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v3.1
  1/*
  2 * Driver for the CS5535/CS5536 Multi-Function General Purpose Timers (MFGPT)
  3 *
  4 * Copyright (C) 2006, Advanced Micro Devices, Inc.
  5 * Copyright (C) 2007  Andres Salomon <dilinger@debian.org>
  6 * Copyright (C) 2009  Andres Salomon <dilinger@collabora.co.uk>
  7 *
  8 * This program is free software; you can redistribute it and/or
  9 * modify it under the terms of version 2 of the GNU General Public License
 10 * as published by the Free Software Foundation.
 11 *
 12 * The MFGPTs are documented in AMD Geode CS5536 Companion Device Data Book.
 13 */
 14
 15#include <linux/kernel.h>
 16#include <linux/spinlock.h>
 17#include <linux/interrupt.h>
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/cs5535.h>
 21#include <linux/slab.h>
 22
 23#define DRV_NAME "cs5535-mfgpt"
 24
 25static int mfgpt_reset_timers;
 26module_param_named(mfgptfix, mfgpt_reset_timers, int, 0644);
 27MODULE_PARM_DESC(mfgptfix, "Reset the MFGPT timers during init; "
 28		"required by some broken BIOSes (ie, TinyBIOS < 0.99).");
 29
 30struct cs5535_mfgpt_timer {
 31	struct cs5535_mfgpt_chip *chip;
 32	int nr;
 33};
 34
 35static struct cs5535_mfgpt_chip {
 36	DECLARE_BITMAP(avail, MFGPT_MAX_TIMERS);
 37	resource_size_t base;
 38
 39	struct platform_device *pdev;
 40	spinlock_t lock;
 41	int initialized;
 42} cs5535_mfgpt_chip;
 43
 44int cs5535_mfgpt_toggle_event(struct cs5535_mfgpt_timer *timer, int cmp,
 45		int event, int enable)
 46{
 47	uint32_t msr, mask, value, dummy;
 48	int shift = (cmp == MFGPT_CMP1) ? 0 : 8;
 49
 50	if (!timer) {
 51		WARN_ON(1);
 52		return -EIO;
 53	}
 54
 55	/*
 56	 * The register maps for these are described in sections 6.17.1.x of
 57	 * the AMD Geode CS5536 Companion Device Data Book.
 58	 */
 59	switch (event) {
 60	case MFGPT_EVENT_RESET:
 61		/*
 62		 * XXX: According to the docs, we cannot reset timers above
 63		 * 6; that is, resets for 7 and 8 will be ignored.  Is this
 64		 * a problem?   -dilinger
 65		 */
 66		msr = MSR_MFGPT_NR;
 67		mask = 1 << (timer->nr + 24);
 68		break;
 69
 70	case MFGPT_EVENT_NMI:
 71		msr = MSR_MFGPT_NR;
 72		mask = 1 << (timer->nr + shift);
 73		break;
 74
 75	case MFGPT_EVENT_IRQ:
 76		msr = MSR_MFGPT_IRQ;
 77		mask = 1 << (timer->nr + shift);
 78		break;
 79
 80	default:
 81		return -EIO;
 82	}
 83
 84	rdmsr(msr, value, dummy);
 85
 86	if (enable)
 87		value |= mask;
 88	else
 89		value &= ~mask;
 90
 91	wrmsr(msr, value, dummy);
 92	return 0;
 93}
 94EXPORT_SYMBOL_GPL(cs5535_mfgpt_toggle_event);
 95
 96int cs5535_mfgpt_set_irq(struct cs5535_mfgpt_timer *timer, int cmp, int *irq,
 97		int enable)
 98{
 99	uint32_t zsel, lpc, dummy;
100	int shift;
101
102	if (!timer) {
103		WARN_ON(1);
104		return -EIO;
105	}
106
107	/*
108	 * Unfortunately, MFGPTs come in pairs sharing their IRQ lines. If VSA
109	 * is using the same CMP of the timer's Siamese twin, the IRQ is set to
110	 * 2, and we mustn't use nor change it.
111	 * XXX: Likewise, 2 Linux drivers might clash if the 2nd overwrites the
112	 * IRQ of the 1st. This can only happen if forcing an IRQ, calling this
113	 * with *irq==0 is safe. Currently there _are_ no 2 drivers.
114	 */
115	rdmsr(MSR_PIC_ZSEL_LOW, zsel, dummy);
116	shift = ((cmp == MFGPT_CMP1 ? 0 : 4) + timer->nr % 4) * 4;
117	if (((zsel >> shift) & 0xF) == 2)
118		return -EIO;
119
120	/* Choose IRQ: if none supplied, keep IRQ already set or use default */
121	if (!*irq)
122		*irq = (zsel >> shift) & 0xF;
123	if (!*irq)
124		*irq = CONFIG_CS5535_MFGPT_DEFAULT_IRQ;
125
126	/* Can't use IRQ if it's 0 (=disabled), 2, or routed to LPC */
127	if (*irq < 1 || *irq == 2 || *irq > 15)
128		return -EIO;
129	rdmsr(MSR_PIC_IRQM_LPC, lpc, dummy);
130	if (lpc & (1 << *irq))
131		return -EIO;
132
133	/* All chosen and checked - go for it */
134	if (cs5535_mfgpt_toggle_event(timer, cmp, MFGPT_EVENT_IRQ, enable))
135		return -EIO;
136	if (enable) {
137		zsel = (zsel & ~(0xF << shift)) | (*irq << shift);
138		wrmsr(MSR_PIC_ZSEL_LOW, zsel, dummy);
139	}
140
141	return 0;
142}
143EXPORT_SYMBOL_GPL(cs5535_mfgpt_set_irq);
144
145struct cs5535_mfgpt_timer *cs5535_mfgpt_alloc_timer(int timer_nr, int domain)
146{
147	struct cs5535_mfgpt_chip *mfgpt = &cs5535_mfgpt_chip;
148	struct cs5535_mfgpt_timer *timer = NULL;
149	unsigned long flags;
150	int max;
151
152	if (!mfgpt->initialized)
153		goto done;
154
155	/* only allocate timers from the working domain if requested */
156	if (domain == MFGPT_DOMAIN_WORKING)
157		max = 6;
158	else
159		max = MFGPT_MAX_TIMERS;
160
161	if (timer_nr >= max) {
162		/* programmer error.  silly programmers! */
163		WARN_ON(1);
164		goto done;
165	}
166
167	spin_lock_irqsave(&mfgpt->lock, flags);
168	if (timer_nr < 0) {
169		unsigned long t;
170
171		/* try to find any available timer */
172		t = find_first_bit(mfgpt->avail, max);
173		/* set timer_nr to -1 if no timers available */
174		timer_nr = t < max ? (int) t : -1;
175	} else {
176		/* check if the requested timer's available */
177		if (!test_bit(timer_nr, mfgpt->avail))
178			timer_nr = -1;
179	}
180
181	if (timer_nr >= 0)
182		/* if timer_nr is not -1, it's an available timer */
183		__clear_bit(timer_nr, mfgpt->avail);
184	spin_unlock_irqrestore(&mfgpt->lock, flags);
185
186	if (timer_nr < 0)
187		goto done;
188
189	timer = kmalloc(sizeof(*timer), GFP_KERNEL);
190	if (!timer) {
191		/* aw hell */
192		spin_lock_irqsave(&mfgpt->lock, flags);
193		__set_bit(timer_nr, mfgpt->avail);
194		spin_unlock_irqrestore(&mfgpt->lock, flags);
195		goto done;
196	}
197	timer->chip = mfgpt;
198	timer->nr = timer_nr;
199	dev_info(&mfgpt->pdev->dev, "registered timer %d\n", timer_nr);
200
201done:
202	return timer;
203}
204EXPORT_SYMBOL_GPL(cs5535_mfgpt_alloc_timer);
205
206/*
207 * XXX: This frees the timer memory, but never resets the actual hardware
208 * timer.  The old geode_mfgpt code did this; it would be good to figure
209 * out a way to actually release the hardware timer.  See comments below.
210 */
211void cs5535_mfgpt_free_timer(struct cs5535_mfgpt_timer *timer)
212{
213	unsigned long flags;
214	uint16_t val;
215
216	/* timer can be made available again only if never set up */
217	val = cs5535_mfgpt_read(timer, MFGPT_REG_SETUP);
218	if (!(val & MFGPT_SETUP_SETUP)) {
219		spin_lock_irqsave(&timer->chip->lock, flags);
220		__set_bit(timer->nr, timer->chip->avail);
221		spin_unlock_irqrestore(&timer->chip->lock, flags);
222	}
223
224	kfree(timer);
225}
226EXPORT_SYMBOL_GPL(cs5535_mfgpt_free_timer);
227
228uint16_t cs5535_mfgpt_read(struct cs5535_mfgpt_timer *timer, uint16_t reg)
229{
230	return inw(timer->chip->base + reg + (timer->nr * 8));
231}
232EXPORT_SYMBOL_GPL(cs5535_mfgpt_read);
233
234void cs5535_mfgpt_write(struct cs5535_mfgpt_timer *timer, uint16_t reg,
235		uint16_t value)
236{
237	outw(value, timer->chip->base + reg + (timer->nr * 8));
238}
239EXPORT_SYMBOL_GPL(cs5535_mfgpt_write);
240
241/*
242 * This is a sledgehammer that resets all MFGPT timers. This is required by
243 * some broken BIOSes which leave the system in an unstable state
244 * (TinyBIOS 0.98, for example; fixed in 0.99).  It's uncertain as to
245 * whether or not this secret MSR can be used to release individual timers.
246 * Jordan tells me that he and Mitch once played w/ it, but it's unclear
247 * what the results of that were (and they experienced some instability).
248 */
249static void __init reset_all_timers(void)
250{
251	uint32_t val, dummy;
252
253	/* The following undocumented bit resets the MFGPT timers */
254	val = 0xFF; dummy = 0;
255	wrmsr(MSR_MFGPT_SETUP, val, dummy);
256}
257
258/*
259 * Check whether any MFGPTs are available for the kernel to use.  In most
260 * cases, firmware that uses AMD's VSA code will claim all timers during
261 * bootup; we certainly don't want to take them if they're already in use.
262 * In other cases (such as with VSAless OpenFirmware), the system firmware
263 * leaves timers available for us to use.
264 */
265static int __init scan_timers(struct cs5535_mfgpt_chip *mfgpt)
266{
267	struct cs5535_mfgpt_timer timer = { .chip = mfgpt };
268	unsigned long flags;
269	int timers = 0;
270	uint16_t val;
271	int i;
272
273	/* bios workaround */
274	if (mfgpt_reset_timers)
275		reset_all_timers();
276
277	/* just to be safe, protect this section w/ lock */
278	spin_lock_irqsave(&mfgpt->lock, flags);
279	for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
280		timer.nr = i;
281		val = cs5535_mfgpt_read(&timer, MFGPT_REG_SETUP);
282		if (!(val & MFGPT_SETUP_SETUP)) {
283			__set_bit(i, mfgpt->avail);
284			timers++;
285		}
286	}
287	spin_unlock_irqrestore(&mfgpt->lock, flags);
288
289	return timers;
290}
291
292static int __devinit cs5535_mfgpt_probe(struct platform_device *pdev)
293{
294	struct resource *res;
295	int err = -EIO, t;
296
297	/* There are two ways to get the MFGPT base address; one is by
298	 * fetching it from MSR_LBAR_MFGPT, the other is by reading the
299	 * PCI BAR info.  The latter method is easier (especially across
300	 * different architectures), so we'll stick with that for now.  If
301	 * it turns out to be unreliable in the face of crappy BIOSes, we
302	 * can always go back to using MSRs.. */
303
304	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
305	if (!res) {
306		dev_err(&pdev->dev, "can't fetch device resource info\n");
307		goto done;
308	}
309
310	if (!request_region(res->start, resource_size(res), pdev->name)) {
311		dev_err(&pdev->dev, "can't request region\n");
312		goto done;
313	}
314
315	/* set up the driver-specific struct */
316	cs5535_mfgpt_chip.base = res->start;
317	cs5535_mfgpt_chip.pdev = pdev;
318	spin_lock_init(&cs5535_mfgpt_chip.lock);
319
320	dev_info(&pdev->dev, "reserved resource region %pR\n", res);
321
322	/* detect the available timers */
323	t = scan_timers(&cs5535_mfgpt_chip);
324	dev_info(&pdev->dev, "%d MFGPT timers available\n", t);
325	cs5535_mfgpt_chip.initialized = 1;
326	return 0;
327
328done:
329	return err;
330}
331
332static struct platform_driver cs5535_mfgpt_driver = {
333	.driver = {
334		.name = DRV_NAME,
335		.owner = THIS_MODULE,
336	},
337	.probe = cs5535_mfgpt_probe,
338};
339
340
341static int __init cs5535_mfgpt_init(void)
342{
343	return platform_driver_register(&cs5535_mfgpt_driver);
344}
345
346module_init(cs5535_mfgpt_init);
347
348MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
349MODULE_DESCRIPTION("CS5535/CS5536 MFGPT timer driver");
350MODULE_LICENSE("GPL");
351MODULE_ALIAS("platform:" DRV_NAME);
v3.5.6
  1/*
  2 * Driver for the CS5535/CS5536 Multi-Function General Purpose Timers (MFGPT)
  3 *
  4 * Copyright (C) 2006, Advanced Micro Devices, Inc.
  5 * Copyright (C) 2007  Andres Salomon <dilinger@debian.org>
  6 * Copyright (C) 2009  Andres Salomon <dilinger@collabora.co.uk>
  7 *
  8 * This program is free software; you can redistribute it and/or
  9 * modify it under the terms of version 2 of the GNU General Public License
 10 * as published by the Free Software Foundation.
 11 *
 12 * The MFGPTs are documented in AMD Geode CS5536 Companion Device Data Book.
 13 */
 14
 15#include <linux/kernel.h>
 16#include <linux/spinlock.h>
 17#include <linux/interrupt.h>
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/cs5535.h>
 21#include <linux/slab.h>
 22
 23#define DRV_NAME "cs5535-mfgpt"
 24
 25static int mfgpt_reset_timers;
 26module_param_named(mfgptfix, mfgpt_reset_timers, int, 0644);
 27MODULE_PARM_DESC(mfgptfix, "Reset the MFGPT timers during init; "
 28		"required by some broken BIOSes (ie, TinyBIOS < 0.99).");
 29
 30struct cs5535_mfgpt_timer {
 31	struct cs5535_mfgpt_chip *chip;
 32	int nr;
 33};
 34
 35static struct cs5535_mfgpt_chip {
 36	DECLARE_BITMAP(avail, MFGPT_MAX_TIMERS);
 37	resource_size_t base;
 38
 39	struct platform_device *pdev;
 40	spinlock_t lock;
 41	int initialized;
 42} cs5535_mfgpt_chip;
 43
 44int cs5535_mfgpt_toggle_event(struct cs5535_mfgpt_timer *timer, int cmp,
 45		int event, int enable)
 46{
 47	uint32_t msr, mask, value, dummy;
 48	int shift = (cmp == MFGPT_CMP1) ? 0 : 8;
 49
 50	if (!timer) {
 51		WARN_ON(1);
 52		return -EIO;
 53	}
 54
 55	/*
 56	 * The register maps for these are described in sections 6.17.1.x of
 57	 * the AMD Geode CS5536 Companion Device Data Book.
 58	 */
 59	switch (event) {
 60	case MFGPT_EVENT_RESET:
 61		/*
 62		 * XXX: According to the docs, we cannot reset timers above
 63		 * 6; that is, resets for 7 and 8 will be ignored.  Is this
 64		 * a problem?   -dilinger
 65		 */
 66		msr = MSR_MFGPT_NR;
 67		mask = 1 << (timer->nr + 24);
 68		break;
 69
 70	case MFGPT_EVENT_NMI:
 71		msr = MSR_MFGPT_NR;
 72		mask = 1 << (timer->nr + shift);
 73		break;
 74
 75	case MFGPT_EVENT_IRQ:
 76		msr = MSR_MFGPT_IRQ;
 77		mask = 1 << (timer->nr + shift);
 78		break;
 79
 80	default:
 81		return -EIO;
 82	}
 83
 84	rdmsr(msr, value, dummy);
 85
 86	if (enable)
 87		value |= mask;
 88	else
 89		value &= ~mask;
 90
 91	wrmsr(msr, value, dummy);
 92	return 0;
 93}
 94EXPORT_SYMBOL_GPL(cs5535_mfgpt_toggle_event);
 95
 96int cs5535_mfgpt_set_irq(struct cs5535_mfgpt_timer *timer, int cmp, int *irq,
 97		int enable)
 98{
 99	uint32_t zsel, lpc, dummy;
100	int shift;
101
102	if (!timer) {
103		WARN_ON(1);
104		return -EIO;
105	}
106
107	/*
108	 * Unfortunately, MFGPTs come in pairs sharing their IRQ lines. If VSA
109	 * is using the same CMP of the timer's Siamese twin, the IRQ is set to
110	 * 2, and we mustn't use nor change it.
111	 * XXX: Likewise, 2 Linux drivers might clash if the 2nd overwrites the
112	 * IRQ of the 1st. This can only happen if forcing an IRQ, calling this
113	 * with *irq==0 is safe. Currently there _are_ no 2 drivers.
114	 */
115	rdmsr(MSR_PIC_ZSEL_LOW, zsel, dummy);
116	shift = ((cmp == MFGPT_CMP1 ? 0 : 4) + timer->nr % 4) * 4;
117	if (((zsel >> shift) & 0xF) == 2)
118		return -EIO;
119
120	/* Choose IRQ: if none supplied, keep IRQ already set or use default */
121	if (!*irq)
122		*irq = (zsel >> shift) & 0xF;
123	if (!*irq)
124		*irq = CONFIG_CS5535_MFGPT_DEFAULT_IRQ;
125
126	/* Can't use IRQ if it's 0 (=disabled), 2, or routed to LPC */
127	if (*irq < 1 || *irq == 2 || *irq > 15)
128		return -EIO;
129	rdmsr(MSR_PIC_IRQM_LPC, lpc, dummy);
130	if (lpc & (1 << *irq))
131		return -EIO;
132
133	/* All chosen and checked - go for it */
134	if (cs5535_mfgpt_toggle_event(timer, cmp, MFGPT_EVENT_IRQ, enable))
135		return -EIO;
136	if (enable) {
137		zsel = (zsel & ~(0xF << shift)) | (*irq << shift);
138		wrmsr(MSR_PIC_ZSEL_LOW, zsel, dummy);
139	}
140
141	return 0;
142}
143EXPORT_SYMBOL_GPL(cs5535_mfgpt_set_irq);
144
145struct cs5535_mfgpt_timer *cs5535_mfgpt_alloc_timer(int timer_nr, int domain)
146{
147	struct cs5535_mfgpt_chip *mfgpt = &cs5535_mfgpt_chip;
148	struct cs5535_mfgpt_timer *timer = NULL;
149	unsigned long flags;
150	int max;
151
152	if (!mfgpt->initialized)
153		goto done;
154
155	/* only allocate timers from the working domain if requested */
156	if (domain == MFGPT_DOMAIN_WORKING)
157		max = 6;
158	else
159		max = MFGPT_MAX_TIMERS;
160
161	if (timer_nr >= max) {
162		/* programmer error.  silly programmers! */
163		WARN_ON(1);
164		goto done;
165	}
166
167	spin_lock_irqsave(&mfgpt->lock, flags);
168	if (timer_nr < 0) {
169		unsigned long t;
170
171		/* try to find any available timer */
172		t = find_first_bit(mfgpt->avail, max);
173		/* set timer_nr to -1 if no timers available */
174		timer_nr = t < max ? (int) t : -1;
175	} else {
176		/* check if the requested timer's available */
177		if (!test_bit(timer_nr, mfgpt->avail))
178			timer_nr = -1;
179	}
180
181	if (timer_nr >= 0)
182		/* if timer_nr is not -1, it's an available timer */
183		__clear_bit(timer_nr, mfgpt->avail);
184	spin_unlock_irqrestore(&mfgpt->lock, flags);
185
186	if (timer_nr < 0)
187		goto done;
188
189	timer = kmalloc(sizeof(*timer), GFP_KERNEL);
190	if (!timer) {
191		/* aw hell */
192		spin_lock_irqsave(&mfgpt->lock, flags);
193		__set_bit(timer_nr, mfgpt->avail);
194		spin_unlock_irqrestore(&mfgpt->lock, flags);
195		goto done;
196	}
197	timer->chip = mfgpt;
198	timer->nr = timer_nr;
199	dev_info(&mfgpt->pdev->dev, "registered timer %d\n", timer_nr);
200
201done:
202	return timer;
203}
204EXPORT_SYMBOL_GPL(cs5535_mfgpt_alloc_timer);
205
206/*
207 * XXX: This frees the timer memory, but never resets the actual hardware
208 * timer.  The old geode_mfgpt code did this; it would be good to figure
209 * out a way to actually release the hardware timer.  See comments below.
210 */
211void cs5535_mfgpt_free_timer(struct cs5535_mfgpt_timer *timer)
212{
213	unsigned long flags;
214	uint16_t val;
215
216	/* timer can be made available again only if never set up */
217	val = cs5535_mfgpt_read(timer, MFGPT_REG_SETUP);
218	if (!(val & MFGPT_SETUP_SETUP)) {
219		spin_lock_irqsave(&timer->chip->lock, flags);
220		__set_bit(timer->nr, timer->chip->avail);
221		spin_unlock_irqrestore(&timer->chip->lock, flags);
222	}
223
224	kfree(timer);
225}
226EXPORT_SYMBOL_GPL(cs5535_mfgpt_free_timer);
227
228uint16_t cs5535_mfgpt_read(struct cs5535_mfgpt_timer *timer, uint16_t reg)
229{
230	return inw(timer->chip->base + reg + (timer->nr * 8));
231}
232EXPORT_SYMBOL_GPL(cs5535_mfgpt_read);
233
234void cs5535_mfgpt_write(struct cs5535_mfgpt_timer *timer, uint16_t reg,
235		uint16_t value)
236{
237	outw(value, timer->chip->base + reg + (timer->nr * 8));
238}
239EXPORT_SYMBOL_GPL(cs5535_mfgpt_write);
240
241/*
242 * This is a sledgehammer that resets all MFGPT timers. This is required by
243 * some broken BIOSes which leave the system in an unstable state
244 * (TinyBIOS 0.98, for example; fixed in 0.99).  It's uncertain as to
245 * whether or not this secret MSR can be used to release individual timers.
246 * Jordan tells me that he and Mitch once played w/ it, but it's unclear
247 * what the results of that were (and they experienced some instability).
248 */
249static void __devinit reset_all_timers(void)
250{
251	uint32_t val, dummy;
252
253	/* The following undocumented bit resets the MFGPT timers */
254	val = 0xFF; dummy = 0;
255	wrmsr(MSR_MFGPT_SETUP, val, dummy);
256}
257
258/*
259 * Check whether any MFGPTs are available for the kernel to use.  In most
260 * cases, firmware that uses AMD's VSA code will claim all timers during
261 * bootup; we certainly don't want to take them if they're already in use.
262 * In other cases (such as with VSAless OpenFirmware), the system firmware
263 * leaves timers available for us to use.
264 */
265static int __devinit scan_timers(struct cs5535_mfgpt_chip *mfgpt)
266{
267	struct cs5535_mfgpt_timer timer = { .chip = mfgpt };
268	unsigned long flags;
269	int timers = 0;
270	uint16_t val;
271	int i;
272
273	/* bios workaround */
274	if (mfgpt_reset_timers)
275		reset_all_timers();
276
277	/* just to be safe, protect this section w/ lock */
278	spin_lock_irqsave(&mfgpt->lock, flags);
279	for (i = 0; i < MFGPT_MAX_TIMERS; i++) {
280		timer.nr = i;
281		val = cs5535_mfgpt_read(&timer, MFGPT_REG_SETUP);
282		if (!(val & MFGPT_SETUP_SETUP)) {
283			__set_bit(i, mfgpt->avail);
284			timers++;
285		}
286	}
287	spin_unlock_irqrestore(&mfgpt->lock, flags);
288
289	return timers;
290}
291
292static int __devinit cs5535_mfgpt_probe(struct platform_device *pdev)
293{
294	struct resource *res;
295	int err = -EIO, t;
296
297	/* There are two ways to get the MFGPT base address; one is by
298	 * fetching it from MSR_LBAR_MFGPT, the other is by reading the
299	 * PCI BAR info.  The latter method is easier (especially across
300	 * different architectures), so we'll stick with that for now.  If
301	 * it turns out to be unreliable in the face of crappy BIOSes, we
302	 * can always go back to using MSRs.. */
303
304	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
305	if (!res) {
306		dev_err(&pdev->dev, "can't fetch device resource info\n");
307		goto done;
308	}
309
310	if (!request_region(res->start, resource_size(res), pdev->name)) {
311		dev_err(&pdev->dev, "can't request region\n");
312		goto done;
313	}
314
315	/* set up the driver-specific struct */
316	cs5535_mfgpt_chip.base = res->start;
317	cs5535_mfgpt_chip.pdev = pdev;
318	spin_lock_init(&cs5535_mfgpt_chip.lock);
319
320	dev_info(&pdev->dev, "reserved resource region %pR\n", res);
321
322	/* detect the available timers */
323	t = scan_timers(&cs5535_mfgpt_chip);
324	dev_info(&pdev->dev, "%d MFGPT timers available\n", t);
325	cs5535_mfgpt_chip.initialized = 1;
326	return 0;
327
328done:
329	return err;
330}
331
332static struct platform_driver cs5535_mfgpt_driver = {
333	.driver = {
334		.name = DRV_NAME,
335		.owner = THIS_MODULE,
336	},
337	.probe = cs5535_mfgpt_probe,
338};
339
340
341static int __init cs5535_mfgpt_init(void)
342{
343	return platform_driver_register(&cs5535_mfgpt_driver);
344}
345
346module_init(cs5535_mfgpt_init);
347
348MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
349MODULE_DESCRIPTION("CS5535/CS5536 MFGPT timer driver");
350MODULE_LICENSE("GPL");
351MODULE_ALIAS("platform:" DRV_NAME);