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/gpio/driver.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/slab.h>
16
17 #include <linux/mfd/arizona/core.h>
18 #include <linux/mfd/arizona/pdata.h>
19 #include <linux/mfd/arizona/registers.h>
20
21 struct arizona_gpio {
22 struct arizona *arizona;
23 struct gpio_chip gpio_chip;
24 };
25
arizona_gpio_direction_in(struct gpio_chip * chip,unsigned offset)26 static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
27 {
28 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
29 struct arizona *arizona = arizona_gpio->arizona;
30 bool persistent = gpiochip_line_is_persistent(chip, offset);
31 bool change;
32 int ret;
33
34 ret = regmap_update_bits_check(arizona->regmap,
35 ARIZONA_GPIO1_CTRL + offset,
36 ARIZONA_GPN_DIR, ARIZONA_GPN_DIR,
37 &change);
38 if (ret < 0)
39 return ret;
40
41 if (change && persistent) {
42 pm_runtime_put_autosuspend(chip->parent);
43 }
44
45 return 0;
46 }
47
arizona_gpio_get(struct gpio_chip * chip,unsigned offset)48 static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
49 {
50 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
51 struct arizona *arizona = arizona_gpio->arizona;
52 unsigned int reg, val;
53 int ret;
54
55 reg = ARIZONA_GPIO1_CTRL + offset;
56 ret = regmap_read(arizona->regmap, reg, &val);
57 if (ret < 0)
58 return ret;
59
60 /* Resume to read actual registers for input pins */
61 if (val & ARIZONA_GPN_DIR) {
62 ret = pm_runtime_get_sync(chip->parent);
63 if (ret < 0) {
64 dev_err(chip->parent, "Failed to resume: %d\n", ret);
65 pm_runtime_put_autosuspend(chip->parent);
66 return ret;
67 }
68
69 /* Register is cached, drop it to ensure a physical read */
70 ret = regcache_drop_region(arizona->regmap, reg, reg);
71 if (ret < 0) {
72 dev_err(chip->parent, "Failed to drop cache: %d\n",
73 ret);
74 pm_runtime_put_autosuspend(chip->parent);
75 return ret;
76 }
77
78 ret = regmap_read(arizona->regmap, reg, &val);
79 if (ret < 0) {
80 pm_runtime_put_autosuspend(chip->parent);
81 return ret;
82 }
83
84 pm_runtime_put_autosuspend(chip->parent);
85 }
86
87 if (val & ARIZONA_GPN_LVL)
88 return 1;
89 else
90 return 0;
91 }
92
arizona_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)93 static int arizona_gpio_direction_out(struct gpio_chip *chip,
94 unsigned offset, int value)
95 {
96 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
97 struct arizona *arizona = arizona_gpio->arizona;
98 bool persistent = gpiochip_line_is_persistent(chip, offset);
99 unsigned int val;
100 int ret;
101
102 ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
103 if (ret < 0)
104 return ret;
105
106 if ((val & ARIZONA_GPN_DIR) && persistent) {
107 ret = pm_runtime_get_sync(chip->parent);
108 if (ret < 0) {
109 dev_err(chip->parent, "Failed to resume: %d\n", ret);
110 pm_runtime_put(chip->parent);
111 return ret;
112 }
113 }
114
115 if (value)
116 value = ARIZONA_GPN_LVL;
117
118 return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
119 ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
120 }
121
arizona_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)122 static int arizona_gpio_set(struct gpio_chip *chip, unsigned int offset,
123 int value)
124 {
125 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
126 struct arizona *arizona = arizona_gpio->arizona;
127
128 if (value)
129 value = ARIZONA_GPN_LVL;
130
131 return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
132 ARIZONA_GPN_LVL, value);
133 }
134
135 static const struct gpio_chip template_chip = {
136 .label = "arizona",
137 .owner = THIS_MODULE,
138 .direction_input = arizona_gpio_direction_in,
139 .get = arizona_gpio_get,
140 .direction_output = arizona_gpio_direction_out,
141 .set = arizona_gpio_set,
142 .can_sleep = true,
143 };
144
arizona_gpio_probe(struct platform_device * pdev)145 static int arizona_gpio_probe(struct platform_device *pdev)
146 {
147 struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
148 struct arizona_pdata *pdata = &arizona->pdata;
149 struct arizona_gpio *arizona_gpio;
150 int ret;
151
152 device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
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
163 switch (arizona->type) {
164 case WM5102:
165 case WM5110:
166 case WM8280:
167 case WM8997:
168 case WM8998:
169 case WM1814:
170 arizona_gpio->gpio_chip.ngpio = 5;
171 break;
172 case WM1831:
173 case CS47L24:
174 arizona_gpio->gpio_chip.ngpio = 2;
175 break;
176 default:
177 dev_err(&pdev->dev, "Unknown chip variant %d\n",
178 arizona->type);
179 return -EINVAL;
180 }
181
182 if (pdata->gpio_base)
183 arizona_gpio->gpio_chip.base = pdata->gpio_base;
184 else
185 arizona_gpio->gpio_chip.base = -1;
186
187 pm_runtime_enable(&pdev->dev);
188
189 ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
190 arizona_gpio);
191 if (ret < 0) {
192 pm_runtime_disable(&pdev->dev);
193 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
194 ret);
195 return ret;
196 }
197
198 return 0;
199 }
200
201 static struct platform_driver arizona_gpio_driver = {
202 .driver.name = "arizona-gpio",
203 .probe = arizona_gpio_probe,
204 };
205
206 module_platform_driver(arizona_gpio_driver);
207
208 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
209 MODULE_DESCRIPTION("GPIO interface for Arizona devices");
210 MODULE_LICENSE("GPL");
211 MODULE_ALIAS("platform:arizona-gpio");
212