media: v4l: fwnode: Support default CSI-2 lane mapping for drivers

Most hardware doesn't support re-mapping of the CSI-2 lanes. Especially
sensor drivers have a default number of lanes. Instead of requiring the
caller (the driver) to provide such a unit mapping, provide one if no
mapping is configured.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Tested-by: Steve Longerbeam <steve_longerbeam@mentor.com>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 040323c..caf4aa9 100644 (file)
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -47,20 +47,35 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
                                               enum v4l2_fwnode_bus_type bus_type)
 {
        struct v4l2_fwnode_bus_mipi_csi2 *bus = &vep->bus.mipi_csi2;
-       bool have_clk_lane = false, have_lane_polarities = false;
+       bool have_clk_lane = false, have_data_lanes = false,
+               have_lane_polarities = false;
        unsigned int flags = 0, lanes_used = 0;
        u32 array[1 + V4L2_FWNODE_CSI2_MAX_DATA_LANES];
+       u32 clock_lane = 0;
        unsigned int num_data_lanes = 0;
+       bool use_default_lane_mapping = false;
        unsigned int i;
        u32 v;
        int rval;
 
        if (bus_type == V4L2_FWNODE_BUS_TYPE_CSI2_DPHY) {
+               use_default_lane_mapping = true;
+
                num_data_lanes = min_t(u32, bus->num_data_lanes,
                                       V4L2_FWNODE_CSI2_MAX_DATA_LANES);
 
-               for (i = 0; i < num_data_lanes; i++)
+               clock_lane = bus->clock_lane;
+               if (clock_lane)
+                       use_default_lane_mapping = false;
+
+               for (i = 0; i < num_data_lanes; i++) {
                        array[i] = bus->data_lanes[i];
+                       if (array[i])
+                               use_default_lane_mapping = false;
+               }
+
+               if (use_default_lane_mapping)
+                       pr_debug("using default lane mapping\n");
        }
 
        rval = fwnode_property_read_u32_array(fwnode, "data-lanes", NULL, 0);
@@ -70,15 +85,21 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
 
                fwnode_property_read_u32_array(fwnode, "data-lanes", array,
                                               num_data_lanes);
+
+               have_data_lanes = true;
        }
 
        for (i = 0; i < num_data_lanes; i++) {
-               if (lanes_used & BIT(array[i]))
-                       pr_warn("duplicated lane %u in data-lanes\n",
-                               array[i]);
+               if (lanes_used & BIT(array[i])) {
+                       if (have_data_lanes || !use_default_lane_mapping)
+                               pr_warn("duplicated lane %u in data-lanes, using defaults\n",
+                                       array[i]);
+                       use_default_lane_mapping = true;
+               }
                lanes_used |= BIT(array[i]);
 
-               pr_debug("lane %u position %u\n", i, array[i]);
+               if (have_data_lanes)
+                       pr_debug("lane %u position %u\n", i, array[i]);
        }
 
        rval = fwnode_property_read_u32_array(fwnode, "lane-polarities", NULL,
@@ -94,13 +115,16 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
        }
 
        if (!fwnode_property_read_u32(fwnode, "clock-lanes", &v)) {
-               if (lanes_used & BIT(v))
-                       pr_warn("duplicated lane %u in clock-lanes\n", v);
-               lanes_used |= BIT(v);
-
-               bus->clock_lane = v;
-               have_clk_lane = true;
+               clock_lane = v;
                pr_debug("clock lane position %u\n", v);
+               have_clk_lane = true;
+       }
+
+       if (lanes_used & BIT(clock_lane)) {
+               if (have_clk_lane || !use_default_lane_mapping)
+                       pr_warn("duplicated lane %u in clock-lanes, using defaults\n",
+                       v);
+               use_default_lane_mapping = true;
        }
 
        if (fwnode_property_present(fwnode, "clock-noncontinuous")) {
@@ -115,8 +139,16 @@ static int v4l2_fwnode_endpoint_parse_csi2_bus(struct fwnode_handle *fwnode,
                bus->flags = flags;
                vep->bus_type = V4L2_MBUS_CSI2_DPHY;
                bus->num_data_lanes = num_data_lanes;
-               for (i = 0; i < num_data_lanes; i++)
-                       bus->data_lanes[i] = array[i];
+
+               if (use_default_lane_mapping) {
+                       bus->clock_lane = 0;
+                       for (i = 0; i < num_data_lanes; i++)
+                               bus->data_lanes[i] = 1 + i;
+               } else {
+                       bus->clock_lane = clock_lane;
+                       for (i = 0; i < num_data_lanes; i++)
+                               bus->data_lanes[i] = array[i];
+               }
 
                if (have_lane_polarities) {
                        fwnode_property_read_u32_array(fwnode,