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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support for the S1 button on Routerboard 532
4 *
5 * Copyright (C) 2009 Phil Sutter <n0-1@freewrt.org>
6 */
7
8#include <linux/input.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/gpio.h>
12
13#include <asm/mach-rc32434/gpio.h>
14#include <asm/mach-rc32434/rb.h>
15
16#define DRV_NAME "rb532-button"
17
18#define RB532_BTN_RATE 100 /* msec */
19#define RB532_BTN_KSYM BTN_0
20
21/* The S1 button state is provided by GPIO pin 1. But as this
22 * pin is also used for uart input as alternate function, the
23 * operational modes must be switched first:
24 * 1) disable uart using set_latch_u5()
25 * 2) turn off alternate function implicitly through
26 * gpio_direction_input()
27 * 3) read the GPIO's current value
28 * 4) undo step 2 by enabling alternate function (in this
29 * mode the GPIO direction is fixed, so no change needed)
30 * 5) turn on uart again
31 * The GPIO value occurs to be inverted, so pin high means
32 * button is not pressed.
33 */
34static bool rb532_button_pressed(void)
35{
36 int val;
37
38 set_latch_u5(0, LO_FOFF);
39 gpio_direction_input(GPIO_BTN_S1);
40
41 val = gpio_get_value(GPIO_BTN_S1);
42
43 rb532_gpio_set_func(GPIO_BTN_S1);
44 set_latch_u5(LO_FOFF, 0);
45
46 return !val;
47}
48
49static void rb532_button_poll(struct input_dev *input)
50{
51 input_report_key(input, RB532_BTN_KSYM, rb532_button_pressed());
52 input_sync(input);
53}
54
55static int rb532_button_probe(struct platform_device *pdev)
56{
57 struct input_dev *input;
58 int error;
59
60 input = devm_input_allocate_device(&pdev->dev);
61 if (!input)
62 return -ENOMEM;
63
64 input->name = "rb532 button";
65 input->phys = "rb532/button0";
66 input->id.bustype = BUS_HOST;
67
68 input_set_capability(input, EV_KEY, RB532_BTN_KSYM);
69
70 error = input_setup_polling(input, rb532_button_poll);
71 if (error)
72 return error;
73
74 input_set_poll_interval(input, RB532_BTN_RATE);
75
76 error = input_register_device(input);
77 if (error)
78 return error;
79
80 return 0;
81}
82
83static struct platform_driver rb532_button_driver = {
84 .probe = rb532_button_probe,
85 .driver = {
86 .name = DRV_NAME,
87 },
88};
89module_platform_driver(rb532_button_driver);
90
91MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
92MODULE_LICENSE("GPL");
93MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
94MODULE_ALIAS("platform:" DRV_NAME);
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#include <linux/gpio.h>
11
12#include <asm/mach-rc32434/gpio.h>
13#include <asm/mach-rc32434/rb.h>
14
15#define DRV_NAME "rb532-button"
16
17#define RB532_BTN_RATE 100 /* msec */
18#define RB532_BTN_KSYM BTN_0
19
20/* The S1 button state is provided by GPIO pin 1. But as this
21 * pin is also used for uart input as alternate function, the
22 * operational modes must be switched first:
23 * 1) disable uart using set_latch_u5()
24 * 2) turn off alternate function implicitly through
25 * gpio_direction_input()
26 * 3) read the GPIO's current value
27 * 4) undo step 2 by enabling alternate function (in this
28 * mode the GPIO direction is fixed, so no change needed)
29 * 5) turn on uart again
30 * The GPIO value occurs to be inverted, so pin high means
31 * button is not pressed.
32 */
33static bool rb532_button_pressed(void)
34{
35 int val;
36
37 set_latch_u5(0, LO_FOFF);
38 gpio_direction_input(GPIO_BTN_S1);
39
40 val = gpio_get_value(GPIO_BTN_S1);
41
42 rb532_gpio_set_func(GPIO_BTN_S1);
43 set_latch_u5(LO_FOFF, 0);
44
45 return !val;
46}
47
48static void rb532_button_poll(struct input_polled_dev *poll_dev)
49{
50 input_report_key(poll_dev->input, RB532_BTN_KSYM,
51 rb532_button_pressed());
52 input_sync(poll_dev->input);
53}
54
55static int rb532_button_probe(struct platform_device *pdev)
56{
57 struct input_polled_dev *poll_dev;
58 int error;
59
60 poll_dev = input_allocate_polled_device();
61 if (!poll_dev)
62 return -ENOMEM;
63
64 poll_dev->poll = rb532_button_poll;
65 poll_dev->poll_interval = RB532_BTN_RATE;
66
67 poll_dev->input->name = "rb532 button";
68 poll_dev->input->phys = "rb532/button0";
69 poll_dev->input->id.bustype = BUS_HOST;
70 poll_dev->input->dev.parent = &pdev->dev;
71
72 dev_set_drvdata(&pdev->dev, poll_dev);
73
74 input_set_capability(poll_dev->input, EV_KEY, RB532_BTN_KSYM);
75
76 error = input_register_polled_device(poll_dev);
77 if (error) {
78 input_free_polled_device(poll_dev);
79 return error;
80 }
81
82 return 0;
83}
84
85static int rb532_button_remove(struct platform_device *pdev)
86{
87 struct input_polled_dev *poll_dev = dev_get_drvdata(&pdev->dev);
88
89 input_unregister_polled_device(poll_dev);
90 input_free_polled_device(poll_dev);
91
92 return 0;
93}
94
95static struct platform_driver rb532_button_driver = {
96 .probe = rb532_button_probe,
97 .remove = rb532_button_remove,
98 .driver = {
99 .name = DRV_NAME,
100 },
101};
102module_platform_driver(rb532_button_driver);
103
104MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
105MODULE_LICENSE("GPL");
106MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
107MODULE_ALIAS("platform:" DRV_NAME);