summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-wm831x.c
blob: 324813e8304e586bf02786ef16d9dcb41e9ba52c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
/*
 * gpiolib support for Wolfson WM831x PMICs
 *
 * Copyright 2009 Wolfson Microelectronics PLC.
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>

#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/gpio.h>
#include <linux/mfd/wm831x/irq.h>

struct wm831x_gpio {
	struct wm831x *wm831x;
	struct gpio_chip gpio_chip;
};

static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;
	int val = WM831X_GPN_DIR;

	if (wm831x->has_gpio_ena)
		val |= WM831X_GPN_TRI;

	return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
			       WM831X_GPN_DIR | WM831X_GPN_TRI |
			       WM831X_GPN_FN_MASK, val);
}

static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;
	int ret;

	ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
	if (ret < 0)
		return ret;

	if (ret & 1 << offset)
		return 1;
	else
		return 0;
}

static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;

	wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
			value << offset);
}

static int wm831x_gpio_direction_out(struct gpio_chip *chip,
				     unsigned offset, int value)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;
	int val = 0;
	int ret;

	if (wm831x->has_gpio_ena)
		val |= WM831X_GPN_TRI;

	ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
			      WM831X_GPN_DIR | WM831X_GPN_TRI |
			      WM831X_GPN_FN_MASK, val);
	if (ret < 0)
		return ret;

	/* Can only set GPIO state once it's in output mode */
	wm831x_gpio_set(chip, offset, value);

	return 0;
}

static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;

	return irq_create_mapping(wm831x->irq_domain,
				  WM831X_IRQ_GPIO_1 + offset);
}

static int wm831x_gpio_set_debounce(struct wm831x *wm831x, unsigned offset,
				    unsigned debounce)
{
	int reg = WM831X_GPIO1_CONTROL + offset;
	int ret, fn;

	ret = wm831x_reg_read(wm831x, reg);
	if (ret < 0)
		return ret;

	switch (ret & WM831X_GPN_FN_MASK) {
	case 0:
	case 1:
		break;
	default:
		/* Not in GPIO mode */
		return -EBUSY;
	}

	if (debounce >= 32 && debounce <= 64)
		fn = 0;
	else if (debounce >= 4000 && debounce <= 8000)
		fn = 1;
	else
		return -EINVAL;

	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
}

static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset,
			     unsigned long config)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;
	int reg = WM831X_GPIO1_CONTROL + offset;

	switch (pinconf_to_config_param(config)) {
	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
		return wm831x_set_bits(wm831x, reg,
				       WM831X_GPN_OD_MASK, WM831X_GPN_OD);
	case PIN_CONFIG_DRIVE_PUSH_PULL:
		return wm831x_set_bits(wm831x, reg,
				       WM831X_GPN_OD_MASK, 0);
	case PIN_CONFIG_INPUT_DEBOUNCE:
		return wm831x_gpio_set_debounce(wm831x, offset,
			pinconf_to_config_argument(config));
	default:
		break;
	}

	return -ENOTSUPP;
}

#ifdef CONFIG_DEBUG_FS
static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
	struct wm831x *wm831x = wm831x_gpio->wm831x;
	int i, tristated;

	for (i = 0; i < chip->ngpio; i++) {
		int gpio = i + chip->base;
		int reg;
		const char *label, *pull, *powerdomain;

		/* We report the GPIO even if it's not requested since
		 * we're also reporting things like alternate
		 * functions which apply even when the GPIO is not in
		 * use as a GPIO.
		 */
		label = gpiochip_is_requested(chip, i);
		if (!label)
			label = "Unrequested";

		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);

		reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
		if (reg < 0) {
			dev_err(wm831x->dev,
				"GPIO control %d read failed: %d\n",
				gpio, reg);
			seq_putc(s, '\n');
			continue;
		}

		switch (reg & WM831X_GPN_PULL_MASK) {
		case WM831X_GPIO_PULL_NONE:
			pull = "nopull";
			break;
		case WM831X_GPIO_PULL_DOWN:
			pull = "pulldown";
			break;
		case WM831X_GPIO_PULL_UP:
			pull = "pullup";
			break;
		default:
			pull = "INVALID PULL";
			break;
		}

		switch (i + 1) {
		case 1 ... 3:
		case 7 ... 9:
			if (reg & WM831X_GPN_PWR_DOM)
				powerdomain = "VPMIC";
			else
				powerdomain = "DBVDD";
			break;

		case 4 ... 6:
		case 10 ... 12:
			if (reg & WM831X_GPN_PWR_DOM)
				powerdomain = "SYSVDD";
			else
				powerdomain = "DBVDD";
			break;

		case 13 ... 16:
			powerdomain = "TPVDD";
			break;

		default:
			BUG();
			break;
		}

		tristated = reg & WM831X_GPN_TRI;
		if (wm831x->has_gpio_ena)
			tristated = !tristated;

		seq_printf(s, " %s %s %s %s%s\n"
			   "                                  %s%s (0x%4x)\n",
			   reg & WM831X_GPN_DIR ? "in" : "out",
			   wm831x_gpio_get(chip, i) ? "high" : "low",
			   pull,
			   powerdomain,
			   reg & WM831X_GPN_POL ? "" : " inverted",
			   reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
			   tristated ? " tristated" : "",
			   reg);
	}
}
#else
#define wm831x_gpio_dbg_show NULL
#endif

static const struct gpio_chip template_chip = {
	.label			= "wm831x",
	.owner			= THIS_MODULE,
	.direction_input	= wm831x_gpio_direction_in,
	.get			= wm831x_gpio_get,
	.direction_output	= wm831x_gpio_direction_out,
	.set			= wm831x_gpio_set,
	.to_irq			= wm831x_gpio_to_irq,
	.set_config		= wm831x_set_config,
	.dbg_show		= wm831x_gpio_dbg_show,
	.can_sleep		= true,
};

static int wm831x_gpio_probe(struct platform_device *pdev)
{
	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
	struct wm831x_pdata *pdata = &wm831x->pdata;
	struct wm831x_gpio *wm831x_gpio;
	int ret;

	wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
				   GFP_KERNEL);
	if (wm831x_gpio == NULL)
		return -ENOMEM;

	wm831x_gpio->wm831x = wm831x;
	wm831x_gpio->gpio_chip = template_chip;
	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
	wm831x_gpio->gpio_chip.parent = &pdev->dev;
	if (pdata && pdata->gpio_base)
		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
	else
		wm831x_gpio->gpio_chip.base = -1;
#ifdef CONFIG_OF_GPIO
	wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node;
#endif

	ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
				     wm831x_gpio);
	if (ret < 0) {
		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, wm831x_gpio);

	return ret;
}

static struct platform_driver wm831x_gpio_driver = {
	.driver.name	= "wm831x-gpio",
	.probe		= wm831x_gpio_probe,
};

static int __init wm831x_gpio_init(void)
{
	return platform_driver_register(&wm831x_gpio_driver);
}
subsys_initcall(wm831x_gpio_init);

static void __exit wm831x_gpio_exit(void)
{
	platform_driver_unregister(&wm831x_gpio_driver);
}
module_exit(wm831x_gpio_exit);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-gpio");