chan_count; i++) {
297 		/* default is: not configured */
298 		new_led &= ~PCA9553_LED_MASK(i);
299 		new_led |= PCA9553_LED_ON(i);
300 
301 		netdev = card->channel[i].netdev;
302 		if (!netdev || !(netdev->flags & IFF_UP))
303 			continue;
304 
305 		up_count++;
306 
307 		/* no activity (but configured) */
308 		new_led &= ~PCA9553_LED_MASK(i);
309 		new_led |= PCA9553_LED_SLOW(i);
310 
311 		/* if bytes counters changed, set fast blinking led */
312 		if (netdev->stats.rx_bytes != card->channel[i].prev_rx_bytes) {
313 			card->channel[i].prev_rx_bytes = netdev->stats.rx_bytes;
314 			new_led &= ~PCA9553_LED_MASK(i);
315 			new_led |= PCA9553_LED_FAST(i);
316 		}
317 		if (netdev->stats.tx_bytes != card->channel[i].prev_tx_bytes) {
318 			card->channel[i].prev_tx_bytes = netdev->stats.tx_bytes;
319 			new_led &= ~PCA9553_LED_MASK(i);
320 			new_led |= PCA9553_LED_FAST(i);
321 		}
322 	}
323 
324 	/* check if LS0 settings changed, only update i2c if so */
325 	peak_pciec_write_pca9553(card, 5, new_led);
326 
327 	/* restart timer (except if no more configured channels) */
328 	if (up_count)
329 		schedule_delayed_work(&card->led_work, HZ);
330 }
331 
332 /* set LEDs blinking state */
333 static void peak_pciec_set_leds(struct peak_pciec_card *card, u8 led_mask, u8 s)
334 {
335 	u8 new_led = card->led_cache;
336 	int i;
337 
338 	/* first check what is to do */
339 	for (i = 0; i < card->chan_count; i++)
340 		if (led_mask & PCA9553_LED(i)) {
341 			new_led &= ~PCA9553_LED_MASK(i);
342 			new_led |= PCA9553_LED_STATE(s, i);
343 		}
344 
345 	/* check if LS0 settings changed, only update i2c if so */
346 	peak_pciec_write_pca9553(card, 5, new_led);
347 }
348 
349 /* start one second delayed work to control LEDs */
350 static void peak_pciec_start_led_work(struct peak_pciec_card *card)
351 {
352 	schedule_delayed_work(&card->led_work, HZ);
353 }
354 
355 /* stop LEDs delayed work */
356 static void peak_pciec_stop_led_work(struct peak_pciec_card *card)
357 {
358 	cancel_delayed_work_sync(&card->led_work);
359 }
360 
361 /* initialize the PCA9553 4-bit I2C-bus LED chip */
362 static int peak_pciec_init_leds(struct peak_pciec_card *card)
363 {
364 	int err;
365 
366 	/* prescaler for frequency 0: "SLOW" = 1 Hz = "44" */
367 	err = peak_pciec_write_pca9553(card, 1, 44 / 1);
368 	if (err)
369 		return err;
370 
371 	/* duty cycle 0: 50% */
372 	err = peak_pciec_write_pca9553(card, 2, 0x80);
373 	if (err)
374 		return err;
375 
376 	/* prescaler for frequency 1: "FAST" = 5 Hz */
377 	err = peak_pciec_write_pca9553(card, 3, 44 / 5);
378 	if (err)
379 		return err;
380 
381 	/* duty cycle 1: 50% */
382 	err = peak_pciec_write_pca9553(card, 4, 0x80);
383 	if (err)
384 		return err;
385 
386 	/* switch LEDs to initial state */
387 	return peak_pciec_write_pca9553(card, 5, PCA9553_LS0_INIT);
388 }
389 
390 /* restore LEDs state to off peak_pciec_leds_exit */
391 static void peak_pciec_leds_exit(struct peak_pciec_card *card)
392 {
393 	/* switch LEDs to off */
394 	peak_pciec_write_pca9553(card, 5, PCA9553_LED_OFF_ALL);
395 }
396 
397 /* normal write sja1000 register method overloaded to catch when controller
398  * is started or stopped, to control leds
399  */
400 static void peak_pciec_write_reg(const struct sja1000_priv *priv,
401 				 int port, u8 val)
402 {
403 	struct peak_pci_chan *chan = priv->priv;
404 	struct peak_pciec_card *card = chan->pciec_card;
405 	int c = (priv->reg_base - card->reg_base) / PEAK_PCI_CHAN_SIZE;
406 
407 	/* sja1000 register changes control the leds state */
408 	if (port == SJA1000_MOD)
409 		switch (val) {
410 		case MOD_RM:
411 			/* Reset Mode: set led on */
412 			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_ON);
413 			break;
414 		case 0x00:
415 			/* Normal Mode: led slow blinking and start led timer */
416 			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_SLOW);
417 			peak_pciec_start_led_work(card);
418 			break;
419 		default:
420 			break;
421 		}
422 
423 	/* call base function */
424 	peak_pci_write_reg(priv, port, val);
425 }
426 
427 static const struct i2c_algo_bit_data peak_pciec_i2c_bit_ops = {
428 	.setsda	= pita_setsda,
429 	.setscl	= pita_setscl,
430 	.getsda	= pita_getsda,
431 	.getscl	= pita_getscl,
432 	.udelay	= 10,
433 	.timeout = HZ,
434 };
435 
436 static int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
437 {
438 	struct sja1000_priv *priv = netdev_priv(dev);
439 	struct peak_pci_chan *chan = priv->priv;
440 	struct peak_pciec_card *card;
441 	int err;
442 
443 	/* copy i2c object address from 1st channel */
444 	if (chan->prev_dev) {
445 		struct sja1000_priv *prev_priv = netdev_priv(chan->prev_dev);
446 		struct peak_pci_chan *prev_chan = prev_priv->priv;
447 
448 		card = prev_chan->pciec_card;
449 		if (!card)
450 			return -ENODEV;
451 
452 	/* channel is the first one: do the init part */
453 	} else {
454 		/* create the bit banging I2C adapter structure */
455 		card = kzalloc(sizeof(*card), GFP_KERNEL);
456 		if (!card)
457 			return -ENOMEM;
458 
459 		card->cfg_base = chan->cfg_base;
460 		card->reg_base = priv->reg_base;
461 
462 		card->led_chip.owner = THIS_MODULE;
463 		card->led_chip.dev.parent = &pdev->dev;
464 		card->led_chip.algo_data = &card->i2c_bit;
465 		strncpy(card->led_chip.name, "peak_i2c",
466 			sizeof(card->led_chip.name));
467 
468 		card->i2c_bit = peak_pciec_i2c_bit_ops;
469 		card->i2c_bit.udelay = 10;
470 		card->i2c_bit.timeout = HZ;
471 		card->i2c_bit.data = card;
472 
473 		peak_pciec_init_pita_gpio(card);
474 
475 		err = i2c_bit_add_bus(&card->led_chip);
476 		if (err) {
477 			dev_err(&pdev->dev, "i2c init failed\n");
478 			goto pciec_init_err_1;
479 		}
480 
481 		err = peak_pciec_init_leds(card);
482 		if (err) {
483 			dev_err(&pdev->dev, "leds hardware init failed\n");
484 			goto pciec_init_err_2;
485 		}
486 
487 		INIT_DELAYED_WORK(&card->led_work, peak_pciec_led_work);
488 		/* PCAN-ExpressCard needs its own callback for leds */
489 		priv->write_reg = peak_pciec_write_reg;
490 	}
491 
492 	chan->pciec_card = card;
493 	card->channel[card->chan_count++].netdev = dev;
494 
495 	return 0;
496 
497 pciec_init_err_2:
498 	i2c_del_adapter(&card->led_chip);
499 
500 pciec_init_err_1:
501 	peak_pciec_init_pita_gpio(card);
502 	kfree(card);
503 
504 	return err;
505 }
506 
507 static void peak_pciec_remove(struct peak_pciec_card *card)
508 {
509 	peak_pciec_stop_led_work(card);
510 	peak_pciec_leds_exit(card);
511 	i2c_del_adapter(&card->led_chip);
512 	peak_pciec_init_pita_gpio(card);
513 	kfree(card);
514 }
515 
516 #else /* CONFIG_CAN_PEAK_PCIEC */
517 
518 /* Placebo functions when PCAN-ExpressCard support is not selected */
519 static inline int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
520 {
521 	return -ENODEV;
522 }
523 
524 static inline void peak_pciec_remove(struct peak_pciec_card *card)
525 {
526 }
527 #endif /* CONFIG_CAN_PEAK_PCIEC */
528 
529 static u8 peak_pci_read_reg(const struct sja1000_priv *priv, int port)
530 {
531 	return readb(priv->reg_base + (port << 2));
532 }
533 
534 static void peak_pci_write_reg(const struct sja1000_priv *priv,
535 			       int port, u8 val)
536 {
537 	writeb(val, priv->reg_base + (port << 2));
538 }
539 
540 static void peak_pci_post_irq(const struct sja1000_priv *priv)
541 {
542 	struct peak_pci_chan *chan = priv->priv;
543 	u16 icr;
544 
545 	/* Select and clear in PITA stored interrupt */
546 	icr = readw(chan->cfg_base + PITA_ICR);
547 	if (icr & chan->icr_mask)
548 		writew(chan->icr_mask, chan->cfg_base + PITA_ICR);
549 }
550 
551 static int peak_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
552 {
553 	struct sja1000_priv *priv;
554 	struct peak_pci_chan *chan;
555 	struct net_device *dev, *prev_dev;
556 	void __iomem *cfg_base, *reg_base;
557 	u16 sub_sys_id, icr;
558 	int i, err, channels;
559 	char fw_str[14] = "";
560 
561 	err = pci_enable_device(pdev);
562 	if (err)
563 		return err;
564 
565 	err = pci_request_regions(pdev, DRV_NAME);
566 	if (err)
567 		goto failure_disable_pci;
568 
569 	err = pci_read_config_word(pdev, 0x2e, &sub_sys_id);
570 	if (err)
571 		goto failure_release_regions;
572 
573 	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
574 		pdev->vendor, pdev->device, sub_sys_id);
575 
576 	err = pci_write_config_word(pdev, 0x44, 0);
577 	if (err)
578 		goto failure_release_regions;
579 
580 	if (sub_sys_id >= 12)
581 		channels = 4;
582 	else if (sub_sys_id >= 10)
583 		channels = 3;
584 	else if (sub_sys_id >= 4)
585 		channels = 2;
586 	else
587 		channels = 1;
588 
589 	cfg_base = pci_iomap(pdev, 0, PEAK_PCI_CFG_SIZE);
590 	if (!cfg_base) {
591 		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
592 		err = -ENOMEM;
593 		goto failure_release_regions;
594 	}
595 
596 	reg_base = pci_iomap(pdev, 1, PEAK_PCI_CHAN_SIZE * channels);
597 	if (!reg_base) {
598 		dev_err(&pdev->dev, "failed to map PCI resource #1\n");
599 		err = -ENOMEM;
600 		goto failure_unmap_cfg_base;
601 	}
602 
603 	/* Set GPIO control register */
604 	writew(0x0005, cfg_base + PITA_GPIOICR + 2);
605 	/* Enable all channels of this card */
606 	writeb(0x00, cfg_base + PITA_GPIOICR);
607 	/* Toggle reset */
608 	writeb(0x05, cfg_base + PITA_MISC + 3);
609 	usleep_range(5000, 6000);
610 	/* Leave parport mux mode */
611 	writeb(0x04, cfg_base + PITA_MISC + 3);
612 
613 	/* FPGA equipped card if not 0 */
614 	if (readl(cfg_base + PEAK_VER_REG1)) {
615 		/* FPGA card: display version of the running firmware */
616 		u32 fw_ver = readl(cfg_base + PEAK_VER_REG2);
617 
618 		snprintf(fw_str, sizeof(fw_str), " FW v%u.%u.%u",
619 			 (fw_ver >> 12) & 0xf,
620 			 (fw_ver >> 8) & 0xf,
621 			 (fw_ver >> 4) & 0xf);
622 	}
623 
624 	/* Display commercial name (and, eventually, FW version) of the card */
625 	dev_info(&pdev->dev, "%ux CAN %s%s\n",
626 		 channels, (const char *)ent->driver_data, fw_str);
627 
628 	icr = readw(cfg_base + PITA_ICR + 2);
629 
630 	for (i = 0; i < channels; i++) {
631 		dev = alloc_sja1000dev(sizeof(struct peak_pci_chan));
632 		if (!dev) {
633 			err = -ENOMEM;
634 			goto failure_remove_channels;
635 		}
636 
637 		priv = netdev_priv(dev);
638 		chan = priv->priv;
639 
640 		chan->cfg_base = cfg_base;
641 		priv->reg_base = reg_base + i * PEAK_PCI_CHAN_SIZE;
642 
643 		priv->read_reg = peak_pci_read_reg;
644 		priv->write_reg = peak_pci_write_reg;
645 		priv->post_irq = peak_pci_post_irq;
646 
647 		priv->can.clock.freq = PEAK_PCI_CAN_CLOCK;
648 		priv->ocr = PEAK_PCI_OCR;
649 		priv->cdr = PEAK_PCI_CDR;
650 		/* Neither a slave nor a single device distributes the clock */
651 		if (channels == 1 || i > 0)
652 			priv->cdr |= CDR_CLK_OFF;
653 
654 		/* Setup interrupt handling */
655 		priv->irq_flags = IRQF_SHARED;
656 		dev->irq = pdev->irq;
657 
658 		chan->icr_mask = peak_pci_icr_masks[i];
659 		icr |= chan->icr_mask;
660 
661 		SET_NETDEV_DEV(dev, &pdev->dev);
662 		dev->dev_id = i;
663 
664 		/* Create chain of SJA1000 devices */
665 		chan->prev_dev = pci_get_drvdata(pdev);
666 		pci_set_drvdata(pdev, dev);
667 
668 		/* PCAN-ExpressCard needs some additional i2c init.
669 		 * This must be done *before* register_sja1000dev() but
670 		 * *after* devices linkage
671 		 */
672 		if (pdev->device == PEAK_PCIEC_DEVICE_ID ||
673 		    pdev->device == PEAK_PCIEC34_DEVICE_ID) {
674 			err = peak_pciec_probe(pdev, dev);
675 			if (err) {
676 				dev_err(&pdev->dev,
677 					"failed to probe device (err %d)\n",
678 					err);
679 				goto failure_free_dev;
680 			}
681 		}
682 
683 		err = register_sja1000dev(dev);
684 		if (err) {
685 			dev_err(&pdev->dev, "failed to register device\n");
686 			goto failure_free_dev;
687 		}
688 
689 		dev_info(&pdev->dev,
690 			 "%s at reg_base=0x%p cfg_base=0x%p irq=%d\n",
691 			 dev->name, priv->reg_base, chan->cfg_base, dev->irq);
692 	}
693 
694 	/* Enable interrupts */
695 	writew(icr, cfg_base + PITA_ICR + 2);
696 
697 	return 0;
698 
699 failure_free_dev:
700 	pci_set_drvdata(pdev, chan->prev_dev);
701 	free_sja1000dev(dev);
702 
703 failure_remove_channels:
704 	/* Disable interrupts */
705 	writew(0x0, cfg_base + PITA_ICR + 2);
706 
707 	chan = NULL;
708 	for (dev = pci_get_drvdata(pdev); dev; dev = prev_dev) {
709 		priv = netdev_priv(dev);
710 		chan = priv->priv;
711 		prev_dev = chan->prev_dev;
712 
713 		unregister_sja1000dev(dev);
714 		free_sja1000dev(dev);
715 	}
716 
717 	/* free any PCIeC resources too */
718 	if (chan && chan->pciec_card)
719 		peak_pciec_remove(chan->pciec_card);
720 
721 	pci_iounmap(pdev, reg_base);
722 
723 failure_unmap_cfg_base:
724 	pci_iounmap(pdev, cfg_base);
725 
726 failure_release_regions:
727 	pci_release_regions(pdev);
728 
729 failure_disable_pci:
730 	pci_disable_device(pdev);
731 
732 	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
733 	 * the probe() function must return a negative errno in case of failure
734 	 * (err is unchanged if negative)
735 	 */
736 	return pcibios_err_to_errno(err);
737 }
738 
739 static void peak_pci_remove(struct pci_dev *pdev)
740 {
741 	struct net_device *dev = pci_get_drvdata(pdev); /* Last device */
742 	struct sja1000_priv *priv = netdev_priv(dev);
743 	struct peak_pci_chan *chan = priv->priv;
744 	void __iomem *cfg_base = chan->cfg_base;
745 	void __iomem *reg_base = priv->reg_base;
746 
747 	/* Disable interrupts */
748 	writew(0x0, cfg_base + PITA_ICR + 2);
749 
750 	/* Loop over all registered devices */
751 	while (1) {
752 		struct net_device *prev_dev = chan->prev_dev;
753 
754 		dev_info(&pdev->dev, "removing device %s\n", dev->name);
755 		/* do that only for first channel */
756 		if (!prev_dev && chan->pciec_card)
757 			peak_pciec_remove(chan->pciec_card);
758 		unregister_sja1000dev(dev);
759 		free_sja1000dev(dev);
760 		dev = prev_dev;
761 
762 		if (!dev)
763 			break;
764 		priv = netdev_priv(dev);
765 		chan = priv->priv;
766 	}
767 
768 	pci_iounmap(pdev, reg_base);
769 	pci_iounmap(pdev, cfg_base);
770 	pci_release_regions(pdev);
771 	pci_disable_device(pdev);
772 }
773 
774 static struct pci_driver peak_pci_driver = {
775 	.name = DRV_NAME,
776 	.id_table = peak_pci_tbl,
777 	.probe = peak_pci_probe,
778 	.remove = peak_pci_remove,
779 };
780 
781 module_pci_driver(peak_pci_driver);
782