xref: /openbmc/linux/drivers/net/can/sja1000/peak_pci.c (revision 63dc02bd)
1 /*
2  * Copyright (C) 2007, 2011 Wolfgang Grandegger <wg@grandegger.com>
3  * Copyright (C) 2012 Stephane Grosjean <s.grosjean@peak-system.com>
4  *
5  * Derived from the PCAN project file driver/src/pcan_pci.c:
6  *
7  * Copyright (C) 2001-2006  PEAK System-Technik GmbH
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the version 2 of the GNU General Public License
11  * as published by the Free Software Foundation
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  */
18 
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/interrupt.h>
22 #include <linux/netdevice.h>
23 #include <linux/delay.h>
24 #include <linux/pci.h>
25 #include <linux/io.h>
26 #include <linux/i2c.h>
27 #include <linux/i2c-algo-bit.h>
28 #include <linux/can.h>
29 #include <linux/can/dev.h>
30 
31 #include "sja1000.h"
32 
33 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
34 MODULE_DESCRIPTION("Socket-CAN driver for PEAK PCAN PCI family cards");
35 MODULE_SUPPORTED_DEVICE("PEAK PCAN PCI/PCIe/PCIeC miniPCI CAN cards");
36 MODULE_LICENSE("GPL v2");
37 
38 #define DRV_NAME  "peak_pci"
39 
40 struct peak_pciec_card;
41 struct peak_pci_chan {
42 	void __iomem *cfg_base;		/* Common for all channels */
43 	struct net_device *prev_dev;	/* Chain of network devices */
44 	u16 icr_mask;			/* Interrupt mask for fast ack */
45 	struct peak_pciec_card *pciec_card;	/* only for PCIeC LEDs */
46 };
47 
48 #define PEAK_PCI_CAN_CLOCK	(16000000 / 2)
49 
50 #define PEAK_PCI_CDR		(CDR_CBP | CDR_CLKOUT_MASK)
51 #define PEAK_PCI_OCR		OCR_TX0_PUSHPULL
52 
53 /*
54  * Important PITA registers
55  */
56 #define PITA_ICR		0x00	/* Interrupt control register */
57 #define PITA_GPIOICR		0x18	/* GPIO interface control register */
58 #define PITA_MISC		0x1C	/* Miscellaneous register */
59 
60 #define PEAK_PCI_CFG_SIZE	0x1000	/* Size of the config PCI bar */
61 #define PEAK_PCI_CHAN_SIZE	0x0400	/* Size used by the channel */
62 
63 #define PEAK_PCI_VENDOR_ID	0x001C	/* The PCI device and vendor IDs */
64 #define PEAK_PCI_DEVICE_ID	0x0001	/* for PCI/PCIe slot cards */
65 #define PEAK_PCIEC_DEVICE_ID	0x0002	/* for ExpressCard slot cards */
66 #define PEAK_PCIE_DEVICE_ID	0x0003	/* for nextgen PCIe slot cards */
67 #define PEAK_MPCI_DEVICE_ID	0x0008	/* The miniPCI slot cards */
68 
69 #define PEAK_PCI_CHAN_MAX	4
70 
71 static const u16 peak_pci_icr_masks[PEAK_PCI_CHAN_MAX] = {
72 	0x02, 0x01, 0x40, 0x80
73 };
74 
75 static DEFINE_PCI_DEVICE_TABLE(peak_pci_tbl) = {
76 	{PEAK_PCI_VENDOR_ID, PEAK_PCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
77 	{PEAK_PCI_VENDOR_ID, PEAK_PCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
78 	{PEAK_PCI_VENDOR_ID, PEAK_MPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
79 #ifdef CONFIG_CAN_PEAK_PCIEC
80 	{PEAK_PCI_VENDOR_ID, PEAK_PCIEC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
81 #endif
82 	{0,}
83 };
84 
85 MODULE_DEVICE_TABLE(pci, peak_pci_tbl);
86 
87 #ifdef CONFIG_CAN_PEAK_PCIEC
88 /*
89  * PCAN-ExpressCard needs I2C bit-banging configuration option.
90  */
91 
92 /* GPIOICR byte access offsets */
93 #define PITA_GPOUT		0x18	/* GPx output value */
94 #define PITA_GPIN		0x19	/* GPx input value */
95 #define PITA_GPOEN		0x1A	/* configure GPx as ouput pin */
96 
97 /* I2C GP bits */
98 #define PITA_GPIN_SCL		0x01	/* Serial Clock Line */
99 #define PITA_GPIN_SDA		0x04	/* Serial DAta line */
100 
101 #define PCA9553_1_SLAVEADDR	(0xC4 >> 1)
102 
103 /* PCA9553 LS0 fields values */
104 enum {
105 	PCA9553_LOW,
106 	PCA9553_HIGHZ,
107 	PCA9553_PWM0,
108 	PCA9553_PWM1
109 };
110 
111 /* LEDs control */
112 #define PCA9553_ON		PCA9553_LOW
113 #define PCA9553_OFF		PCA9553_HIGHZ
114 #define PCA9553_SLOW		PCA9553_PWM0
115 #define PCA9553_FAST		PCA9553_PWM1
116 
117 #define PCA9553_LED(c)		(1 << (c))
118 #define PCA9553_LED_STATE(s, c)	((s) << ((c) << 1))
119 
120 #define PCA9553_LED_ON(c)	PCA9553_LED_STATE(PCA9553_ON, c)
121 #define PCA9553_LED_OFF(c)	PCA9553_LED_STATE(PCA9553_OFF, c)
122 #define PCA9553_LED_SLOW(c)	PCA9553_LED_STATE(PCA9553_SLOW, c)
123 #define PCA9553_LED_FAST(c)	PCA9553_LED_STATE(PCA9553_FAST, c)
124 #define PCA9553_LED_MASK(c)	PCA9553_LED_STATE(0x03, c)
125 
126 #define PCA9553_LED_OFF_ALL	(PCA9553_LED_OFF(0) | PCA9553_LED_OFF(1))
127 
128 #define PCA9553_LS0_INIT	0x40 /* initial value (!= from 0x00) */
129 
130 struct peak_pciec_chan {
131 	struct net_device *netdev;
132 	unsigned long prev_rx_bytes;
133 	unsigned long prev_tx_bytes;
134 };
135 
136 struct peak_pciec_card {
137 	void __iomem *cfg_base;		/* Common for all channels */
138 	void __iomem *reg_base;		/* first channel base address */
139 	u8 led_cache;			/* leds state cache */
140 
141 	/* PCIExpressCard i2c data */
142 	struct i2c_algo_bit_data i2c_bit;
143 	struct i2c_adapter led_chip;
144 	struct delayed_work led_work;	/* led delayed work */
145 	int chan_count;
146 	struct peak_pciec_chan channel[PEAK_PCI_CHAN_MAX];
147 };
148 
149 /* "normal" pci register write callback is overloaded for leds control */
150 static void peak_pci_write_reg(const struct sja1000_priv *priv,
151 			       int port, u8 val);
152 
153 static inline void pita_set_scl_highz(struct peak_pciec_card *card)
154 {
155 	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SCL;
156 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
157 }
158 
159 static inline void pita_set_sda_highz(struct peak_pciec_card *card)
160 {
161 	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SDA;
162 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
163 }
164 
165 static void peak_pciec_init_pita_gpio(struct peak_pciec_card *card)
166 {
167 	/* raise SCL & SDA GPIOs to high-Z */
168 	pita_set_scl_highz(card);
169 	pita_set_sda_highz(card);
170 }
171 
172 static void pita_setsda(void *data, int state)
173 {
174 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
175 	u8 gp_out, gp_outen;
176 
177 	/* set output sda always to 0 */
178 	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SDA;
179 	writeb(gp_out, card->cfg_base + PITA_GPOUT);
180 
181 	/* control output sda with GPOEN */
182 	gp_outen = readb(card->cfg_base + PITA_GPOEN);
183 	if (state)
184 		gp_outen &= ~PITA_GPIN_SDA;
185 	else
186 		gp_outen |= PITA_GPIN_SDA;
187 
188 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
189 }
190 
191 static void pita_setscl(void *data, int state)
192 {
193 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
194 	u8 gp_out, gp_outen;
195 
196 	/* set output scl always to 0 */
197 	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SCL;
198 	writeb(gp_out, card->cfg_base + PITA_GPOUT);
199 
200 	/* control output scl with GPOEN */
201 	gp_outen = readb(card->cfg_base + PITA_GPOEN);
202 	if (state)
203 		gp_outen &= ~PITA_GPIN_SCL;
204 	else
205 		gp_outen |= PITA_GPIN_SCL;
206 
207 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
208 }
209 
210 static int pita_getsda(void *data)
211 {
212 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
213 
214 	/* set tristate */
215 	pita_set_sda_highz(card);
216 
217 	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SDA) ? 1 : 0;
218 }
219 
220 static int pita_getscl(void *data)
221 {
222 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
223 
224 	/* set tristate */
225 	pita_set_scl_highz(card);
226 
227 	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SCL) ? 1 : 0;
228 }
229 
230 /*
231  * write commands to the LED chip though the I2C-bus of the PCAN-PCIeC
232  */
233 static int peak_pciec_write_pca9553(struct peak_pciec_card *card,
234 				    u8 offset, u8 data)
235 {
236 	u8 buffer[2] = {
237 		offset,
238 		data
239 	};
240 	struct i2c_msg msg = {
241 		.addr = PCA9553_1_SLAVEADDR,
242 		.len = 2,
243 		.buf = buffer,
244 	};
245 	int ret;
246 
247 	/* cache led mask */
248 	if ((offset == 5) && (data == card->led_cache))
249 		return 0;
250 
251 	ret = i2c_transfer(&card->led_chip, &msg, 1);
252 	if (ret < 0)
253 		return ret;
254 
255 	if (offset == 5)
256 		card->led_cache = data;
257 
258 	return 0;
259 }
260 
261 /*
262  * delayed work callback used to control the LEDs
263  */
264 static void peak_pciec_led_work(struct work_struct *work)
265 {
266 	struct peak_pciec_card *card =
267 		container_of(work, struct peak_pciec_card, led_work.work);
268 	struct net_device *netdev;
269 	u8 new_led = card->led_cache;
270 	int i, up_count = 0;
271 
272 	/* first check what is to do */
273 	for (i = 0; i < card->chan_count; i++) {
274 		/* default is: not configured */
275 		new_led &= ~PCA9553_LED_MASK(i);
276 		new_led |= PCA9553_LED_ON(i);
277 
278 		netdev = card->channel[i].netdev;
279 		if (!netdev || !(netdev->flags & IFF_UP))
280 			continue;
281 
282 		up_count++;
283 
284 		/* no activity (but configured) */
285 		new_led &= ~PCA9553_LED_MASK(i);
286 		new_led |= PCA9553_LED_SLOW(i);
287 
288 		/* if bytes counters changed, set fast blinking led */
289 		if (netdev->stats.rx_bytes != card->channel[i].prev_rx_bytes) {
290 			card->channel[i].prev_rx_bytes = netdev->stats.rx_bytes;
291 			new_led &= ~PCA9553_LED_MASK(i);
292 			new_led |= PCA9553_LED_FAST(i);
293 		}
294 		if (netdev->stats.tx_bytes != card->channel[i].prev_tx_bytes) {
295 			card->channel[i].prev_tx_bytes = netdev->stats.tx_bytes;
296 			new_led &= ~PCA9553_LED_MASK(i);
297 			new_led |= PCA9553_LED_FAST(i);
298 		}
299 	}
300 
301 	/* check if LS0 settings changed, only update i2c if so */
302 	peak_pciec_write_pca9553(card, 5, new_led);
303 
304 	/* restart timer (except if no more configured channels) */
305 	if (up_count)
306 		schedule_delayed_work(&card->led_work, HZ);
307 }
308 
309 /*
310  * set LEDs blinking state
311  */
312 static void peak_pciec_set_leds(struct peak_pciec_card *card, u8 led_mask, u8 s)
313 {
314 	u8 new_led = card->led_cache;
315 	int i;
316 
317 	/* first check what is to do */
318 	for (i = 0; i < card->chan_count; i++)
319 		if (led_mask & PCA9553_LED(i)) {
320 			new_led &= ~PCA9553_LED_MASK(i);
321 			new_led |= PCA9553_LED_STATE(s, i);
322 		}
323 
324 	/* check if LS0 settings changed, only update i2c if so */
325 	peak_pciec_write_pca9553(card, 5, new_led);
326 }
327 
328 /*
329  * start one second delayed work to control LEDs
330  */
331 static void peak_pciec_start_led_work(struct peak_pciec_card *card)
332 {
333 	if (!delayed_work_pending(&card->led_work))
334 		schedule_delayed_work(&card->led_work, HZ);
335 }
336 
337 /*
338  * stop LEDs delayed work
339  */
340 static void peak_pciec_stop_led_work(struct peak_pciec_card *card)
341 {
342 	cancel_delayed_work_sync(&card->led_work);
343 }
344 
345 /*
346  * initialize the PCA9553 4-bit I2C-bus LED chip
347  */
348 static int peak_pciec_init_leds(struct peak_pciec_card *card)
349 {
350 	int err;
351 
352 	/* prescaler for frequency 0: "SLOW" = 1 Hz = "44" */
353 	err = peak_pciec_write_pca9553(card, 1, 44 / 1);
354 	if (err)
355 		return err;
356 
357 	/* duty cycle 0: 50% */
358 	err = peak_pciec_write_pca9553(card, 2, 0x80);
359 	if (err)
360 		return err;
361 
362 	/* prescaler for frequency 1: "FAST" = 5 Hz */
363 	err = peak_pciec_write_pca9553(card, 3, 44 / 5);
364 	if (err)
365 		return err;
366 
367 	/* duty cycle 1: 50% */
368 	err = peak_pciec_write_pca9553(card, 4, 0x80);
369 	if (err)
370 		return err;
371 
372 	/* switch LEDs to initial state */
373 	return peak_pciec_write_pca9553(card, 5, PCA9553_LS0_INIT);
374 }
375 
376 /*
377  * restore LEDs state to off peak_pciec_leds_exit
378  */
379 static void peak_pciec_leds_exit(struct peak_pciec_card *card)
380 {
381 	/* switch LEDs to off */
382 	peak_pciec_write_pca9553(card, 5, PCA9553_LED_OFF_ALL);
383 }
384 
385 /*
386  * normal write sja1000 register method overloaded to catch when controller
387  * is started or stopped, to control leds
388  */
389 static void peak_pciec_write_reg(const struct sja1000_priv *priv,
390 				 int port, u8 val)
391 {
392 	struct peak_pci_chan *chan = priv->priv;
393 	struct peak_pciec_card *card = chan->pciec_card;
394 	int c = (priv->reg_base - card->reg_base) / PEAK_PCI_CHAN_SIZE;
395 
396 	/* sja1000 register changes control the leds state */
397 	if (port == REG_MOD)
398 		switch (val) {
399 		case MOD_RM:
400 			/* Reset Mode: set led on */
401 			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_ON);
402 			break;
403 		case 0x00:
404 			/* Normal Mode: led slow blinking and start led timer */
405 			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_SLOW);
406 			peak_pciec_start_led_work(card);
407 			break;
408 		default:
409 			break;
410 		}
411 
412 	/* call base function */
413 	peak_pci_write_reg(priv, port, val);
414 }
415 
416 static struct i2c_algo_bit_data peak_pciec_i2c_bit_ops = {
417 	.setsda	= pita_setsda,
418 	.setscl	= pita_setscl,
419 	.getsda	= pita_getsda,
420 	.getscl	= pita_getscl,
421 	.udelay	= 10,
422 	.timeout = HZ,
423 };
424 
425 static int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
426 {
427 	struct sja1000_priv *priv = netdev_priv(dev);
428 	struct peak_pci_chan *chan = priv->priv;
429 	struct peak_pciec_card *card;
430 	int err;
431 
432 	/* copy i2c object address from 1st channel */
433 	if (chan->prev_dev) {
434 		struct sja1000_priv *prev_priv = netdev_priv(chan->prev_dev);
435 		struct peak_pci_chan *prev_chan = prev_priv->priv;
436 
437 		card = prev_chan->pciec_card;
438 		if (!card)
439 			return -ENODEV;
440 
441 	/* channel is the first one: do the init part */
442 	} else {
443 		/* create the bit banging I2C adapter structure */
444 		card = kzalloc(sizeof(struct peak_pciec_card), GFP_KERNEL);
445 		if (!card) {
446 			dev_err(&pdev->dev,
447 				 "failed allocating memory for i2c chip\n");
448 			return -ENOMEM;
449 		}
450 
451 		card->cfg_base = chan->cfg_base;
452 		card->reg_base = priv->reg_base;
453 
454 		card->led_chip.owner = THIS_MODULE;
455 		card->led_chip.dev.parent = &pdev->dev;
456 		card->led_chip.algo_data = &card->i2c_bit;
457 		strncpy(card->led_chip.name, "peak_i2c",
458 			sizeof(card->led_chip.name));
459 
460 		card->i2c_bit = peak_pciec_i2c_bit_ops;
461 		card->i2c_bit.udelay = 10;
462 		card->i2c_bit.timeout = HZ;
463 		card->i2c_bit.data = card;
464 
465 		peak_pciec_init_pita_gpio(card);
466 
467 		err = i2c_bit_add_bus(&card->led_chip);
468 		if (err) {
469 			dev_err(&pdev->dev, "i2c init failed\n");
470 			goto pciec_init_err_1;
471 		}
472 
473 		err = peak_pciec_init_leds(card);
474 		if (err) {
475 			dev_err(&pdev->dev, "leds hardware init failed\n");
476 			goto pciec_init_err_2;
477 		}
478 
479 		INIT_DELAYED_WORK(&card->led_work, peak_pciec_led_work);
480 		/* PCAN-ExpressCard needs its own callback for leds */
481 		priv->write_reg = peak_pciec_write_reg;
482 	}
483 
484 	chan->pciec_card = card;
485 	card->channel[card->chan_count++].netdev = dev;
486 
487 	return 0;
488 
489 pciec_init_err_2:
490 	i2c_del_adapter(&card->led_chip);
491 
492 pciec_init_err_1:
493 	peak_pciec_init_pita_gpio(card);
494 	kfree(card);
495 
496 	return err;
497 }
498 
499 static void peak_pciec_remove(struct peak_pciec_card *card)
500 {
501 	peak_pciec_stop_led_work(card);
502 	peak_pciec_leds_exit(card);
503 	i2c_del_adapter(&card->led_chip);
504 	peak_pciec_init_pita_gpio(card);
505 	kfree(card);
506 }
507 
508 #else /* CONFIG_CAN_PEAK_PCIEC */
509 
510 /*
511  * Placebo functions when PCAN-ExpressCard support is not selected
512  */
513 static inline int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
514 {
515 	return -ENODEV;
516 }
517 
518 static inline void peak_pciec_remove(struct peak_pciec_card *card)
519 {
520 }
521 #endif /* CONFIG_CAN_PEAK_PCIEC */
522 
523 static u8 peak_pci_read_reg(const struct sja1000_priv *priv, int port)
524 {
525 	return readb(priv->reg_base + (port << 2));
526 }
527 
528 static void peak_pci_write_reg(const struct sja1000_priv *priv,
529 			       int port, u8 val)
530 {
531 	writeb(val, priv->reg_base + (port << 2));
532 }
533 
534 static void peak_pci_post_irq(const struct sja1000_priv *priv)
535 {
536 	struct peak_pci_chan *chan = priv->priv;
537 	u16 icr;
538 
539 	/* Select and clear in PITA stored interrupt */
540 	icr = readw(chan->cfg_base + PITA_ICR);
541 	if (icr & chan->icr_mask)
542 		writew(chan->icr_mask, chan->cfg_base + PITA_ICR);
543 }
544 
545 static int __devinit peak_pci_probe(struct pci_dev *pdev,
546 				    const struct pci_device_id *ent)
547 {
548 	struct sja1000_priv *priv;
549 	struct peak_pci_chan *chan;
550 	struct net_device *dev;
551 	void __iomem *cfg_base, *reg_base;
552 	u16 sub_sys_id, icr;
553 	int i, err, channels;
554 
555 	err = pci_enable_device(pdev);
556 	if (err)
557 		return err;
558 
559 	err = pci_request_regions(pdev, DRV_NAME);
560 	if (err)
561 		goto failure_disable_pci;
562 
563 	err = pci_read_config_word(pdev, 0x2e, &sub_sys_id);
564 	if (err)
565 		goto failure_release_regions;
566 
567 	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
568 		pdev->vendor, pdev->device, sub_sys_id);
569 
570 	err = pci_write_config_word(pdev, 0x44, 0);
571 	if (err)
572 		goto failure_release_regions;
573 
574 	if (sub_sys_id >= 12)
575 		channels = 4;
576 	else if (sub_sys_id >= 10)
577 		channels = 3;
578 	else if (sub_sys_id >= 4)
579 		channels = 2;
580 	else
581 		channels = 1;
582 
583 	cfg_base = pci_iomap(pdev, 0, PEAK_PCI_CFG_SIZE);
584 	if (!cfg_base) {
585 		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
586 		goto failure_release_regions;
587 	}
588 
589 	reg_base = pci_iomap(pdev, 1, PEAK_PCI_CHAN_SIZE * channels);
590 	if (!reg_base) {
591 		dev_err(&pdev->dev, "failed to map PCI resource #1\n");
592 		goto failure_unmap_cfg_base;
593 	}
594 
595 	/* Set GPIO control register */
596 	writew(0x0005, cfg_base + PITA_GPIOICR + 2);
597 	/* Enable all channels of this card */
598 	writeb(0x00, cfg_base + PITA_GPIOICR);
599 	/* Toggle reset */
600 	writeb(0x05, cfg_base + PITA_MISC + 3);
601 	mdelay(5);
602 	/* Leave parport mux mode */
603 	writeb(0x04, cfg_base + PITA_MISC + 3);
604 
605 	icr = readw(cfg_base + PITA_ICR + 2);
606 
607 	for (i = 0; i < channels; i++) {
608 		dev = alloc_sja1000dev(sizeof(struct peak_pci_chan));
609 		if (!dev) {
610 			err = -ENOMEM;
611 			goto failure_remove_channels;
612 		}
613 
614 		priv = netdev_priv(dev);
615 		chan = priv->priv;
616 
617 		chan->cfg_base = cfg_base;
618 		priv->reg_base = reg_base + i * PEAK_PCI_CHAN_SIZE;
619 
620 		priv->read_reg = peak_pci_read_reg;
621 		priv->write_reg = peak_pci_write_reg;
622 		priv->post_irq = peak_pci_post_irq;
623 
624 		priv->can.clock.freq = PEAK_PCI_CAN_CLOCK;
625 		priv->ocr = PEAK_PCI_OCR;
626 		priv->cdr = PEAK_PCI_CDR;
627 		/* Neither a slave nor a single device distributes the clock */
628 		if (channels == 1 || i > 0)
629 			priv->cdr |= CDR_CLK_OFF;
630 
631 		/* Setup interrupt handling */
632 		priv->irq_flags = IRQF_SHARED;
633 		dev->irq = pdev->irq;
634 
635 		chan->icr_mask = peak_pci_icr_masks[i];
636 		icr |= chan->icr_mask;
637 
638 		SET_NETDEV_DEV(dev, &pdev->dev);
639 
640 		/* Create chain of SJA1000 devices */
641 		chan->prev_dev = pci_get_drvdata(pdev);
642 		pci_set_drvdata(pdev, dev);
643 
644 		/*
645 		 * PCAN-ExpressCard needs some additional i2c init.
646 		 * This must be done *before* register_sja1000dev() but
647 		 * *after* devices linkage
648 		 */
649 		if (pdev->device == PEAK_PCIEC_DEVICE_ID) {
650 			err = peak_pciec_probe(pdev, dev);
651 			if (err) {
652 				dev_err(&pdev->dev,
653 					"failed to probe device (err %d)\n",
654 					err);
655 				goto failure_free_dev;
656 			}
657 		}
658 
659 		err = register_sja1000dev(dev);
660 		if (err) {
661 			dev_err(&pdev->dev, "failed to register device\n");
662 			goto failure_free_dev;
663 		}
664 
665 		dev_info(&pdev->dev,
666 			 "%s at reg_base=0x%p cfg_base=0x%p irq=%d\n",
667 			 dev->name, priv->reg_base, chan->cfg_base, dev->irq);
668 	}
669 
670 	/* Enable interrupts */
671 	writew(icr, cfg_base + PITA_ICR + 2);
672 
673 	return 0;
674 
675 failure_free_dev:
676 	pci_set_drvdata(pdev, chan->prev_dev);
677 	free_sja1000dev(dev);
678 
679 failure_remove_channels:
680 	/* Disable interrupts */
681 	writew(0x0, cfg_base + PITA_ICR + 2);
682 
683 	chan = NULL;
684 	for (dev = pci_get_drvdata(pdev); dev; dev = chan->prev_dev) {
685 		unregister_sja1000dev(dev);
686 		free_sja1000dev(dev);
687 		priv = netdev_priv(dev);
688 		chan = priv->priv;
689 	}
690 
691 	/* free any PCIeC resources too */
692 	if (chan && chan->pciec_card)
693 		peak_pciec_remove(chan->pciec_card);
694 
695 	pci_iounmap(pdev, reg_base);
696 
697 failure_unmap_cfg_base:
698 	pci_iounmap(pdev, cfg_base);
699 
700 failure_release_regions:
701 	pci_release_regions(pdev);
702 
703 failure_disable_pci:
704 	pci_disable_device(pdev);
705 
706 	return err;
707 }
708 
709 static void __devexit peak_pci_remove(struct pci_dev *pdev)
710 {
711 	struct net_device *dev = pci_get_drvdata(pdev); /* Last device */
712 	struct sja1000_priv *priv = netdev_priv(dev);
713 	struct peak_pci_chan *chan = priv->priv;
714 	void __iomem *cfg_base = chan->cfg_base;
715 	void __iomem *reg_base = priv->reg_base;
716 
717 	/* Disable interrupts */
718 	writew(0x0, cfg_base + PITA_ICR + 2);
719 
720 	/* Loop over all registered devices */
721 	while (1) {
722 		dev_info(&pdev->dev, "removing device %s\n", dev->name);
723 		unregister_sja1000dev(dev);
724 		free_sja1000dev(dev);
725 		dev = chan->prev_dev;
726 
727 		if (!dev) {
728 			/* do that only for first channel */
729 			if (chan->pciec_card)
730 				peak_pciec_remove(chan->pciec_card);
731 			break;
732 		}
733 		priv = netdev_priv(dev);
734 		chan = priv->priv;
735 	}
736 
737 	pci_iounmap(pdev, reg_base);
738 	pci_iounmap(pdev, cfg_base);
739 	pci_release_regions(pdev);
740 	pci_disable_device(pdev);
741 
742 	pci_set_drvdata(pdev, NULL);
743 }
744 
745 static struct pci_driver peak_pci_driver = {
746 	.name = DRV_NAME,
747 	.id_table = peak_pci_tbl,
748 	.probe = peak_pci_probe,
749 	.remove = __devexit_p(peak_pci_remove),
750 };
751 
752 static int __init peak_pci_init(void)
753 {
754 	return pci_register_driver(&peak_pci_driver);
755 }
756 module_init(peak_pci_init);
757 
758 static void __exit peak_pci_exit(void)
759 {
760 	pci_unregister_driver(&peak_pci_driver);
761 }
762 module_exit(peak_pci_exit);
763