media: v4l: fwnode: Parse MiPI DisCo for C-PHY line-orders

Extend the fwnode parsing to validate and fill in the CSI-2 C-PHY
line-orders order properties as defined in MIPI Discovery and
Configuration (DisCo) Specification for Imaging.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
[Sakari Ailus: Use ARRAY_SIZE() instead of an integer.]
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

2 files changed, 63 insertions, 1 deletions

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index f19c8adf2c61..cb153ce42c45 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -127,7 +127,7 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
 {
 	struct v4l2_mbus_config_mipi_csi2 *bus = &vep->bus.mipi_csi2;
 	bool have_clk_lane = false, have_data_lanes = false,
-		have_lane_polarities = false;
+		have_lane_polarities = false, have_line_orders = false;
 	unsigned int flags = 0, lanes_used = 0;
 	u32 array[1 + V4L2_MBUS_CSI2_MAX_DATA_LANES];
 	u32 clock_lane = 0;
@@ -197,6 +197,17 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
 		have_lane_polarities = true;
 	}
 
+	rval = fwnode_property_count_u32(fwnode, "line-orders");
+	if (rval > 0) {
+		if (rval != num_data_lanes) {
+			pr_warn("invalid number of line-orders entries (need %u, got %u)\n",
+				num_data_lanes, rval);
+			return -EINVAL;
+		}
+
+		have_line_orders = true;
+	}
+
 	if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) {
 		clock_lane = v;
 		pr_debug("clock lane position %u\n", v);
@@ -250,6 +261,36 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
 		} else {
 			pr_debug("no lane polarities defined, assuming not inverted\n");
 		}
+
+		if (have_line_orders) {
+			fwnode_property_read_u32_array(fwnode,
+						       "line-orders", array,
+						       num_data_lanes);
+
+			for (i = 0; i < num_data_lanes; i++) {
+				static const char * const orders[] = {
+					"ABC", "ACB", "BAC", "BCA", "CAB", "CBA"
+				};
+
+				if (array[i] >= ARRAY_SIZE(orders)) {
+					pr_warn("lane %u invalid line-order assuming ABC (got %u)\n",
+						i, array[i]);
+					bus->line_orders[i] =
+						V4L2_MBUS_CSI2_CPHY_LINE_ORDER_ABC;
+					continue;
+				}
+
+				bus->line_orders[i] = array[i];
+				pr_debug("lane %u line order %s", i,
+					 orders[array[i]]);
+			}
+		} else {
+			for (i = 0; i < num_data_lanes; i++)
+				bus->line_orders[i] =
+					V4L2_MBUS_CSI2_CPHY_LINE_ORDER_ABC;
+
+			pr_debug("no line orders defined, assuming ABC\n");
+		}
 	}
 
 	return 0;
diff --git a/include/media/v4l2-mediabus.h b/include/media/v4l2-mediabus.h
index 5bce6e423e94..e7f019f68c8d 100644
--- a/include/media/v4l2-mediabus.h
+++ b/include/media/v4l2-mediabus.h
@@ -74,6 +74,24 @@
 #define V4L2_MBUS_CSI2_MAX_DATA_LANES		8
 
 /**
+ * enum v4l2_mbus_csi2_cphy_line_orders_type - CSI-2 C-PHY line order
+ * @V4L2_MBUS_CSI2_CPHY_LINE_ORDER_ABC: C-PHY line order ABC (default)
+ * @V4L2_MBUS_CSI2_CPHY_LINE_ORDER_ACB: C-PHY line order ACB
+ * @V4L2_MBUS_CSI2_CPHY_LINE_ORDER_BAC: C-PHY line order BAC
+ * @V4L2_MBUS_CSI2_CPHY_LINE_ORDER_BCA: C-PHY line order BCA
+ * @V4L2_MBUS_CSI2_CPHY_LINE_ORDER_CAB: C-PHY line order CAB
+ * @V4L2_MBUS_CSI2_CPHY_LINE_ORDER_CBA: C-PHY line order CBA
+ */
+enum v4l2_mbus_csi2_cphy_line_orders_type {
+	V4L2_MBUS_CSI2_CPHY_LINE_ORDER_ABC,
+	V4L2_MBUS_CSI2_CPHY_LINE_ORDER_ACB,
+	V4L2_MBUS_CSI2_CPHY_LINE_ORDER_BAC,
+	V4L2_MBUS_CSI2_CPHY_LINE_ORDER_BCA,
+	V4L2_MBUS_CSI2_CPHY_LINE_ORDER_CAB,
+	V4L2_MBUS_CSI2_CPHY_LINE_ORDER_CBA,
+};
+
+/**
  * struct v4l2_mbus_config_mipi_csi2 - MIPI CSI-2 data bus configuration
  * @flags: media bus (V4L2_MBUS_*) flags
  * @data_lanes: an array of physical data lane indexes
@@ -81,6 +99,8 @@
  * @num_data_lanes: number of data lanes
  * @lane_polarities: polarity of the lanes. The order is the same of
  *		   the physical lanes.
+ * @line_orders: line order of the data lanes. The order is the same of the
+ *		   physical lanes.
  */
 struct v4l2_mbus_config_mipi_csi2 {
 	unsigned int flags;
@@ -88,6 +108,7 @@ struct v4l2_mbus_config_mipi_csi2 {
 	unsigned char clock_lane;
 	unsigned char num_data_lanes;
 	bool lane_polarities[1 + V4L2_MBUS_CSI2_MAX_DATA_LANES];
+	enum v4l2_mbus_csi2_cphy_line_orders_type line_orders[V4L2_MBUS_CSI2_MAX_DATA_LANES];
 };
 
 /**