1/*
2 * GPIO driver for RICOH583 power management chip.
3 *
4 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
5 * Author: Laxman dewangan <ldewangan@nvidia.com>
6 *
7 * Based on code
8 *	Copyright (C) 2011 RICOH COMPANY,LTD
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms and conditions of the GNU General Public License,
12 * version 2, as published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope it will be useful, but WITHOUT
15 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17 * more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 *
22 */
23#include <linux/init.h>
24#include <linux/kernel.h>
25#include <linux/slab.h>
26#include <linux/module.h>
27#include <linux/platform_device.h>
28#include <linux/device.h>
29#include <linux/gpio.h>
30#include <linux/mfd/rc5t583.h>
31
32struct rc5t583_gpio {
33	struct gpio_chip gpio_chip;
34	struct rc5t583 *rc5t583;
35};
36
37static inline struct rc5t583_gpio *to_rc5t583_gpio(struct gpio_chip *chip)
38{
39	return container_of(chip, struct rc5t583_gpio, gpio_chip);
40}
41
42static int rc5t583_gpio_get(struct gpio_chip *gc, unsigned int offset)
43{
44	struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
45	struct device *parent = rc5t583_gpio->rc5t583->dev;
46	uint8_t val = 0;
47	int ret;
48
49	ret = rc5t583_read(parent, RC5T583_GPIO_MON_IOIN, &val);
50	if (ret < 0)
51		return ret;
52
53	return !!(val & BIT(offset));
54}
55
56static void rc5t583_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
57{
58	struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
59	struct device *parent = rc5t583_gpio->rc5t583->dev;
60	if (val)
61		rc5t583_set_bits(parent, RC5T583_GPIO_IOOUT, BIT(offset));
62	else
63		rc5t583_clear_bits(parent, RC5T583_GPIO_IOOUT, BIT(offset));
64}
65
66static int rc5t583_gpio_dir_input(struct gpio_chip *gc, unsigned int offset)
67{
68	struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
69	struct device *parent = rc5t583_gpio->rc5t583->dev;
70	int ret;
71
72	ret = rc5t583_clear_bits(parent, RC5T583_GPIO_IOSEL, BIT(offset));
73	if (ret < 0)
74		return ret;
75
76	/* Set pin to gpio mode */
77	return rc5t583_clear_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
78}
79
80static int rc5t583_gpio_dir_output(struct gpio_chip *gc, unsigned offset,
81			int value)
82{
83	struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
84	struct device *parent = rc5t583_gpio->rc5t583->dev;
85	int ret;
86
87	rc5t583_gpio_set(gc, offset, value);
88	ret = rc5t583_set_bits(parent, RC5T583_GPIO_IOSEL, BIT(offset));
89	if (ret < 0)
90		return ret;
91
92	/* Set pin to gpio mode */
93	return rc5t583_clear_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
94}
95
96static int rc5t583_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
97{
98	struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
99
100	if (offset < RC5T583_MAX_GPIO)
101		return rc5t583_gpio->rc5t583->irq_base +
102				RC5T583_IRQ_GPIO0 + offset;
103	return -EINVAL;
104}
105
106static void rc5t583_gpio_free(struct gpio_chip *gc, unsigned offset)
107{
108	struct rc5t583_gpio *rc5t583_gpio = to_rc5t583_gpio(gc);
109	struct device *parent = rc5t583_gpio->rc5t583->dev;
110
111	rc5t583_set_bits(parent, RC5T583_GPIO_PGSEL, BIT(offset));
112}
113
114static int rc5t583_gpio_probe(struct platform_device *pdev)
115{
116	struct rc5t583 *rc5t583 = dev_get_drvdata(pdev->dev.parent);
117	struct rc5t583_platform_data *pdata = dev_get_platdata(rc5t583->dev);
118	struct rc5t583_gpio *rc5t583_gpio;
119
120	rc5t583_gpio = devm_kzalloc(&pdev->dev, sizeof(*rc5t583_gpio),
121					GFP_KERNEL);
122	if (!rc5t583_gpio)
123		return -ENOMEM;
124
125	rc5t583_gpio->gpio_chip.label = "gpio-rc5t583",
126	rc5t583_gpio->gpio_chip.owner = THIS_MODULE,
127	rc5t583_gpio->gpio_chip.free = rc5t583_gpio_free,
128	rc5t583_gpio->gpio_chip.direction_input = rc5t583_gpio_dir_input,
129	rc5t583_gpio->gpio_chip.direction_output = rc5t583_gpio_dir_output,
130	rc5t583_gpio->gpio_chip.set = rc5t583_gpio_set,
131	rc5t583_gpio->gpio_chip.get = rc5t583_gpio_get,
132	rc5t583_gpio->gpio_chip.to_irq = rc5t583_gpio_to_irq,
133	rc5t583_gpio->gpio_chip.ngpio = RC5T583_MAX_GPIO,
134	rc5t583_gpio->gpio_chip.can_sleep = true,
135	rc5t583_gpio->gpio_chip.dev = &pdev->dev;
136	rc5t583_gpio->gpio_chip.base = -1;
137	rc5t583_gpio->rc5t583 = rc5t583;
138
139	if (pdata && pdata->gpio_base)
140		rc5t583_gpio->gpio_chip.base = pdata->gpio_base;
141
142	platform_set_drvdata(pdev, rc5t583_gpio);
143
144	return gpiochip_add(&rc5t583_gpio->gpio_chip);
145}
146
147static int rc5t583_gpio_remove(struct platform_device *pdev)
148{
149	struct rc5t583_gpio *rc5t583_gpio = platform_get_drvdata(pdev);
150
151	gpiochip_remove(&rc5t583_gpio->gpio_chip);
152	return 0;
153}
154
155static struct platform_driver rc5t583_gpio_driver = {
156	.driver = {
157		.name    = "rc5t583-gpio",
158	},
159	.probe		= rc5t583_gpio_probe,
160	.remove		= rc5t583_gpio_remove,
161};
162
163static int __init rc5t583_gpio_init(void)
164{
165	return platform_driver_register(&rc5t583_gpio_driver);
166}
167subsys_initcall(rc5t583_gpio_init);
168
169static void __exit rc5t583_gpio_exit(void)
170{
171	platform_driver_unregister(&rc5t583_gpio_driver);
172}
173module_exit(rc5t583_gpio_exit);
174
175MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
176MODULE_DESCRIPTION("GPIO interface for RC5T583");
177MODULE_LICENSE("GPL v2");
178MODULE_ALIAS("platform:rc5t583-gpio");
179