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/kernel.h>
 11#include <linux/slab.h>
 12#include <linux/module.h>
 13#include <linux/gpio/driver.h>
 14#include <linux/platform_device.h>
 15#include <linux/pm_runtime.h>
 16#include <linux/seq_file.h>
 17
 18#include <linux/mfd/arizona/core.h>
 19#include <linux/mfd/arizona/pdata.h>
 20#include <linux/mfd/arizona/registers.h>
 21
 22struct arizona_gpio {
 23	struct arizona *arizona;
 24	struct gpio_chip gpio_chip;
 25};
 26
 27static int arizona_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
 28{
 29	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
 30	struct arizona *arizona = arizona_gpio->arizona;
 31	bool persistent = gpiochip_line_is_persistent(chip, offset);
 32	bool change;
 33	int ret;
 34
 35	ret = regmap_update_bits_check(arizona->regmap,
 36				       ARIZONA_GPIO1_CTRL + offset,
 37				       ARIZONA_GPN_DIR, ARIZONA_GPN_DIR,
 38				       &change);
 39	if (ret < 0)
 40		return ret;
 41
 42	if (change && persistent) {
 43		pm_runtime_mark_last_busy(chip->parent);
 44		pm_runtime_put_autosuspend(chip->parent);
 45	}
 46
 47	return 0;
 48}
 49
 50static int arizona_gpio_get(struct gpio_chip *chip, unsigned offset)
 51{
 52	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
 53	struct arizona *arizona = arizona_gpio->arizona;
 54	unsigned int reg, val;
 55	int ret;
 56
 57	reg = ARIZONA_GPIO1_CTRL + offset;
 58	ret = regmap_read(arizona->regmap, reg, &val);
 59	if (ret < 0)
 60		return ret;
 61
 62	/* Resume to read actual registers for input pins */
 63	if (val & ARIZONA_GPN_DIR) {
 64		ret = pm_runtime_get_sync(chip->parent);
 65		if (ret < 0) {
 66			dev_err(chip->parent, "Failed to resume: %d\n", ret);
 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			return ret;
 76		}
 77
 78		ret = regmap_read(arizona->regmap, reg, &val);
 79		if (ret < 0)
 80			return ret;
 81
 82		pm_runtime_mark_last_busy(chip->parent);
 83		pm_runtime_put_autosuspend(chip->parent);
 84	}
 85
 86	if (val & ARIZONA_GPN_LVL)
 87		return 1;
 88	else
 89		return 0;
 90}
 91
 92static int arizona_gpio_direction_out(struct gpio_chip *chip,
 93				     unsigned offset, int value)
 94{
 95	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
 96	struct arizona *arizona = arizona_gpio->arizona;
 97	bool persistent = gpiochip_line_is_persistent(chip, offset);
 98	unsigned int val;
 99	int ret;
100
101	ret = regmap_read(arizona->regmap, ARIZONA_GPIO1_CTRL + offset, &val);
102	if (ret < 0)
103		return ret;
104
105	if ((val & ARIZONA_GPN_DIR) && persistent) {
106		ret = pm_runtime_get_sync(chip->parent);
107		if (ret < 0) {
108			dev_err(chip->parent, "Failed to resume: %d\n", ret);
109			return ret;
110		}
111	}
112
113	if (value)
114		value = ARIZONA_GPN_LVL;
115
116	return regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
117				  ARIZONA_GPN_DIR | ARIZONA_GPN_LVL, value);
118}
119
120static void arizona_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
121{
122	struct arizona_gpio *arizona_gpio = gpiochip_get_data(chip);
123	struct arizona *arizona = arizona_gpio->arizona;
124
125	if (value)
126		value = ARIZONA_GPN_LVL;
127
128	regmap_update_bits(arizona->regmap, ARIZONA_GPIO1_CTRL + offset,
129			   ARIZONA_GPN_LVL, value);
130}
131
132static const struct gpio_chip template_chip = {
133	.label			= "arizona",
134	.owner			= THIS_MODULE,
135	.direction_input	= arizona_gpio_direction_in,
136	.get			= arizona_gpio_get,
137	.direction_output	= arizona_gpio_direction_out,
138	.set			= arizona_gpio_set,
139	.can_sleep		= true,
140};
141
142static int arizona_gpio_probe(struct platform_device *pdev)
143{
144	struct arizona *arizona = dev_get_drvdata(pdev->dev.parent);
145	struct arizona_pdata *pdata = &arizona->pdata;
146	struct arizona_gpio *arizona_gpio;
147	int ret;
148
149	arizona_gpio = devm_kzalloc(&pdev->dev, sizeof(*arizona_gpio),
150				    GFP_KERNEL);
151	if (!arizona_gpio)
152		return -ENOMEM;
153
154	arizona_gpio->arizona = arizona;
155	arizona_gpio->gpio_chip = template_chip;
156	arizona_gpio->gpio_chip.parent = &pdev->dev;
157#ifdef CONFIG_OF_GPIO
158	arizona_gpio->gpio_chip.of_node = arizona->dev->of_node;
159#endif
160
161	switch (arizona->type) {
162	case WM5102:
163	case WM5110:
164	case WM8280:
165	case WM8997:
166	case WM8998:
167	case WM1814:
168		arizona_gpio->gpio_chip.ngpio = 5;
169		break;
170	case WM1831:
171	case CS47L24:
172		arizona_gpio->gpio_chip.ngpio = 2;
173		break;
174	default:
175		dev_err(&pdev->dev, "Unknown chip variant %d\n",
176			arizona->type);
177		return -EINVAL;
178	}
179
180	if (pdata->gpio_base)
181		arizona_gpio->gpio_chip.base = pdata->gpio_base;
182	else
183		arizona_gpio->gpio_chip.base = -1;
184
185	pm_runtime_enable(&pdev->dev);
186
187	ret = devm_gpiochip_add_data(&pdev->dev, &arizona_gpio->gpio_chip,
188				     arizona_gpio);
189	if (ret < 0) {
190		dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
191			ret);
192		return ret;
193	}
194
195	return 0;
196}
197
198static struct platform_driver arizona_gpio_driver = {
199	.driver.name	= "arizona-gpio",
200	.probe		= arizona_gpio_probe,
201};
202
203module_platform_driver(arizona_gpio_driver);
204
205MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
206MODULE_DESCRIPTION("GPIO interface for Arizona devices");
207MODULE_LICENSE("GPL");
208MODULE_ALIAS("platform:arizona-gpio");