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