iio: ad7266: Convert to use GPIO descriptors

The AD7266 have no in-tree users making use of the platform
data mechanism to pass address GPIO lines when not using
a fixed address, so we can easily convert this to use
GPIO descriptors instead of the platform data integers
currently passed.

Lowercase the labels "ad0".."ad2" as this will make a better
fit for platform descriptions like device tree that prefer
lowercase names such as "ad0-gpios" rather than "AD0-gpios".

Board files and other static users of this device can pass
the same GPIO descriptors using machine descriptor
tables if need be.

Cc: Alison Schofield <[e-mail]>
Cc: Lars-Peter Clausen <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>
Reviewed-by: Alexandru Ardelean <[e-mail]>
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/adc/ad7266.c

···
 #include <linux/spi/spi.h>
 #include <linux/regulator/consumer.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/module.h>
 
 #include <linux/interrupt.h>
···
 	enum ad7266_range	range;
 	enum ad7266_mode	mode;
 	bool			fixed_addr;
-	struct gpio		gpios[3];
+	struct gpio_desc	*gpios[3];
 
 	/*
 	 * DMA (thus cache coherency maintenance) requires the
···
 	}
 
 	for (i = 0; i < 3; ++i)
-		gpio_set_value(st->gpios[i].gpio, (bool)(nr & BIT(i)));
+		gpiod_set_value(st->gpios[i], (bool)(nr & BIT(i)));
 }
 
 static int ad7266_update_scan_mode(struct iio_dev *indio_dev,
···
 }
 
 static const char * const ad7266_gpio_labels[] = {
-	"AD0", "AD1", "AD2",
+	"ad0", "ad1", "ad2",
 };
 
 static int ad7266_probe(struct spi_device *spi)
···
 
 		if (!st->fixed_addr) {
 			for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) {
-				st->gpios[i].gpio = pdata->addr_gpios[i];
-				st->gpios[i].flags = GPIOF_OUT_INIT_LOW;
-				st->gpios[i].label = ad7266_gpio_labels[i];
+				st->gpios[i] = devm_gpiod_get(&spi->dev,
+						      ad7266_gpio_labels[i],
+						      GPIOD_OUT_LOW);
+				if (IS_ERR(st->gpios[i])) {
+					ret = PTR_ERR(st->gpios[i]);
+					goto error_disable_reg;
+				}
 			}
-			ret = gpio_request_array(st->gpios,
-				ARRAY_SIZE(st->gpios));
-			if (ret)
-				goto error_disable_reg;
 		}
 	} else {
 		st->fixed_addr = true;
···
 	ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
 		&ad7266_trigger_handler, &iio_triggered_buffer_setup_ops);
 	if (ret)
-		goto error_free_gpios;
+		goto error_disable_reg;
 
 	ret = iio_device_register(indio_dev);
 	if (ret)
···
 
 error_buffer_cleanup:
 	iio_triggered_buffer_cleanup(indio_dev);
-error_free_gpios:
-	if (!st->fixed_addr)
-		gpio_free_array(st->gpios, ARRAY_SIZE(st->gpios));
 error_disable_reg:
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);
···
 
 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);
-	if (!st->fixed_addr)
-		gpio_free_array(st->gpios, ARRAY_SIZE(st->gpios));
 	if (!IS_ERR(st->reg))
 		regulator_disable(st->reg);
 

include/linux/platform_data/ad7266.h

···
  * @range: Reference voltage range the device is configured for
  * @mode: Sample mode the device is configured for
  * @fixed_addr: Whether the address pins are hard-wired
- * @addr_gpios: GPIOs used for controlling the address pins, only used if
- *		fixed_addr is set to false.
  */
 struct ad7266_platform_data {
 	enum ad7266_range range;
 	enum ad7266_mode mode;
 	bool fixed_addr;
-	unsigned int addr_gpios[3];
 };
 
 #endif