pcmcia: do not use io_req_t after call to pcmcia_request_io()
[linux-2.6.git] / drivers / input / misc / rb532_button.c
1 /*
2  * Support for the S1 button on Routerboard 532
3  *
4  * Copyright (C) 2009  Phil Sutter <n0-1@freewrt.org>
5  */
6
7 #include <linux/input-polldev.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10
11 #include <asm/mach-rc32434/gpio.h>
12 #include <asm/mach-rc32434/rb.h>
13
14 #define DRV_NAME "rb532-button"
15
16 #define RB532_BTN_RATE 100 /* msec */
17 #define RB532_BTN_KSYM BTN_0
18
19 /* The S1 button state is provided by GPIO pin 1. But as this
20  * pin is also used for uart input as alternate function, the
21  * operational modes must be switched first:
22  * 1) disable uart using set_latch_u5()
23  * 2) turn off alternate function implicitly through
24  *    gpio_direction_input()
25  * 3) read the GPIO's current value
26  * 4) undo step 2 by enabling alternate function (in this
27  *    mode the GPIO direction is fixed, so no change needed)
28  * 5) turn on uart again
29  * The GPIO value occurs to be inverted, so pin high means
30  * button is not pressed.
31  */
32 static bool rb532_button_pressed(void)
33 {
34         int val;
35
36         set_latch_u5(0, LO_FOFF);
37         gpio_direction_input(GPIO_BTN_S1);
38
39         val = gpio_get_value(GPIO_BTN_S1);
40
41         rb532_gpio_set_func(GPIO_BTN_S1);
42         set_latch_u5(LO_FOFF, 0);
43
44         return !val;
45 }
46
47 static void rb532_button_poll(struct input_polled_dev *poll_dev)
48 {
49         input_report_key(poll_dev->input, RB532_BTN_KSYM,
50                          rb532_button_pressed());
51         input_sync(poll_dev->input);
52 }
53
54 static int __devinit rb532_button_probe(struct platform_device *pdev)
55 {
56         struct input_polled_dev *poll_dev;
57         int error;
58
59         poll_dev = input_allocate_polled_device();
60         if (!poll_dev)
61                 return -ENOMEM;
62
63         poll_dev->poll = rb532_button_poll;
64         poll_dev->poll_interval = RB532_BTN_RATE;
65
66         poll_dev->input->name = "rb532 button";
67         poll_dev->input->phys = "rb532/button0";
68         poll_dev->input->id.bustype = BUS_HOST;
69         poll_dev->input->dev.parent = &pdev->dev;
70
71         dev_set_drvdata(&pdev->dev, poll_dev);
72
73         input_set_capability(poll_dev->input, EV_KEY, RB532_BTN_KSYM);
74
75         error = input_register_polled_device(poll_dev);
76         if (error) {
77                 input_free_polled_device(poll_dev);
78                 return error;
79         }
80
81         return 0;
82 }
83
84 static int __devexit rb532_button_remove(struct platform_device *pdev)
85 {
86         struct input_polled_dev *poll_dev = dev_get_drvdata(&pdev->dev);
87
88         input_unregister_polled_device(poll_dev);
89         input_free_polled_device(poll_dev);
90         dev_set_drvdata(&pdev->dev, NULL);
91
92         return 0;
93 }
94
95 static struct platform_driver rb532_button_driver = {
96         .probe = rb532_button_probe,
97         .remove = __devexit_p(rb532_button_remove),
98         .driver = {
99                 .name = DRV_NAME,
100                 .owner = THIS_MODULE,
101         },
102 };
103
104 static int __init rb532_button_init(void)
105 {
106         return platform_driver_register(&rb532_button_driver);
107 }
108
109 static void __exit rb532_button_exit(void)
110 {
111         platform_driver_unregister(&rb532_button_driver);
112 }
113
114 module_init(rb532_button_init);
115 module_exit(rb532_button_exit);
116
117 MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
118 MODULE_LICENSE("GPL");
119 MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
120 MODULE_ALIAS("platform:" DRV_NAME);