1 /*
2 * 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/slab.h>
17 #include <linux/module.h>
18 #include <linux/gpio.h>
19 #include <linux/mfd/core.h>
20 #include <linux/platform_device.h>
21 #include <linux/seq_file.h>
22
23 #include <linux/mfd/wm831x/core.h>
24 #include <linux/mfd/wm831x/pdata.h>
25 #include <linux/mfd/wm831x/gpio.h>
26 #include <linux/mfd/wm831x/irq.h>
27
28 struct wm831x_gpio {
29 struct wm831x *wm831x;
30 struct gpio_chip gpio_chip;
31 };
32
to_wm831x_gpio(struct gpio_chip * chip)33 static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
34 {
35 return container_of(chip, struct wm831x_gpio, gpio_chip);
36 }
37
wm831x_gpio_direction_in(struct gpio_chip * chip,unsigned offset)38 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
39 {
40 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
41 struct wm831x *wm831x = wm831x_gpio->wm831x;
42 int val = WM831X_GPN_DIR;
43
44 if (wm831x->has_gpio_ena)
45 val |= WM831X_GPN_TRI;
46
47 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
48 WM831X_GPN_DIR | WM831X_GPN_TRI |
49 WM831X_GPN_FN_MASK, val);
50 }
51
wm831x_gpio_get(struct gpio_chip * chip,unsigned offset)52 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
53 {
54 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
55 struct wm831x *wm831x = wm831x_gpio->wm831x;
56 int ret;
57
58 ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
59 if (ret < 0)
60 return ret;
61
62 if (ret & 1 << offset)
63 return 1;
64 else
65 return 0;
66 }
67
wm831x_gpio_set(struct gpio_chip * chip,unsigned offset,int value)68 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
69 {
70 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
71 struct wm831x *wm831x = wm831x_gpio->wm831x;
72
73 wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
74 value << offset);
75 }
76
wm831x_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)77 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
78 unsigned offset, int value)
79 {
80 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
81 struct wm831x *wm831x = wm831x_gpio->wm831x;
82 int val = 0;
83 int ret;
84
85 if (wm831x->has_gpio_ena)
86 val |= WM831X_GPN_TRI;
87
88 ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
89 WM831X_GPN_DIR | WM831X_GPN_TRI |
90 WM831X_GPN_FN_MASK, val);
91 if (ret < 0)
92 return ret;
93
94 /* Can only set GPIO state once it's in output mode */
95 wm831x_gpio_set(chip, offset, value);
96
97 return 0;
98 }
99
wm831x_gpio_to_irq(struct gpio_chip * chip,unsigned offset)100 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
101 {
102 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
103 struct wm831x *wm831x = wm831x_gpio->wm831x;
104
105 if (!wm831x->irq_base)
106 return -EINVAL;
107
108 return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
109 }
110
wm831x_gpio_set_debounce(struct gpio_chip * chip,unsigned offset,unsigned debounce)111 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
112 unsigned debounce)
113 {
114 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
115 struct wm831x *wm831x = wm831x_gpio->wm831x;
116 int reg = WM831X_GPIO1_CONTROL + offset;
117 int ret, fn;
118
119 ret = wm831x_reg_read(wm831x, reg);
120 if (ret < 0)
121 return ret;
122
123 switch (ret & WM831X_GPN_FN_MASK) {
124 case 0:
125 case 1:
126 break;
127 default:
128 /* Not in GPIO mode */
129 return -EBUSY;
130 }
131
132 if (debounce >= 32 && debounce <= 64)
133 fn = 0;
134 else if (debounce >= 4000 && debounce <= 8000)
135 fn = 1;
136 else
137 return -EINVAL;
138
139 return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
140 }
141
142 #ifdef CONFIG_DEBUG_FS
wm831x_gpio_dbg_show(struct seq_file * s,struct gpio_chip * chip)143 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
144 {
145 struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
146 struct wm831x *wm831x = wm831x_gpio->wm831x;
147 int i, tristated;
148
149 for (i = 0; i < chip->ngpio; i++) {
150 int gpio = i + chip->base;
151 int reg;
152 const char *label, *pull, *powerdomain;
153
154 /* We report the GPIO even if it's not requested since
155 * we're also reporting things like alternate
156 * functions which apply even when the GPIO is not in
157 * use as a GPIO.
158 */
159 label = gpiochip_is_requested(chip, i);
160 if (!label)
161 label = "Unrequested";
162
163 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
164
165 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
166 if (reg < 0) {
167 dev_err(wm831x->dev,
168 "GPIO control %d read failed: %d\n",
169 gpio, reg);
170 seq_printf(s, "\n");
171 continue;
172 }
173
174 switch (reg & WM831X_GPN_PULL_MASK) {
175 case WM831X_GPIO_PULL_NONE:
176 pull = "nopull";
177 break;
178 case WM831X_GPIO_PULL_DOWN:
179 pull = "pulldown";
180 break;
181 case WM831X_GPIO_PULL_UP:
182 pull = "pullup";
183 break;
184 default:
185 pull = "INVALID PULL";
186 break;
187 }
188
189 switch (i + 1) {
190 case 1 ... 3:
191 case 7 ... 9:
192 if (reg & WM831X_GPN_PWR_DOM)
193 powerdomain = "VPMIC";
194 else
195 powerdomain = "DBVDD";
196 break;
197
198 case 4 ... 6:
199 case 10 ... 12:
200 if (reg & WM831X_GPN_PWR_DOM)
201 powerdomain = "SYSVDD";
202 else
203 powerdomain = "DBVDD";
204 break;
205
206 case 13 ... 16:
207 powerdomain = "TPVDD";
208 break;
209
210 default:
211 BUG();
212 break;
213 }
214
215 tristated = reg & WM831X_GPN_TRI;
216 if (wm831x->has_gpio_ena)
217 tristated = !tristated;
218
219 seq_printf(s, " %s %s %s %s%s\n"
220 " %s%s (0x%4x)\n",
221 reg & WM831X_GPN_DIR ? "in" : "out",
222 wm831x_gpio_get(chip, i) ? "high" : "low",
223 pull,
224 powerdomain,
225 reg & WM831X_GPN_POL ? "" : " inverted",
226 reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
227 tristated ? " tristated" : "",
228 reg);
229 }
230 }
231 #else
232 #define wm831x_gpio_dbg_show NULL
233 #endif
234
235 static struct gpio_chip template_chip = {
236 .label = "wm831x",
237 .owner = THIS_MODULE,
238 .direction_input = wm831x_gpio_direction_in,
239 .get = wm831x_gpio_get,
240 .direction_output = wm831x_gpio_direction_out,
241 .set = wm831x_gpio_set,
242 .to_irq = wm831x_gpio_to_irq,
243 .set_debounce = wm831x_gpio_set_debounce,
244 .dbg_show = wm831x_gpio_dbg_show,
245 .can_sleep = 1,
246 };
247
wm831x_gpio_probe(struct platform_device * pdev)248 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
249 {
250 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
251 struct wm831x_pdata *pdata = wm831x->dev->platform_data;
252 struct wm831x_gpio *wm831x_gpio;
253 int ret;
254
255 wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
256 if (wm831x_gpio == NULL)
257 return -ENOMEM;
258
259 wm831x_gpio->wm831x = wm831x;
260 wm831x_gpio->gpio_chip = template_chip;
261 wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
262 wm831x_gpio->gpio_chip.dev = &pdev->dev;
263 if (pdata && pdata->gpio_base)
264 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
265 else
266 wm831x_gpio->gpio_chip.base = -1;
267
268 ret = gpiochip_add(&wm831x_gpio->gpio_chip);
269 if (ret < 0) {
270 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
271 ret);
272 goto err;
273 }
274
275 platform_set_drvdata(pdev, wm831x_gpio);
276
277 return ret;
278
279 err:
280 kfree(wm831x_gpio);
281 return ret;
282 }
283
wm831x_gpio_remove(struct platform_device * pdev)284 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
285 {
286 struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
287 int ret;
288
289 ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
290 if (ret == 0)
291 kfree(wm831x_gpio);
292
293 return ret;
294 }
295
296 static struct platform_driver wm831x_gpio_driver = {
297 .driver.name = "wm831x-gpio",
298 .driver.owner = THIS_MODULE,
299 .probe = wm831x_gpio_probe,
300 .remove = __devexit_p(wm831x_gpio_remove),
301 };
302
wm831x_gpio_init(void)303 static int __init wm831x_gpio_init(void)
304 {
305 return platform_driver_register(&wm831x_gpio_driver);
306 }
307 subsys_initcall(wm831x_gpio_init);
308
wm831x_gpio_exit(void)309 static void __exit wm831x_gpio_exit(void)
310 {
311 platform_driver_unregister(&wm831x_gpio_driver);
312 }
313 module_exit(wm831x_gpio_exit);
314
315 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
316 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
317 MODULE_LICENSE("GPL");
318 MODULE_ALIAS("platform:wm831x-gpio");
319