tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * wm831x-gpio.c -- gpiolib support for Wolfson WM831x PMICs
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/wm831x/core.h>
23#include <linux/mfd/wm831x/pdata.h>
24#include <linux/mfd/wm831x/gpio.h>
25#include <linux/mfd/wm831x/irq.h>
26
27struct wm831x_gpio {
28 struct wm831x *wm831x;
29 struct gpio_chip gpio_chip;
30};
31
32static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
33{
34 return container_of(chip, struct wm831x_gpio, gpio_chip);
35}
36
37static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
38{
39 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
40 struct wm831x *wm831x = wm831x_gpio->wm831x;
41 int val = WM831X_GPN_DIR;
42
43 if (wm831x->has_gpio_ena)
44 val |= WM831X_GPN_TRI;
45
46 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
47 WM831X_GPN_DIR | WM831X_GPN_TRI |
48 WM831X_GPN_FN_MASK, val);
49}
50
51static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
52{
53 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
54 struct wm831x *wm831x = wm831x_gpio->wm831x;
55 int ret;
56
57 ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
58 if (ret < 0)
59 return ret;
60
61 if (ret & 1 << offset)
62 return 1;
63 else
64 return 0;
65}
66
67static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
68{
69 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
70 struct wm831x *wm831x = wm831x_gpio->wm831x;
71
72 wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
73 value << offset);
74}
75
76static int wm831x_gpio_direction_out(struct gpio_chip *chip,
77 unsigned offset, int value)
78{
79 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
80 struct wm831x *wm831x = wm831x_gpio->wm831x;
81 int val = 0;
82 int ret;
83
84 if (wm831x->has_gpio_ena)
85 val |= WM831X_GPN_TRI;
86
87 ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
88 WM831X_GPN_DIR | WM831X_GPN_TRI |
89 WM831X_GPN_FN_MASK, val);
90 if (ret < 0)
91 return ret;
92
93 /* Can only set GPIO state once it's in output mode */
94 wm831x_gpio_set(chip, offset, value);
95
96 return 0;
97}
98
99static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
100{
101 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
102 struct wm831x *wm831x = wm831x_gpio->wm831x;
103
104 if (!wm831x->irq_base)
105 return -EINVAL;
106
107 return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
108}
109
110#ifdef CONFIG_DEBUG_FS
111static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
112{
113 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
114 struct wm831x *wm831x = wm831x_gpio->wm831x;
115 int i, tristated;
116
117 for (i = 0; i < chip->ngpio; i++) {
118 int gpio = i + chip->base;
119 int reg;
120 const char *label, *pull, *powerdomain;
121
122 /* We report the GPIO even if it's not requested since
123 * we're also reporting things like alternate
124 * functions which apply even when the GPIO is not in
125 * use as a GPIO.
126 */
127 label = gpiochip_is_requested(chip, i);
128 if (!label)
129 label = "Unrequested";
130
131 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
132
133 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
134 if (reg < 0) {
135 dev_err(wm831x->dev,
136 "GPIO control %d read failed: %d\n",
137 gpio, reg);
138 seq_printf(s, "\n");
139 continue;
140 }
141
142 switch (reg & WM831X_GPN_PULL_MASK) {
143 case WM831X_GPIO_PULL_NONE:
144 pull = "nopull";
145 break;
146 case WM831X_GPIO_PULL_DOWN:
147 pull = "pulldown";
148 break;
149 case WM831X_GPIO_PULL_UP:
150 pull = "pullup";
151 default:
152 pull = "INVALID PULL";
153 break;
154 }
155
156 switch (i + 1) {
157 case 1 ... 3:
158 case 7 ... 9:
159 if (reg & WM831X_GPN_PWR_DOM)
160 powerdomain = "VPMIC";
161 else
162 powerdomain = "DBVDD";
163 break;
164
165 case 4 ... 6:
166 case 10 ... 12:
167 if (reg & WM831X_GPN_PWR_DOM)
168 powerdomain = "SYSVDD";
169 else
170 powerdomain = "DBVDD";
171 break;
172
173 case 13 ... 16:
174 powerdomain = "TPVDD";
175 break;
176
177 default:
178 BUG();
179 break;
180 }
181
182 tristated = reg & WM831X_GPN_TRI;
183 if (wm831x->has_gpio_ena)
184 tristated = !tristated;
185
186 seq_printf(s, " %s %s %s %s%s\n"
187 " %s%s (0x%4x)\n",
188 reg & WM831X_GPN_DIR ? "in" : "out",
189 wm831x_gpio_get(chip, i) ? "high" : "low",
190 pull,
191 powerdomain,
192 reg & WM831X_GPN_POL ? "" : " inverted",
193 reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
194 tristated ? " tristated" : "",
195 reg);
196 }
197}
198#else
199#define wm831x_gpio_dbg_show NULL
200#endif
201
202static struct gpio_chip template_chip = {
203 .label = "wm831x",
204 .owner = THIS_MODULE,
205 .direction_input = wm831x_gpio_direction_in,
206 .get = wm831x_gpio_get,
207 .direction_output = wm831x_gpio_direction_out,
208 .set = wm831x_gpio_set,
209 .to_irq = wm831x_gpio_to_irq,
210 .dbg_show = wm831x_gpio_dbg_show,
211 .can_sleep = 1,
212};
213
214static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
215{
216 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
217 struct wm831x_pdata *pdata = wm831x->dev->platform_data;
218 struct wm831x_gpio *wm831x_gpio;
219 int ret;
220
221 wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
222 if (wm831x_gpio == NULL)
223 return -ENOMEM;
224
225 wm831x_gpio->wm831x = wm831x;
226 wm831x_gpio->gpio_chip = template_chip;
227 wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
228 wm831x_gpio->gpio_chip.dev = &pdev->dev;
229 if (pdata && pdata->gpio_base)
230 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
231 else
232 wm831x_gpio->gpio_chip.base = -1;
233
234 ret = gpiochip_add(&wm831x_gpio->gpio_chip);
235 if (ret < 0) {
236 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
237 ret);
238 goto err;
239 }
240
241 platform_set_drvdata(pdev, wm831x_gpio);
242
243 return ret;
244
245err:
246 kfree(wm831x_gpio);
247 return ret;
248}
249
250static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
251{
252 struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
253 int ret;
254
255 ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
256 if (ret == 0)
257 kfree(wm831x_gpio);
258
259 return ret;
260}
261
262static struct platform_driver wm831x_gpio_driver = {
263 .driver.name = "wm831x-gpio",
264 .driver.owner = THIS_MODULE,
265 .probe = wm831x_gpio_probe,
266 .remove = __devexit_p(wm831x_gpio_remove),
267};
268
269static int __init wm831x_gpio_init(void)
270{
271 return platform_driver_register(&wm831x_gpio_driver);
272}
273subsys_initcall(wm831x_gpio_init);
274
275static void __exit wm831x_gpio_exit(void)
276{
277 platform_driver_unregister(&wm831x_gpio_driver);
278}
279module_exit(wm831x_gpio_exit);
280
281MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
282MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
283MODULE_LICENSE("GPL");
284MODULE_ALIAS("platform:wm831x-gpio");