1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * gpiolib support for Wolfson Arizona class devices
4 *
5 * Copyright 2012 Wolfson Microelectronics PLC.
6 *
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/gpio/driver.h>
14 #include <linux/platform_device.h>
15 #include <linux/pm_runtime.h>
16 #include <linux/seq_file.h>
17
18 #include <linux/mfd/arizona/core.h>
19 #include <linux/mfd/arizona/pdata.h>
20 #include <linux/mfd/arizona/registers.h>
21
22 struct arizona_gpio {
23 struct arizona *arizona;
24 struct gpio_chip gpio_chip;
25 };
26
arizona_gpio_direction_in(struct gpio_chip * chip,unsigned offset)27 static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
28 {
29 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
30 struct arizona *arizona = arizona_gpio->arizona;
31 bool persistent = gpiochip_line_is_persistent(chip, offset);
32 bool change;
33 int ret;
34
35 ret = regmap_update_bits_check(arizona->regmap,
36 ARIZONA_GPIO1_CTRL + offset,
37 ARIZONA_GPN_DIR, ARIZONA_GPN_DIR,
38 &change);
39 if (ret < 0)
40 return ret;
41
42 if (change && persistent) {
43 pm_runtime_mark_last_busy(chip->parent);
44 pm_runtime_put_autosuspend(chip->parent);
45 }
46
47 return 0;
48 }
49
arizona_gpio_get(struct gpio_chip * chip,unsigned offset)50 static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
51 {
52 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
53 struct arizona *arizona = arizona_gpio->arizona;
54 unsigned int reg, val;
55 int ret;
56
57 reg = ARIZONA_GPIO1_CTRL + offset;
58 ret = regmap_read(arizona->regmap, reg, &val);
59 if (ret < 0)
60 return ret;
61
62 /* Resume to read actual registers for input pins */
63 if (val & ARIZONA_GPN_DIR) {
64 ret = pm_runtime_get_sync(chip->parent);
65 if (ret < 0) {
66 dev_err(chip->parent, "Failed to resume: %d\n", ret);
67 pm_runtime_put_autosuspend(chip->parent);
68 return ret;
69 }
70
71 /* Register is cached, drop it to ensure a physical read */
72 ret = regcache_drop_region(arizona->regmap, reg, reg);
73 if (ret < 0) {
74 dev_err(chip->parent, "Failed to drop cache: %d\n",
75 ret);
76 pm_runtime_put_autosuspend(chip->parent);
77 return ret;
78 }
79
80 ret = regmap_read(arizona->regmap, reg, &val);
81 if (ret < 0) {
82 pm_runtime_put_autosuspend(chip->parent);
83 return ret;
84 }
85
86 pm_runtime_mark_last_busy(chip->parent);
87 pm_runtime_put_autosuspend(chip->parent);
88 }
89
90 if (val & ARIZONA_GPN_LVL)
91 return 1;
92 else
93 return 0;
94 }
95
arizona_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)96 static int arizona_gpio_direction_out(struct gpio_chip *chip,
97 unsigned offset, int value)
98 {
99 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
100 struct arizona *arizona = arizona_gpio->arizona;
101 bool persistent = gpiochip_line_is_persistent(chip, offset);
102 unsigned int val;
103 int ret;
104
105 ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
106 if (ret < 0)
107 return ret;
108
109 if ((val & ARIZONA_GPN_DIR) && persistent) {
110 ret = pm_runtime_get_sync(chip->parent);
111 if (ret < 0) {
112 dev_err(chip->parent, "Failed to resume: %d\n", ret);
113 pm_runtime_put(chip->parent);
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
arizona_gpio_set(struct gpio_chip * chip,unsigned offset,int value)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
arizona_gpio_probe(struct platform_device * pdev)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 = &arizona->pdata;
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->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 pm_runtime_disable(&pdev->dev);
196 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
197 ret);
198 return ret;
199 }
200
201 return 0;
202 }
203
204 static struct platform_driver arizona_gpio_driver = {
205 .driver.name = "arizona-gpio",
206 .probe = arizona_gpio_probe,
207 };
208
209 module_platform_driver(arizona_gpio_driver);
210
211 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
212 MODULE_DESCRIPTION("GPIO interface for Arizona devices");
213 MODULE_LICENSE("GPL");
214 MODULE_ALIAS("platform:arizona-gpio");
215