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	if (!wm831x->irq_base)
106		return -EINVAL;
107
108	return wm831x->irq_base + WM831X_IRQ_GPIO_1 + offset;
109}
110
111static int wm831x_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
112				    unsigned debounce)
113{
114	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
115	struct wm831x *wm831x = wm831x_gpio->wm831x;
116	int reg = WM831X_GPIO1_CONTROL + offset;
117	int ret, fn;
118
119	ret = wm831x_reg_read(wm831x, reg);
120	if (ret < 0)
121		return ret;
122
123	switch (ret & WM831X_GPN_FN_MASK) {
124	case 0:
125	case 1:
126		break;
127	default:
128		/* Not in GPIO mode */
129		return -EBUSY;
130	}
131
132	if (debounce >= 32 && debounce <= 64)
133		fn = 0;
134	else if (debounce >= 4000 && debounce <= 8000)
135		fn = 1;
136	else
137		return -EINVAL;
138
139	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
140}
141
142#ifdef CONFIG_DEBUG_FS
143static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
144{
145	struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
146	struct wm831x *wm831x = wm831x_gpio->wm831x;
147	int i, tristated;
148
149	for (i = 0; i < chip->ngpio; i++) {
150		int gpio = i + chip->base;
151		int reg;
152		const char *label, *pull, *powerdomain;
153
154		/* We report the GPIO even if it's not requested since
155		 * we're also reporting things like alternate
156		 * functions which apply even when the GPIO is not in
157		 * use as a GPIO.
158		 */
159		label = gpiochip_is_requested(chip, i);
160		if (!label)
161			label = "Unrequested";
162
163		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
164
165		reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
166		if (reg < 0) {
167			dev_err(wm831x->dev,
168				"GPIO control %d read failed: %d\n",
169				gpio, reg);
170			seq_printf(s, "\n");
171			continue;
172		}
173
174		switch (reg & WM831X_GPN_PULL_MASK) {
175		case WM831X_GPIO_PULL_NONE:
176			pull = "nopull";
177			break;
178		case WM831X_GPIO_PULL_DOWN:
179			pull = "pulldown";
180			break;
181		case WM831X_GPIO_PULL_UP:
182			pull = "pullup";
183			break;
184		default:
185			pull = "INVALID PULL";
186			break;
187		}
188
189		switch (i + 1) {
190		case 1 ... 3:
191		case 7 ... 9:
192			if (reg & WM831X_GPN_PWR_DOM)
193				powerdomain = "VPMIC";
194			else
195				powerdomain = "DBVDD";
196			break;
197
198		case 4 ... 6:
199		case 10 ... 12:
200			if (reg & WM831X_GPN_PWR_DOM)
201				powerdomain = "SYSVDD";
202			else
203				powerdomain = "DBVDD";
204			break;
205
206		case 13 ... 16:
207			powerdomain = "TPVDD";
208			break;
209
210		default:
211			BUG();
212			break;
213		}
214
215		tristated = reg & WM831X_GPN_TRI;
216		if (wm831x->has_gpio_ena)
217			tristated = !tristated;
218
219		seq_printf(s, " %s %s %s %s%s\n"
220			   "                                  %s%s (0x%4x)\n",
221			   reg & WM831X_GPN_DIR ? "in" : "out",
222			   wm831x_gpio_get(chip, i) ? "high" : "low",
223			   pull,
224			   powerdomain,
225			   reg & WM831X_GPN_POL ? "" : " inverted",
226			   reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
227			   tristated ? " tristated" : "",
228			   reg);
229	}
230}
231#else
232#define wm831x_gpio_dbg_show NULL
233#endif
234
235static struct gpio_chip template_chip = {
236	.label			= "wm831x",
237	.owner			= THIS_MODULE,
238	.direction_input	= wm831x_gpio_direction_in,
239	.get			= wm831x_gpio_get,
240	.direction_output	= wm831x_gpio_direction_out,
241	.set			= wm831x_gpio_set,
242	.to_irq			= wm831x_gpio_to_irq,
243	.set_debounce		= wm831x_gpio_set_debounce,
244	.dbg_show		= wm831x_gpio_dbg_show,
245	.can_sleep		= 1,
246};
247
248static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
249{
250	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
251	struct wm831x_pdata *pdata = wm831x->dev->platform_data;
252	struct wm831x_gpio *wm831x_gpio;
253	int ret;
254
255	wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
256	if (wm831x_gpio == NULL)
257		return -ENOMEM;
258
259	wm831x_gpio->wm831x = wm831x;
260	wm831x_gpio->gpio_chip = template_chip;
261	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
262	wm831x_gpio->gpio_chip.dev = &pdev->dev;
263	if (pdata && pdata->gpio_base)
264		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
265	else
266		wm831x_gpio->gpio_chip.base = -1;
267
268	ret = gpiochip_add(&wm831x_gpio->gpio_chip);
269	if (ret < 0) {
270		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
271			ret);
272		goto err;
273	}
274
275	platform_set_drvdata(pdev, wm831x_gpio);
276
277	return ret;
278
279err:
280	kfree(wm831x_gpio);
281	return ret;
282}
283
284static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
285{
286	struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
287	int ret;
288
289	ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
290	if (ret == 0)
291		kfree(wm831x_gpio);
292
293	return ret;
294}
295
296static struct platform_driver wm831x_gpio_driver = {
297	.driver.name	= "wm831x-gpio",
298	.driver.owner	= THIS_MODULE,
299	.probe		= wm831x_gpio_probe,
300	.remove		= __devexit_p(wm831x_gpio_remove),
301};
302
303static int __init wm831x_gpio_init(void)
304{
305	return platform_driver_register(&wm831x_gpio_driver);
306}
307subsys_initcall(wm831x_gpio_init);
308
309static void __exit wm831x_gpio_exit(void)
310{
311	platform_driver_unregister(&wm831x_gpio_driver);
312}
313module_exit(wm831x_gpio_exit);
314
315MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
316MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
317MODULE_LICENSE("GPL");
318MODULE_ALIAS("platform:wm831x-gpio");
319