xref: /openbmc/linux/drivers/gpio/gpio-wm831x.c (revision 82003e04)
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 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 
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 
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 
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 
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 
104 static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
105 				    unsigned debounce)
106 {
107 	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
108 	struct wm831x *wm831x = wm831x_gpio->wm831x;
109 	int reg = WM831X_GPIO1_CONTROL + offset;
110 	int ret, fn;
111 
112 	ret = wm831x_reg_read(wm831x, reg);
113 	if (ret < 0)
114 		return ret;
115 
116 	switch (ret & WM831X_GPN_FN_MASK) {
117 	case 0:
118 	case 1:
119 		break;
120 	default:
121 		/* Not in GPIO mode */
122 		return -EBUSY;
123 	}
124 
125 	if (debounce >= 32 && debounce <= 64)
126 		fn = 0;
127 	else if (debounce >= 4000 && debounce <= 8000)
128 		fn = 1;
129 	else
130 		return -EINVAL;
131 
132 	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
133 }
134 
135 static int wm831x_set_single_ended(struct gpio_chip *chip,
136 				   unsigned int offset,
137 				   enum single_ended_mode mode)
138 {
139 	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
140 	struct wm831x *wm831x = wm831x_gpio->wm831x;
141 	int reg = WM831X_GPIO1_CONTROL + offset;
142 
143 	switch (mode) {
144 	case LINE_MODE_OPEN_DRAIN:
145 		return wm831x_set_bits(wm831x, reg,
146 				       WM831X_GPN_OD_MASK, WM831X_GPN_OD);
147 	case LINE_MODE_PUSH_PULL:
148 		return wm831x_set_bits(wm831x, reg,
149 				       WM831X_GPN_OD_MASK, 0);
150 	default:
151 		break;
152 	}
153 
154 	return -ENOTSUPP;
155 }
156 
157 #ifdef CONFIG_DEBUG_FS
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_printf(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_debounce		= wm831x_gpio_set_debounce,
259 	.set_single_ended	= wm831x_set_single_ended,
260 	.dbg_show		= wm831x_gpio_dbg_show,
261 	.can_sleep		= true,
262 };
263 
264 static int wm831x_gpio_probe(struct platform_device *pdev)
265 {
266 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
267 	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
268 	struct wm831x_gpio *wm831x_gpio;
269 	int ret;
270 
271 	wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
272 				   GFP_KERNEL);
273 	if (wm831x_gpio == NULL)
274 		return -ENOMEM;
275 
276 	wm831x_gpio->wm831x = wm831x;
277 	wm831x_gpio->gpio_chip = template_chip;
278 	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
279 	wm831x_gpio->gpio_chip.parent = &pdev->dev;
280 	if (pdata && pdata->gpio_base)
281 		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
282 	else
283 		wm831x_gpio->gpio_chip.base = -1;
284 
285 	ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
286 				     wm831x_gpio);
287 	if (ret < 0) {
288 		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
289 		return ret;
290 	}
291 
292 	platform_set_drvdata(pdev, wm831x_gpio);
293 
294 	return ret;
295 }
296 
297 static struct platform_driver wm831x_gpio_driver = {
298 	.driver.name	= "wm831x-gpio",
299 	.probe		= wm831x_gpio_probe,
300 };
301 
302 static int __init wm831x_gpio_init(void)
303 {
304 	return platform_driver_register(&wm831x_gpio_driver);
305 }
306 subsys_initcall(wm831x_gpio_init);
307 
308 static void __exit wm831x_gpio_exit(void)
309 {
310 	platform_driver_unregister(&wm831x_gpio_driver);
311 }
312 module_exit(wm831x_gpio_exit);
313 
314 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
315 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
316 MODULE_LICENSE("GPL");
317 MODULE_ALIAS("platform:wm831x-gpio");
318