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/kernel.h>
12#include <linux/slab.h>
13#include <linux/module.h>
14#include <linux/gpio/driver.h>
15#include <linux/mfd/core.h>
16#include <linux/platform_device.h>
17#include <linux/seq_file.h>
18
19#include <linux/mfd/wm831x/core.h>
20#include <linux/mfd/wm831x/pdata.h>
21#include <linux/mfd/wm831x/gpio.h>
22#include <linux/mfd/wm831x/irq.h>
23
24struct wm831x_gpio {
25	struct wm831x *wm831x;
26	struct gpio_chip gpio_chip;
27};
28
29static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
30{
31	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
32	struct wm831x *wm831x = wm831x_gpio->wm831x;
33	int val = WM831X_GPN_DIR;
34
35	if (wm831x->has_gpio_ena)
36		val |= WM831X_GPN_TRI;
37
38	return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
39			       WM831X_GPN_DIR | WM831X_GPN_TRI |
40			       WM831X_GPN_FN_MASK, val);
41}
42
43static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
44{
45	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
46	struct wm831x *wm831x = wm831x_gpio->wm831x;
47	int ret;
48
49	ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
50	if (ret < 0)
51		return ret;
52
53	if (ret & 1 << offset)
54		return 1;
55	else
56		return 0;
57}
58
59static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
60{
61	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
62	struct wm831x *wm831x = wm831x_gpio->wm831x;
63
64	wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
65			value << offset);
66}
67
68static int wm831x_gpio_direction_out(struct gpio_chip *chip,
69				     unsigned offset, int value)
70{
71	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
72	struct wm831x *wm831x = wm831x_gpio->wm831x;
73	int val = 0;
74	int ret;
75
76	if (wm831x->has_gpio_ena)
77		val |= WM831X_GPN_TRI;
78
79	ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
80			      WM831X_GPN_DIR | WM831X_GPN_TRI |
81			      WM831X_GPN_FN_MASK, val);
82	if (ret < 0)
83		return ret;
84
85	/* Can only set GPIO state once it's in output mode */
86	wm831x_gpio_set(chip, offset, value);
87
88	return 0;
89}
90
91static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
92{
93	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
94	struct wm831x *wm831x = wm831x_gpio->wm831x;
95
96	return irq_create_mapping(wm831x->irq_domain,
97				  WM831X_IRQ_GPIO_1 + offset);
98}
99
100static int wm831x_gpio_set_debounce(struct wm831x *wm831x, unsigned offset,
101				    unsigned debounce)
102{
103	int reg = WM831X_GPIO1_CONTROL + offset;
104	int ret, fn;
105
106	ret = wm831x_reg_read(wm831x, reg);
107	if (ret < 0)
108		return ret;
109
110	switch (ret & WM831X_GPN_FN_MASK) {
111	case 0:
112	case 1:
113		break;
114	default:
115		/* Not in GPIO mode */
116		return -EBUSY;
117	}
118
119	if (debounce >= 32 && debounce <= 64)
120		fn = 0;
121	else if (debounce >= 4000 && debounce <= 8000)
122		fn = 1;
123	else
124		return -EINVAL;
125
126	return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn);
127}
128
129static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset,
130			     unsigned long config)
131{
132	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
133	struct wm831x *wm831x = wm831x_gpio->wm831x;
134	int reg = WM831X_GPIO1_CONTROL + offset;
135
136	switch (pinconf_to_config_param(config)) {
137	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
138		return wm831x_set_bits(wm831x, reg,
139				       WM831X_GPN_OD_MASK, WM831X_GPN_OD);
140	case PIN_CONFIG_DRIVE_PUSH_PULL:
141		return wm831x_set_bits(wm831x, reg,
142				       WM831X_GPN_OD_MASK, 0);
143	case PIN_CONFIG_INPUT_DEBOUNCE:
144		return wm831x_gpio_set_debounce(wm831x, offset,
145			pinconf_to_config_argument(config));
146	default:
147		break;
148	}
149
150	return -ENOTSUPP;
151}
152
153#ifdef CONFIG_DEBUG_FS
154static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
155{
156	struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip);
157	struct wm831x *wm831x = wm831x_gpio->wm831x;
158	int i, tristated;
159
160	for (i = 0; i < chip->ngpio; i++) {
161		int gpio = i + chip->base;
162		int reg;
163		const char *label, *pull, *powerdomain;
164
165		/* We report the GPIO even if it's not requested since
166		 * we're also reporting things like alternate
167		 * functions which apply even when the GPIO is not in
168		 * use as a GPIO.
169		 */
170		label = gpiochip_is_requested(chip, i);
171		if (!label)
172			label = "Unrequested";
173
174		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
175
176		reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
177		if (reg < 0) {
178			dev_err(wm831x->dev,
179				"GPIO control %d read failed: %d\n",
180				gpio, reg);
181			seq_putc(s, '\n');
182			continue;
183		}
184
185		switch (reg & WM831X_GPN_PULL_MASK) {
186		case WM831X_GPIO_PULL_NONE:
187			pull = "nopull";
188			break;
189		case WM831X_GPIO_PULL_DOWN:
190			pull = "pulldown";
191			break;
192		case WM831X_GPIO_PULL_UP:
193			pull = "pullup";
194			break;
195		default:
196			pull = "INVALID PULL";
197			break;
198		}
199
200		switch (i + 1) {
201		case 1 ... 3:
202		case 7 ... 9:
203			if (reg & WM831X_GPN_PWR_DOM)
204				powerdomain = "VPMIC";
205			else
206				powerdomain = "DBVDD";
207			break;
208
209		case 4 ... 6:
210		case 10 ... 12:
211			if (reg & WM831X_GPN_PWR_DOM)
212				powerdomain = "SYSVDD";
213			else
214				powerdomain = "DBVDD";
215			break;
216
217		case 13 ... 16:
218			powerdomain = "TPVDD";
219			break;
220
221		default:
222			BUG();
223			break;
224		}
225
226		tristated = reg & WM831X_GPN_TRI;
227		if (wm831x->has_gpio_ena)
228			tristated = !tristated;
229
230		seq_printf(s, " %s %s %s %s%s\n"
231			   "                                  %s%s (0x%4x)\n",
232			   reg & WM831X_GPN_DIR ? "in" : "out",
233			   wm831x_gpio_get(chip, i) ? "high" : "low",
234			   pull,
235			   powerdomain,
236			   reg & WM831X_GPN_POL ? "" : " inverted",
237			   reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
238			   tristated ? " tristated" : "",
239			   reg);
240	}
241}
242#else
243#define wm831x_gpio_dbg_show NULL
244#endif
245
246static const struct gpio_chip template_chip = {
247	.label			= "wm831x",
248	.owner			= THIS_MODULE,
249	.direction_input	= wm831x_gpio_direction_in,
250	.get			= wm831x_gpio_get,
251	.direction_output	= wm831x_gpio_direction_out,
252	.set			= wm831x_gpio_set,
253	.to_irq			= wm831x_gpio_to_irq,
254	.set_config		= wm831x_set_config,
255	.dbg_show		= wm831x_gpio_dbg_show,
256	.can_sleep		= true,
257};
258
259static int wm831x_gpio_probe(struct platform_device *pdev)
260{
261	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
262	struct wm831x_pdata *pdata = &wm831x->pdata;
263	struct wm831x_gpio *wm831x_gpio;
264
265	device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
266
267	wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
268				   GFP_KERNEL);
269	if (wm831x_gpio == NULL)
270		return -ENOMEM;
271
272	wm831x_gpio->wm831x = wm831x;
273	wm831x_gpio->gpio_chip = template_chip;
274	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
275	wm831x_gpio->gpio_chip.parent = &pdev->dev;
276	if (pdata && pdata->gpio_base)
277		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
278	else
279		wm831x_gpio->gpio_chip.base = -1;
280
281	return devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip, wm831x_gpio);
282}
283
284static struct platform_driver wm831x_gpio_driver = {
285	.driver.name	= "wm831x-gpio",
286	.probe		= wm831x_gpio_probe,
287};
288
289static int __init wm831x_gpio_init(void)
290{
291	return platform_driver_register(&wm831x_gpio_driver);
292}
293subsys_initcall(wm831x_gpio_init);
294
295static void __exit wm831x_gpio_exit(void)
296{
297	platform_driver_unregister(&wm831x_gpio_driver);
298}
299module_exit(wm831x_gpio_exit);
300
301MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
302MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
303MODULE_LICENSE("GPL");
304MODULE_ALIAS("platform:wm831x-gpio");
305