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 return ret;
68 }
69
70 /* Register is cached, drop it to ensure a physical read */
71 ret = regcache_drop_region(arizona->regmap, reg, reg);
72 if (ret < 0) {
73 dev_err(chip->parent, "Failed to drop cache: %d\n",
74 ret);
75 return ret;
76 }
77
78 ret = regmap_read(arizona->regmap, reg, &val);
79 if (ret < 0)
80 return ret;
81
82 pm_runtime_mark_last_busy(chip->parent);
83 pm_runtime_put_autosuspend(chip->parent);
84 }
85
86 if (val & ARIZONA_GPN_LVL)
87 return 1;
88 else
89 return 0;
90 }
91
arizona_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)92 static int arizona_gpio_direction_out(struct gpio_chip *chip,
93 unsigned offset, int value)
94 {
95 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
96 struct arizona *arizona = arizona_gpio->arizona;
97 bool persistent = gpiochip_line_is_persistent(chip, offset);
98 unsigned int val;
99 int ret;
100
101 ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
102 if (ret < 0)
103 return ret;
104
105 if ((val & ARIZONA_GPN_DIR) && persistent) {
106 ret = pm_runtime_get_sync(chip->parent);
107 if (ret < 0) {
108 dev_err(chip->parent, "Failed to resume: %d\n", ret);
109 return ret;
110 }
111 }
112
113 if (value)
114 value = ARIZONA_GPN_LVL;
115
116 return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
117 ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
118 }
119
arizona_gpio_set(struct gpio_chip * chip,unsigned offset,int value)120 static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
121 {
122 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
123 struct arizona *arizona = arizona_gpio->arizona;
124
125 if (value)
126 value = ARIZONA_GPN_LVL;
127
128 regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
129 ARIZONA_GPN_LVL, value);
130 }
131
132 static const struct gpio_chip template_chip = {
133 .label = "arizona",
134 .owner = THIS_MODULE,
135 .direction_input = arizona_gpio_direction_in,
136 .get = arizona_gpio_get,
137 .direction_output = arizona_gpio_direction_out,
138 .set = arizona_gpio_set,
139 .can_sleep = true,
140 };
141
arizona_gpio_probe(struct platform_device * pdev)142 static int arizona_gpio_probe(struct platform_device *pdev)
143 {
144 struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
145 struct arizona_pdata *pdata = &arizona->pdata;
146 struct arizona_gpio *arizona_gpio;
147 int ret;
148
149 arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
150 GFP_KERNEL);
151 if (!arizona_gpio)
152 return -ENOMEM;
153
154 arizona_gpio->arizona = arizona;
155 arizona_gpio->gpio_chip = template_chip;
156 arizona_gpio->gpio_chip.parent = &pdev->dev;
157 #ifdef CONFIG_OF_GPIO
158 arizona_gpio->gpio_chip.of_node = arizona->dev->of_node;
159 #endif
160
161 switch (arizona->type) {
162 case WM5102:
163 case WM5110:
164 case WM8280:
165 case WM8997:
166 case WM8998:
167 case WM1814:
168 arizona_gpio->gpio_chip.ngpio = 5;
169 break;
170 case WM1831:
171 case CS47L24:
172 arizona_gpio->gpio_chip.ngpio = 2;
173 break;
174 default:
175 dev_err(&pdev->dev, "Unknown chip variant %d\n",
176 arizona->type);
177 return -EINVAL;
178 }
179
180 if (pdata->gpio_base)
181 arizona_gpio->gpio_chip.base = pdata->gpio_base;
182 else
183 arizona_gpio->gpio_chip.base = -1;
184
185 pm_runtime_enable(&pdev->dev);
186
187 ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
188 arizona_gpio);
189 if (ret < 0) {
190 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
191 ret);
192 return ret;
193 }
194
195 return 0;
196 }
197
198 static struct platform_driver arizona_gpio_driver = {
199 .driver.name = "arizona-gpio",
200 .probe = arizona_gpio_probe,
201 };
202
203 module_platform_driver(arizona_gpio_driver);
204
205 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
206 MODULE_DESCRIPTION("GPIO interface for Arizona devices");
207 MODULE_LICENSE("GPL");
208 MODULE_ALIAS("platform:arizona-gpio");
209