2 * Support for the S1 button on Routerboard 532
4 * Copyright (C) 2009 Phil Sutter <n0-1@freewrt.org>
7 #include <linux/input-polldev.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
11 #include <asm/mach-rc32434/gpio.h>
12 #include <asm/mach-rc32434/rb.h>
14 #define DRV_NAME "rb532-button"
16 #define RB532_BTN_RATE 100 /* msec */
17 #define RB532_BTN_KSYM BTN_0
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.
32 static bool rb532_button_pressed(void)
36 set_latch_u5(0, LO_FOFF
);
37 gpio_direction_input(GPIO_BTN_S1
);
39 val
= gpio_get_value(GPIO_BTN_S1
);
41 rb532_gpio_set_func(GPIO_BTN_S1
);
42 set_latch_u5(LO_FOFF
, 0);
47 static void rb532_button_poll(struct input_polled_dev
*poll_dev
)
49 input_report_key(poll_dev
->input
, RB532_BTN_KSYM
,
50 rb532_button_pressed());
51 input_sync(poll_dev
->input
);
54 static int rb532_button_probe(struct platform_device
*pdev
)
56 struct input_polled_dev
*poll_dev
;
59 poll_dev
= input_allocate_polled_device();
63 poll_dev
->poll
= rb532_button_poll
;
64 poll_dev
->poll_interval
= RB532_BTN_RATE
;
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
;
71 dev_set_drvdata(&pdev
->dev
, poll_dev
);
73 input_set_capability(poll_dev
->input
, EV_KEY
, RB532_BTN_KSYM
);
75 error
= input_register_polled_device(poll_dev
);
77 input_free_polled_device(poll_dev
);
84 static int rb532_button_remove(struct platform_device
*pdev
)
86 struct input_polled_dev
*poll_dev
= dev_get_drvdata(&pdev
->dev
);
88 input_unregister_polled_device(poll_dev
);
89 input_free_polled_device(poll_dev
);
90 dev_set_drvdata(&pdev
->dev
, NULL
);
95 static struct platform_driver rb532_button_driver
= {
96 .probe
= rb532_button_probe
,
97 .remove
= rb532_button_remove
,
100 .owner
= THIS_MODULE
,
103 module_platform_driver(rb532_button_driver
);
105 MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
106 MODULE_LICENSE("GPL");
107 MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
108 MODULE_ALIAS("platform:" DRV_NAME
);