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path: root/drivers/gpio/wm8994-gpio.c
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Diffstat (limited to 'drivers/gpio/wm8994-gpio.c')
-rw-r--r--drivers/gpio/wm8994-gpio.c204
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/gpio/wm8994-gpio.c b/drivers/gpio/wm8994-gpio.c
new file mode 100644
index 000000000000..de28b4a470ea
--- /dev/null
+++ b/drivers/gpio/wm8994-gpio.c
@@ -0,0 +1,204 @@
1/*
2 * wm8994-gpio.c -- gpiolib support for Wolfson WM8994
3 *
4 * Copyright 2009 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/gpio.h>
18#include <linux/mfd/core.h>
19#include <linux/platform_device.h>
20#include <linux/seq_file.h>
21
22#include <linux/mfd/wm8994/core.h>
23#include <linux/mfd/wm8994/pdata.h>
24#include <linux/mfd/wm8994/gpio.h>
25#include <linux/mfd/wm8994/registers.h>
26
27struct wm8994_gpio {
28 struct wm8994 *wm8994;
29 struct gpio_chip gpio_chip;
30};
31
32static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
33{
34 return container_of(chip, struct wm8994_gpio, gpio_chip);
35}
36
37static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
38{
39 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
40 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
41
42 return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
43 WM8994_GPN_DIR, WM8994_GPN_DIR);
44}
45
46static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
47{
48 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
49 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
50 int ret;
51
52 ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
53 if (ret < 0)
54 return ret;
55
56 if (ret & WM8994_GPN_LVL)
57 return 1;
58 else
59 return 0;
60}
61
62static int wm8994_gpio_direction_out(struct gpio_chip *chip,
63 unsigned offset, int value)
64{
65 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
66 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
67
68 return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
69 WM8994_GPN_DIR, 0);
70}
71
72static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
73{
74 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
75 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
76
77 if (value)
78 value = WM8994_GPN_LVL;
79
80 wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
81}
82
83#ifdef CONFIG_DEBUG_FS
84static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
85{
86 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
87 struct wm8994 *wm8994 = wm8994_gpio->wm8994;
88 int i;
89
90 for (i = 0; i < chip->ngpio; i++) {
91 int gpio = i + chip->base;
92 int reg;
93 const char *label;
94
95 /* We report the GPIO even if it's not requested since
96 * we're also reporting things like alternate
97 * functions which apply even when the GPIO is not in
98 * use as a GPIO.
99 */
100 label = gpiochip_is_requested(chip, i);
101 if (!label)
102 label = "Unrequested";
103
104 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
105
106 reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
107 if (reg < 0) {
108 dev_err(wm8994->dev,
109 "GPIO control %d read failed: %d\n",
110 gpio, reg);
111 seq_printf(s, "\n");
112 continue;
113 }
114
115 /* No decode yet; note that GPIO2 is special */
116 seq_printf(s, "(%x)\n", reg);
117 }
118}
119#else
120#define wm8994_gpio_dbg_show NULL
121#endif
122
123static struct gpio_chip template_chip = {
124 .label = "wm8994",
125 .owner = THIS_MODULE,
126 .direction_input = wm8994_gpio_direction_in,
127 .get = wm8994_gpio_get,
128 .direction_output = wm8994_gpio_direction_out,
129 .set = wm8994_gpio_set,
130 .dbg_show = wm8994_gpio_dbg_show,
131 .can_sleep = 1,
132};
133
134static int __devinit wm8994_gpio_probe(struct platform_device *pdev)
135{
136 struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
137 struct wm8994_pdata *pdata = wm8994->dev->platform_data;
138 struct wm8994_gpio *wm8994_gpio;
139 int ret;
140
141 wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL);
142 if (wm8994_gpio == NULL)
143 return -ENOMEM;
144
145 wm8994_gpio->wm8994 = wm8994;
146 wm8994_gpio->gpio_chip = template_chip;
147 wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
148 wm8994_gpio->gpio_chip.dev = &pdev->dev;
149 if (pdata && pdata->gpio_base)
150 wm8994_gpio->gpio_chip.base = pdata->gpio_base;
151 else
152 wm8994_gpio->gpio_chip.base = -1;
153
154 ret = gpiochip_add(&wm8994_gpio->gpio_chip);
155 if (ret < 0) {
156 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
157 ret);
158 goto err;
159 }
160
161 platform_set_drvdata(pdev, wm8994_gpio);
162
163 return ret;
164
165err:
166 kfree(wm8994_gpio);
167 return ret;
168}
169
170static int __devexit wm8994_gpio_remove(struct platform_device *pdev)
171{
172 struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
173 int ret;
174
175 ret = gpiochip_remove(&wm8994_gpio->gpio_chip);
176 if (ret == 0)
177 kfree(wm8994_gpio);
178
179 return ret;
180}
181
182static struct platform_driver wm8994_gpio_driver = {
183 .driver.name = "wm8994-gpio",
184 .driver.owner = THIS_MODULE,
185 .probe = wm8994_gpio_probe,
186 .remove = __devexit_p(wm8994_gpio_remove),
187};
188
189static int __init wm8994_gpio_init(void)
190{
191 return platform_driver_register(&wm8994_gpio_driver);
192}
193subsys_initcall(wm8994_gpio_init);
194
195static void __exit wm8994_gpio_exit(void)
196{
197 platform_driver_unregister(&wm8994_gpio_driver);
198}
199module_exit(wm8994_gpio_exit);
200
201MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
202MODULE_DESCRIPTION("GPIO interface for WM8994");
203MODULE_LICENSE("GPL");
204MODULE_ALIAS("platform:wm8994-gpio");
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-15 01:23:54 -0500