109c434b8SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 2d9bdffd2SPhil Sutter /* 3d9bdffd2SPhil Sutter * Support for the S1 button on Routerboard 532 4d9bdffd2SPhil Sutter * 5d9bdffd2SPhil Sutter * Copyright (C) 2009 Phil Sutter <n0-1@freewrt.org> 6d9bdffd2SPhil Sutter */ 7d9bdffd2SPhil Sutter 8d9bdffd2SPhil Sutter #include <linux/input-polldev.h> 9d9bdffd2SPhil Sutter #include <linux/module.h> 10d9bdffd2SPhil Sutter #include <linux/platform_device.h> 11832f5dacSAlban Bedel #include <linux/gpio.h> 12d9bdffd2SPhil Sutter 13d9bdffd2SPhil Sutter #include <asm/mach-rc32434/gpio.h> 14d9bdffd2SPhil Sutter #include <asm/mach-rc32434/rb.h> 15d9bdffd2SPhil Sutter 16d9bdffd2SPhil Sutter #define DRV_NAME "rb532-button" 17d9bdffd2SPhil Sutter 18d9bdffd2SPhil Sutter #define RB532_BTN_RATE 100 /* msec */ 19d9bdffd2SPhil Sutter #define RB532_BTN_KSYM BTN_0 20d9bdffd2SPhil Sutter 21d9bdffd2SPhil Sutter /* The S1 button state is provided by GPIO pin 1. But as this 22d9bdffd2SPhil Sutter * pin is also used for uart input as alternate function, the 23d9bdffd2SPhil Sutter * operational modes must be switched first: 24d9bdffd2SPhil Sutter * 1) disable uart using set_latch_u5() 25d9bdffd2SPhil Sutter * 2) turn off alternate function implicitly through 26d9bdffd2SPhil Sutter * gpio_direction_input() 27d9bdffd2SPhil Sutter * 3) read the GPIO's current value 28d9bdffd2SPhil Sutter * 4) undo step 2 by enabling alternate function (in this 29d9bdffd2SPhil Sutter * mode the GPIO direction is fixed, so no change needed) 30d9bdffd2SPhil Sutter * 5) turn on uart again 31d9bdffd2SPhil Sutter * The GPIO value occurs to be inverted, so pin high means 32d9bdffd2SPhil Sutter * button is not pressed. 33d9bdffd2SPhil Sutter */ 34d9bdffd2SPhil Sutter static bool rb532_button_pressed(void) 35d9bdffd2SPhil Sutter { 36d9bdffd2SPhil Sutter int val; 37d9bdffd2SPhil Sutter 38d9bdffd2SPhil Sutter set_latch_u5(0, LO_FOFF); 39d9bdffd2SPhil Sutter gpio_direction_input(GPIO_BTN_S1); 40d9bdffd2SPhil Sutter 41d9bdffd2SPhil Sutter val = gpio_get_value(GPIO_BTN_S1); 42d9bdffd2SPhil Sutter 43d9bdffd2SPhil Sutter rb532_gpio_set_func(GPIO_BTN_S1); 44d9bdffd2SPhil Sutter set_latch_u5(LO_FOFF, 0); 45d9bdffd2SPhil Sutter 46d9bdffd2SPhil Sutter return !val; 47d9bdffd2SPhil Sutter } 48d9bdffd2SPhil Sutter 49d9bdffd2SPhil Sutter static void rb532_button_poll(struct input_polled_dev *poll_dev) 50d9bdffd2SPhil Sutter { 51d9bdffd2SPhil Sutter input_report_key(poll_dev->input, RB532_BTN_KSYM, 52d9bdffd2SPhil Sutter rb532_button_pressed()); 53d9bdffd2SPhil Sutter input_sync(poll_dev->input); 54d9bdffd2SPhil Sutter } 55d9bdffd2SPhil Sutter 565298cc4cSBill Pemberton static int rb532_button_probe(struct platform_device *pdev) 57d9bdffd2SPhil Sutter { 58d9bdffd2SPhil Sutter struct input_polled_dev *poll_dev; 59d9bdffd2SPhil Sutter int error; 60d9bdffd2SPhil Sutter 61528c7d02SDmitry Torokhov poll_dev = devm_input_allocate_polled_device(&pdev->dev); 62d9bdffd2SPhil Sutter if (!poll_dev) 63d9bdffd2SPhil Sutter return -ENOMEM; 64d9bdffd2SPhil Sutter 65d9bdffd2SPhil Sutter poll_dev->poll = rb532_button_poll; 66d9bdffd2SPhil Sutter poll_dev->poll_interval = RB532_BTN_RATE; 67d9bdffd2SPhil Sutter 68d9bdffd2SPhil Sutter poll_dev->input->name = "rb532 button"; 69d9bdffd2SPhil Sutter poll_dev->input->phys = "rb532/button0"; 70d9bdffd2SPhil Sutter poll_dev->input->id.bustype = BUS_HOST; 71d9bdffd2SPhil Sutter 72d9bdffd2SPhil Sutter input_set_capability(poll_dev->input, EV_KEY, RB532_BTN_KSYM); 73d9bdffd2SPhil Sutter 74d9bdffd2SPhil Sutter error = input_register_polled_device(poll_dev); 75528c7d02SDmitry Torokhov if (error) 76d9bdffd2SPhil Sutter return error; 77d9bdffd2SPhil Sutter 78d9bdffd2SPhil Sutter return 0; 79d9bdffd2SPhil Sutter } 80d9bdffd2SPhil Sutter 81d9bdffd2SPhil Sutter static struct platform_driver rb532_button_driver = { 82d9bdffd2SPhil Sutter .probe = rb532_button_probe, 83d9bdffd2SPhil Sutter .driver = { 84d9bdffd2SPhil Sutter .name = DRV_NAME, 85d9bdffd2SPhil Sutter }, 86d9bdffd2SPhil Sutter }; 87840a746bSJJ Ding module_platform_driver(rb532_button_driver); 88d9bdffd2SPhil Sutter 89d9bdffd2SPhil Sutter MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>"); 90d9bdffd2SPhil Sutter MODULE_LICENSE("GPL"); 91d9bdffd2SPhil Sutter MODULE_DESCRIPTION("Support for S1 button on Routerboard 532"); 92d9bdffd2SPhil Sutter MODULE_ALIAS("platform:" DRV_NAME); 93