1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * gpiolib support for Wolfson WM831x PMICs
4 *
5 * Copyright 2009 Wolfson Microelectronics PLC.
6 *
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 *
9 */
10
11#include <linux/cleanup.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/gpio/driver.h>
16#include <linux/mfd/core.h>
17#include <linux/platform_device.h>
18#include <linux/seq_file.h>
19
20#include <linux/mfd/wm831x/core.h>
21#include <linux/mfd/wm831x/pdata.h>
22#include <linux/mfd/wm831x/gpio.h>
23#include <linux/mfd/wm831x/irq.h>
24
25struct wm831x_gpio {
26	struct wm831x *wm831x;
27	struct gpio_chip gpio_chip;
28};
29
30static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
31{
32	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
33	struct wm831x *wm831x = wm831x_gpio->wm831x;
34	int val = WM831X_GPN_DIR;
35
36	if (wm831x->has_gpio_ena)
37		val |= WM831X_GPN_TRI;
38
39	return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
40			       WM831X_GPN_DIR | WM831X_GPN_TRI |
41			       WM831X_GPN_FN_MASK, val);
42}
43
44static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
45{
46	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
47	struct wm831x *wm831x = wm831x_gpio->wm831x;
48	int ret;
49
50	ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
51	if (ret < 0)
52		return ret;
53
54	if (ret & 1 << offset)
55		return 1;
56	else
57		return 0;
58}
59
60static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
61{
62	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
63	struct wm831x *wm831x = wm831x_gpio->wm831x;
64
65	wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
66			value << offset);
67}
68
69static int wm831x_gpio_direction_out(struct gpio_chip *chip,
70				     unsigned offset, int value)
71{
72	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
73	struct wm831x *wm831x = wm831x_gpio->wm831x;
74	int val = 0;
75	int ret;
76
77	if (wm831x->has_gpio_ena)
78		val |= WM831X_GPN_TRI;
79
80	ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
81			      WM831X_GPN_DIR | WM831X_GPN_TRI |
82			      WM831X_GPN_FN_MASK, val);
83	if (ret < 0)
84		return ret;
85
86	/* Can only set GPIO state once it's in output mode */
87	wm831x_gpio_set(chip, offset, value);
88
89	return 0;
90}
91
92static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
93{
94	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
95	struct wm831x *wm831x = wm831x_gpio->wm831x;
96
97	return irq_create_mapping(wm831x->irq_domain,
98				  WM831X_IRQ_GPIO_1 + offset);
99}
100
101static int wm831x_gpio_set_debounce(struct wm831x *wm831x, unsigned offset,
102				    unsigned debounce)
103{
104	int reg = WM831X_GPIO1_CONTROL + offset;
105	int ret, fn;
106
107	ret = wm831x_reg_read(wm831x, reg);
108	if (ret < 0)
109		return ret;
110
111	switch (ret & WM831X_GPN_FN_MASK) {
112	case 0:
113	case 1:
114		break;
115	default:
116		/* Not in GPIO mode */
117		return -EBUSY;
118	}
119
120	if (debounce >= 32 && debounce <= 64)
121		fn = 0;
122	else if (debounce >= 4000 && debounce <= 8000)
123		fn = 1;
124	else
125		return -EINVAL;
126
127	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
128}
129
130static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset,
131			     unsigned long config)
132{
133	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
134	struct wm831x *wm831x = wm831x_gpio->wm831x;
135	int reg = WM831X_GPIO1_CONTROL + offset;
136
137	switch (pinconf_to_config_param(config)) {
138	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
139		return wm831x_set_bits(wm831x, reg,
140				       WM831X_GPN_OD_MASK, WM831X_GPN_OD);
141	case PIN_CONFIG_DRIVE_PUSH_PULL:
142		return wm831x_set_bits(wm831x, reg,
143				       WM831X_GPN_OD_MASK, 0);
144	case PIN_CONFIG_INPUT_DEBOUNCE:
145		return wm831x_gpio_set_debounce(wm831x, offset,
146			pinconf_to_config_argument(config));
147	default:
148		break;
149	}
150
151	return -ENOTSUPP;
152}
153
154#ifdef CONFIG_DEBUG_FS
155static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
156{
157	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
158	struct wm831x *wm831x = wm831x_gpio->wm831x;
159	int i, tristated;
160
161	for (i = 0; i < chip->ngpio; i++) {
162		int gpio = i + chip->base;
163		int reg;
164		const char *pull, *powerdomain;
165
166		/* We report the GPIO even if it's not requested since
167		 * we're also reporting things like alternate
168		 * functions which apply even when the GPIO is not in
169		 * use as a GPIO.
170		 */
171		char *label __free(kfree) = gpiochip_dup_line_label(chip, i);
172		if (IS_ERR(label)) {
173			dev_err(wm831x->dev, "Failed to duplicate label\n");
174			continue;
175		}
176
177		seq_printf(s, " gpio-%-3d (%-20.20s) ",
178			   gpio, label ?: "Unrequested");
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_putc(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
250static 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_config		= wm831x_set_config,
259	.dbg_show		= wm831x_gpio_dbg_show,
260	.can_sleep		= true,
261};
262
263static int wm831x_gpio_probe(struct platform_device *pdev)
264{
265	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
266	struct wm831x_pdata *pdata = &wm831x->pdata;
267	struct wm831x_gpio *wm831x_gpio;
268
269	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
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	return devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip, wm831x_gpio);
286}
287
288static struct platform_driver wm831x_gpio_driver = {
289	.driver.name	= "wm831x-gpio",
290	.probe		= wm831x_gpio_probe,
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