Fixed MTP to work with TWRP

drivers/input/misc/rb532_button.c

@@ -0,0 +1,107 @@
+/*
+ * Support for the S1 button on Routerboard 532
+ *
+ * Copyright (C) 2009  Phil Sutter <n0-1@freewrt.org>
+ */
+
+#include <linux/input-polldev.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <asm/mach-rc32434/gpio.h>
+#include <asm/mach-rc32434/rb.h>
+
+#define DRV_NAME "rb532-button"
+
+#define RB532_BTN_RATE 100 /* msec */
+#define RB532_BTN_KSYM BTN_0
+
+/* The S1 button state is provided by GPIO pin 1. But as this
+ * pin is also used for uart input as alternate function, the
+ * operational modes must be switched first:
+ * 1) disable uart using set_latch_u5()
+ * 2) turn off alternate function implicitly through
+ *    gpio_direction_input()
+ * 3) read the GPIO's current value
+ * 4) undo step 2 by enabling alternate function (in this
+ *    mode the GPIO direction is fixed, so no change needed)
+ * 5) turn on uart again
+ * The GPIO value occurs to be inverted, so pin high means
+ * button is not pressed.
+ */
+static bool rb532_button_pressed(void)
+{
+	int val;
+
+	set_latch_u5(0, LO_FOFF);
+	gpio_direction_input(GPIO_BTN_S1);
+
+	val = gpio_get_value(GPIO_BTN_S1);
+
+	rb532_gpio_set_func(GPIO_BTN_S1);
+	set_latch_u5(LO_FOFF, 0);
+
+	return !val;
+}
+
+static void rb532_button_poll(struct input_polled_dev *poll_dev)
+{
+	input_report_key(poll_dev->input, RB532_BTN_KSYM,
+			 rb532_button_pressed());
+	input_sync(poll_dev->input);
+}
+
+static int rb532_button_probe(struct platform_device *pdev)
+{
+	struct input_polled_dev *poll_dev;
+	int error;
+
+	poll_dev = input_allocate_polled_device();
+	if (!poll_dev)
+		return -ENOMEM;
+
+	poll_dev->poll = rb532_button_poll;
+	poll_dev->poll_interval = RB532_BTN_RATE;
+
+	poll_dev->input->name = "rb532 button";
+	poll_dev->input->phys = "rb532/button0";
+	poll_dev->input->id.bustype = BUS_HOST;
+	poll_dev->input->dev.parent = &pdev->dev;
+
+	dev_set_drvdata(&pdev->dev, poll_dev);
+
+	input_set_capability(poll_dev->input, EV_KEY, RB532_BTN_KSYM);
+
+	error = input_register_polled_device(poll_dev);
+	if (error) {
+		input_free_polled_device(poll_dev);
+		return error;
+	}
+
+	return 0;
+}
+
+static int rb532_button_remove(struct platform_device *pdev)
+{
+	struct input_polled_dev *poll_dev = dev_get_drvdata(&pdev->dev);
+
+	input_unregister_polled_device(poll_dev);
+	input_free_polled_device(poll_dev);
+
+	return 0;
+}
+
+static struct platform_driver rb532_button_driver = {
+	.probe = rb532_button_probe,
+	.remove = rb532_button_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.owner = THIS_MODULE,
+	},
+};
+module_platform_driver(rb532_button_driver);
+
+MODULE_AUTHOR("Phil Sutter <n0-1@freewrt.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Support for S1 button on Routerboard 532");
+MODULE_ALIAS("platform:" DRV_NAME);