xref: /openbmc/linux/drivers/gpio/gpio-arizona.c (revision 4da722ca)
1 /*
2  * gpiolib support for Wolfson Arizona class devices
3  *
4  * Copyright 2012 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/platform_device.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/seq_file.h>
22 
23 #include <linux/mfd/arizona/core.h>
24 #include <linux/mfd/arizona/pdata.h>
25 #include <linux/mfd/arizona/registers.h>
26 
27 struct arizona_gpio {
28 	struct arizona *arizona;
29 	struct gpio_chip gpio_chip;
30 };
31 
32 static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
33 {
34 	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
35 	struct arizona *arizona = arizona_gpio->arizona;
36 	bool persistent = gpiochip_line_is_persistent(chip, offset);
37 	bool change;
38 	int ret;
39 
40 	ret = regmap_update_bits_check(arizona->regmap,
41 				       ARIZONA_GPIO1_CTRL + offset,
42 				       ARIZONA_GPN_DIR, ARIZONA_GPN_DIR,
43 				       &change);
44 	if (ret < 0)
45 		return ret;
46 
47 	if (change && persistent) {
48 		pm_runtime_mark_last_busy(chip->parent);
49 		pm_runtime_put_autosuspend(chip->parent);
50 	}
51 
52 	return 0;
53 }
54 
55 static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
56 {
57 	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
58 	struct arizona *arizona = arizona_gpio->arizona;
59 	unsigned int reg, val;
60 	int ret;
61 
62 	reg = ARIZONA_GPIO1_CTRL + offset;
63 	ret = regmap_read(arizona->regmap, reg, &val);
64 	if (ret < 0)
65 		return ret;
66 
67 	/* Resume to read actual registers for input pins */
68 	if (val & ARIZONA_GPN_DIR) {
69 		ret = pm_runtime_get_sync(chip->parent);
70 		if (ret < 0) {
71 			dev_err(chip->parent, "Failed to resume: %d\n", ret);
72 			return ret;
73 		}
74 
75 		/* Register is cached, drop it to ensure a physical read */
76 		ret = regcache_drop_region(arizona->regmap, reg, reg);
77 		if (ret < 0) {
78 			dev_err(chip->parent, "Failed to drop cache: %d\n",
79 				ret);
80 			return ret;
81 		}
82 
83 		ret = regmap_read(arizona->regmap, reg, &val);
84 		if (ret < 0)
85 			return ret;
86 
87 		pm_runtime_mark_last_busy(chip->parent);
88 		pm_runtime_put_autosuspend(chip->parent);
89 	}
90 
91 	if (val & ARIZONA_GPN_LVL)
92 		return 1;
93 	else
94 		return 0;
95 }
96 
97 static int arizona_gpio_direction_out(struct gpio_chip *chip,
98 				     unsigned offset, int value)
99 {
100 	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
101 	struct arizona *arizona = arizona_gpio->arizona;
102 	bool persistent = gpiochip_line_is_persistent(chip, offset);
103 	unsigned int val;
104 	int ret;
105 
106 	ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
107 	if (ret < 0)
108 		return ret;
109 
110 	if ((val & ARIZONA_GPN_DIR) && persistent) {
111 		ret = pm_runtime_get_sync(chip->parent);
112 		if (ret < 0) {
113 			dev_err(chip->parent, "Failed to resume: %d\n", ret);
114 			return ret;
115 		}
116 	}
117 
118 	if (value)
119 		value = ARIZONA_GPN_LVL;
120 
121 	return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
122 				  ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
123 }
124 
125 static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
126 {
127 	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
128 	struct arizona *arizona = arizona_gpio->arizona;
129 
130 	if (value)
131 		value = ARIZONA_GPN_LVL;
132 
133 	regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
134 			   ARIZONA_GPN_LVL, value);
135 }
136 
137 static const struct gpio_chip template_chip = {
138 	.label			= "arizona",
139 	.owner			= THIS_MODULE,
140 	.direction_input	= arizona_gpio_direction_in,
141 	.get			= arizona_gpio_get,
142 	.direction_output	= arizona_gpio_direction_out,
143 	.set			= arizona_gpio_set,
144 	.can_sleep		= true,
145 };
146 
147 static int arizona_gpio_probe(struct platform_device *pdev)
148 {
149 	struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
150 	struct arizona_pdata *pdata = dev_get_platdata(arizona->dev);
151 	struct arizona_gpio *arizona_gpio;
152 	int ret;
153 
154 	arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
155 				    GFP_KERNEL);
156 	if (!arizona_gpio)
157 		return -ENOMEM;
158 
159 	arizona_gpio->arizona = arizona;
160 	arizona_gpio->gpio_chip = template_chip;
161 	arizona_gpio->gpio_chip.parent = &pdev->dev;
162 #ifdef CONFIG_OF_GPIO
163 	arizona_gpio->gpio_chip.of_node = arizona->dev->of_node;
164 #endif
165 
166 	switch (arizona->type) {
167 	case WM5102:
168 	case WM5110:
169 	case WM8280:
170 	case WM8997:
171 	case WM8998:
172 	case WM1814:
173 		arizona_gpio->gpio_chip.ngpio = 5;
174 		break;
175 	case WM1831:
176 	case CS47L24:
177 		arizona_gpio->gpio_chip.ngpio = 2;
178 		break;
179 	default:
180 		dev_err(&pdev->dev, "Unknown chip variant %d\n",
181 			arizona->type);
182 		return -EINVAL;
183 	}
184 
185 	if (pdata && pdata->gpio_base)
186 		arizona_gpio->gpio_chip.base = pdata->gpio_base;
187 	else
188 		arizona_gpio->gpio_chip.base = -1;
189 
190 	pm_runtime_enable(&pdev->dev);
191 
192 	ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
193 				     arizona_gpio);
194 	if (ret < 0) {
195 		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
196 			ret);
197 		return ret;
198 	}
199 
200 	return 0;
201 }
202 
203 static struct platform_driver arizona_gpio_driver = {
204 	.driver.name	= "arizona-gpio",
205 	.probe		= arizona_gpio_probe,
206 };
207 
208 module_platform_driver(arizona_gpio_driver);
209 
210 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
211 MODULE_DESCRIPTION("GPIO interface for Arizona devices");
212 MODULE_LICENSE("GPL");
213 MODULE_ALIAS("platform:arizona-gpio");
214