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#include <linux/string_choices.h>
20
21#include <linux/mfd/wm831x/core.h>
22#include <linux/mfd/wm831x/pdata.h>
23#include <linux/mfd/wm831x/gpio.h>
24#include <linux/mfd/wm831x/irq.h>
25
26struct wm831x_gpio {
27 struct wm831x *wm831x;
28 struct gpio_chip gpio_chip;
29};
30
31static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
32{
33 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(gc: chip);
34 struct wm831x *wm831x = wm831x_gpio->wm831x;
35 int val = WM831X_GPN_DIR;
36
37 if (wm831x->has_gpio_ena)
38 val |= WM831X_GPN_TRI;
39
40 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
41 WM831X_GPN_DIR | WM831X_GPN_TRI |
42 WM831X_GPN_FN_MASK, val);
43}
44
45static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
46{
47 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(gc: chip);
48 struct wm831x *wm831x = wm831x_gpio->wm831x;
49 int ret;
50
51 ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
52 if (ret < 0)
53 return ret;
54
55 if (ret & 1 << offset)
56 return 1;
57 else
58 return 0;
59}
60
61static int wm831x_gpio_set(struct gpio_chip *chip, unsigned int offset,
62 int value)
63{
64 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(gc: chip);
65 struct wm831x *wm831x = wm831x_gpio->wm831x;
66
67 return wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, mask: 1 << offset,
68 val: value << offset);
69}
70
71static int wm831x_gpio_direction_out(struct gpio_chip *chip,
72 unsigned offset, int value)
73{
74 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(gc: chip);
75 struct wm831x *wm831x = wm831x_gpio->wm831x;
76 int val = 0;
77 int ret;
78
79 if (wm831x->has_gpio_ena)
80 val |= WM831X_GPN_TRI;
81
82 ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
83 WM831X_GPN_DIR | WM831X_GPN_TRI |
84 WM831X_GPN_FN_MASK, val);
85 if (ret < 0)
86 return ret;
87
88 /* Can only set GPIO state once it's in output mode */
89 return wm831x_gpio_set(chip, offset, value);
90}
91
92static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
93{
94 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(gc: chip);
95 struct wm831x *wm831x = wm831x_gpio->wm831x;
96
97 return irq_create_mapping(domain: 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, val: 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(gc: 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, val: 0);
144 case PIN_CONFIG_INPUT_DEBOUNCE:
145 return wm831x_gpio_set_debounce(wm831x, offset,
146 debounce: 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(gc: chip);
158 struct wm831x *wm831x = wm831x_gpio->wm831x;
159 int i, tristated;
160
161 for (i = 0; i < chip->ngpio; i++) {
162 int reg;
163 const char *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 char *label __free(kfree) = gpiochip_dup_line_label(gc: chip, offset: i);
171 if (IS_ERR(ptr: label)) {
172 dev_err(wm831x->dev, "Failed to duplicate label\n");
173 continue;
174 }
175
176 seq_printf(m: s, fmt: " gpio-%-3d (%-20.20s) ",
177 i, label ?: "Unrequested");
178
179 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
180 if (reg < 0) {
181 dev_err(wm831x->dev,
182 "GPIO control %d read failed: %d\n",
183 i, reg);
184 seq_putc(m: s, c: '\n');
185 continue;
186 }
187
188 switch (reg & WM831X_GPN_PULL_MASK) {
189 case WM831X_GPIO_PULL_NONE:
190 pull = "nopull";
191 break;
192 case WM831X_GPIO_PULL_DOWN:
193 pull = "pulldown";
194 break;
195 case WM831X_GPIO_PULL_UP:
196 pull = "pullup";
197 break;
198 default:
199 pull = "INVALID PULL";
200 break;
201 }
202
203 switch (i + 1) {
204 case 1 ... 3:
205 case 7 ... 9:
206 if (reg & WM831X_GPN_PWR_DOM)
207 powerdomain = "VPMIC";
208 else
209 powerdomain = "DBVDD";
210 break;
211
212 case 4 ... 6:
213 case 10 ... 12:
214 if (reg & WM831X_GPN_PWR_DOM)
215 powerdomain = "SYSVDD";
216 else
217 powerdomain = "DBVDD";
218 break;
219
220 case 13 ... 16:
221 powerdomain = "TPVDD";
222 break;
223
224 default:
225 BUG();
226 break;
227 }
228
229 tristated = reg & WM831X_GPN_TRI;
230 if (wm831x->has_gpio_ena)
231 tristated = !tristated;
232
233 seq_printf(m: s, fmt: " %s %s %s %s%s\n"
234 " %s%s (0x%4x)\n",
235 reg & WM831X_GPN_DIR ? "in" : "out",
236 str_high_low(v: wm831x_gpio_get(chip, offset: i)),
237 pull,
238 powerdomain,
239 reg & WM831X_GPN_POL ? "" : " inverted",
240 reg & WM831X_GPN_OD ? "open-drain" : "push-pull",
241 tristated ? " tristated" : "",
242 reg);
243 }
244}
245#else
246#define wm831x_gpio_dbg_show NULL
247#endif
248
249static const struct gpio_chip template_chip = {
250 .label = "wm831x",
251 .owner = THIS_MODULE,
252 .direction_input = wm831x_gpio_direction_in,
253 .get = wm831x_gpio_get,
254 .direction_output = wm831x_gpio_direction_out,
255 .set = wm831x_gpio_set,
256 .to_irq = wm831x_gpio_to_irq,
257 .set_config = wm831x_set_config,
258 .dbg_show = wm831x_gpio_dbg_show,
259 .can_sleep = true,
260};
261
262static int wm831x_gpio_probe(struct platform_device *pdev)
263{
264 struct wm831x *wm831x = dev_get_drvdata(dev: pdev->dev.parent);
265 struct wm831x_pdata *pdata = &wm831x->pdata;
266 struct wm831x_gpio *wm831x_gpio;
267
268 device_set_node(dev: &pdev->dev, dev_fwnode(pdev->dev.parent));
269
270 wm831x_gpio = devm_kzalloc(dev: &pdev->dev, size: sizeof(*wm831x_gpio),
271 GFP_KERNEL);
272 if (wm831x_gpio == NULL)
273 return -ENOMEM;
274
275 wm831x_gpio->wm831x = wm831x;
276 wm831x_gpio->gpio_chip = template_chip;
277 wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
278 wm831x_gpio->gpio_chip.parent = &pdev->dev;
279 if (pdata && pdata->gpio_base)
280 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
281 else
282 wm831x_gpio->gpio_chip.base = -1;
283
284 return devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip, wm831x_gpio);
285}
286
287static struct platform_driver wm831x_gpio_driver = {
288 .driver.name = "wm831x-gpio",
289 .probe = wm831x_gpio_probe,
290};
291
292static int __init wm831x_gpio_init(void)
293{
294 return platform_driver_register(&wm831x_gpio_driver);
295}
296subsys_initcall(wm831x_gpio_init);
297
298static void __exit wm831x_gpio_exit(void)
299{
300 platform_driver_unregister(&wm831x_gpio_driver);
301}
302module_exit(wm831x_gpio_exit);
303
304MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
305MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
306MODULE_LICENSE("GPL");
307MODULE_ALIAS("platform:wm831x-gpio");
308

source code of linux/drivers/gpio/gpio-wm831x.c