projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| d9bdffd2 PS |
1 | /* |
| 2 | * Support for the S1 button on Routerboard 532 | |
| 3 | * | |
| 4 | * Copyright (C) 2009 Phil Sutter <[email protected]> | |
| 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 <[email protected]>"); | |
| 118 | MODULE_LICENSE("GPL"); | |
| 119 | MODULE_DESCRIPTION("Support for S1 button on Routerboard 532"); | |
| 120 | MODULE_ALIAS("platform:" DRV_NAME); |