MIPS/input: Move RB532 button to GPIO descriptors

Convert the Mikrotik RouterBoard RB532 to use GPIO descriptors
by defining a software node for the GPIO chip, then register
the button platform device with full info passing the GPIO
as a device property.

This can be used as a base to move more of the RB532 devices
over to passing GPIOs using device properties.

Use the GPIO_ACTIVE_LOW flag and drop the inversion in the
rb532_button_pressed() function.

Signed-off-by: Linus Walleij <linusw@kernel.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

1 files changed, 29 insertions, 6 deletions

diff --git a/drivers/input/misc/rb532_button.c b/drivers/input/misc/rb532_button.c
index 190a80e1e2c1..40173bf7a235 100644
--- a/drivers/input/misc/rb532_button.c
+++ b/drivers/input/misc/rb532_button.c
@@ -8,7 +8,7 @@
 #include <linux/input.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 
 #include <asm/mach-rc32434/gpio.h>
 #include <asm/mach-rc32434/rb.h>
@@ -18,6 +18,14 @@
 #define RB532_BTN_RATE 100 /* msec */
 #define RB532_BTN_KSYM BTN_0
 
+/**
+ * struct rb532_button - RB532 button information
+ * @gpio: GPIO connected to the button
+ */
+struct rb532_button {
+	struct gpio_desc	*gpio;
+};
+
 /* 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:
@@ -31,35 +39,48 @@
  * The GPIO value occurs to be inverted, so pin high means
  * button is not pressed.
  */
-static bool rb532_button_pressed(void)
+static bool rb532_button_pressed(struct rb532_button *button)
 {
 	int val;
 
 	set_latch_u5(0, LO_FOFF);
-	gpio_direction_input(GPIO_BTN_S1);
+	gpiod_direction_input(button->gpio);
 
-	val = gpio_get_value(GPIO_BTN_S1);
+	val = gpiod_get_value(button->gpio);
 
 	rb532_gpio_set_func(GPIO_BTN_S1);
 	set_latch_u5(LO_FOFF, 0);
 
-	return !val;
+	return val;
 }
 
 static void rb532_button_poll(struct input_dev *input)
 {
-	input_report_key(input, RB532_BTN_KSYM, rb532_button_pressed());
+	struct rb532_button *button = input_get_drvdata(input);
+
+	input_report_key(input, RB532_BTN_KSYM, rb532_button_pressed(button));
 	input_sync(input);
 }
 
 static int rb532_button_probe(struct platform_device *pdev)
 {
+	struct rb532_button *button;
 	struct input_dev *input;
 	int error;
 
+	button = devm_kzalloc(&pdev->dev, sizeof(*button), GFP_KERNEL);
+	if (!button)
+		return -ENOMEM;
+
+	button->gpio = devm_gpiod_get(&pdev->dev, "button", GPIOD_IN);
+	if (IS_ERR(button->gpio))
+		return dev_err_probe(&pdev->dev, PTR_ERR(button->gpio),
+				     "error getting button GPIO\n");
+
 	input = devm_input_allocate_device(&pdev->dev);
 	if (!input)
 		return -ENOMEM;
+	input_set_drvdata(input, button);
 
 	input->name = "rb532 button";
 	input->phys = "rb532/button0";
@@ -77,6 +98,8 @@ static int rb532_button_probe(struct platform_device *pdev)
 	if (error)
 		return error;
 
+	platform_set_drvdata(pdev, button);
+
 	return 0;
 }