Input: gpio_decoder - switch to using polled mode of input devices

We have added polled mode to the normal input devices with the intent of
retiring input_polled_dev. This converts gpio_decoder driver to use
the polling mode of standard input devices and removes dependency on
INPUT_POLLDEV.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/misc/Kconfig

···
 config INPUT_GPIO_DECODER
 	tristate "Polled GPIO Decoder Input driver"
 	depends on GPIOLIB || COMPILE_TEST
-	select INPUT_POLLDEV
 	help
 	 Say Y here if you want driver to read status of multiple GPIO
 	 lines and report the encoded value as an absolute integer to

drivers/input/misc/gpio_decoder.c

···
 #include <linux/device.h>
 #include <linux/gpio/consumer.h>
 #include <linux/input.h>
-#include <linux/input-polldev.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 
 struct gpio_decoder {
-	struct input_polled_dev *poll_dev;
 	struct gpio_descs *input_gpios;
 	struct device *dev;
 	u32 axis;
···
 	return ret;
 }
 
-static void gpio_decoder_poll_gpios(struct input_polled_dev *poll_dev)
+static void gpio_decoder_poll_gpios(struct input_dev *input)
 {
-	struct gpio_decoder *decoder = poll_dev->private;
+	struct gpio_decoder *decoder = input_get_drvdata(input);
 	int state;
 
 	state = gpio_decoder_get_gpios_state(decoder);
 	if (state >= 0 && state != decoder->last_stable) {
-		input_report_abs(poll_dev->input, decoder->axis, state);
-		input_sync(poll_dev->input);
+		input_report_abs(input, decoder->axis, state);
+		input_sync(input);
 		decoder->last_stable = state;
 	}
 }
···
 {
 	struct device *dev = &pdev->dev;
 	struct gpio_decoder *decoder;
-	struct input_polled_dev *poll_dev;
+	struct input_dev *input;
 	u32  max;
 	int err;
 
-	decoder = devm_kzalloc(dev, sizeof(struct gpio_decoder), GFP_KERNEL);
+	decoder = devm_kzalloc(dev, sizeof(*decoder), GFP_KERNEL);
 	if (!decoder)
 		return -ENOMEM;
 
+	decoder->dev = dev;
 	device_property_read_u32(dev, "linux,axis", &decoder->axis);
+
 	decoder->input_gpios = devm_gpiod_get_array(dev, NULL, GPIOD_IN);
 	if (IS_ERR(decoder->input_gpios)) {
 		dev_err(dev, "unable to acquire input gpios\n");
 		return PTR_ERR(decoder->input_gpios);
 	}
+
 	if (decoder->input_gpios->ndescs < 2) {
 		dev_err(dev, "not enough gpios found\n");
 		return -EINVAL;
···
 	if (device_property_read_u32(dev, "decoder-max-value", &max))
 		max = (1U << decoder->input_gpios->ndescs) - 1;
 
-	decoder->dev = dev;
-	poll_dev = devm_input_allocate_polled_device(decoder->dev);
-	if (!poll_dev)
+	input = devm_input_allocate_device(dev);
+	if (!input)
 		return -ENOMEM;
 
-	poll_dev->private = decoder;
-	poll_dev->poll = gpio_decoder_poll_gpios;
-	decoder->poll_dev = poll_dev;
+	input_set_drvdata(input, decoder);
 
-	poll_dev->input->name = pdev->name;
-	poll_dev->input->id.bustype = BUS_HOST;
-	input_set_abs_params(poll_dev->input, decoder->axis, 0, max, 0, 0);
+	input->name = pdev->name;
+	input->id.bustype = BUS_HOST;
+	input_set_abs_params(input, decoder->axis, 0, max, 0, 0);
 
-	err = input_register_polled_device(poll_dev);
+	err = input_setup_polling(input, gpio_decoder_poll_gpios);
 	if (err) {
-		dev_err(dev, "failed to register polled  device\n");
+		dev_err(dev, "failed to set up polling\n");
+		return err;
+	}
+
+	err = input_register_device(input);
+	if (err) {
+		dev_err(dev, "failed to register input device\n");
 		return err;
 	}