summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/timbgpio.c
blob: 45293662e95045594c2a9ed12ece640c2590f93f (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
/*
 * timbgpio.c timberdale FPGA GPIO driver
 * Copyright (c) 2009 Intel Corporation
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* Supports:
 * Timberdale FPGA GPIO
 */

#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/timb_gpio.h>
#include <linux/interrupt.h>
#include <linux/slab.h>

#define DRIVER_NAME "timb-gpio"

#define TGPIOVAL	0x00
#define TGPIODIR	0x04
#define TGPIO_IER	0x08
#define TGPIO_ISR	0x0c
#define TGPIO_IPR	0x10
#define TGPIO_ICR	0x14
#define TGPIO_FLR	0x18
#define TGPIO_LVR	0x1c
#define TGPIO_VER	0x20
#define TGPIO_BFLR	0x24

struct timbgpio {
	void __iomem		*membase;
	spinlock_t		lock; /* mutual exclusion */
	struct gpio_chip	gpio;
	int			irq_base;
	unsigned long		last_ier;
};

static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index,
	unsigned offset, bool enabled)
{
	struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
	u32 reg;

	spin_lock(&tgpio->lock);
	reg = ioread32(tgpio->membase + offset);

	if (enabled)
		reg |= (1 << index);
	else
		reg &= ~(1 << index);

	iowrite32(reg, tgpio->membase + offset);
	spin_unlock(&tgpio->lock);

	return 0;
}

static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr)
{
	return timbgpio_update_bit(gpio, nr, TGPIODIR, true);
}

static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr)
{
	struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);
	u32 value;

	value = ioread32(tgpio->membase + TGPIOVAL);
	return (value & (1 << nr)) ? 1 : 0;
}

static int timbgpio_gpio_direction_output(struct gpio_chip *gpio,
						unsigned nr, int val)
{
	return timbgpio_update_bit(gpio, nr, TGPIODIR, false);
}

static void timbgpio_gpio_set(struct gpio_chip *gpio,
				unsigned nr, int val)
{
	timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0);
}

static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset)
{
	struct timbgpio *tgpio = container_of(gpio, struct timbgpio, gpio);

	if (tgpio->irq_base <= 0)
		return -EINVAL;

	return tgpio->irq_base + offset;
}

/*
 * GPIO IRQ
 */
static void timbgpio_irq_disable(unsigned irq)
{
	struct timbgpio *tgpio = get_irq_chip_data(irq);
	int offset = irq - tgpio->irq_base;
	unsigned long flags;

	spin_lock_irqsave(&tgpio->lock, flags);
	tgpio->last_ier &= ~(1 << offset);
	iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
	spin_unlock_irqrestore(&tgpio->lock, flags);
}

static void timbgpio_irq_enable(unsigned irq)
{
	struct timbgpio *tgpio = get_irq_chip_data(irq);
	int offset = irq - tgpio->irq_base;
	unsigned long flags;

	spin_lock_irqsave(&tgpio->lock, flags);
	tgpio->last_ier |= 1 << offset;
	iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
	spin_unlock_irqrestore(&tgpio->lock, flags);
}

static int timbgpio_irq_type(unsigned irq, unsigned trigger)
{
	struct timbgpio *tgpio = get_irq_chip_data(irq);
	int offset = irq - tgpio->irq_base;
	unsigned long flags;
	u32 lvr, flr, bflr = 0;
	u32 ver;
	int ret = 0;

	if (offset < 0 || offset > tgpio->gpio.ngpio)
		return -EINVAL;

	ver = ioread32(tgpio->membase + TGPIO_VER);

	spin_lock_irqsave(&tgpio->lock, flags);

	lvr = ioread32(tgpio->membase + TGPIO_LVR);
	flr = ioread32(tgpio->membase + TGPIO_FLR);
	if (ver > 2)
		bflr = ioread32(tgpio->membase + TGPIO_BFLR);

	if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
		bflr &= ~(1 << offset);
		flr &= ~(1 << offset);
		if (trigger & IRQ_TYPE_LEVEL_HIGH)
			lvr |= 1 << offset;
		else
			lvr &= ~(1 << offset);
	}

	if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
		if (ver < 3) {
			ret = -EINVAL;
			goto out;
		}
		else {
			flr |= 1 << offset;
			bflr |= 1 << offset;
		}
	} else {
		bflr &= ~(1 << offset);
		flr |= 1 << offset;
		if (trigger & IRQ_TYPE_EDGE_FALLING)
			lvr &= ~(1 << offset);
		else
			lvr |= 1 << offset;
	}

	iowrite32(lvr, tgpio->membase + TGPIO_LVR);
	iowrite32(flr, tgpio->membase + TGPIO_FLR);
	if (ver > 2)
		iowrite32(bflr, tgpio->membase + TGPIO_BFLR);

	iowrite32(1 << offset, tgpio->membase + TGPIO_ICR);

out:
	spin_unlock_irqrestore(&tgpio->lock, flags);
	return ret;
}

static void timbgpio_irq(unsigned int irq, struct irq_desc *desc)
{
	struct timbgpio *tgpio = get_irq_data(irq);
	unsigned long ipr;
	int offset;

	desc->chip->ack(irq);
	ipr = ioread32(tgpio->membase + TGPIO_IPR);
	iowrite32(ipr, tgpio->membase + TGPIO_ICR);

	/*
	 * Some versions of the hardware trash the IER register if more than
	 * one interrupt is received simultaneously.
	 */
	iowrite32(0, tgpio->membase + TGPIO_IER);

	for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio)
		generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset));

	iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER);
}

static struct irq_chip timbgpio_irqchip = {
	.name		= "GPIO",
	.enable		= timbgpio_irq_enable,
	.disable	= timbgpio_irq_disable,
	.set_type	= timbgpio_irq_type,
};

static int __devinit timbgpio_probe(struct platform_device *pdev)
{
	int err, i;
	struct gpio_chip *gc;
	struct timbgpio *tgpio;
	struct resource *iomem;
	struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
	int irq = platform_get_irq(pdev, 0);

	if (!pdata || pdata->nr_pins > 32) {
		err = -EINVAL;
		goto err_mem;
	}

	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!iomem) {
		err = -EINVAL;
		goto err_mem;
	}

	tgpio = kzalloc(sizeof(*tgpio), GFP_KERNEL);
	if (!tgpio) {
		err = -EINVAL;
		goto err_mem;
	}
	tgpio->irq_base = pdata->irq_base;

	spin_lock_init(&tgpio->lock);

	if (!request_mem_region(iomem->start, resource_size(iomem),
		DRIVER_NAME)) {
		err = -EBUSY;
		goto err_request;
	}

	tgpio->membase = ioremap(iomem->start, resource_size(iomem));
	if (!tgpio->membase) {
		err = -ENOMEM;
		goto err_ioremap;
	}

	gc = &tgpio->gpio;

	gc->label = dev_name(&pdev->dev);
	gc->owner = THIS_MODULE;
	gc->dev = &pdev->dev;
	gc->direction_input = timbgpio_gpio_direction_input;
	gc->get = timbgpio_gpio_get;
	gc->direction_output = timbgpio_gpio_direction_output;
	gc->set = timbgpio_gpio_set;
	gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL;
	gc->dbg_show = NULL;
	gc->base = pdata->gpio_base;
	gc->ngpio = pdata->nr_pins;
	gc->can_sleep = 0;

	err = gpiochip_add(gc);
	if (err)
		goto err_chipadd;

	platform_set_drvdata(pdev, tgpio);

	/* make sure to disable interrupts */
	iowrite32(0x0, tgpio->membase + TGPIO_IER);

	if (irq < 0 || tgpio->irq_base <= 0)
		return 0;

	for (i = 0; i < pdata->nr_pins; i++) {
		set_irq_chip_and_handler_name(tgpio->irq_base + i,
			&timbgpio_irqchip, handle_simple_irq, "mux");
		set_irq_chip_data(tgpio->irq_base + i, tgpio);
#ifdef CONFIG_ARM
		set_irq_flags(tgpio->irq_base + i, IRQF_VALID | IRQF_PROBE);
#endif
	}

	set_irq_data(irq, tgpio);
	set_irq_chained_handler(irq, timbgpio_irq);

	return 0;

err_chipadd:
	iounmap(tgpio->membase);
err_ioremap:
	release_mem_region(iomem->start, resource_size(iomem));
err_request:
	kfree(tgpio);
err_mem:
	printk(KERN_ERR DRIVER_NAME": Failed to register GPIOs: %d\n", err);

	return err;
}

static int __devexit timbgpio_remove(struct platform_device *pdev)
{
	int err;
	struct timbgpio_platform_data *pdata = pdev->dev.platform_data;
	struct timbgpio *tgpio = platform_get_drvdata(pdev);
	struct resource *iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	int irq = platform_get_irq(pdev, 0);

	if (irq >= 0 && tgpio->irq_base > 0) {
		int i;
		for (i = 0; i < pdata->nr_pins; i++) {
			set_irq_chip(tgpio->irq_base + i, NULL);
			set_irq_chip_data(tgpio->irq_base + i, NULL);
		}

		set_irq_handler(irq, NULL);
		set_irq_data(irq, NULL);
	}

	err = gpiochip_remove(&tgpio->gpio);
	if (err)
		printk(KERN_ERR DRIVER_NAME": failed to remove gpio_chip\n");

	iounmap(tgpio->membase);
	release_mem_region(iomem->start, resource_size(iomem));
	kfree(tgpio);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

static struct platform_driver timbgpio_platform_driver = {
	.driver = {
		.name	= DRIVER_NAME,
		.owner	= THIS_MODULE,
	},
	.probe		= timbgpio_probe,
	.remove		= timbgpio_remove,
};

/*--------------------------------------------------------------------------*/

static int __init timbgpio_init(void)
{
	return platform_driver_register(&timbgpio_platform_driver);
}

static void __exit timbgpio_exit(void)
{
	platform_driver_unregister(&timbgpio_platform_driver);
}

module_init(timbgpio_init);
module_exit(timbgpio_exit);

MODULE_DESCRIPTION("Timberdale GPIO driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Mocean Laboratories");
MODULE_ALIAS("platform:"DRIVER_NAME);