media: v4l2-subdev: better document IO pin configuration flags

Convert V4L2_SUBDEV_IO_PIN_* to enums, use BIT() and document
via kernel-doc.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/i2c/cx25840/cx25840-core.c

@@ -201,14 +201,14 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			} else {
 				/* IRQ_N */
 				if (p[i].flags &
-					(V4L2_SUBDEV_IO_PIN_DISABLE |
-					 V4L2_SUBDEV_IO_PIN_INPUT)) {
+					(BIT(V4L2_SUBDEV_IO_PIN_DISABLE) |
+					 BIT(V4L2_SUBDEV_IO_PIN_INPUT))) {
 					pin_ctrl &= ~(0x1 << 25);
 				} else {
 					pin_ctrl |= (0x1 << 25);
 				}
 				if (p[i].flags &
-					V4L2_SUBDEV_IO_PIN_ACTIVE_LOW) {
+					BIT(V4L2_SUBDEV_IO_PIN_ACTIVE_LOW)) {
 					pin_ctrl &= ~(0x1 << 24);
 				} else {
 					pin_ctrl |= (0x1 << 24);
@@ -224,7 +224,7 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			} else {
 				/* GPIO19 */
 				gpio_oe &= ~(0x1 << 0);
-				if (p[i].flags & V4L2_SUBDEV_IO_PIN_SET_VALUE) {
+				if (p[i].flags & BIT(V4L2_SUBDEV_IO_PIN_SET_VALUE)) {
 					gpio_data &= ~(0x1 << 0);
 					gpio_data |= ((p[i].value & 0x1) << 0);
 				}
@@ -236,7 +236,7 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			if (p[i].function != CX23885_PAD_GPIO20) {
 				/* IR_TX */
 				gpio_oe |= (0x1 << 1);
-				if (p[i].flags & V4L2_SUBDEV_IO_PIN_DISABLE)
+				if (p[i].flags & BIT(V4L2_SUBDEV_IO_PIN_DISABLE))
 					pin_ctrl &= ~(0x1 << 10);
 				else
 					pin_ctrl |= (0x1 << 10);
@@ -245,7 +245,7 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			} else {
 				/* GPIO20 */
 				gpio_oe &= ~(0x1 << 1);
-				if (p[i].flags & V4L2_SUBDEV_IO_PIN_SET_VALUE) {
+				if (p[i].flags & BIT(V4L2_SUBDEV_IO_PIN_SET_VALUE)) {
 					gpio_data &= ~(0x1 << 1);
 					gpio_data |= ((p[i].value & 0x1) << 1);
 				}
@@ -263,7 +263,7 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			} else {
 				/* GPIO21 */
 				gpio_oe &= ~(0x1 << 2);
-				if (p[i].flags & V4L2_SUBDEV_IO_PIN_SET_VALUE) {
+				if (p[i].flags & BIT(V4L2_SUBDEV_IO_PIN_SET_VALUE)) {
 					gpio_data &= ~(0x1 << 2);
 					gpio_data |= ((p[i].value & 0x1) << 2);
 				}
@@ -281,7 +281,7 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			} else {
 				/* GPIO22 */
 				gpio_oe &= ~(0x1 << 3);
-				if (p[i].flags & V4L2_SUBDEV_IO_PIN_SET_VALUE) {
+				if (p[i].flags & BIT(V4L2_SUBDEV_IO_PIN_SET_VALUE)) {
 					gpio_data &= ~(0x1 << 3);
 					gpio_data |= ((p[i].value & 0x1) << 3);
 				}
@@ -299,7 +299,7 @@ static int cx23885_s_io_pin_config(struct v4l2_subdev *sd, size_t n,
 			} else {
 				/* GPIO23 */
 				gpio_oe &= ~(0x1 << 4);
-				if (p[i].flags & V4L2_SUBDEV_IO_PIN_SET_VALUE) {
+				if (p[i].flags & BIT(V4L2_SUBDEV_IO_PIN_SET_VALUE)) {
 					gpio_data &= ~(0x1 << 4);
 					gpio_data |= ((p[i].value & 0x1) << 4);
 				}

drivers/media/pci/cx23885/cx23885-cards.c

@@ -1816,13 +1816,13 @@ int cx23885_ir_init(struct cx23885_dev *dev)
 {
 	static struct v4l2_subdev_io_pin_config ir_rxtx_pin_cfg[] = {
 		{
-			.flags	  = V4L2_SUBDEV_IO_PIN_INPUT,
+			.flags	  = BIT(V4L2_SUBDEV_IO_PIN_INPUT),
 			.pin	  = CX23885_PIN_IR_RX_GPIO19,
 			.function = CX23885_PAD_IR_RX,
 			.value	  = 0,
 			.strength = CX25840_PIN_DRIVE_MEDIUM,
 		}, {
-			.flags	  = V4L2_SUBDEV_IO_PIN_OUTPUT,
+			.flags	  = BIT(V4L2_SUBDEV_IO_PIN_OUTPUT),
 			.pin	  = CX23885_PIN_IR_TX_GPIO20,
 			.function = CX23885_PAD_IR_TX,
 			.value	  = 0,
@@ -1833,7 +1833,7 @@ int cx23885_ir_init(struct cx23885_dev *dev)
 
 	static struct v4l2_subdev_io_pin_config ir_rx_pin_cfg[] = {
 		{
-			.flags	  = V4L2_SUBDEV_IO_PIN_INPUT,
+			.flags	  = BIT(V4L2_SUBDEV_IO_PIN_INPUT),
 			.pin	  = CX23885_PIN_IR_RX_GPIO19,
 			.function = CX23885_PAD_IR_RX,
 			.value	  = 0,

include/media/v4l2-subdev.h

@@ -108,22 +108,31 @@ struct v4l2_decode_vbi_line {
  * not yet implemented) since ops provide proper type-checking.
  */
 
-/* Subdevice external IO pin configuration */
-#define V4L2_SUBDEV_IO_PIN_DISABLE	(1 << 0) /* ENABLE assumed */
-#define V4L2_SUBDEV_IO_PIN_OUTPUT	(1 << 1)
-#define V4L2_SUBDEV_IO_PIN_INPUT	(1 << 2)
-#define V4L2_SUBDEV_IO_PIN_SET_VALUE	(1 << 3) /* Set output value */
-#define V4L2_SUBDEV_IO_PIN_ACTIVE_LOW	(1 << 4) /* ACTIVE HIGH assumed */
+/**
+ * enum v4l2_subdev_io_pin_bits - Subdevice external IO pin configuration
+ *	bits
+ *
+ * @V4L2_SUBDEV_IO_PIN_DISABLE: disables a pin config. ENABLE assumed.
+ * @V4L2_SUBDEV_IO_PIN_OUTPUT: set it if pin is an output.
+ * @V4L2_SUBDEV_IO_PIN_INPUT: set it if pin is an input.
+ * @V4L2_SUBDEV_IO_PIN_SET_VALUE: to set the output value via
+ * 				  &struct v4l2_subdev_io_pin_config->value.
+ * @V4L2_SUBDEV_IO_PIN_ACTIVE_LOW: pin active is bit 0.
+ *				   Otherwise, ACTIVE HIGH is assumed.
+ */
+enum v4l2_subdev_io_pin_bits {
+	V4L2_SUBDEV_IO_PIN_DISABLE	= 0,
+	V4L2_SUBDEV_IO_PIN_OUTPUT	= 1,
+	V4L2_SUBDEV_IO_PIN_INPUT	= 2,
+	V4L2_SUBDEV_IO_PIN_SET_VALUE	= 3,
+	V4L2_SUBDEV_IO_PIN_ACTIVE_LOW	= 4,
+};
 
 /**
  * struct v4l2_subdev_io_pin_config - Subdevice external IO pin configuration
  *
- * @flags: bitmask with flags for this pin's config:
- *	   %V4L2_SUBDEV_IO_PIN_DISABLE - disables a pin config,
- *	   %V4L2_SUBDEV_IO_PIN_OUTPUT - if pin is an output,
- *	   %V4L2_SUBDEV_IO_PIN_INPUT - if pin is an input,
- *	   %V4L2_SUBDEV_IO_PIN_SET_VALUE - to set the output value via @value
- *	   and %V4L2_SUBDEV_IO_PIN_ACTIVE_LOW - if active is 0.
+ * @flags: bitmask with flags for this pin's config, whose bits are defined by
+ *	   &enum v4l2_subdev_io_pin_bits.
  * @pin: Chip external IO pin to configure
  * @function: Internal signal pad/function to route to IO pin
  * @value: Initial value for pin - e.g. GPIO output value