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 int offset,int value)124 static int arizona_gpio_set(struct gpio_chip *chip, unsigned int offset,
125 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 return 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_rv = 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 device_set_node(&pdev->dev, dev_fwnode(pdev->dev.parent));
155
156 arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
157 GFP_KERNEL);
158 if (!arizona_gpio)
159 return -ENOMEM;
160
161 arizona_gpio->arizona = arizona;
162 arizona_gpio->gpio_chip = template_chip;
163 arizona_gpio->gpio_chip.parent = &pdev->dev;
164
165 switch (arizona->type) {
166 case WM5102:
167 case WM5110:
168 case WM8280:
169 case WM8997:
170 case WM8998:
171 case WM1814:
172 arizona_gpio->gpio_chip.ngpio = 5;
173 break;
174 case WM1831:
175 case CS47L24:
176 arizona_gpio->gpio_chip.ngpio = 2;
177 break;
178 default:
179 dev_err(&pdev->dev, "Unknown chip variant %d\n",
180 arizona->type);
181 return -EINVAL;
182 }
183
184 if (pdata->gpio_base)
185 arizona_gpio->gpio_chip.base = pdata->gpio_base;
186 else
187 arizona_gpio->gpio_chip.base = -1;
188
189 pm_runtime_enable(&pdev->dev);
190
191 ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
192 arizona_gpio);
193 if (ret < 0) {
194 pm_runtime_disable(&pdev->dev);
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