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
twl6040gpo_get(struct gpio_chip * chip,unsigned offset)35 static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
36 {
37 struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
38 int ret = 0;
39
40 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
41 if (ret < 0)
42 return ret;
43
44 return (ret >> offset) & 1;
45 }
46
twl6040gpo_direction_out(struct gpio_chip * chip,unsigned offset,int value)47 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
48 int value)
49 {
50 /* This only drives GPOs, and can't change direction */
51 return 0;
52 }
53
twl6040gpo_set(struct gpio_chip * chip,unsigned offset,int value)54 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
55 {
56 struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
57 int ret;
58 u8 gpoctl;
59
60 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
61 if (ret < 0)
62 return;
63
64 if (value)
65 gpoctl = ret | (1 << offset);
66 else
67 gpoctl = ret & ~(1 << offset);
68
69 twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
70 }
71
72 static struct gpio_chip twl6040gpo_chip = {
73 .label = "twl6040",
74 .owner = THIS_MODULE,
75 .get = twl6040gpo_get,
76 .direction_output = twl6040gpo_direction_out,
77 .set = twl6040gpo_set,
78 .can_sleep = true,
79 };
80
81 /*----------------------------------------------------------------------*/
82
gpo_twl6040_probe(struct platform_device * pdev)83 static int gpo_twl6040_probe(struct platform_device *pdev)
84 {
85 struct device *twl6040_core_dev = pdev->dev.parent;
86 struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
87 int ret;
88
89 twl6040gpo_chip.base = -1;
90
91 if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
92 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
93 else
94 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
95
96 twl6040gpo_chip.parent = &pdev->dev;
97 #ifdef CONFIG_OF_GPIO
98 twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
99 #endif
100
101 ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
102 if (ret < 0) {
103 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
104 twl6040gpo_chip.ngpio = 0;
105 }
106
107 return ret;
108 }
109
110 /* Note: this hardware lives inside an I2C-based multi-function device. */
111 MODULE_ALIAS("platform:twl6040-gpo");
112
113 static struct platform_driver gpo_twl6040_driver = {
114 .driver = {
115 .name = "twl6040-gpo",
116 },
117 .probe = gpo_twl6040_probe,
118 };
119
120 module_platform_driver(gpo_twl6040_driver);
121
122 MODULE_AUTHOR("Texas Instruments, Inc.");
123 MODULE_DESCRIPTION("GPO interface for TWL6040");
124 MODULE_LICENSE("GPL");
125