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
24 struct wm831x_gpio {
25 struct wm831x *wm831x;
26 struct gpio_chip gpio_chip;
27 };
28
wm831x_gpio_direction_in(struct gpio_chip * chip,unsigned offset)29 static 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
wm831x_gpio_get(struct gpio_chip * chip,unsigned offset)43 static 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
wm831x_gpio_set(struct gpio_chip * chip,unsigned offset,int value)59 static 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
wm831x_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)68 static 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
wm831x_gpio_to_irq(struct gpio_chip * chip,unsigned offset)91 static 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
wm831x_gpio_set_debounce(struct wm831x * wm831x,unsigned offset,unsigned debounce)100 static 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
wm831x_set_config(struct gpio_chip * chip,unsigned int offset,unsigned long config)129 static 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
wm831x_gpio_dbg_show(struct seq_file * s,struct gpio_chip * chip)154 static 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
246 static 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
wm831x_gpio_probe(struct platform_device * pdev)259 static 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 wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
266 GFP_KERNEL);
267 if (wm831x_gpio == NULL)
268 return -ENOMEM;
269
270 wm831x_gpio->wm831x = wm831x;
271 wm831x_gpio->gpio_chip = template_chip;
272 wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
273 wm831x_gpio->gpio_chip.parent = &pdev->dev;
274 if (pdata && pdata->gpio_base)
275 wm831x_gpio->gpio_chip.base = pdata->gpio_base;
276 else
277 wm831x_gpio->gpio_chip.base = -1;
278 #ifdef CONFIG_OF_GPIO
279 wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node;
280 #endif
281
282 return devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip, wm831x_gpio);
283 }
284
285 static struct platform_driver wm831x_gpio_driver = {
286 .driver.name = "wm831x-gpio",
287 .probe = wm831x_gpio_probe,
288 };
289
wm831x_gpio_init(void)290 static int __init wm831x_gpio_init(void)
291 {
292 return platform_driver_register(&wm831x_gpio_driver);
293 }
294 subsys_initcall(wm831x_gpio_init);
295
wm831x_gpio_exit(void)296 static void __exit wm831x_gpio_exit(void)
297 {
298 platform_driver_unregister(&wm831x_gpio_driver);
299 }
300 module_exit(wm831x_gpio_exit);
301
302 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
303 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
304 MODULE_LICENSE("GPL");
305 MODULE_ALIAS("platform:wm831x-gpio");
306