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 	int ret;
265 
266 	wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio),
267 				   GFP_KERNEL);
268 	if (wm831x_gpio == NULL)
269 		return -ENOMEM;
270 
271 	wm831x_gpio->wm831x = wm831x;
272 	wm831x_gpio->gpio_chip = template_chip;
273 	wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio;
274 	wm831x_gpio->gpio_chip.parent = &pdev->dev;
275 	if (pdata && pdata->gpio_base)
276 		wm831x_gpio->gpio_chip.base = pdata->gpio_base;
277 	else
278 		wm831x_gpio->gpio_chip.base = -1;
279 #ifdef CONFIG_OF_GPIO
280 	wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node;
281 #endif
282 
283 	ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip,
284 				     wm831x_gpio);
285 	if (ret < 0) {
286 		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
287 		return ret;
288 	}
289 
290 	platform_set_drvdata(pdev, wm831x_gpio);
291 
292 	return ret;
293 }
294 
295 static struct platform_driver wm831x_gpio_driver = {
296 	.driver.name	= "wm831x-gpio",
297 	.probe		= wm831x_gpio_probe,
298 };
299 
wm831x_gpio_init(void)300 static int __init wm831x_gpio_init(void)
301 {
302 	return platform_driver_register(&wm831x_gpio_driver);
303 }
304 subsys_initcall(wm831x_gpio_init);
305 
wm831x_gpio_exit(void)306 static void __exit wm831x_gpio_exit(void)
307 {
308 	platform_driver_unregister(&wm831x_gpio_driver);
309 }
310 module_exit(wm831x_gpio_exit);
311 
312 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
313 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
314 MODULE_LICENSE("GPL");
315 MODULE_ALIAS("platform:wm831x-gpio");
316