xref: /openbmc/linux/drivers/net/can/sja1000/peak_pci.c (revision 7ce05074)
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 struct peak_pciec_card;
32 struct peak_pci_chan {
33 	void __iomem *cfg_base;		/* Common for all channels */
34 	struct net_device *prev_dev;	/* Chain of network devices */
35 	u16 icr_mask;			/* Interrupt mask for fast ack */
36 	struct peak_pciec_card *pciec_card;	/* only for PCIeC LEDs */
37 };
38 
39 #define PEAK_PCI_CAN_CLOCK	(16000000 / 2)
40 
41 #define PEAK_PCI_CDR		(CDR_CBP | CDR_CLKOUT_MASK)
42 #define PEAK_PCI_OCR		OCR_TX0_PUSHPULL
43 
44 /*
45  * Important PITA registers
46  */
47 #define PITA_ICR		0x00	/* Interrupt control register */
48 #define PITA_GPIOICR		0x18	/* GPIO interface control register */
49 #define PITA_MISC		0x1C	/* Miscellaneous register */
50 
51 #define PEAK_PCI_CFG_SIZE	0x1000	/* Size of the config PCI bar */
52 #define PEAK_PCI_CHAN_SIZE	0x0400	/* Size used by the channel */
53 
54 #define PEAK_PCI_VENDOR_ID	0x001C	/* The PCI device and vendor IDs */
55 #define PEAK_PCI_DEVICE_ID	0x0001	/* for PCI/PCIe slot cards */
56 #define PEAK_PCIEC_DEVICE_ID	0x0002	/* for ExpressCard slot cards */
57 #define PEAK_PCIE_DEVICE_ID	0x0003	/* for nextgen PCIe slot cards */
58 #define PEAK_CPCI_DEVICE_ID	0x0004	/* for nextgen cPCI slot cards */
59 #define PEAK_MPCI_DEVICE_ID	0x0005	/* for nextgen miniPCI slot cards */
60 #define PEAK_PC_104P_DEVICE_ID	0x0006	/* PCAN-PC/104+ cards */
61 #define PEAK_PCI_104E_DEVICE_ID	0x0007	/* PCAN-PCI/104 Express cards */
62 #define PEAK_MPCIE_DEVICE_ID	0x0008	/* The miniPCIe slot cards */
63 #define PEAK_PCIE_OEM_ID	0x0009	/* PCAN-PCI Express OEM */
64 #define PEAK_PCIEC34_DEVICE_ID	0x000A	/* PCAN-PCI Express 34 (one channel) */
65 
66 #define PEAK_PCI_CHAN_MAX	4
67 
68 static const u16 peak_pci_icr_masks[PEAK_PCI_CHAN_MAX] = {
69 	0x02, 0x01, 0x40, 0x80
70 };
71 
72 static const struct pci_device_id peak_pci_tbl[] = {
73 	{PEAK_PCI_VENDOR_ID, PEAK_PCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
74 	{PEAK_PCI_VENDOR_ID, PEAK_PCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
75 	{PEAK_PCI_VENDOR_ID, PEAK_MPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
76 	{PEAK_PCI_VENDOR_ID, PEAK_MPCIE_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
77 	{PEAK_PCI_VENDOR_ID, PEAK_PC_104P_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
78 	{PEAK_PCI_VENDOR_ID, PEAK_PCI_104E_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
79 	{PEAK_PCI_VENDOR_ID, PEAK_CPCI_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
80 	{PEAK_PCI_VENDOR_ID, PEAK_PCIE_OEM_ID, PCI_ANY_ID, PCI_ANY_ID,},
81 #ifdef CONFIG_CAN_PEAK_PCIEC
82 	{PEAK_PCI_VENDOR_ID, PEAK_PCIEC_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
83 	{PEAK_PCI_VENDOR_ID, PEAK_PCIEC34_DEVICE_ID, PCI_ANY_ID, PCI_ANY_ID,},
84 #endif
85 	{0,}
86 };
87 
88 MODULE_DEVICE_TABLE(pci, peak_pci_tbl);
89 
90 #ifdef CONFIG_CAN_PEAK_PCIEC
91 /*
92  * PCAN-ExpressCard needs I2C bit-banging configuration option.
93  */
94 
95 /* GPIOICR byte access offsets */
96 #define PITA_GPOUT		0x18	/* GPx output value */
97 #define PITA_GPIN		0x19	/* GPx input value */
98 #define PITA_GPOEN		0x1A	/* configure GPx as output pin */
99 
100 /* I2C GP bits */
101 #define PITA_GPIN_SCL		0x01	/* Serial Clock Line */
102 #define PITA_GPIN_SDA		0x04	/* Serial DAta line */
103 
104 #define PCA9553_1_SLAVEADDR	(0xC4 >> 1)
105 
106 /* PCA9553 LS0 fields values */
107 enum {
108 	PCA9553_LOW,
109 	PCA9553_HIGHZ,
110 	PCA9553_PWM0,
111 	PCA9553_PWM1
112 };
113 
114 /* LEDs control */
115 #define PCA9553_ON		PCA9553_LOW
116 #define PCA9553_OFF		PCA9553_HIGHZ
117 #define PCA9553_SLOW		PCA9553_PWM0
118 #define PCA9553_FAST		PCA9553_PWM1
119 
120 #define PCA9553_LED(c)		(1 << (c))
121 #define PCA9553_LED_STATE(s, c)	((s) << ((c) << 1))
122 
123 #define PCA9553_LED_ON(c)	PCA9553_LED_STATE(PCA9553_ON, c)
124 #define PCA9553_LED_OFF(c)	PCA9553_LED_STATE(PCA9553_OFF, c)
125 #define PCA9553_LED_SLOW(c)	PCA9553_LED_STATE(PCA9553_SLOW, c)
126 #define PCA9553_LED_FAST(c)	PCA9553_LED_STATE(PCA9553_FAST, c)
127 #define PCA9553_LED_MASK(c)	PCA9553_LED_STATE(0x03, c)
128 
129 #define PCA9553_LED_OFF_ALL	(PCA9553_LED_OFF(0) | PCA9553_LED_OFF(1))
130 
131 #define PCA9553_LS0_INIT	0x40 /* initial value (!= from 0x00) */
132 
133 struct peak_pciec_chan {
134 	struct net_device *netdev;
135 	unsigned long prev_rx_bytes;
136 	unsigned long prev_tx_bytes;
137 };
138 
139 struct peak_pciec_card {
140 	void __iomem *cfg_base;		/* Common for all channels */
141 	void __iomem *reg_base;		/* first channel base address */
142 	u8 led_cache;			/* leds state cache */
143 
144 	/* PCIExpressCard i2c data */
145 	struct i2c_algo_bit_data i2c_bit;
146 	struct i2c_adapter led_chip;
147 	struct delayed_work led_work;	/* led delayed work */
148 	int chan_count;
149 	struct peak_pciec_chan channel[PEAK_PCI_CHAN_MAX];
150 };
151 
152 /* "normal" pci register write callback is overloaded for leds control */
153 static void peak_pci_write_reg(const struct sja1000_priv *priv,
154 			       int port, u8 val);
155 
156 static inline void pita_set_scl_highz(struct peak_pciec_card *card)
157 {
158 	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SCL;
159 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
160 }
161 
162 static inline void pita_set_sda_highz(struct peak_pciec_card *card)
163 {
164 	u8 gp_outen = readb(card->cfg_base + PITA_GPOEN) & ~PITA_GPIN_SDA;
165 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
166 }
167 
168 static void peak_pciec_init_pita_gpio(struct peak_pciec_card *card)
169 {
170 	/* raise SCL & SDA GPIOs to high-Z */
171 	pita_set_scl_highz(card);
172 	pita_set_sda_highz(card);
173 }
174 
175 static void pita_setsda(void *data, int state)
176 {
177 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
178 	u8 gp_out, gp_outen;
179 
180 	/* set output sda always to 0 */
181 	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SDA;
182 	writeb(gp_out, card->cfg_base + PITA_GPOUT);
183 
184 	/* control output sda with GPOEN */
185 	gp_outen = readb(card->cfg_base + PITA_GPOEN);
186 	if (state)
187 		gp_outen &= ~PITA_GPIN_SDA;
188 	else
189 		gp_outen |= PITA_GPIN_SDA;
190 
191 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
192 }
193 
194 static void pita_setscl(void *data, int state)
195 {
196 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
197 	u8 gp_out, gp_outen;
198 
199 	/* set output scl always to 0 */
200 	gp_out = readb(card->cfg_base + PITA_GPOUT) & ~PITA_GPIN_SCL;
201 	writeb(gp_out, card->cfg_base + PITA_GPOUT);
202 
203 	/* control output scl with GPOEN */
204 	gp_outen = readb(card->cfg_base + PITA_GPOEN);
205 	if (state)
206 		gp_outen &= ~PITA_GPIN_SCL;
207 	else
208 		gp_outen |= PITA_GPIN_SCL;
209 
210 	writeb(gp_outen, card->cfg_base + PITA_GPOEN);
211 }
212 
213 static int pita_getsda(void *data)
214 {
215 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
216 
217 	/* set tristate */
218 	pita_set_sda_highz(card);
219 
220 	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SDA) ? 1 : 0;
221 }
222 
223 static int pita_getscl(void *data)
224 {
225 	struct peak_pciec_card *card = (struct peak_pciec_card *)data;
226 
227 	/* set tristate */
228 	pita_set_scl_highz(card);
229 
230 	return (readb(card->cfg_base + PITA_GPIN) & PITA_GPIN_SCL) ? 1 : 0;
231 }
232 
233 /*
234  * write commands to the LED chip though the I2C-bus of the PCAN-PCIeC
235  */
236 static int peak_pciec_write_pca9553(struct peak_pciec_card *card,
237 				    u8 offset, u8 data)
238 {
239 	u8 buffer[2] = {
240 		offset,
241 		data
242 	};
243 	struct i2c_msg msg = {
244 		.addr = PCA9553_1_SLAVEADDR,
245 		.len = 2,
246 		.buf = buffer,
247 	};
248 	int ret;
249 
250 	/* cache led mask */
251 	if ((offset == 5) && (data == card->led_cache))
252 		return 0;
253 
254 	ret = i2c_transfer(&card->led_chip, &msg, 1);
255 	if (ret < 0)
256 		return ret;
257 
258 	if (offset == 5)
259 		card->led_cache = data;
260 
261 	return 0;
262 }
263 
264 /*
265  * delayed work callback used to control the LEDs
266  */
267 static void peak_pciec_led_work(struct work_struct *work)
268 {
269 	struct peak_pciec_card *card =
270 		container_of(work, struct peak_pciec_card, led_work.work);
271 	struct net_device *netdev;
272 	u8 new_led = card->led_cache;
273 	int i, up_count = 0;
274 
275 	/* first check what is to do */
276 	for (i = 0; i < card->chan_count; i++) {
277 		/* default is: not configured */
278 		new_led &= ~PCA9553_LED_MASK(i);
279 		new_led |= PCA9553_LED_ON(i);
280 
281 		netdev = card->channel[i].netdev;
282 		if (!netdev || !(netdev->flags & IFF_UP))
283 			continue;
284 
285 		up_count++;
286 
287 		/* no activity (but configured) */
288 		new_led &= ~PCA9553_LED_MASK(i);
289 		new_led |= PCA9553_LED_SLOW(i);
290 
291 		/* if bytes counters changed, set fast blinking led */
292 		if (netdev->stats.rx_bytes != card->channel[i].prev_rx_bytes) {
293 			card->channel[i].prev_rx_bytes = netdev->stats.rx_bytes;
294 			new_led &= ~PCA9553_LED_MASK(i);
295 			new_led |= PCA9553_LED_FAST(i);
296 		}
297 		if (netdev->stats.tx_bytes != card->channel[i].prev_tx_bytes) {
298 			card->channel[i].prev_tx_bytes = netdev->stats.tx_bytes;
299 			new_led &= ~PCA9553_LED_MASK(i);
300 			new_led |= PCA9553_LED_FAST(i);
301 		}
302 	}
303 
304 	/* check if LS0 settings changed, only update i2c if so */
305 	peak_pciec_write_pca9553(card, 5, new_led);
306 
307 	/* restart timer (except if no more configured channels) */
308 	if (up_count)
309 		schedule_delayed_work(&card->led_work, HZ);
310 }
311 
312 /*
313  * set LEDs blinking state
314  */
315 static void peak_pciec_set_leds(struct peak_pciec_card *card, u8 led_mask, u8 s)
316 {
317 	u8 new_led = card->led_cache;
318 	int i;
319 
320 	/* first check what is to do */
321 	for (i = 0; i < card->chan_count; i++)
322 		if (led_mask & PCA9553_LED(i)) {
323 			new_led &= ~PCA9553_LED_MASK(i);
324 			new_led |= PCA9553_LED_STATE(s, i);
325 		}
326 
327 	/* check if LS0 settings changed, only update i2c if so */
328 	peak_pciec_write_pca9553(card, 5, new_led);
329 }
330 
331 /*
332  * start one second delayed work to control LEDs
333  */
334 static void peak_pciec_start_led_work(struct peak_pciec_card *card)
335 {
336 	schedule_delayed_work(&card->led_work, HZ);
337 }
338 
339 /*
340  * stop LEDs delayed work
341  */
342 static void peak_pciec_stop_led_work(struct peak_pciec_card *card)
343 {
344 	cancel_delayed_work_sync(&card->led_work);
345 }
346 
347 /*
348  * initialize the PCA9553 4-bit I2C-bus LED chip
349  */
350 static int peak_pciec_init_leds(struct peak_pciec_card *card)
351 {
352 	int err;
353 
354 	/* prescaler for frequency 0: "SLOW" = 1 Hz = "44" */
355 	err = peak_pciec_write_pca9553(card, 1, 44 / 1);
356 	if (err)
357 		return err;
358 
359 	/* duty cycle 0: 50% */
360 	err = peak_pciec_write_pca9553(card, 2, 0x80);
361 	if (err)
362 		return err;
363 
364 	/* prescaler for frequency 1: "FAST" = 5 Hz */
365 	err = peak_pciec_write_pca9553(card, 3, 44 / 5);
366 	if (err)
367 		return err;
368 
369 	/* duty cycle 1: 50% */
370 	err = peak_pciec_write_pca9553(card, 4, 0x80);
371 	if (err)
372 		return err;
373 
374 	/* switch LEDs to initial state */
375 	return peak_pciec_write_pca9553(card, 5, PCA9553_LS0_INIT);
376 }
377 
378 /*
379  * restore LEDs state to off peak_pciec_leds_exit
380  */
381 static void peak_pciec_leds_exit(struct peak_pciec_card *card)
382 {
383 	/* switch LEDs to off */
384 	peak_pciec_write_pca9553(card, 5, PCA9553_LED_OFF_ALL);
385 }
386 
387 /*
388  * normal write sja1000 register method overloaded to catch when controller
389  * is started or stopped, to control leds
390  */
391 static void peak_pciec_write_reg(const struct sja1000_priv *priv,
392 				 int port, u8 val)
393 {
394 	struct peak_pci_chan *chan = priv->priv;
395 	struct peak_pciec_card *card = chan->pciec_card;
396 	int c = (priv->reg_base - card->reg_base) / PEAK_PCI_CHAN_SIZE;
397 
398 	/* sja1000 register changes control the leds state */
399 	if (port == SJA1000_MOD)
400 		switch (val) {
401 		case MOD_RM:
402 			/* Reset Mode: set led on */
403 			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_ON);
404 			break;
405 		case 0x00:
406 			/* Normal Mode: led slow blinking and start led timer */
407 			peak_pciec_set_leds(card, PCA9553_LED(c), PCA9553_SLOW);
408 			peak_pciec_start_led_work(card);
409 			break;
410 		default:
411 			break;
412 		}
413 
414 	/* call base function */
415 	peak_pci_write_reg(priv, port, val);
416 }
417 
418 static const struct i2c_algo_bit_data peak_pciec_i2c_bit_ops = {
419 	.setsda	= pita_setsda,
420 	.setscl	= pita_setscl,
421 	.getsda	= pita_getsda,
422 	.getscl	= pita_getscl,
423 	.udelay	= 10,
424 	.timeout = HZ,
425 };
426 
427 static int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
428 {
429 	struct sja1000_priv *priv = netdev_priv(dev);
430 	struct peak_pci_chan *chan = priv->priv;
431 	struct peak_pciec_card *card;
432 	int err;
433 
434 	/* copy i2c object address from 1st channel */
435 	if (chan->prev_dev) {
436 		struct sja1000_priv *prev_priv = netdev_priv(chan->prev_dev);
437 		struct peak_pci_chan *prev_chan = prev_priv->priv;
438 
439 		card = prev_chan->pciec_card;
440 		if (!card)
441 			return -ENODEV;
442 
443 	/* channel is the first one: do the init part */
444 	} else {
445 		/* create the bit banging I2C adapter structure */
446 		card = kzalloc(sizeof(struct peak_pciec_card), GFP_KERNEL);
447 		if (!card)
448 			return -ENOMEM;
449 
450 		card->cfg_base = chan->cfg_base;
451 		card->reg_base = priv->reg_base;
452 
453 		card->led_chip.owner = THIS_MODULE;
454 		card->led_chip.dev.parent = &pdev->dev;
455 		card->led_chip.algo_data = &card->i2c_bit;
456 		strncpy(card->led_chip.name, "peak_i2c",
457 			sizeof(card->led_chip.name));
458 
459 		card->i2c_bit = peak_pciec_i2c_bit_ops;
460 		card->i2c_bit.udelay = 10;
461 		card->i2c_bit.timeout = HZ;
462 		card->i2c_bit.data = card;
463 
464 		peak_pciec_init_pita_gpio(card);
465 
466 		err = i2c_bit_add_bus(&card->led_chip);
467 		if (err) {
468 			dev_err(&pdev->dev, "i2c init failed\n");
469 			goto pciec_init_err_1;
470 		}
471 
472 		err = peak_pciec_init_leds(card);
473 		if (err) {
474 			dev_err(&pdev->dev, "leds hardware init failed\n");
475 			goto pciec_init_err_2;
476 		}
477 
478 		INIT_DELAYED_WORK(&card->led_work, peak_pciec_led_work);
479 		/* PCAN-ExpressCard needs its own callback for leds */
480 		priv->write_reg = peak_pciec_write_reg;
481 	}
482 
483 	chan->pciec_card = card;
484 	card->channel[card->chan_count++].netdev = dev;
485 
486 	return 0;
487 
488 pciec_init_err_2:
489 	i2c_del_adapter(&card->led_chip);
490 
491 pciec_init_err_1:
492 	peak_pciec_init_pita_gpio(card);
493 	kfree(card);
494 
495 	return err;
496 }
497 
498 static void peak_pciec_remove(struct peak_pciec_card *card)
499 {
500 	peak_pciec_stop_led_work(card);
501 	peak_pciec_leds_exit(card);
502 	i2c_del_adapter(&card->led_chip);
503 	peak_pciec_init_pita_gpio(card);
504 	kfree(card);
505 }
506 
507 #else /* CONFIG_CAN_PEAK_PCIEC */
508 
509 /*
510  * Placebo functions when PCAN-ExpressCard support is not selected
511  */
512 static inline int peak_pciec_probe(struct pci_dev *pdev, struct net_device *dev)
513 {
514 	return -ENODEV;
515 }
516 
517 static inline void peak_pciec_remove(struct peak_pciec_card *card)
518 {
519 }
520 #endif /* CONFIG_CAN_PEAK_PCIEC */
521 
522 static u8 peak_pci_read_reg(const struct sja1000_priv *priv, int port)
523 {
524 	return readb(priv->reg_base + (port << 2));
525 }
526 
527 static void peak_pci_write_reg(const struct sja1000_priv *priv,
528 			       int port, u8 val)
529 {
530 	writeb(val, priv->reg_base + (port << 2));
531 }
532 
533 static void peak_pci_post_irq(const struct sja1000_priv *priv)
534 {
535 	struct peak_pci_chan *chan = priv->priv;
536 	u16 icr;
537 
538 	/* Select and clear in PITA stored interrupt */
539 	icr = readw(chan->cfg_base + PITA_ICR);
540 	if (icr & chan->icr_mask)
541 		writew(chan->icr_mask, chan->cfg_base + PITA_ICR);
542 }
543 
544 static int peak_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
545 {
546 	struct sja1000_priv *priv;
547 	struct peak_pci_chan *chan;
548 	struct net_device *dev, *prev_dev;
549 	void __iomem *cfg_base, *reg_base;
550 	u16 sub_sys_id, icr;
551 	int i, err, channels;
552 
553 	err = pci_enable_device(pdev);
554 	if (err)
555 		return err;
556 
557 	err = pci_request_regions(pdev, DRV_NAME);
558 	if (err)
559 		goto failure_disable_pci;
560 
561 	err = pci_read_config_word(pdev, 0x2e, &sub_sys_id);
562 	if (err)
563 		goto failure_release_regions;
564 
565 	dev_dbg(&pdev->dev, "probing device %04x:%04x:%04x\n",
566 		pdev->vendor, pdev->device, sub_sys_id);
567 
568 	err = pci_write_config_word(pdev, 0x44, 0);
569 	if (err)
570 		goto failure_release_regions;
571 
572 	if (sub_sys_id >= 12)
573 		channels = 4;
574 	else if (sub_sys_id >= 10)
575 		channels = 3;
576 	else if (sub_sys_id >= 4)
577 		channels = 2;
578 	else
579 		channels = 1;
580 
581 	cfg_base = pci_iomap(pdev, 0, PEAK_PCI_CFG_SIZE);
582 	if (!cfg_base) {
583 		dev_err(&pdev->dev, "failed to map PCI resource #0\n");
584 		err = -ENOMEM;
585 		goto failure_release_regions;
586 	}
587 
588 	reg_base = pci_iomap(pdev, 1, PEAK_PCI_CHAN_SIZE * channels);
589 	if (!reg_base) {
590 		dev_err(&pdev->dev, "failed to map PCI resource #1\n");
591 		err = -ENOMEM;
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 	usleep_range(5000, 6000);
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 		dev->dev_id = i;
640 
641 		/* Create chain of SJA1000 devices */
642 		chan->prev_dev = pci_get_drvdata(pdev);
643 		pci_set_drvdata(pdev, dev);
644 
645 		/*
646 		 * PCAN-ExpressCard needs some additional i2c init.
647 		 * This must be done *before* register_sja1000dev() but
648 		 * *after* devices linkage
649 		 */
650 		if (pdev->device == PEAK_PCIEC_DEVICE_ID ||
651 		    pdev->device == PEAK_PCIEC34_DEVICE_ID) {
652 			err = peak_pciec_probe(pdev, dev);
653 			if (err) {
654 				dev_err(&pdev->dev,
655 					"failed to probe device (err %d)\n",
656 					err);
657 				goto failure_free_dev;
658 			}
659 		}
660 
661 		err = register_sja1000dev(dev);
662 		if (err) {
663 			dev_err(&pdev->dev, "failed to register device\n");
664 			goto failure_free_dev;
665 		}
666 
667 		dev_info(&pdev->dev,
668 			 "%s at reg_base=0x%p cfg_base=0x%p irq=%d\n",
669 			 dev->name, priv->reg_base, chan->cfg_base, dev->irq);
670 	}
671 
672 	/* Enable interrupts */
673 	writew(icr, cfg_base + PITA_ICR + 2);
674 
675 	return 0;
676 
677 failure_free_dev:
678 	pci_set_drvdata(pdev, chan->prev_dev);
679 	free_sja1000dev(dev);
680 
681 failure_remove_channels:
682 	/* Disable interrupts */
683 	writew(0x0, cfg_base + PITA_ICR + 2);
684 
685 	chan = NULL;
686 	for (dev = pci_get_drvdata(pdev); dev; dev = prev_dev) {
687 		priv = netdev_priv(dev);
688 		chan = priv->priv;
689 		prev_dev = chan->prev_dev;
690 
691 		unregister_sja1000dev(dev);
692 		free_sja1000dev(dev);
693 	}
694 
695 	/* free any PCIeC resources too */
696 	if (chan && chan->pciec_card)
697 		peak_pciec_remove(chan->pciec_card);
698 
699 	pci_iounmap(pdev, reg_base);
700 
701 failure_unmap_cfg_base:
702 	pci_iounmap(pdev, cfg_base);
703 
704 failure_release_regions:
705 	pci_release_regions(pdev);
706 
707 failure_disable_pci:
708 	pci_disable_device(pdev);
709 
710 	/* pci_xxx_config_word() return positive PCIBIOS_xxx error codes while
711 	 * the probe() function must return a negative errno in case of failure
712 	 * (err is unchanged if negative) */
713 	return pcibios_err_to_errno(err);
714 }
715 
716 static void peak_pci_remove(struct pci_dev *pdev)
717 {
718 	struct net_device *dev = pci_get_drvdata(pdev); /* Last device */
719 	struct sja1000_priv *priv = netdev_priv(dev);
720 	struct peak_pci_chan *chan = priv->priv;
721 	void __iomem *cfg_base = chan->cfg_base;
722 	void __iomem *reg_base = priv->reg_base;
723 
724 	/* Disable interrupts */
725 	writew(0x0, cfg_base + PITA_ICR + 2);
726 
727 	/* Loop over all registered devices */
728 	while (1) {
729 		struct net_device *prev_dev = chan->prev_dev;
730 
731 		dev_info(&pdev->dev, "removing device %s\n", dev->name);
732 		unregister_sja1000dev(dev);
733 		free_sja1000dev(dev);
734 		dev = prev_dev;
735 
736 		if (!dev) {
737 			/* do that only for first channel */
738 			if (chan->pciec_card)
739 				peak_pciec_remove(chan->pciec_card);
740 			break;
741 		}
742 		priv = netdev_priv(dev);
743 		chan = priv->priv;
744 	}
745 
746 	pci_iounmap(pdev, reg_base);
747 	pci_iounmap(pdev, cfg_base);
748 	pci_release_regions(pdev);
749 	pci_disable_device(pdev);
750 }
751 
752 static struct pci_driver peak_pci_driver = {
753 	.name = DRV_NAME,
754 	.id_table = peak_pci_tbl,
755 	.probe = peak_pci_probe,
756 	.remove = peak_pci_remove,
757 };
758 
759 module_pci_driver(peak_pci_driver);
760