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
21struct arizona_gpio {
22	struct arizona *arizona;
23	struct gpio_chip gpio_chip;
24};
25
26static 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
49static 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
95static 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
124static 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
136static 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
146static 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
202static struct platform_driver arizona_gpio_driver = {
203	.driver.name	= "arizona-gpio",
204	.probe		= arizona_gpio_probe,
205};
206
207module_platform_driver(arizona_gpio_driver);
208
209MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
210MODULE_DESCRIPTION("GPIO interface for Arizona devices");
211MODULE_LICENSE("GPL");
212MODULE_ALIAS("platform:arizona-gpio");
213