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
twl6040gpo_get(struct gpio_chip * chip,unsigned offset)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
twl6040gpo_direction_out(struct gpio_chip * chip,unsigned offset,int value)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
twl6040gpo_set(struct gpio_chip * chip,unsigned offset,int value)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 = 1,
81 };
82
83 /*----------------------------------------------------------------------*/
84
gpo_twl6040_probe(struct platform_device * pdev)85 static int gpo_twl6040_probe(struct platform_device *pdev)
86 {
87 struct twl6040_gpo_data *pdata = pdev->dev.platform_data;
88 struct device *twl6040_core_dev = pdev->dev.parent;
89 struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
90 int ret;
91
92 if (pdata)
93 twl6040gpo_chip.base = pdata->gpio_base;
94 else
95 twl6040gpo_chip.base = -1;
96
97 if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
98 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
99 else
100 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
101
102 twl6040gpo_chip.dev = &pdev->dev;
103 #ifdef CONFIG_OF_GPIO
104 twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
105 #endif
106
107 ret = gpiochip_add(&twl6040gpo_chip);
108 if (ret < 0) {
109 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
110 twl6040gpo_chip.ngpio = 0;
111 }
112
113 return ret;
114 }
115
gpo_twl6040_remove(struct platform_device * pdev)116 static int gpo_twl6040_remove(struct platform_device *pdev)
117 {
118 return gpiochip_remove(&twl6040gpo_chip);
119 }
120
121 /* Note: this hardware lives inside an I2C-based multi-function device. */
122 MODULE_ALIAS("platform:twl6040-gpo");
123
124 static struct platform_driver gpo_twl6040_driver = {
125 .driver = {
126 .name = "twl6040-gpo",
127 .owner = THIS_MODULE,
128 },
129 .probe = gpo_twl6040_probe,
130 .remove = gpo_twl6040_remove,
131 };
132
133 module_platform_driver(gpo_twl6040_driver);
134
135 MODULE_AUTHOR("Texas Instruments, Inc.");
136 MODULE_DESCRIPTION("GPO interface for TWL6040");
137 MODULE_LICENSE("GPL");
138