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
wm831x_gpio_direction_in(struct gpio_chip * chip,unsigned offset)33 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
34 {
35 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
36 struct wm831x *wm831x = wm831x_gpio->wm831x;
37 int val = WM831X_GPN_DIR;
38
39 if (wm831x->has_gpio_ena)
40 val |= WM831X_GPN_TRI;
41
42 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
43 WM831X_GPN_DIR | WM831X_GPN_TRI |
44 WM831X_GPN_FN_MASK, val);
45 }
46
wm831x_gpio_get(struct gpio_chip * chip,unsigned offset)47 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
48 {
49 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
50 struct wm831x *wm831x = wm831x_gpio->wm831x;
51 int ret;
52
53 ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
54 if (ret < 0)
55 return ret;
56
57 if (ret & 1 << offset)
58 return 1;
59 else
60 return 0;
61 }
62
wm831x_gpio_set(struct gpio_chip * chip,unsigned offset,int value)63 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
64 {
65 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
66 struct wm831x *wm831x = wm831x_gpio->wm831x;
67
68 wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
69 value << offset);
70 }
71
wm831x_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)72 static int wm831x_gpio_direction_out(struct gpio_chip *chip,
73 unsigned offset, int value)
74 {
75 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
76 struct wm831x *wm831x = wm831x_gpio->wm831x;
77 int val = 0;
78 int ret;
79
80 if (wm831x->has_gpio_ena)
81 val |= WM831X_GPN_TRI;
82
83 ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
84 WM831X_GPN_DIR | WM831X_GPN_TRI |
85 WM831X_GPN_FN_MASK, val);
86 if (ret < 0)
87 return ret;
88
89 /* Can only set GPIO state once it's in output mode */
90 wm831x_gpio_set(chip, offset, value);
91
92 return 0;
93 }
94
wm831x_gpio_to_irq(struct gpio_chip * chip,unsigned offset)95 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
96 {
97 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
98 struct wm831x *wm831x = wm831x_gpio->wm831x;
99
100 return irq_create_mapping(wm831x->irq_domain,
101 WM831X_IRQ_GPIO_1 + offset);
102 }
103
wm831x_gpio_set_debounce(struct wm831x * wm831x,unsigned offset,unsigned debounce)104 static int wm831x_gpio_set_debounce(struct wm831x *wm831x, unsigned offset,
105 unsigned debounce)
106 {
107 int reg = WM831X_GPIO1_CONTROL + offset;
108 int ret, fn;
109
110 ret = wm831x_reg_read(wm831x, reg);
111 if (ret < 0)
112 return ret;
113
114 switch (ret & WM831X_GPN_FN_MASK) {
115 case 0:
116 case 1:
117 break;
118 default:
119 /* Not in GPIO mode */
120 return -EBUSY;
121 }
122
123 if (debounce >= 32 && debounce <= 64)
124 fn = 0;
125 else if (debounce >= 4000 && debounce <= 8000)
126 fn = 1;
127 else
128 return -EINVAL;
129
130 return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
131 }
132
wm831x_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)133 static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset,
134 unsigned long config)
135 {
136 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
137 struct wm831x *wm831x = wm831x_gpio->wm831x;
138 int reg = WM831X_GPIO1_CONTROL + offset;
139
140 switch (pinconf_to_config_param(config)) {
141 case PIN_CONFIG_DRIVE_OPEN_DRAIN:
142 return wm831x_set_bits(wm831x, reg,
143 WM831X_GPN_OD_MASK, WM831X_GPN_OD);
144 case PIN_CONFIG_DRIVE_PUSH_PULL:
145 return wm831x_set_bits(wm831x, reg,
146 WM831X_GPN_OD_MASK, 0);
147 case PIN_CONFIG_INPUT_DEBOUNCE:
148 return wm831x_gpio_set_debounce(wm831x, offset,
149 pinconf_to_config_argument(config));
150 default:
151 break;
152 }
153
154 return -ENOTSUPP;
155 }
156
157 #ifdef CONFIG_DEBUG_FS
wm831x_gpio_dbg_show(struct seq_file * s,struct gpio_chip * chip)158 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
159 {
160 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
161 struct wm831x *wm831x = wm831x_gpio->wm831x;
162 int i, tristated;
163
164 for (i = 0; i < chip->ngpio; i++) {
165 int gpio = i + chip->base;
166 int reg;
167 const char *label, *pull, *powerdomain;
168
169 /* We report the GPIO even if it's not requested since
170 * we're also reporting things like alternate
171 * functions which apply even when the GPIO is not in
172 * use as a GPIO.
173 */
174 label = gpiochip_is_requested(chip, i);
175 if (!label)
176 label = "Unrequested";
177
178 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
179
180 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
181 if (reg < 0) {
182 dev_err(wm831x->dev,
183 "GPIO control %d read failed: %d\n",
184 gpio, reg);
185 seq_putc(s, '\n');
186 continue;
187 }
188
189 switch (reg & WM831X_GPN_PULL_MASK) {
190 case WM831X_GPIO_PULL_NONE:
191 pull = "nopull";
192 break;
193 case WM831X_GPIO_PULL_DOWN:
194 pull = "pulldown";
195 break;
196 case WM831X_GPIO_PULL_UP:
197 pull = "pullup";
198 break;
199 default:
200 pull = "INVALID PULL";
201 break;
202 }
203
204 switch (i + 1) {
205 case 1 ... 3:
206 case 7 ... 9:
207 if (reg & WM831X_GPN_PWR_DOM)
208 powerdomain = "VPMIC";
209 else
210 powerdomain = "DBVDD";
211 break;
212
213 case 4 ... 6:
214 case 10 ... 12:
215 if (reg & WM831X_GPN_PWR_DOM)
216 powerdomain = "SYSVDD";
217 else
218 powerdomain = "DBVDD";
219 break;
220
221 case 13 ... 16:
222 powerdomain = "TPVDD";
223 break;
224
225 default:
226 BUG();
227 break;
228 }
229
230 tristated = reg & WM831X_GPN_TRI;
231 if (wm831x->has_gpio_ena)
232 tristated = !tristated;
233
234 seq_printf(s, " %s %s %s %s%s\n"
235 " %s%s (0x%4x)\n",
236 reg & WM831X_GPN_DIR ? "in" : "out",
237 wm831x_gpio_get(chip, i) ? "high" : "low",
238 pull,
239 powerdomain,
240 reg & WM831X_GPN_POL ? "" : " inverted",
241 reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
242 tristated ? " tristated" : "",
243 reg);
244 }
245 }
246 #else
247 #define wm831x_gpio_dbg_show NULL
248 #endif
249
250 static const struct gpio_chip template_chip = {
251 .label = "wm831x",
252 .owner = THIS_MODULE,
253 .direction_input = wm831x_gpio_direction_in,
254 .get = wm831x_gpio_get,
255 .direction_output = wm831x_gpio_direction_out,
256 .set = wm831x_gpio_set,
257 .to_irq = wm831x_gpio_to_irq,
258 .set_config = wm831x_set_config,
259 .dbg_show = wm831x_gpio_dbg_show,
260 .can_sleep = true,
261 };
262
wm831x_gpio_probe(struct platform_device * pdev)263 static int wm831x_gpio_probe(struct platform_device *pdev)
264 {
265 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
266 struct wm831x_pdata *pdata = &wm831x->pdata;
267 struct wm831x_gpio *wm831x_gpio;
268 int ret;
269
270 wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
271 GFP_KERNEL);
272 if (wm831x_gpio == NULL)
273 return -ENOMEM;
274
275 wm831x_gpio->wm831x = wm831x;
276 wm831x_gpio->gpio_chip = template_chip;
277 wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
278 wm831x_gpio->gpio_chip.parent = &pdev->dev;
279 if (pdata && pdata->gpio_base)
280 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
281 else
282 wm831x_gpio->gpio_chip.base = -1;
283 #ifdef CONFIG_OF_GPIO
284 wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node;
285 #endif
286
287 ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
288 wm831x_gpio);
289 if (ret < 0) {
290 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
291 return ret;
292 }
293
294 platform_set_drvdata(pdev, wm831x_gpio);
295
296 return ret;
297 }
298
299 static struct platform_driver wm831x_gpio_driver = {
300 .driver.name = "wm831x-gpio",
301 .probe = wm831x_gpio_probe,
302 };
303
wm831x_gpio_init(void)304 static int __init wm831x_gpio_init(void)
305 {
306 return platform_driver_register(&wm831x_gpio_driver);
307 }
308 subsys_initcall(wm831x_gpio_init);
309
wm831x_gpio_exit(void)310 static void __exit wm831x_gpio_exit(void)
311 {
312 platform_driver_unregister(&wm831x_gpio_driver);
313 }
314 module_exit(wm831x_gpio_exit);
315
316 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
317 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
318 MODULE_LICENSE("GPL");
319 MODULE_ALIAS("platform:wm831x-gpio");
320
