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 GPIO_LINE_DIRECTION_OUT;
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");
184