[PATCHv2] v4l: split lane parsing code

Pavel Machek
2017-01-12T10:24:15Z

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From: Sakari Ailus <sakari.ailus@iki.fi>

The function to parse CSI2 bus parameters was called
v4l2_of_parse_csi_bus(), rename it as v4l2_of_parse_csi2_bus() in
anticipation of CSI1/CCP2 support.

Obtain data bus type from bus-type property. Only try parsing bus
specific properties in this case.

Separate lane parsing from CSI-2 bus parameter parsing. The CSI-1 will
need these as well, separate them into a different
function. have_clk_lane and num_data_lanes arguments may be NULL; the
CSI-1 bus will have no use for them.

Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>

diff --git a/drivers/media/v4l2-core/v4l2-of.c b/drivers/media/v4l2-core/v4l2-of.c
index 93b3368..60bbc5f 100644
--- a/drivers/media/v4l2-core/v4l2-of.c
+++ b/drivers/media/v4l2-core/v4l2-of.c
@@ -20,53 +20,88 @@

#include <media/v4l2-of.h>

-static int v4l2_of_parse_csi_bus(const struct device_node *node,
- struct v4l2_of_endpoint *endpoint)
+enum v4l2_of_bus_type {
+ V4L2_OF_BUS_TYPE_CSI2 = 0,
+ V4L2_OF_BUS_TYPE_PARALLEL,
+};
+
+static int v4l2_of_parse_lanes(const struct device_node *node,
+ unsigned char *clock_lane,
+ bool *have_clk_lane,
+ unsigned char *data_lanes,
+ bool *lane_polarities,
+ unsigned short *__num_data_lanes,
+ unsigned int max_data_lanes)
{
- struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
struct property *prop;
- bool have_clk_lane = false;
- unsigned int flags = 0;
+ unsigned short num_data_lanes = 0;
u32 v;

prop = of_find_property(node, "data-lanes", NULL);
if (prop) {
const __be32 *lane = NULL;
- unsigned int i;

- for (i = 0; i < ARRAY_SIZE(bus->data_lanes); i++) {
+ for (num_data_lanes = 0; num_data_lanes < max_data_lanes;
+ num_data_lanes++) {
lane = of_prop_next_u32(prop, lane, &v);
if (!lane)
break;
- bus->data_lanes[i] = v;
+ data_lanes[num_data_lanes] = v;
}
- bus->num_data_lanes = i;
}
+ if (__num_data_lanes)
+ *__num_data_lanes = num_data_lanes;

prop = of_find_property(node, "lane-polarities", NULL);
if (prop) {
const __be32 *polarity = NULL;
unsigned int i;

- for (i = 0; i < ARRAY_SIZE(bus->lane_polarities); i++) {
+ for (i = 0; i < 1 + max_data_lanes; i++) {
polarity = of_prop_next_u32(prop, polarity, &v);
if (!polarity)
break;
- bus->lane_polarities[i] = v;
+ lane_polarities[i] = v;
}

- if (i < 1 + bus->num_data_lanes /* clock + data */) {
+ if (i < 1 + num_data_lanes /* clock + data */) {
pr_warn("%s: too few lane-polarities entries (need %u, got %u)\n",
- node->full_name, 1 + bus->num_data_lanes, i);
+ node->full_name, 1 + num_data_lanes, i);
return -EINVAL;
}
}

+ if (have_clk_lane)
+ *have_clk_lane = false;
+
if (!of_property_read_u32(node, "clock-lanes", &v)) {
- bus->clock_lane = v;
- have_clk_lane = true;
+ *clock_lane = v;
+ if (have_clk_lane)
+ *have_clk_lane = true;
}

+ return 0;
+}
+
+static int v4l2_of_parse_csi2_bus(const struct device_node *node,
+ struct v4l2_of_endpoint *endpoint)
+{
+ struct v4l2_of_bus_mipi_csi2 *bus = &endpoint->bus.mipi_csi2;
+ bool have_clk_lane = false;
+ unsigned int flags = 0;
+ int rval;
+ u32 v;
+
+ rval = v4l2_of_parse_lanes(node, &bus->clock_lane, &have_clk_lane,
+ bus->data_lanes, bus->lane_polarities,
+ &bus->num_data_lanes,
+ ARRAY_SIZE(bus->data_lanes));
+ if (rval)
+ return rval;
+
+ BUILD_BUG_ON(1 + ARRAY_SIZE(bus->data_lanes)
+ != ARRAY_SIZE(bus->lane_polarities));
+
if (of_get_property(node, "clock-noncontinuous", &v))
flags |= V4L2_MBUS_CSI2_NONCONTINUOUS_CLOCK;
else if (have_clk_lane || bus->num_data_lanes > 0)
@@ -151,6 +186,7 @@ static void v4l2_of_parse_parallel_bus(const struct device_node *node,
int v4l2_of_parse_endpoint(const struct device_node *node,
struct v4l2_of_endpoint *endpoint)
{
+ u32 bus_type;
int rval;

of_graph_parse_endpoint(node, &endpoint->base);
@@ -158,17 +194,33 @@ int v4l2_of_parse_endpoint(const struct device_node *node,
memset(&endpoint->bus_type, 0, sizeof(*endpoint) -
offsetof(typeof(*endpoint), bus_type));

- rval = v4l2_of_parse_csi_bus(node, endpoint);
- if (rval)
- return rval;
- /*
- * Parse the parallel video bus properties only if none
- * of the MIPI CSI-2 specific properties were found.
- */
- if (endpoint->bus.mipi_csi2.flags == 0)
- v4l2_of_parse_parallel_bus(node, endpoint);
+ rval = of_property_read_u32(node, "bus-type", &bus_type);
+ if (rval < 0) {
+ endpoint->bus_type = 0;
+ rval = v4l2_of_parse_csi2_bus(node, endpoint);
+ if (rval)
+ return rval;
+ /*
+ * Parse the parallel video bus properties only if none
+ * of the MIPI CSI-2 specific properties were found.
+ */
+ if (endpoint->bus.mipi_csi2.flags == 0)
+ v4l2_of_parse_parallel_bus(node, endpoint);
+
+ return 0;
+ }

- return 0;
+ switch (bus_type) {
+ case V4L2_OF_BUS_TYPE_CSI2:
+ return v4l2_of_parse_csi2_bus(node, endpoint);
+ case V4L2_OF_BUS_TYPE_PARALLEL:
+ v4l2_of_parse_parallel_bus(node, endpoint);
+ return 0;
+ default:
+ pr_warn("bad bus-type %u, device_node \"%s\"\n",
+ bus_type, node->full_name);
+ return -EINVAL;
+ }
}
EXPORT_SYMBOL(v4l2_of_parse_endpoint);