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authorPhil Sutter <n0-1@freewrt.org>2009-03-05 02:27:15 -0500
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2009-03-09 23:10:12 -0400
commitd9bdffd2102404e8ea5f71c5b88dad890984164d (patch)
treec8deba7479dc3ba6140dd6c55742dbb16f819db7
parent73969ff0eda233f140bcbed1251431387b43f383 (diff)
Input: add driver for S1 button of rb532
Mikrotik's Routerboard 532 has two builtin buttons, from which one triggers a hardware reset. The other one is accessible through GPIO pin 1. Sadly, this pin is being multiplexed with UART0 input, so enabling it as interrupt source (as implied by the gpio-keys driver) is not possible unless UART0 has been turned off. The later one though is a rather bad idea as the Routerboard is an embedded device with only a single serial port, so it's almost always used as serial console device. This patch adds a driver based on INPUT_POLLDEV, which disables the UART and reconfigures GPIO pin 1 temporarily while reading the button state. This procedure works fine and has been tested as part of another, unpublished driver for this device. Signed-off-by: Phil Sutter <n0-1@freewrt.org> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
-rw-r--r--arch/mips/include/asm/mach-rc32434/gpio.h3
-rw-r--r--arch/mips/rb532/devices.c19
-rw-r--r--drivers/input/misc/Kconfig12
-rw-r--r--drivers/input/misc/Makefile1
-rw-r--r--drivers/input/misc/rb532_button.c120
5 files changed, 137 insertions, 18 deletions
diff --git a/arch/mips/include/asm/mach-rc32434/gpio.h b/arch/mips/include/asm/mach-rc32434/gpio.h
index 3cb50d17b62d..12ee8d510160 100644
--- a/arch/mips/include/asm/mach-rc32434/gpio.h
+++ b/arch/mips/include/asm/mach-rc32434/gpio.h
@@ -80,6 +80,9 @@ struct rb532_gpio_reg {
80/* Compact Flash GPIO pin */ 80/* Compact Flash GPIO pin */
81#define CF_GPIO_NUM 13 81#define CF_GPIO_NUM 13
82 82
83/* S1 button GPIO (shared with UART0_SIN) */
84#define GPIO_BTN_S1 1
85
83extern void rb532_gpio_set_ilevel(int bit, unsigned gpio); 86extern void rb532_gpio_set_ilevel(int bit, unsigned gpio);
84extern void rb532_gpio_set_istat(int bit, unsigned gpio); 87extern void rb532_gpio_set_istat(int bit, unsigned gpio);
85extern void rb532_gpio_set_func(unsigned gpio); 88extern void rb532_gpio_set_func(unsigned gpio);
diff --git a/arch/mips/rb532/devices.c b/arch/mips/rb532/devices.c
index 4a5f05b662ae..9f40e1ff9b4f 100644
--- a/arch/mips/rb532/devices.c
+++ b/arch/mips/rb532/devices.c
@@ -200,26 +200,9 @@ static struct platform_device rb532_led = {
200 .id = -1, 200 .id = -1,
201}; 201};
202 202
203static struct gpio_keys_button rb532_gpio_btn[] = {
204 {
205 .gpio = 1,
206 .code = BTN_0,
207 .desc = "S1",
208 .active_low = 1,
209 }
210};
211
212static struct gpio_keys_platform_data rb532_gpio_btn_data = {
213 .buttons = rb532_gpio_btn,
214 .nbuttons = ARRAY_SIZE(rb532_gpio_btn),
215};
216
217static struct platform_device rb532_button = { 203static struct platform_device rb532_button = {
218 .name = "gpio-keys", 204 .name = "rb532-button",
219 .id = -1, 205 .id = -1,
220 .dev = {
221 .platform_data = &rb532_gpio_btn_data,
222 }
223}; 206};
224 207
225static struct resource rb532_wdt_res[] = { 208static struct resource rb532_wdt_res[] = {
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 806d2e66d249..203abac1e23e 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -238,4 +238,16 @@ config INPUT_GPIO_ROTARY_ENCODER
238 To compile this driver as a module, choose M here: the 238 To compile this driver as a module, choose M here: the
239 module will be called rotary_encoder. 239 module will be called rotary_encoder.
240 240
241config INPUT_RB532_BUTTON
242 tristate "Mikrotik Routerboard 532 button interface"
243 depends on MIKROTIK_RB532
244 depends on GPIOLIB && GENERIC_GPIO
245 select INPUT_POLLDEV
246 help
247 Say Y here if you want support for the S1 button built into
248 Mikrotik's Routerboard 532.
249
250 To compile this driver as a module, choose M here: the
251 module will be called rb532_button.
252
241endif 253endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index e86cee66c914..e94cfd9be6cc 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -23,4 +23,5 @@ obj-$(CONFIG_INPUT_APANEL) += apanel.o
23obj-$(CONFIG_INPUT_SGI_BTNS) += sgi_btns.o 23obj-$(CONFIG_INPUT_SGI_BTNS) += sgi_btns.o
24obj-$(CONFIG_INPUT_PCF50633_PMU) += pcf50633-input.o 24obj-$(CONFIG_INPUT_PCF50633_PMU) += pcf50633-input.o
25obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER) += rotary_encoder.o 25obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER) += rotary_encoder.o
26obj-$(CONFIG_INPUT_RB532_BUTTON) += rb532_button.o
26 27
diff --git a/drivers/input/misc/rb532_button.c b/drivers/input/misc/rb532_button.c
new file mode 100644
index 000000000000..e2c7f622a0b5
--- /dev/null
+++ b/drivers/input/misc/rb532_button.c
@@ -0,0 +1,120 @@
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 */
32static 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
47static 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
54static 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
84static 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
95static 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
104static int __init rb532_button_init(void)
105{
106 return platform_driver_register(&rb532_button_driver);
107}
108
109static void __exit rb532_button_exit(void)
110{
111 platform_driver_unregister(&rb532_button_driver);
112}
113
114module_init(rb532_button_init);
115module_exit(rb532_button_exit);
116
117MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
118MODULE_LICENSE("GPL");
119MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
120MODULE_ALIAS("platform:" DRV_NAME);