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_mark_last_busy(chip->parent);
43 pm_runtime_put_autosuspend(chip->parent);
44 }
45
46 return 0;
47 }
48
arizona_gpio_get(struct gpio_chip * chip,unsigned offset)49 static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
50 {
51 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
52 struct arizona *arizona = arizona_gpio->arizona;
53 unsigned int reg, val;
54 int ret;
55
56 reg = ARIZONA_GPIO1_CTRL + offset;
57 ret = regmap_read(arizona->regmap, reg, &val);
58 if (ret < 0)
59 return ret;
60
61 /* Resume to read actual registers for input pins */
62 if (val & ARIZONA_GPN_DIR) {
63 ret = pm_runtime_get_sync(chip->parent);
64 if (ret < 0) {
65 dev_err(chip->parent, "Failed to resume: %d\n", ret);
66 pm_runtime_put_autosuspend(chip->parent);
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 pm_runtime_put_autosuspend(chip->parent);
76 return ret;
77 }
78
79 ret = regmap_read(arizona->regmap, reg, &val);
80 if (ret < 0) {
81 pm_runtime_put_autosuspend(chip->parent);
82 return ret;
83 }
84
85 pm_runtime_mark_last_busy(chip->parent);
86 pm_runtime_put_autosuspend(chip->parent);
87 }
88
89 if (val & ARIZONA_GPN_LVL)
90 return 1;
91 else
92 return 0;
93 }
94
arizona_gpio_direction_out(struct gpio_chip * chip,unsigned offset,int value)95 static int arizona_gpio_direction_out(struct gpio_chip *chip,
96 unsigned offset, int value)
97 {
98 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
99 struct arizona *arizona = arizona_gpio->arizona;
100 bool persistent = gpiochip_line_is_persistent(chip, offset);
101 unsigned int val;
102 int ret;
103
104 ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
105 if (ret < 0)
106 return ret;
107
108 if ((val & ARIZONA_GPN_DIR) && persistent) {
109 ret = pm_runtime_get_sync(chip->parent);
110 if (ret < 0) {
111 dev_err(chip->parent, "Failed to resume: %d\n", ret);
112 pm_runtime_put(chip->parent);
113 return ret;
114 }
115 }
116
117 if (value)
118 value = ARIZONA_GPN_LVL;
119
120 return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
121 ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
122 }
123
arizona_gpio_set(struct gpio_chip * chip,unsigned offset,int value)124 static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
125 {
126 struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
127 struct arizona *arizona = arizona_gpio->arizona;
128
129 if (value)
130 value = ARIZONA_GPN_LVL;
131
132 regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
133 ARIZONA_GPN_LVL, value);
134 }
135
136 static const struct gpio_chip template_chip = {
137 .label = "arizona",
138 .owner = THIS_MODULE,
139 .direction_input = arizona_gpio_direction_in,
140 .get = arizona_gpio_get,
141 .direction_output = arizona_gpio_direction_out,
142 .set = arizona_gpio_set,
143 .can_sleep = true,
144 };
145
arizona_gpio_probe(struct platform_device * pdev)146 static int arizona_gpio_probe(struct platform_device *pdev)
147 {
148 struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
149 struct arizona_pdata *pdata = &arizona->pdata;
150 struct arizona_gpio *arizona_gpio;
151 int ret;
152
153 device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
154
155 arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
156 GFP_KERNEL);
157 if (!arizona_gpio)
158 return -ENOMEM;
159
160 arizona_gpio->arizona = arizona;
161 arizona_gpio->gpio_chip = template_chip;
162 arizona_gpio->gpio_chip.parent = &pdev->dev;
163
164 switch (arizona->type) {
165 case WM5102:
166 case WM5110:
167 case WM8280:
168 case WM8997:
169 case WM8998:
170 case WM1814:
171 arizona_gpio->gpio_chip.ngpio = 5;
172 break;
173 case WM1831:
174 case CS47L24:
175 arizona_gpio->gpio_chip.ngpio = 2;
176 break;
177 default:
178 dev_err(&pdev->dev, "Unknown chip variant %d\n",
179 arizona->type);
180 return -EINVAL;
181 }
182
183 if (pdata->gpio_base)
184 arizona_gpio->gpio_chip.base = pdata->gpio_base;
185 else
186 arizona_gpio->gpio_chip.base = -1;
187
188 pm_runtime_enable(&pdev->dev);
189
190 ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
191 arizona_gpio);
192 if (ret < 0) {
193 pm_runtime_disable(&pdev->dev);
194 dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
195 ret);
196 return ret;
197 }
198
199 return 0;
200 }
201
202 static struct platform_driver arizona_gpio_driver = {
203 .driver.name = "arizona-gpio",
204 .probe = arizona_gpio_probe,
205 };
206
207 module_platform_driver(arizona_gpio_driver);
208
209 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
210 MODULE_DESCRIPTION("GPIO interface for Arizona devices");
211 MODULE_LICENSE("GPL");
212 MODULE_ALIAS("platform:arizona-gpio");
213
