aboutsummaryrefslogtreecommitdiff
path: root/drivers/gpio/wm8994-gpio.c
blob: 2ac9a16d3daa9723dd9f2c34b6d774c62392dd58 (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
/*
 * wm8994-gpio.c  --  gpiolib support for Wolfson WM8994
 *
 * Copyright 2009 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>

#include <linux/mfd/wm8994/core.h>
#include <linux/mfd/wm8994/pdata.h>
#include <linux/mfd/wm8994/gpio.h>
#include <linux/mfd/wm8994/registers.h>

struct wm8994_gpio {
	struct wm8994 *wm8994;
	struct gpio_chip gpio_chip;
};

static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
{
	return container_of(chip, struct wm8994_gpio, gpio_chip);
}

static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
	struct wm8994 *wm8994 = wm8994_gpio->wm8994;

	return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
			       WM8994_GPN_DIR, WM8994_GPN_DIR);
}

static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
	int ret;

	ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
	if (ret < 0)
		return ret;

	if (ret & WM8994_GPN_LVL)
		return 1;
	else
		return 0;
}

static int wm8994_gpio_direction_out(struct gpio_chip *chip,
				     unsigned offset, int value)
{
	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
	struct wm8994 *wm8994 = wm8994_gpio->wm8994;

	return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
			       WM8994_GPN_DIR, 0);
}

static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
	struct wm8994 *wm8994 = wm8994_gpio->wm8994;

	if (value)
		value = WM8994_GPN_LVL;

	wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
}

static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
	struct wm8994 *wm8994 = wm8994_gpio->wm8994;

	if (!wm8994->irq_base)
		return -EINVAL;

	return wm8994->irq_base + offset;
}


#ifdef CONFIG_DEBUG_FS
static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
	int i;

	for (i = 0; i < chip->ngpio; i++) {
		int gpio = i + chip->base;
		int reg;
		const char *label;

		/* We report the GPIO even if it's not requested since
		 * we're also reporting things like alternate
		 * functions which apply even when the GPIO is not in
		 * use as a GPIO.
		 */
		label = gpiochip_is_requested(chip, i);
		if (!label)
			label = "Unrequested";

		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);

		reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
		if (reg < 0) {
			dev_err(wm8994->dev,
				"GPIO control %d read failed: %d\n",
				gpio, reg);
			seq_printf(s, "\n");
			continue;
		}

		/* No decode yet; note that GPIO2 is special */
		seq_printf(s, "(%x)\n", reg);
	}
}
#else
#define wm8994_gpio_dbg_show NULL
#endif

static struct gpio_chip template_chip = {
	.label			= "wm8994",
	.owner			= THIS_MODULE,
	.direction_input	= wm8994_gpio_direction_in,
	.get			= wm8994_gpio_get,
	.direction_output	= wm8994_gpio_direction_out,
	.set			= wm8994_gpio_set,
	.dbg_show		= wm8994_gpio_dbg_show,
	.can_sleep		= 1,
};

static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
{
	struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
	struct wm8994_pdata *pdata = wm8994->dev->platform_data;
	struct wm8994_gpio *wm8994_gpio;
	int ret;

	wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
	if (wm8994_gpio == NULL)
		return -ENOMEM;

	wm8994_gpio->wm8994 = wm8994;
	wm8994_gpio->gpio_chip = template_chip;
	wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
	wm8994_gpio->gpio_chip.dev = &pdev->dev;
	if (pdata && pdata->gpio_base)
		wm8994_gpio->gpio_chip.base = pdata->gpio_base;
	else
		wm8994_gpio->gpio_chip.base = -1;

	ret = gpiochip_add(&wm8994_gpio->gpio_chip);
	if (ret < 0) {
		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
			ret);
		goto err;
	}

	platform_set_drvdata(pdev, wm8994_gpio);

	return ret;

err:
	kfree(wm8994_gpio);
	return ret;
}

static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
{
	struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
	int ret;

	ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
	if (ret == 0)
		kfree(wm8994_gpio);

	return ret;
}

static struct platform_driver wm8994_gpio_driver = {
	.driver.name	= "wm8994-gpio",
	.driver.owner	= THIS_MODULE,
	.probe		= wm8994_gpio_probe,
	.remove		= __devexit_p(wm8994_gpio_remove),
};

static int __init wm8994_gpio_init(void)
{
	return platform_driver_register(&wm8994_gpio_driver);
}
subsys_initcall(wm8994_gpio_init);

static void __exit wm8994_gpio_exit(void)
{
	platform_driver_unregister(&wm8994_gpio_driver);
}
module_exit(wm8994_gpio_exit);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("GPIO interface for WM8994");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm8994-gpio");