gpio-arizona.c

  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_put_autosuspend(chip->parent);
 43	}
 44
 45	return 0;
 46}
 47
 48static 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
 93static 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
122static 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
135static 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
145static 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
201static struct platform_driver arizona_gpio_driver = {
202	.driver.name	= "arizona-gpio",
203	.probe		= arizona_gpio_probe,
204};
205
206module_platform_driver(arizona_gpio_driver);
207
208MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
209MODULE_DESCRIPTION("GPIO interface for Arizona devices");
210MODULE_LICENSE("GPL");
211MODULE_ALIAS("platform:arizona-gpio");