1/*
  2 * Copyright (C) 2016 Texas Instruments Incorporated - http://www.ti.com/
  3 *	Keerthy <j-keerthy@ti.com>
  4 *
  5 * This program is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU General Public License version 2 as
  7 * published by the Free Software Foundation.
  8 *
  9 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 10 * kind, whether expressed or implied; without even the implied warranty
 11 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12 * GNU General Public License version 2 for more details.
 13 *
 14 * Based on the TPS65218 driver
 15 */
 16
 17#include <linux/gpio/driver.h>
 18#include <linux/module.h>
 19#include <linux/platform_device.h>
 20#include <linux/regmap.h>
 21
 22#include <linux/mfd/lp873x.h>
 23
 24#define BITS_PER_GPO		0x4
 25#define LP873X_GPO_CTRL_OD	0x2
 26
 27struct lp873x_gpio {
 28	struct gpio_chip chip;
 29	struct lp873x *lp873;
 30};
 31
 32static int lp873x_gpio_get_direction(struct gpio_chip *chip,
 33				     unsigned int offset)
 34{
 35	/* This device is output only */
 36	return 0;
 37}
 38
 39static int lp873x_gpio_direction_input(struct gpio_chip *chip,
 40				       unsigned int offset)
 41{
 42	/* This device is output only */
 43	return -EINVAL;
 44}
 45
 46static int lp873x_gpio_direction_output(struct gpio_chip *chip,
 47					unsigned int offset, int value)
 48{
 49	struct lp873x_gpio *gpio = gpiochip_get_data(chip);
 50
 51	/* Set the initial value */
 52	return regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
 53				  BIT(offset * BITS_PER_GPO),
 54				  value ? BIT(offset * BITS_PER_GPO) : 0);
 55}
 56
 57static int lp873x_gpio_get(struct gpio_chip *chip, unsigned int offset)
 58{
 59	struct lp873x_gpio *gpio = gpiochip_get_data(chip);
 60	int ret, val;
 61
 62	ret = regmap_read(gpio->lp873->regmap, LP873X_REG_GPO_CTRL, &val);
 63	if (ret < 0)
 64		return ret;
 65
 66	return val & BIT(offset * BITS_PER_GPO);
 67}
 68
 69static void lp873x_gpio_set(struct gpio_chip *chip, unsigned int offset,
 70			    int value)
 71{
 72	struct lp873x_gpio *gpio = gpiochip_get_data(chip);
 73
 74	regmap_update_bits(gpio->lp873->regmap, LP873X_REG_GPO_CTRL,
 75			   BIT(offset * BITS_PER_GPO),
 76			   value ? BIT(offset * BITS_PER_GPO) : 0);
 77}
 78
 79static int lp873x_gpio_request(struct gpio_chip *gc, unsigned int offset)
 80{
 81	struct lp873x_gpio *gpio = gpiochip_get_data(gc);
 82	int ret;
 83
 84	switch (offset) {
 85	case 0:
 86		/* No MUX Set up Needed for GPO */
 87		break;
 88	case 1:
 89		/* Setup the CLKIN_PIN_SEL MUX to GPO2 */
 90		ret = regmap_update_bits(gpio->lp873->regmap, LP873X_REG_CONFIG,
 91					 LP873X_CONFIG_CLKIN_PIN_SEL, 0);
 92		if (ret)
 93			return ret;
 94
 95		break;
 96	default:
 97		return -EINVAL;
 98	}
 99
100	return 0;
101}
102
103static int lp873x_gpio_set_config(struct gpio_chip *gc, unsigned offset,
104				  unsigned long config)
105{
106	struct lp873x_gpio *gpio = gpiochip_get_data(gc);
107
108	switch (pinconf_to_config_param(config)) {
109	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
110		return regmap_update_bits(gpio->lp873->regmap,
111					  LP873X_REG_GPO_CTRL,
112					  BIT(offset * BITS_PER_GPO +
113					  LP873X_GPO_CTRL_OD),
114					  BIT(offset * BITS_PER_GPO +
115					  LP873X_GPO_CTRL_OD));
116
117	case PIN_CONFIG_DRIVE_PUSH_PULL:
118		return regmap_update_bits(gpio->lp873->regmap,
119					  LP873X_REG_GPO_CTRL,
120					  BIT(offset * BITS_PER_GPO +
121					  LP873X_GPO_CTRL_OD), 0);
122	default:
123		return -ENOTSUPP;
124	}
125}
126
127static const struct gpio_chip template_chip = {
128	.label			= "lp873x-gpio",
129	.owner			= THIS_MODULE,
130	.request		= lp873x_gpio_request,
131	.get_direction		= lp873x_gpio_get_direction,
132	.direction_input	= lp873x_gpio_direction_input,
133	.direction_output	= lp873x_gpio_direction_output,
134	.get			= lp873x_gpio_get,
135	.set			= lp873x_gpio_set,
136	.set_config		= lp873x_gpio_set_config,
137	.base			= -1,
138	.ngpio			= 2,
139	.can_sleep		= true,
140};
141
142static int lp873x_gpio_probe(struct platform_device *pdev)
143{
144	struct lp873x_gpio *gpio;
145	int ret;
146
147	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
148	if (!gpio)
149		return -ENOMEM;
150
151	platform_set_drvdata(pdev, gpio);
152
153	gpio->lp873 = dev_get_drvdata(pdev->dev.parent);
154	gpio->chip = template_chip;
155	gpio->chip.parent = gpio->lp873->dev;
156
157	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
158	if (ret < 0) {
159		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
160		return ret;
161	}
162
163	return 0;
164}
165
166static const struct platform_device_id lp873x_gpio_id_table[] = {
167	{ "lp873x-gpio", },
168	{ /* sentinel */ }
169};
170MODULE_DEVICE_TABLE(platform, lp873x_gpio_id_table);
171
172static struct platform_driver lp873x_gpio_driver = {
173	.driver = {
174		.name = "lp873x-gpio",
175	},
176	.probe = lp873x_gpio_probe,
177	.id_table = lp873x_gpio_id_table,
178};
179module_platform_driver(lp873x_gpio_driver);
180
181MODULE_AUTHOR("Keerthy <j-keerthy@ti.com>");
182MODULE_DESCRIPTION("LP873X GPIO driver");
183MODULE_LICENSE("GPL v2");