summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-cs5535.c
blob: 00f98f934d36020b35662263d38e894b363e29d2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
/*
 * AMD CS5535/CS5536 GPIO driver
 * Copyright (C) 2006  Advanced Micro Devices, Inc.
 * Copyright (C) 2007-2009  Andres Salomon <dilinger@collabora.co.uk>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public License
 * as published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/cs5535.h>
#include <asm/msr.h>

#define DRV_NAME "cs5535-gpio"

/*
 * Some GPIO pins
 *  31-29,23 : reserved (always mask out)
 *  28       : Power Button
 *  26       : PME#
 *  22-16    : LPC
 *  14,15    : SMBus
 *  9,8      : UART1
 *  7        : PCI INTB
 *  3,4      : UART2/DDC
 *  2        : IDE_IRQ0
 *  1        : AC_BEEP
 *  0        : PCI INTA
 *
 * If a mask was not specified, allow all except
 * reserved and Power Button
 */
#define GPIO_DEFAULT_MASK 0x0F7FFFFF

static ulong mask = GPIO_DEFAULT_MASK;
module_param_named(mask, mask, ulong, 0444);
MODULE_PARM_DESC(mask, "GPIO channel mask.");

static struct cs5535_gpio_chip {
	struct gpio_chip chip;
	resource_size_t base;

	struct platform_device *pdev;
	spinlock_t lock;
} cs5535_gpio_chip;

/*
 * The CS5535/CS5536 GPIOs support a number of extra features not defined
 * by the gpio_chip API, so these are exported.  For a full list of the
 * registers, see include/linux/cs5535.h.
 */

static void errata_outl(struct cs5535_gpio_chip *chip, u32 val,
		unsigned int reg)
{
	unsigned long addr = chip->base + 0x80 + reg;

	/*
	 * According to the CS5536 errata (#36), after suspend
	 * a write to the high bank GPIO register will clear all
	 * non-selected bits; the recommended workaround is a
	 * read-modify-write operation.
	 *
	 * Don't apply this errata to the edge status GPIOs, as writing
	 * to their lower bits will clear them.
	 */
	if (reg != GPIO_POSITIVE_EDGE_STS && reg != GPIO_NEGATIVE_EDGE_STS) {
		if (val & 0xffff)
			val |= (inl(addr) & 0xffff); /* ignore the high bits */
		else
			val |= (inl(addr) ^ (val >> 16));
	}
	outl(val, addr);
}

static void __cs5535_gpio_set(struct cs5535_gpio_chip *chip, unsigned offset,
		unsigned int reg)
{
	if (offset < 16)
		/* low bank register */
		outl(1 << offset, chip->base + reg);
	else
		/* high bank register */
		errata_outl(chip, 1 << (offset - 16), reg);
}

void cs5535_gpio_set(unsigned offset, unsigned int reg)
{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__cs5535_gpio_set(chip, offset, reg);
	spin_unlock_irqrestore(&chip->lock, flags);
}
EXPORT_SYMBOL_GPL(cs5535_gpio_set);

static void __cs5535_gpio_clear(struct cs5535_gpio_chip *chip, unsigned offset,
		unsigned int reg)
{
	if (offset < 16)
		/* low bank register */
		outl(1 << (offset + 16), chip->base + reg);
	else
		/* high bank register */
		errata_outl(chip, 1 << offset, reg);
}

void cs5535_gpio_clear(unsigned offset, unsigned int reg)
{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__cs5535_gpio_clear(chip, offset, reg);
	spin_unlock_irqrestore(&chip->lock, flags);
}
EXPORT_SYMBOL_GPL(cs5535_gpio_clear);

int cs5535_gpio_isset(unsigned offset, unsigned int reg)
{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	unsigned long flags;
	long val;

	spin_lock_irqsave(&chip->lock, flags);
	if (offset < 16)
		/* low bank register */
		val = inl(chip->base + reg);
	else {
		/* high bank register */
		val = inl(chip->base + 0x80 + reg);
		offset -= 16;
	}
	spin_unlock_irqrestore(&chip->lock, flags);

	return (val & (1 << offset)) ? 1 : 0;
}
EXPORT_SYMBOL_GPL(cs5535_gpio_isset);

int cs5535_gpio_set_irq(unsigned group, unsigned irq)
{
	uint32_t lo, hi;

	if (group > 7 || irq > 15)
		return -EINVAL;

	rdmsr(MSR_PIC_ZSEL_HIGH, lo, hi);

	lo &= ~(0xF << (group * 4));
	lo |= (irq & 0xF) << (group * 4);

	wrmsr(MSR_PIC_ZSEL_HIGH, lo, hi);
	return 0;
}
EXPORT_SYMBOL_GPL(cs5535_gpio_set_irq);

void cs5535_gpio_setup_event(unsigned offset, int pair, int pme)
{
	struct cs5535_gpio_chip *chip = &cs5535_gpio_chip;
	uint32_t shift = (offset % 8) * 4;
	unsigned long flags;
	uint32_t val;

	if (offset >= 24)
		offset = GPIO_MAP_W;
	else if (offset >= 16)
		offset = GPIO_MAP_Z;
	else if (offset >= 8)
		offset = GPIO_MAP_Y;
	else
		offset = GPIO_MAP_X;

	spin_lock_irqsave(&chip->lock, flags);
	val = inl(chip->base + offset);

	/* Clear whatever was there before */
	val &= ~(0xF << shift);

	/* Set the new value */
	val |= ((pair & 7) << shift);

	/* Set the PME bit if this is a PME event */
	if (pme)
		val |= (1 << (shift + 3));

	outl(val, chip->base + offset);
	spin_unlock_irqrestore(&chip->lock, flags);
}
EXPORT_SYMBOL_GPL(cs5535_gpio_setup_event);

/*
 * Generic gpio_chip API support.
 */

static int chip_gpio_request(struct gpio_chip *c, unsigned offset)
{
	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);

	/* check if this pin is available */
	if ((mask & (1 << offset)) == 0) {
		dev_info(&chip->pdev->dev,
			"pin %u is not available (check mask)\n", offset);
		spin_unlock_irqrestore(&chip->lock, flags);
		return -EINVAL;
	}

	/* disable output aux 1 & 2 on this pin */
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX1);
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_AUX2);

	/* disable input aux 1 on this pin */
	__cs5535_gpio_clear(chip, offset, GPIO_INPUT_AUX1);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static int chip_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	return cs5535_gpio_isset(offset, GPIO_READ_BACK);
}

static void chip_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
{
	if (val)
		cs5535_gpio_set(offset, GPIO_OUTPUT_VAL);
	else
		cs5535_gpio_clear(offset, GPIO_OUTPUT_VAL);
}

static int chip_direction_input(struct gpio_chip *c, unsigned offset)
{
	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
	__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_ENABLE);
	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static int chip_direction_output(struct gpio_chip *c, unsigned offset, int val)
{
	struct cs5535_gpio_chip *chip = (struct cs5535_gpio_chip *) c;
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);

	__cs5535_gpio_set(chip, offset, GPIO_INPUT_ENABLE);
	__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_ENABLE);
	if (val)
		__cs5535_gpio_set(chip, offset, GPIO_OUTPUT_VAL);
	else
		__cs5535_gpio_clear(chip, offset, GPIO_OUTPUT_VAL);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static const char * const cs5535_gpio_names[] = {
	"GPIO0", "GPIO1", "GPIO2", "GPIO3",
	"GPIO4", "GPIO5", "GPIO6", "GPIO7",
	"GPIO8", "GPIO9", "GPIO10", "GPIO11",
	"GPIO12", "GPIO13", "GPIO14", "GPIO15",
	"GPIO16", "GPIO17", "GPIO18", "GPIO19",
	"GPIO20", "GPIO21", "GPIO22", NULL,
	"GPIO24", "GPIO25", "GPIO26", "GPIO27",
	"GPIO28", NULL, NULL, NULL,
};

static struct cs5535_gpio_chip cs5535_gpio_chip = {
	.chip = {
		.owner = THIS_MODULE,
		.label = DRV_NAME,

		.base = 0,
		.ngpio = 32,
		.names = cs5535_gpio_names,
		.request = chip_gpio_request,

		.get = chip_gpio_get,
		.set = chip_gpio_set,

		.direction_input = chip_direction_input,
		.direction_output = chip_direction_output,
	},
};

static int __devinit cs5535_gpio_probe(struct platform_device *pdev)
{
	struct resource *res;
	int err = -EIO;
	ulong mask_orig = mask;

	/* There are two ways to get the GPIO base address; one is by
	 * fetching it from MSR_LBAR_GPIO, the other is by reading the
	 * PCI BAR info.  The latter method is easier (especially across
	 * different architectures), so we'll stick with that for now.  If
	 * it turns out to be unreliable in the face of crappy BIOSes, we
	 * can always go back to using MSRs.. */

	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
	if (!res) {
		dev_err(&pdev->dev, "can't fetch device resource info\n");
		goto done;
	}

	if (!request_region(res->start, resource_size(res), pdev->name)) {
		dev_err(&pdev->dev, "can't request region\n");
		goto done;
	}

	/* set up the driver-specific struct */
	cs5535_gpio_chip.base = res->start;
	cs5535_gpio_chip.pdev = pdev;
	spin_lock_init(&cs5535_gpio_chip.lock);

	dev_info(&pdev->dev, "reserved resource region %pR\n", res);

	/* mask out reserved pins */
	mask &= 0x1F7FFFFF;

	/* do not allow pin 28, Power Button, as there's special handling
	 * in the PMC needed. (note 12, p. 48) */
	mask &= ~(1 << 28);

	if (mask_orig != mask)
		dev_info(&pdev->dev, "mask changed from 0x%08lX to 0x%08lX\n",
				mask_orig, mask);

	/* finally, register with the generic GPIO API */
	err = gpiochip_add(&cs5535_gpio_chip.chip);
	if (err)
		goto release_region;

	return 0;

release_region:
	release_region(res->start, resource_size(res));
done:
	return err;
}

static int __devexit cs5535_gpio_remove(struct platform_device *pdev)
{
	struct resource *r;
	int err;

	err = gpiochip_remove(&cs5535_gpio_chip.chip);
	if (err) {
		/* uhh? */
		dev_err(&pdev->dev, "unable to remove gpio_chip?\n");
		return err;
	}

	r = platform_get_resource(pdev, IORESOURCE_IO, 0);
	release_region(r->start, resource_size(r));
	return 0;
}

static struct platform_driver cs5535_gpio_driver = {
	.driver = {
		.name = DRV_NAME,
		.owner = THIS_MODULE,
	},
	.probe = cs5535_gpio_probe,
	.remove = cs5535_gpio_remove,
};

module_platform_driver(cs5535_gpio_driver);

MODULE_AUTHOR("Andres Salomon <dilinger@queued.net>");
MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);