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
28struct wm831x_gpio {
29	struct wm831x *wm831x;
30	struct gpio_chip gpio_chip;
31};
32
33static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
34{
35	return container_of(chip, struct wm831x_gpio, gpio_chip);
36}
37
38static 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
52static 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
68static 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
77static 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
100static 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
109static 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
141static 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
233static 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		= true,
244};
245
246static int wm831x_gpio_probe(struct platform_device *pdev)
247{
248	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
249	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
250	struct wm831x_gpio *wm831x_gpio;
251	int ret;
252
253	wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
254				   GFP_KERNEL);
255	if (wm831x_gpio == NULL)
256		return -ENOMEM;
257
258	wm831x_gpio->wm831x = wm831x;
259	wm831x_gpio->gpio_chip = template_chip;
260	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
261	wm831x_gpio->gpio_chip.dev = &pdev->dev;
262	if (pdata && pdata->gpio_base)
263		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
264	else
265		wm831x_gpio->gpio_chip.base = -1;
266
267	ret = gpiochip_add(&wm831x_gpio->gpio_chip);
268	if (ret < 0) {
269		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
270		return ret;
271	}
272
273	platform_set_drvdata(pdev, wm831x_gpio);
274
275	return ret;
276}
277
278static int wm831x_gpio_remove(struct platform_device *pdev)
279{
280	struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
281
282	gpiochip_remove(&wm831x_gpio->gpio_chip);
283	return 0;
284}
285
286static struct platform_driver wm831x_gpio_driver = {
287	.driver.name	= "wm831x-gpio",
288	.driver.owner	= THIS_MODULE,
289	.probe		= wm831x_gpio_probe,
290	.remove		= wm831x_gpio_remove,
291};
292
293static int __init wm831x_gpio_init(void)
294{
295	return platform_driver_register(&wm831x_gpio_driver);
296}
297subsys_initcall(wm831x_gpio_init);
298
299static void __exit wm831x_gpio_exit(void)
300{
301	platform_driver_unregister(&wm831x_gpio_driver);
302}
303module_exit(wm831x_gpio_exit);
304
305MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
306MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
307MODULE_LICENSE("GPL");
308MODULE_ALIAS("platform:wm831x-gpio");
309