xref: /linux/drivers/gpio/gpio-wm831x.c (revision 26b0d14106954ae46d2f4f7eec3481828a210f7d)
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 
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 
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 
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 
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 
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 
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 	return irq_create_mapping(wm831x->irq_domain,
106 				  WM831X_IRQ_GPIO_1 + offset);
107 }
108 
109 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
110 				    unsigned debounce)
111 {
112 	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
113 	struct wm831x *wm831x = wm831x_gpio->wm831x;
114 	int reg = WM831X_GPIO1_CONTROL + offset;
115 	int ret, fn;
116 
117 	ret = wm831x_reg_read(wm831x, reg);
118 	if (ret < 0)
119 		return ret;
120 
121 	switch (ret & WM831X_GPN_FN_MASK) {
122 	case 0:
123 	case 1:
124 		break;
125 	default:
126 		/* Not in GPIO mode */
127 		return -EBUSY;
128 	}
129 
130 	if (debounce >= 32 && debounce <= 64)
131 		fn = 0;
132 	else if (debounce >= 4000 && debounce <= 8000)
133 		fn = 1;
134 	else
135 		return -EINVAL;
136 
137 	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
138 }
139 
140 #ifdef CONFIG_DEBUG_FS
141 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
142 {
143 	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
144 	struct wm831x *wm831x = wm831x_gpio->wm831x;
145 	int i, tristated;
146 
147 	for (i = 0; i < chip->ngpio; i++) {
148 		int gpio = i + chip->base;
149 		int reg;
150 		const char *label, *pull, *powerdomain;
151 
152 		/* We report the GPIO even if it's not requested since
153 		 * we're also reporting things like alternate
154 		 * functions which apply even when the GPIO is not in
155 		 * use as a GPIO.
156 		 */
157 		label = gpiochip_is_requested(chip, i);
158 		if (!label)
159 			label = "Unrequested";
160 
161 		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
162 
163 		reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
164 		if (reg < 0) {
165 			dev_err(wm831x->dev,
166 				"GPIO control %d read failed: %d\n",
167 				gpio, reg);
168 			seq_printf(s, "\n");
169 			continue;
170 		}
171 
172 		switch (reg & WM831X_GPN_PULL_MASK) {
173 		case WM831X_GPIO_PULL_NONE:
174 			pull = "nopull";
175 			break;
176 		case WM831X_GPIO_PULL_DOWN:
177 			pull = "pulldown";
178 			break;
179 		case WM831X_GPIO_PULL_UP:
180 			pull = "pullup";
181 			break;
182 		default:
183 			pull = "INVALID PULL";
184 			break;
185 		}
186 
187 		switch (i + 1) {
188 		case 1 ... 3:
189 		case 7 ... 9:
190 			if (reg & WM831X_GPN_PWR_DOM)
191 				powerdomain = "VPMIC";
192 			else
193 				powerdomain = "DBVDD";
194 			break;
195 
196 		case 4 ... 6:
197 		case 10 ... 12:
198 			if (reg & WM831X_GPN_PWR_DOM)
199 				powerdomain = "SYSVDD";
200 			else
201 				powerdomain = "DBVDD";
202 			break;
203 
204 		case 13 ... 16:
205 			powerdomain = "TPVDD";
206 			break;
207 
208 		default:
209 			BUG();
210 			break;
211 		}
212 
213 		tristated = reg & WM831X_GPN_TRI;
214 		if (wm831x->has_gpio_ena)
215 			tristated = !tristated;
216 
217 		seq_printf(s, " %s %s %s %s%s\n"
218 			   "                                  %s%s (0x%4x)\n",
219 			   reg & WM831X_GPN_DIR ? "in" : "out",
220 			   wm831x_gpio_get(chip, i) ? "high" : "low",
221 			   pull,
222 			   powerdomain,
223 			   reg & WM831X_GPN_POL ? "" : " inverted",
224 			   reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
225 			   tristated ? " tristated" : "",
226 			   reg);
227 	}
228 }
229 #else
230 #define wm831x_gpio_dbg_show NULL
231 #endif
232 
233 static struct gpio_chip template_chip = {
234 	.label			= "wm831x",
235 	.owner			= THIS_MODULE,
236 	.direction_input	= wm831x_gpio_direction_in,
237 	.get			= wm831x_gpio_get,
238 	.direction_output	= wm831x_gpio_direction_out,
239 	.set			= wm831x_gpio_set,
240 	.to_irq			= wm831x_gpio_to_irq,
241 	.set_debounce		= wm831x_gpio_set_debounce,
242 	.dbg_show		= wm831x_gpio_dbg_show,
243 	.can_sleep		= 1,
244 };
245 
246 static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
247 {
248 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
249 	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
250 	struct wm831x_gpio *wm831x_gpio;
251 	int ret;
252 
253 	wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
254 	if (wm831x_gpio == NULL)
255 		return -ENOMEM;
256 
257 	wm831x_gpio->wm831x = wm831x;
258 	wm831x_gpio->gpio_chip = template_chip;
259 	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
260 	wm831x_gpio->gpio_chip.dev = &pdev->dev;
261 	if (pdata && pdata->gpio_base)
262 		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
263 	else
264 		wm831x_gpio->gpio_chip.base = -1;
265 
266 	ret = gpiochip_add(&wm831x_gpio->gpio_chip);
267 	if (ret < 0) {
268 		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
269 			ret);
270 		goto err;
271 	}
272 
273 	platform_set_drvdata(pdev, wm831x_gpio);
274 
275 	return ret;
276 
277 err:
278 	kfree(wm831x_gpio);
279 	return ret;
280 }
281 
282 static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
283 {
284 	struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
285 	int ret;
286 
287 	ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
288 	if (ret == 0)
289 		kfree(wm831x_gpio);
290 
291 	return ret;
292 }
293 
294 static struct platform_driver wm831x_gpio_driver = {
295 	.driver.name	= "wm831x-gpio",
296 	.driver.owner	= THIS_MODULE,
297 	.probe		= wm831x_gpio_probe,
298 	.remove		= __devexit_p(wm831x_gpio_remove),
299 };
300 
301 static int __init wm831x_gpio_init(void)
302 {
303 	return platform_driver_register(&wm831x_gpio_driver);
304 }
305 subsys_initcall(wm831x_gpio_init);
306 
307 static void __exit wm831x_gpio_exit(void)
308 {
309 	platform_driver_unregister(&wm831x_gpio_driver);
310 }
311 module_exit(wm831x_gpio_exit);
312 
313 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
314 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
315 MODULE_LICENSE("GPL");
316 MODULE_ALIAS("platform:wm831x-gpio");
317