Merge tag 'v3.3.7' into 3.3/master
[zen-stable.git] / drivers / w1 / masters / w1-gpio.c
blobfcbe742188a50e93b15105e6ccfa77d7a53663a6
1 /*
2 * w1-gpio - GPIO w1 bus master driver
4 * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
9 */
11 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/w1-gpio.h>
17 #include "../w1.h"
18 #include "../w1_int.h"
20 #include <asm/gpio.h>
22 static void w1_gpio_write_bit_dir(void *data, u8 bit)
24 struct w1_gpio_platform_data *pdata = data;
26 if (bit)
27 gpio_direction_input(pdata->pin);
28 else
29 gpio_direction_output(pdata->pin, 0);
32 static void w1_gpio_write_bit_val(void *data, u8 bit)
34 struct w1_gpio_platform_data *pdata = data;
36 gpio_set_value(pdata->pin, bit);
39 static u8 w1_gpio_read_bit(void *data)
41 struct w1_gpio_platform_data *pdata = data;
43 return gpio_get_value(pdata->pin) ? 1 : 0;
46 static int __init w1_gpio_probe(struct platform_device *pdev)
48 struct w1_bus_master *master;
49 struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
50 int err;
52 if (!pdata)
53 return -ENXIO;
55 master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL);
56 if (!master)
57 return -ENOMEM;
59 err = gpio_request(pdata->pin, "w1");
60 if (err)
61 goto free_master;
63 master->data = pdata;
64 master->read_bit = w1_gpio_read_bit;
66 if (pdata->is_open_drain) {
67 gpio_direction_output(pdata->pin, 1);
68 master->write_bit = w1_gpio_write_bit_val;
69 } else {
70 gpio_direction_input(pdata->pin);
71 master->write_bit = w1_gpio_write_bit_dir;
74 err = w1_add_master_device(master);
75 if (err)
76 goto free_gpio;
78 if (pdata->enable_external_pullup)
79 pdata->enable_external_pullup(1);
81 platform_set_drvdata(pdev, master);
83 return 0;
85 free_gpio:
86 gpio_free(pdata->pin);
87 free_master:
88 kfree(master);
90 return err;
93 static int __exit w1_gpio_remove(struct platform_device *pdev)
95 struct w1_bus_master *master = platform_get_drvdata(pdev);
96 struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
98 if (pdata->enable_external_pullup)
99 pdata->enable_external_pullup(0);
101 w1_remove_master_device(master);
102 gpio_free(pdata->pin);
103 kfree(master);
105 return 0;
108 #ifdef CONFIG_PM
110 static int w1_gpio_suspend(struct platform_device *pdev, pm_message_t state)
112 struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
114 if (pdata->enable_external_pullup)
115 pdata->enable_external_pullup(0);
117 return 0;
120 static int w1_gpio_resume(struct platform_device *pdev)
122 struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
124 if (pdata->enable_external_pullup)
125 pdata->enable_external_pullup(1);
127 return 0;
130 #else
131 #define w1_gpio_suspend NULL
132 #define w1_gpio_resume NULL
133 #endif
135 static struct platform_driver w1_gpio_driver = {
136 .driver = {
137 .name = "w1-gpio",
138 .owner = THIS_MODULE,
140 .remove = __exit_p(w1_gpio_remove),
141 .suspend = w1_gpio_suspend,
142 .resume = w1_gpio_resume,
145 static int __init w1_gpio_init(void)
147 return platform_driver_probe(&w1_gpio_driver, w1_gpio_probe);
150 static void __exit w1_gpio_exit(void)
152 platform_driver_unregister(&w1_gpio_driver);
155 module_init(w1_gpio_init);
156 module_exit(w1_gpio_exit);
158 MODULE_DESCRIPTION("GPIO w1 bus master driver");
159 MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
160 MODULE_LICENSE("GPL");