xref: /openbmc/linux/drivers/gpio/gpio-twl6040.c (revision b34e08d5)
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 
35 static struct gpio_chip twl6040gpo_chip;
36 
37 static 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 
49 static 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 
56 static 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 
74 static 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 
85 static 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 
112 static int gpo_twl6040_remove(struct platform_device *pdev)
113 {
114 	return gpiochip_remove(&twl6040gpo_chip);
115 }
116 
117 /* Note:  this hardware lives inside an I2C-based multi-function device. */
118 MODULE_ALIAS("platform:twl6040-gpo");
119 
120 static struct platform_driver gpo_twl6040_driver = {
121 	.driver = {
122 		.name	= "twl6040-gpo",
123 		.owner	= THIS_MODULE,
124 	},
125 	.probe		= gpo_twl6040_probe,
126 	.remove		= gpo_twl6040_remove,
127 };
128 
129 module_platform_driver(gpo_twl6040_driver);
130 
131 MODULE_AUTHOR("Texas Instruments, Inc.");
132 MODULE_DESCRIPTION("GPO interface for TWL6040");
133 MODULE_LICENSE("GPL");
134