V4L/DVB: v4l2_subdev: Add s_io_pin_config to v4l2_subdev_core_ops

Add a method to v4l2_sudev_core_ops to allow bridge drivers to
manage what signal pads/functions are routed out to multiplexed IO pins on a
pin by pin basis.  The interface also allows specifying initial output settings
for pins and disabling an IO pin altogether.
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/media/v4l2-subdev.h

@@ -90,10 +90,31 @@ 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 */
+
+struct v4l2_subdev_io_pin_config {
+	u32 flags;	/* V4L2_SUBDEV_IO_PIN_* flags for this pin's config */
+	u8 pin;		/* Chip external IO pin to configure */
+	u8 function;	/* Internal signal pad/function to route to IO pin */
+	u8 value;	/* Initial value for pin - e.g. GPIO output value */
+	u8 strength;	/* Pin drive strength */
+};
+
 /* s_config: if set, then it is always called by the v4l2_i2c_new_subdev*
 	functions after the v4l2_subdev was registered. It is used to pass
 	platform data to the subdev which can be used during initialization.
 
+   s_io_pin_config: configure one or more chip I/O pins for chips that
+	multiplex different internal signal pads out to IO pins.  This function
+	takes a pointer to an array of 'n' pin configuration entries, one for
+	each pin being configured.  This function could be called at times
+	other than just subdevice initialization.
+
    init: initialize the sensor registors to some sort of reasonable default
 	values. Do not use for new drivers and should be removed in existing
 	drivers.
@@ -115,6 +136,8 @@ struct v4l2_subdev_core_ops {
 	int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip);
 	int (*log_status)(struct v4l2_subdev *sd);
 	int (*s_config)(struct v4l2_subdev *sd, int irq, void *platform_data);
+	int (*s_io_pin_config)(struct v4l2_subdev *sd, size_t n,
+				      struct v4l2_subdev_io_pin_config *pincfg);
 	int (*init)(struct v4l2_subdev *sd, u32 val);
 	int (*load_fw)(struct v4l2_subdev *sd);
 	int (*reset)(struct v4l2_subdev *sd, u32 val);