xref: /openbmc/linux/drivers/gpio/gpio-wm8994.c (revision f7777dcc)
1 /*
2  * gpiolib support for Wolfson WM8994
3  *
4  * Copyright 2009 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  *
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/module.h>
18 #include <linux/gpio.h>
19 #include <linux/mfd/core.h>
20 #include <linux/platform_device.h>
21 #include <linux/seq_file.h>
22 #include <linux/regmap.h>
23 
24 #include <linux/mfd/wm8994/core.h>
25 #include <linux/mfd/wm8994/pdata.h>
26 #include <linux/mfd/wm8994/gpio.h>
27 #include <linux/mfd/wm8994/registers.h>
28 
29 struct wm8994_gpio {
30 	struct wm8994 *wm8994;
31 	struct gpio_chip gpio_chip;
32 };
33 
34 static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip)
35 {
36 	return container_of(chip, struct wm8994_gpio, gpio_chip);
37 }
38 
39 static int wm8994_gpio_request(struct gpio_chip *chip, unsigned offset)
40 {
41 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
42 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
43 
44 	switch (wm8994->type) {
45 	case WM8958:
46 		switch (offset) {
47 		case 1:
48 		case 2:
49 		case 3:
50 		case 4:
51 		case 6:
52 			return -EINVAL;
53 		}
54 		break;
55 	default:
56 		break;
57 	}
58 
59 	return 0;
60 }
61 
62 static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
63 {
64 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
65 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
66 
67 	return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
68 			       WM8994_GPN_DIR, WM8994_GPN_DIR);
69 }
70 
71 static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset)
72 {
73 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
74 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
75 	int ret;
76 
77 	ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset);
78 	if (ret < 0)
79 		return ret;
80 
81 	if (ret & WM8994_GPN_LVL)
82 		return 1;
83 	else
84 		return 0;
85 }
86 
87 static int wm8994_gpio_direction_out(struct gpio_chip *chip,
88 				     unsigned offset, int value)
89 {
90 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
91 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
92 
93 	if (value)
94 		value = WM8994_GPN_LVL;
95 
96 	return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset,
97 			       WM8994_GPN_DIR | WM8994_GPN_LVL, value);
98 }
99 
100 static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
101 {
102 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
103 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
104 
105 	if (value)
106 		value = WM8994_GPN_LVL;
107 
108 	wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value);
109 }
110 
111 static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
112 {
113 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
114 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
115 
116 	return regmap_irq_get_virq(wm8994->irq_data, offset);
117 }
118 
119 
120 #ifdef CONFIG_DEBUG_FS
121 static const char *wm8994_gpio_fn(u16 fn)
122 {
123 	switch (fn) {
124 	case WM8994_GP_FN_PIN_SPECIFIC:
125 		return "pin-specific";
126 	case WM8994_GP_FN_GPIO:
127 		return "GPIO";
128 	case WM8994_GP_FN_SDOUT:
129 		return "SDOUT";
130 	case WM8994_GP_FN_IRQ:
131 		return "IRQ";
132 	case WM8994_GP_FN_TEMPERATURE:
133 		return "Temperature";
134 	case WM8994_GP_FN_MICBIAS1_DET:
135 		return "MICBIAS1 detect";
136 	case WM8994_GP_FN_MICBIAS1_SHORT:
137 		return "MICBIAS1 short";
138 	case WM8994_GP_FN_MICBIAS2_DET:
139 		return "MICBIAS2 detect";
140 	case WM8994_GP_FN_MICBIAS2_SHORT:
141 		return "MICBIAS2 short";
142 	case WM8994_GP_FN_FLL1_LOCK:
143 		return "FLL1 lock";
144 	case WM8994_GP_FN_FLL2_LOCK:
145 		return "FLL2 lock";
146 	case WM8994_GP_FN_SRC1_LOCK:
147 		return "SRC1 lock";
148 	case WM8994_GP_FN_SRC2_LOCK:
149 		return "SRC2 lock";
150 	case WM8994_GP_FN_DRC1_ACT:
151 		return "DRC1 activity";
152 	case WM8994_GP_FN_DRC2_ACT:
153 		return "DRC2 activity";
154 	case WM8994_GP_FN_DRC3_ACT:
155 		return "DRC3 activity";
156 	case WM8994_GP_FN_WSEQ_STATUS:
157 		return "Write sequencer";
158 	case WM8994_GP_FN_FIFO_ERROR:
159 		return "FIFO error";
160 	case WM8994_GP_FN_OPCLK:
161 		return "OPCLK";
162 	case WM8994_GP_FN_THW:
163 		return "Thermal warning";
164 	case WM8994_GP_FN_DCS_DONE:
165 		return "DC servo";
166 	case WM8994_GP_FN_FLL1_OUT:
167 		return "FLL1 output";
168 	case WM8994_GP_FN_FLL2_OUT:
169 		return "FLL1 output";
170 	default:
171 		return "Unknown";
172 	}
173 }
174 
175 static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
176 {
177 	struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip);
178 	struct wm8994 *wm8994 = wm8994_gpio->wm8994;
179 	int i;
180 
181 	for (i = 0; i < chip->ngpio; i++) {
182 		int gpio = i + chip->base;
183 		int reg;
184 		const char *label;
185 
186 		/* We report the GPIO even if it's not requested since
187 		 * we're also reporting things like alternate
188 		 * functions which apply even when the GPIO is not in
189 		 * use as a GPIO.
190 		 */
191 		label = gpiochip_is_requested(chip, i);
192 		if (!label)
193 			label = "Unrequested";
194 
195 		seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
196 
197 		reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i);
198 		if (reg < 0) {
199 			dev_err(wm8994->dev,
200 				"GPIO control %d read failed: %d\n",
201 				gpio, reg);
202 			seq_printf(s, "\n");
203 			continue;
204 		}
205 
206 		if (reg & WM8994_GPN_DIR)
207 			seq_printf(s, "in ");
208 		else
209 			seq_printf(s, "out ");
210 
211 		if (reg & WM8994_GPN_PU)
212 			seq_printf(s, "pull up ");
213 
214 		if (reg & WM8994_GPN_PD)
215 			seq_printf(s, "pull down ");
216 
217 		if (reg & WM8994_GPN_POL)
218 			seq_printf(s, "inverted ");
219 		else
220 			seq_printf(s, "noninverted ");
221 
222 		if (reg & WM8994_GPN_OP_CFG)
223 			seq_printf(s, "open drain ");
224 		else
225 			seq_printf(s, "CMOS ");
226 
227 		seq_printf(s, "%s (%x)\n",
228 			   wm8994_gpio_fn(reg & WM8994_GPN_FN_MASK), reg);
229 	}
230 }
231 #else
232 #define wm8994_gpio_dbg_show NULL
233 #endif
234 
235 static struct gpio_chip template_chip = {
236 	.label			= "wm8994",
237 	.owner			= THIS_MODULE,
238 	.request		= wm8994_gpio_request,
239 	.direction_input	= wm8994_gpio_direction_in,
240 	.get			= wm8994_gpio_get,
241 	.direction_output	= wm8994_gpio_direction_out,
242 	.set			= wm8994_gpio_set,
243 	.to_irq			= wm8994_gpio_to_irq,
244 	.dbg_show		= wm8994_gpio_dbg_show,
245 	.can_sleep		= 1,
246 };
247 
248 static int wm8994_gpio_probe(struct platform_device *pdev)
249 {
250 	struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
251 	struct wm8994_pdata *pdata = dev_get_platdata(wm8994->dev);
252 	struct wm8994_gpio *wm8994_gpio;
253 	int ret;
254 
255 	wm8994_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm8994_gpio),
256 				   GFP_KERNEL);
257 	if (wm8994_gpio == NULL)
258 		return -ENOMEM;
259 
260 	wm8994_gpio->wm8994 = wm8994;
261 	wm8994_gpio->gpio_chip = template_chip;
262 	wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX;
263 	wm8994_gpio->gpio_chip.dev = &pdev->dev;
264 	if (pdata && pdata->gpio_base)
265 		wm8994_gpio->gpio_chip.base = pdata->gpio_base;
266 	else
267 		wm8994_gpio->gpio_chip.base = -1;
268 
269 	ret = gpiochip_add(&wm8994_gpio->gpio_chip);
270 	if (ret < 0) {
271 		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
272 			ret);
273 		goto err;
274 	}
275 
276 	platform_set_drvdata(pdev, wm8994_gpio);
277 
278 	return ret;
279 
280 err:
281 	return ret;
282 }
283 
284 static int wm8994_gpio_remove(struct platform_device *pdev)
285 {
286 	struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev);
287 
288 	return gpiochip_remove(&wm8994_gpio->gpio_chip);
289 }
290 
291 static struct platform_driver wm8994_gpio_driver = {
292 	.driver.name	= "wm8994-gpio",
293 	.driver.owner	= THIS_MODULE,
294 	.probe		= wm8994_gpio_probe,
295 	.remove		= wm8994_gpio_remove,
296 };
297 
298 static int __init wm8994_gpio_init(void)
299 {
300 	return platform_driver_register(&wm8994_gpio_driver);
301 }
302 subsys_initcall(wm8994_gpio_init);
303 
304 static void __exit wm8994_gpio_exit(void)
305 {
306 	platform_driver_unregister(&wm8994_gpio_driver);
307 }
308 module_exit(wm8994_gpio_exit);
309 
310 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
311 MODULE_DESCRIPTION("GPIO interface for WM8994");
312 MODULE_LICENSE("GPL");
313 MODULE_ALIAS("platform:wm8994-gpio");
314