Currently, the CSI2 subdevice is using the data-lanes from the
neareast endpoint to config the CSI2 lanes.
While this may work, the proper way to configure the hardware is
to obtain the remote subdevice in v4l2_async_notifier_operations.bound(),
and then call get_mbus_config using the remote subdevice to get
the active lanes.
Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
---
drivers/staging/media/imx/TODO | 12 ---
drivers/staging/media/imx/imx6-mipi-csi2.c | 101 ++++++++++++++++++---
2 files changed, 90 insertions(+), 23 deletions(-)
diff --git a/drivers/staging/media/imx/TODO b/drivers/staging/media/imx/TODO
index 9cfc1c1e78dc..c575f419204a 100644
--- a/drivers/staging/media/imx/TODO
+++ b/drivers/staging/media/imx/TODO
@@ -2,18 +2,6 @@
- The Frame Interval Monitor could be exported to v4l2-core for
general use.
-- The CSI subdevice parses its nearest upstream neighbor's device-tree
- bus config in order to setup the CSI. Laurent Pinchart argues that
- instead the CSI subdev should call its neighbor's g_mbus_config op
- (which should be propagated if necessary) to get this info. However
- Hans Verkuil is planning to remove the g_mbus_config op. For now this
- driver uses the parsed DT bus config method until this issue is
- resolved.
-
- 2020-06: g_mbus has been removed in favour of the get_mbus_config pad
- operation which should be used to avoid parsing the remote endpoint
- configuration.
-
- This media driver supports inheriting V4L2 controls to the
video capture devices, from the subdevices in the capture device's
pipeline. The controls for each capture device are updated in the
diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index 94d87d27d389..bf6a61dd34c2 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -42,7 +42,10 @@ struct csi2_dev {
struct clk *pllref_clk;
struct clk *pix_clk; /* what is this? */
void __iomem *base;
- struct v4l2_fwnode_bus_mipi_csi2 bus;
+
+ struct v4l2_subdev *remote;
+ unsigned int remote_pad;
+ unsigned short data_lanes;
/* lock to protect all members below */
struct mutex lock;
@@ -138,10 +141,8 @@ static void csi2_enable(struct csi2_dev *csi2, bool enable)
}
}
-static void csi2_set_lanes(struct csi2_dev *csi2)
+static void csi2_set_lanes(struct csi2_dev *csi2, unsigned int lanes)
{
- int lanes = csi2->bus.num_data_lanes;
-
writel(lanes - 1, csi2->base + CSI2_N_LANES);
}
@@ -250,12 +251,13 @@ static int __maybe_unused csi2_dphy_wait_ulp(struct csi2_dev *csi2)
}
/* Waits for low-power LP-11 state on data and clock lanes. */
-static void csi2_dphy_wait_stopstate(struct csi2_dev *csi2)
+static void csi2_dphy_wait_stopstate(struct csi2_dev *csi2,
+ unsigned int lanes)
{
u32 mask, reg;
int ret;
- mask = PHY_STOPSTATECLK | (((1 << csi2->bus.num_data_lanes) - 1) <<
+ mask = PHY_STOPSTATECLK | (((1 << lanes) - 1) <<
PHY_STOPSTATEDATA_BIT);
ret = readl_poll_timeout(csi2->base + CSI2_PHY_STATE, reg,
@@ -300,8 +302,56 @@ static void csi2ipu_gasket_init(struct csi2_dev *csi2)
writel(reg, csi2->base + CSI2IPU_GASKET);
}
+static int csi2_get_active_lanes(struct csi2_dev *csi2, unsigned int *lanes)
+{
+ struct v4l2_mbus_config mbus_config = { 0 };
+ unsigned int num_lanes = UINT_MAX;
+ int ret;
+
+ *lanes = csi2->data_lanes;
+
+ ret = v4l2_subdev_call(csi2->remote, pad, get_mbus_config,
+ csi2->remote_pad, &mbus_config);
+ if (ret == -ENOIOCTLCMD) {
+ dev_dbg(csi2->dev, "No remote mbus configuration available\n");
+ return 0;
+ }
+
+ if (ret) {
+ dev_err(csi2->dev, "Failed to get remote mbus configuration\n");
+ return ret;
+ }
+
+ if (mbus_config.type != V4L2_MBUS_CSI2_DPHY) {
+ dev_err(csi2->dev, "Unsupported media bus type %u\n",
+ mbus_config.type);
+ return -EINVAL;
+ }
+
+ if (mbus_config.flags & V4L2_MBUS_CSI2_1_LANE)
+ num_lanes = 1;
+ else if (mbus_config.flags & V4L2_MBUS_CSI2_2_LANE)
+ num_lanes = 2;
+ else if (mbus_config.flags & V4L2_MBUS_CSI2_3_LANE)
+ num_lanes = 3;
+ else if (mbus_config.flags & V4L2_MBUS_CSI2_4_LANE)
+ num_lanes = 4;
+
+ if (num_lanes > csi2->data_lanes) {
+ dev_err(csi2->dev,
+ "Unsupported mbus config: too many data lanes %u\n",
+ num_lanes);
+ return -EINVAL;
+ }
+
+ *lanes = num_lanes;
+
+ return 0;
+}
+
static int csi2_start(struct csi2_dev *csi2)
{
+ unsigned int lanes;
int ret;
ret = clk_prepare_enable(csi2->pix_clk);
@@ -316,12 +366,16 @@ static int csi2_start(struct csi2_dev *csi2)
if (ret)
goto err_disable_clk;
+ ret = csi2_get_active_lanes(csi2, &lanes);
+ if (ret)
+ goto err_disable_clk;
+
/* Step 4 */
- csi2_set_lanes(csi2);
+ csi2_set_lanes(csi2, lanes);
csi2_enable(csi2, true);
/* Step 5 */
- csi2_dphy_wait_stopstate(csi2);
+ csi2_dphy_wait_stopstate(csi2, lanes);
/* Step 6 */
ret = v4l2_subdev_call(csi2->src_sd, video, s_stream, 1);
@@ -544,12 +598,37 @@ static int csi2_notify_bound(struct v4l2_async_notifier *notifier,
{
struct csi2_dev *csi2 = notifier_to_dev(notifier);
struct media_pad *sink = &csi2->sd.entity.pads[CSI2_SINK_PAD];
+ int pad;
+
+ pad = media_entity_get_fwnode_pad(&sd->entity, asd->match.fwnode,
+ MEDIA_PAD_FL_SOURCE);
+ if (pad < 0) {
+ dev_err(csi2->dev, "Failed to find pad for %s\n", sd->name);
+ return pad;
+ }
+
+ csi2->remote = sd;
+ csi2->remote_pad = pad;
+
+ dev_dbg(csi2->dev, "Bound %s pad: %d\n", sd->name, pad);
return v4l2_create_fwnode_links_to_pad(sd, sink);
}
+static void csi2_notify_unbind(struct v4l2_async_notifier *notifier,
+ struct v4l2_subdev *sd,
+ struct v4l2_async_subdev *asd)
+{
+ struct csi2_dev *csi2 = notifier_to_dev(notifier);
+
+ csi2->remote = NULL;
+
+ dev_dbg(csi2->dev, "Unbind %s\n", sd->name);
+}
+
static const struct v4l2_async_notifier_operations csi2_notify_ops = {
.bound = csi2_notify_bound,
+ .unbind = csi2_notify_unbind,
};
static int csi2_async_register(struct csi2_dev *csi2)
@@ -572,10 +651,10 @@ static int csi2_async_register(struct csi2_dev *csi2)
if (ret)
goto err_parse;
- csi2->bus = vep.bus.mipi_csi2;
+ csi2->data_lanes = vep.bus.mipi_csi2.num_data_lanes;
- dev_dbg(csi2->dev, "data lanes: %d\n", csi2->bus.num_data_lanes);
- dev_dbg(csi2->dev, "flags: 0x%08x\n", csi2->bus.flags);
+ dev_dbg(csi2->dev, "data lanes: %d\n", vep.bus.mipi_csi2.num_data_lanes);
+ dev_dbg(csi2->dev, "flags: 0x%08x\n", vep.bus.mipi_csi2.flags);
asd = kzalloc(sizeof(*asd), GFP_KERNEL);
if (!asd) {
--
2.29.2
