1/*
2 * Access to GPOs on TWL6040 chip
3 *
4 * Copyright (C) 2012 Texas Instruments, Inc.
5 *
6 * Authors:
7 *	Sergio Aguirre <saaguirre@ti.com>
8 *	Peter Ujfalusi <peter.ujfalusi@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
23 */
24
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/kthread.h>
28#include <linux/irq.h>
29#include <linux/gpio.h>
30#include <linux/platform_device.h>
31#include <linux/of.h>
32
33#include <linux/mfd/twl6040.h>
34
35static struct gpio_chip twl6040gpo_chip;
36
37static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
38{
39	struct twl6040 *twl6040 = dev_get_drvdata(chip->dev->parent);
40	int ret = 0;
41
42	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
43	if (ret < 0)
44		return ret;
45
46	return (ret >> offset) & 1;
47}
48
49static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
50				    int value)
51{
52	/* This only drives GPOs, and can't change direction */
53	return 0;
54}
55
56static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
57{
58	struct twl6040 *twl6040 = dev_get_drvdata(chip->dev->parent);
59	int ret;
60	u8 gpoctl;
61
62	ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
63	if (ret < 0)
64		return;
65
66	if (value)
67		gpoctl = ret | (1 << offset);
68	else
69		gpoctl = ret & ~(1 << offset);
70
71	twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
72}
73
74static struct gpio_chip twl6040gpo_chip = {
75	.label			= "twl6040",
76	.owner			= THIS_MODULE,
77	.get			= twl6040gpo_get,
78	.direction_output	= twl6040gpo_direction_out,
79	.set			= twl6040gpo_set,
80	.can_sleep		= true,
81};
82
83/*----------------------------------------------------------------------*/
84
85static int gpo_twl6040_probe(struct platform_device *pdev)
86{
87	struct device *twl6040_core_dev = pdev->dev.parent;
88	struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
89	int ret;
90
91	twl6040gpo_chip.base = -1;
92
93	if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
94		twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
95	else
96		twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
97
98	twl6040gpo_chip.dev = &pdev->dev;
99#ifdef CONFIG_OF_GPIO
100	twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
101#endif
102
103	ret = gpiochip_add(&twl6040gpo_chip);
104	if (ret < 0) {
105		dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
106		twl6040gpo_chip.ngpio = 0;
107	}
108
109	return ret;
110}
111
112static int gpo_twl6040_remove(struct platform_device *pdev)
113{
114	gpiochip_remove(&twl6040gpo_chip);
115	return 0;
116}
117
118/* Note:  this hardware lives inside an I2C-based multi-function device. */
119MODULE_ALIAS("platform:twl6040-gpo");
120
121static struct platform_driver gpo_twl6040_driver = {
122	.driver = {
123		.name	= "twl6040-gpo",
124		.owner	= THIS_MODULE,
125	},
126	.probe		= gpo_twl6040_probe,
127	.remove		= gpo_twl6040_remove,
128};
129
130module_platform_driver(gpo_twl6040_driver);
131
132MODULE_AUTHOR("Texas Instruments, Inc.");
133MODULE_DESCRIPTION("GPO interface for TWL6040");
134MODULE_LICENSE("GPL");
135