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authorVille Syrjala <syrjala@sci.fi>2008-02-06 04:39:01 -0500
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-06 13:41:15 -0500
commitad8dc96e3b2c3e28854e0de4ab49351ed547b30c (patch)
tree6faab05e76206f130333ccff4c080600ed00d332 /drivers/w1
parent4cdf854f7d60498bbda436068a118b95059b244b (diff)
w1-gpio: add GPIO w1 bus master driver
Add a GPIO 1-wire bus master driver. The driver used the GPIO API to control the wire and the GPIO pin can be specified using platform data similar to i2c-gpio. The driver was tested with AT91SAM9260 + DS2401. Signed-off-by: Ville Syrjala <syrjala@sci.fi> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/w1')
-rw-r--r--drivers/w1/masters/Kconfig10
-rw-r--r--drivers/w1/masters/Makefile1
-rw-r--r--drivers/w1/masters/w1-gpio.c124
3 files changed, 135 insertions, 0 deletions
diff --git a/drivers/w1/masters/Kconfig b/drivers/w1/masters/Kconfig
index 8236d447adf5..c4493091c655 100644
--- a/drivers/w1/masters/Kconfig
+++ b/drivers/w1/masters/Kconfig
@@ -42,5 +42,15 @@ config W1_MASTER_DS1WM
42 in HP iPAQ devices like h5xxx, h2200, and ASIC3-based like 42 in HP iPAQ devices like h5xxx, h2200, and ASIC3-based like
43 hx4700. 43 hx4700.
44 44
45config W1_MASTER_GPIO
46 tristate "GPIO 1-wire busmaster"
47 depends on GENERIC_GPIO
48 help
49 Say Y here if you want to communicate with your 1-wire devices using
50 GPIO pins. This driver uses the GPIO API to control the wire.
51
52 This support is also available as a module. If so, the module
53 will be called w1-gpio.ko.
54
45endmenu 55endmenu
46 56
diff --git a/drivers/w1/masters/Makefile b/drivers/w1/masters/Makefile
index 11551b328186..1420b5bbdda8 100644
--- a/drivers/w1/masters/Makefile
+++ b/drivers/w1/masters/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_W1_MASTER_MATROX) += matrox_w1.o
6obj-$(CONFIG_W1_MASTER_DS2490) += ds2490.o 6obj-$(CONFIG_W1_MASTER_DS2490) += ds2490.o
7obj-$(CONFIG_W1_MASTER_DS2482) += ds2482.o 7obj-$(CONFIG_W1_MASTER_DS2482) += ds2482.o
8obj-$(CONFIG_W1_MASTER_DS1WM) += ds1wm.o 8obj-$(CONFIG_W1_MASTER_DS1WM) += ds1wm.o
9obj-$(CONFIG_W1_MASTER_GPIO) += w1-gpio.o
diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
new file mode 100644
index 000000000000..9e1138a75e8b
--- /dev/null
+++ b/drivers/w1/masters/w1-gpio.c
@@ -0,0 +1,124 @@
1/*
2 * w1-gpio - GPIO w1 bus master driver
3 *
4 * Copyright (C) 2007 Ville Syrjala <syrjala@sci.fi>
5 *
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 */
10
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/w1-gpio.h>
15
16#include "../w1.h"
17#include "../w1_int.h"
18
19#include <asm/gpio.h>
20
21static void w1_gpio_write_bit_dir(void *data, u8 bit)
22{
23 struct w1_gpio_platform_data *pdata = data;
24
25 if (bit)
26 gpio_direction_input(pdata->pin);
27 else
28 gpio_direction_output(pdata->pin, 0);
29}
30
31static void w1_gpio_write_bit_val(void *data, u8 bit)
32{
33 struct w1_gpio_platform_data *pdata = data;
34
35 gpio_set_value(pdata->pin, bit);
36}
37
38static u8 w1_gpio_read_bit(void *data)
39{
40 struct w1_gpio_platform_data *pdata = data;
41
42 return gpio_get_value(pdata->pin);
43}
44
45static int __init w1_gpio_probe(struct platform_device *pdev)
46{
47 struct w1_bus_master *master;
48 struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
49 int err;
50
51 if (!pdata)
52 return -ENXIO;
53
54 master = kzalloc(sizeof(struct w1_bus_master), GFP_KERNEL);
55 if (!master)
56 return -ENOMEM;
57
58 err = gpio_request(pdata->pin, "w1");
59 if (err)
60 goto free_master;
61
62 master->data = pdata;
63 master->read_bit = w1_gpio_read_bit;
64
65 if (pdata->is_open_drain) {
66 gpio_direction_output(pdata->pin, 1);
67 master->write_bit = w1_gpio_write_bit_val;
68 } else {
69 gpio_direction_input(pdata->pin);
70 master->write_bit = w1_gpio_write_bit_dir;
71 }
72
73 err = w1_add_master_device(master);
74 if (err)
75 goto free_gpio;
76
77 platform_set_drvdata(pdev, master);
78
79 return 0;
80
81 free_gpio:
82 gpio_free(pdata->pin);
83 free_master:
84 kfree(master);
85
86 return err;
87}
88
89static int __exit w1_gpio_remove(struct platform_device *pdev)
90{
91 struct w1_bus_master *master = platform_get_drvdata(pdev);
92 struct w1_gpio_platform_data *pdata = pdev->dev.platform_data;
93
94 w1_remove_master_device(master);
95 gpio_free(pdata->pin);
96 kfree(master);
97
98 return 0;
99}
100
101static struct platform_driver w1_gpio_driver = {
102 .driver = {
103 .name = "w1-gpio",
104 .owner = THIS_MODULE,
105 },
106 .remove = __exit_p(w1_gpio_remove),
107};
108
109static int __init w1_gpio_init(void)
110{
111 return platform_driver_probe(&w1_gpio_driver, w1_gpio_probe);
112}
113
114static void __exit w1_gpio_exit(void)
115{
116 platform_driver_unregister(&w1_gpio_driver);
117}
118
119module_init(w1_gpio_init);
120module_exit(w1_gpio_exit);
121
122MODULE_DESCRIPTION("GPIO w1 bus master driver");
123MODULE_AUTHOR("Ville Syrjala <syrjala@sci.fi>");
124MODULE_LICENSE("GPL");