summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/pl061.c
blob: 838ddbdf90cc22fe0a69ec7b84153f52cdaf4baf (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
/*
 *  linux/drivers/gpio/pl061.c
 *
 *  Copyright (C) 2008, 2009 Provigent Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Driver for the ARM PrimeCell(tm) General Purpose Input/Output (PL061)
 *
 * Data sheet: ARM DDI 0190B, September 2000
 */
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/bitops.h>
#include <linux/workqueue.h>
#include <linux/gpio.h>
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/amba/pl061.h>
#include <linux/slab.h>

#define GPIODIR 0x400
#define GPIOIS  0x404
#define GPIOIBE 0x408
#define GPIOIEV 0x40C
#define GPIOIE  0x410
#define GPIORIS 0x414
#define GPIOMIS 0x418
#define GPIOIC  0x41C

#define PL061_GPIO_NR	8

struct pl061_gpio {
	/* We use a list of pl061_gpio structs for each trigger IRQ in the main
	 * interrupts controller of the system. We need this to support systems
	 * in which more that one PL061s are connected to the same IRQ. The ISR
	 * interates through this list to find the source of the interrupt.
	 */
	struct list_head	list;

	/* Each of the two spinlocks protects a different set of hardware
	 * regiters and data structurs. This decouples the code of the IRQ from
	 * the GPIO code. This also makes the case of a GPIO routine call from
	 * the IRQ code simpler.
	 */
	spinlock_t		lock;		/* GPIO registers */
	spinlock_t		irq_lock;	/* IRQ registers */

	void __iomem		*base;
	unsigned		irq_base;
	struct gpio_chip	gc;
};

static int pl061_direction_input(struct gpio_chip *gc, unsigned offset)
{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
	unsigned long flags;
	unsigned char gpiodir;

	if (offset >= gc->ngpio)
		return -EINVAL;

	spin_lock_irqsave(&chip->lock, flags);
	gpiodir = readb(chip->base + GPIODIR);
	gpiodir &= ~(1 << offset);
	writeb(gpiodir, chip->base + GPIODIR);
	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static int pl061_direction_output(struct gpio_chip *gc, unsigned offset,
		int value)
{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);
	unsigned long flags;
	unsigned char gpiodir;

	if (offset >= gc->ngpio)
		return -EINVAL;

	spin_lock_irqsave(&chip->lock, flags);
	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
	gpiodir = readb(chip->base + GPIODIR);
	gpiodir |= 1 << offset;
	writeb(gpiodir, chip->base + GPIODIR);

	/*
	 * gpio value is set again, because pl061 doesn't allow to set value of
	 * a gpio pin before configuring it in OUT mode.
	 */
	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static int pl061_get_value(struct gpio_chip *gc, unsigned offset)
{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

	return !!readb(chip->base + (1 << (offset + 2)));
}

static void pl061_set_value(struct gpio_chip *gc, unsigned offset, int value)
{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

	writeb(!!value << offset, chip->base + (1 << (offset + 2)));
}

static int pl061_to_irq(struct gpio_chip *gc, unsigned offset)
{
	struct pl061_gpio *chip = container_of(gc, struct pl061_gpio, gc);

	if (chip->irq_base == (unsigned) -1)
		return -EINVAL;

	return chip->irq_base + offset;
}

/*
 * PL061 GPIO IRQ
 */
static void pl061_irq_disable(struct irq_data *d)
{
	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
	int offset = d->irq - chip->irq_base;
	unsigned long flags;
	u8 gpioie;

	spin_lock_irqsave(&chip->irq_lock, flags);
	gpioie = readb(chip->base + GPIOIE);
	gpioie &= ~(1 << offset);
	writeb(gpioie, chip->base + GPIOIE);
	spin_unlock_irqrestore(&chip->irq_lock, flags);
}

static void pl061_irq_enable(struct irq_data *d)
{
	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
	int offset = d->irq - chip->irq_base;
	unsigned long flags;
	u8 gpioie;

	spin_lock_irqsave(&chip->irq_lock, flags);
	gpioie = readb(chip->base + GPIOIE);
	gpioie |= 1 << offset;
	writeb(gpioie, chip->base + GPIOIE);
	spin_unlock_irqrestore(&chip->irq_lock, flags);
}

static int pl061_irq_type(struct irq_data *d, unsigned trigger)
{
	struct pl061_gpio *chip = irq_data_get_irq_chip_data(d);
	int offset = d->irq - chip->irq_base;
	unsigned long flags;
	u8 gpiois, gpioibe, gpioiev;

	if (offset < 0 || offset >= PL061_GPIO_NR)
		return -EINVAL;

	spin_lock_irqsave(&chip->irq_lock, flags);

	gpioiev = readb(chip->base + GPIOIEV);

	gpiois = readb(chip->base + GPIOIS);
	if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
		gpiois |= 1 << offset;
		if (trigger & IRQ_TYPE_LEVEL_HIGH)
			gpioiev |= 1 << offset;
		else
			gpioiev &= ~(1 << offset);
	} else
		gpiois &= ~(1 << offset);
	writeb(gpiois, chip->base + GPIOIS);

	gpioibe = readb(chip->base + GPIOIBE);
	if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
		gpioibe |= 1 << offset;
	else {
		gpioibe &= ~(1 << offset);
		if (trigger & IRQ_TYPE_EDGE_RISING)
			gpioiev |= 1 << offset;
		else if (trigger & IRQ_TYPE_EDGE_FALLING)
			gpioiev &= ~(1 << offset);
	}
	writeb(gpioibe, chip->base + GPIOIBE);

	writeb(gpioiev, chip->base + GPIOIEV);

	spin_unlock_irqrestore(&chip->irq_lock, flags);

	return 0;
}

static struct irq_chip pl061_irqchip = {
	.name		= "GPIO",
	.irq_enable	= pl061_irq_enable,
	.irq_disable	= pl061_irq_disable,
	.irq_set_type	= pl061_irq_type,
};

static void pl061_irq_handler(unsigned irq, struct irq_desc *desc)
{
	struct list_head *chip_list = get_irq_data(irq);
	struct list_head *ptr;
	struct pl061_gpio *chip;

	desc->irq_data.chip->irq_ack(&desc->irq_data);
	list_for_each(ptr, chip_list) {
		unsigned long pending;
		int offset;

		chip = list_entry(ptr, struct pl061_gpio, list);
		pending = readb(chip->base + GPIOMIS);
		writeb(pending, chip->base + GPIOIC);

		if (pending == 0)
			continue;

		for_each_set_bit(offset, &pending, PL061_GPIO_NR)
			generic_handle_irq(pl061_to_irq(&chip->gc, offset));
	}
	desc->irq_data.chip->irq_unmask(&desc->irq_data);
}

static int pl061_probe(struct amba_device *dev, const struct amba_id *id)
{
	struct pl061_platform_data *pdata;
	struct pl061_gpio *chip;
	struct list_head *chip_list;
	int ret, irq, i;
	static DECLARE_BITMAP(init_irq, NR_IRQS);

	pdata = dev->dev.platform_data;
	if (pdata == NULL)
		return -ENODEV;

	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
	if (chip == NULL)
		return -ENOMEM;

	if (!request_mem_region(dev->res.start,
				resource_size(&dev->res), "pl061")) {
		ret = -EBUSY;
		goto free_mem;
	}

	chip->base = ioremap(dev->res.start, resource_size(&dev->res));
	if (chip->base == NULL) {
		ret = -ENOMEM;
		goto release_region;
	}

	spin_lock_init(&chip->lock);
	spin_lock_init(&chip->irq_lock);
	INIT_LIST_HEAD(&chip->list);

	chip->gc.direction_input = pl061_direction_input;
	chip->gc.direction_output = pl061_direction_output;
	chip->gc.get = pl061_get_value;
	chip->gc.set = pl061_set_value;
	chip->gc.to_irq = pl061_to_irq;
	chip->gc.base = pdata->gpio_base;
	chip->gc.ngpio = PL061_GPIO_NR;
	chip->gc.label = dev_name(&dev->dev);
	chip->gc.dev = &dev->dev;
	chip->gc.owner = THIS_MODULE;

	chip->irq_base = pdata->irq_base;

	ret = gpiochip_add(&chip->gc);
	if (ret)
		goto iounmap;

	/*
	 * irq_chip support
	 */

	if (chip->irq_base == (unsigned) -1)
		return 0;

	writeb(0, chip->base + GPIOIE); /* disable irqs */
	irq = dev->irq[0];
	if (irq < 0) {
		ret = -ENODEV;
		goto iounmap;
	}
	set_irq_chained_handler(irq, pl061_irq_handler);
	if (!test_and_set_bit(irq, init_irq)) { /* list initialized? */
		chip_list = kmalloc(sizeof(*chip_list), GFP_KERNEL);
		if (chip_list == NULL) {
			clear_bit(irq, init_irq);
			ret = -ENOMEM;
			goto iounmap;
		}
		INIT_LIST_HEAD(chip_list);
		set_irq_data(irq, chip_list);
	} else
		chip_list = get_irq_data(irq);
	list_add(&chip->list, chip_list);

	for (i = 0; i < PL061_GPIO_NR; i++) {
		if (pdata->directions & (1 << i))
			pl061_direction_output(&chip->gc, i,
					pdata->values & (1 << i));
		else
			pl061_direction_input(&chip->gc, i);

		set_irq_chip(i+chip->irq_base, &pl061_irqchip);
		set_irq_handler(i+chip->irq_base, handle_simple_irq);
		set_irq_flags(i+chip->irq_base, IRQF_VALID);
		set_irq_chip_data(i+chip->irq_base, chip);
	}

	return 0;

iounmap:
	iounmap(chip->base);
release_region:
	release_mem_region(dev->res.start, resource_size(&dev->res));
free_mem:
	kfree(chip);

	return ret;
}

static struct amba_id pl061_ids[] = {
	{
		.id	= 0x00041061,
		.mask	= 0x000fffff,
	},
	{ 0, 0 },
};

static struct amba_driver pl061_gpio_driver = {
	.drv = {
		.name	= "pl061_gpio",
	},
	.id_table	= pl061_ids,
	.probe		= pl061_probe,
};

static int __init pl061_gpio_init(void)
{
	return amba_driver_register(&pl061_gpio_driver);
}
subsys_initcall(pl061_gpio_init);

MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
MODULE_DESCRIPTION("PL061 GPIO driver");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud