diff mbox series

[v6.1,9/9] media: rcar-csi2: Negotiate data lanes number

Message ID 20200715143820.132677-1-jacopo+renesas@jmondi.org (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Jacopo Mondi July 15, 2020, 2:38 p.m. UTC 
Use the newly introduced get_mbus_config() subdevice pad operation to
retrieve the remote subdevice MIPI CSI-2 bus configuration and configure
the number of active data lanes accordingly.

In order to be able to call the remote subdevice operation cache the
index of the remote pad connected to the single CSI-2 input port.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
v6.1 diff to address Niklas' comments:

- s/rcsi2_config_active_lanes()/rcsi2_get_active_lanes()
- s/unsigned int num_lanes = (-1U);/unsigned int num_lanes = UINT_MAX;/
- s/active_lanes/lanes

---
 drivers/media/platform/rcar-vin/rcar-csi2.c | 74 +++++++++++++++++++--
 1 file changed, 67 insertions(+), 7 deletions(-)

--
2.27.0

Comments

Niklas Söderlund July 15, 2020, 3:14 p.m. UTC | #1 
Hi Jacopo,

Thanks for your work.

On 2020-07-15 16:38:20 +0200, Jacopo Mondi wrote:
> Use the newly introduced get_mbus_config() subdevice pad operation to
> retrieve the remote subdevice MIPI CSI-2 bus configuration and configure
> the number of active data lanes accordingly.
> 
> In order to be able to call the remote subdevice operation cache the
> index of the remote pad connected to the single CSI-2 input port.
> 
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
> v6.1 diff to address Niklas' comments:
> 
> - s/rcsi2_config_active_lanes()/rcsi2_get_active_lanes()
> - s/unsigned int num_lanes = (-1U);/unsigned int num_lanes = UINT_MAX;/
> - s/active_lanes/lanes
> 
> ---
>  drivers/media/platform/rcar-vin/rcar-csi2.c | 74 +++++++++++++++++++--
>  1 file changed, 67 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> index c6cc4f473a07..5dac8ea66358 100644
> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> @@ -364,6 +364,7 @@ struct rcar_csi2 {
>  	struct v4l2_async_notifier notifier;
>  	struct v4l2_async_subdev asd;
>  	struct v4l2_subdev *remote;
> +	unsigned int remote_pad;
> 
>  	struct v4l2_mbus_framefmt mf;
> 
> @@ -409,13 +410,14 @@ static void rcsi2_exit_standby(struct rcar_csi2 *priv)
>  	reset_control_deassert(priv->rstc);
>  }
> 
> -static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
> +static int rcsi2_wait_phy_start(struct rcar_csi2 *priv,
> +				unsigned int lanes)
>  {
>  	unsigned int timeout;
> 
>  	/* Wait for the clock and data lanes to enter LP-11 state. */
>  	for (timeout = 0; timeout <= 20; timeout++) {
> -		const u32 lane_mask = (1 << priv->lanes) - 1;
> +		const u32 lane_mask = (1 << lanes) - 1;
> 
>  		if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL)  &&
>  		    (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
> @@ -447,7 +449,8 @@ static int rcsi2_set_phypll(struct rcar_csi2 *priv, unsigned int mbps)
>  	return 0;
>  }
> 
> -static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
> +static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp,
> +			   unsigned int lanes)
>  {
>  	struct v4l2_subdev *source;
>  	struct v4l2_ctrl *ctrl;
> @@ -472,15 +475,63 @@ static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
>  	 * bps = link_freq * 2
>  	 */
>  	mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * bpp;
> -	do_div(mbps, priv->lanes * 1000000);
> +	do_div(mbps, lanes * 1000000);
> 
>  	return mbps;
>  }
> 
> +static int rcsi2_get_active_lanes(struct rcar_csi2 *priv,
> +				  unsigned int *lanes)
> +{
> +	struct v4l2_mbus_config mbus_config = { 0 };
> +	unsigned int num_lanes = UINT_MAX;
> +	int ret;
> +
> +	*lanes = priv->lanes;

I would add a blank line here as assigning *lanes is quiet different 
from trying to updated it bellow. With this fixed,

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> +	ret = v4l2_subdev_call(priv->remote, pad, get_mbus_config,
> +			       priv->remote_pad, &mbus_config);
> +	if (ret == -ENOIOCTLCMD) {
> +		dev_dbg(priv->dev, "No remote mbus configuration available\n");
> +		return 0;
> +	}
> +
> +	if (ret) {
> +		dev_err(priv->dev, "Failed to get remote mbus configuration\n");
> +		return ret;
> +	}
> +
> +	if (mbus_config.type != V4L2_MBUS_CSI2_DPHY) {
> +		dev_err(priv->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 > priv->lanes) {
> +		dev_err(priv->dev,
> +			"Unsupported mbus config: too many data lanes %u\n",
> +			num_lanes);
> +		return -EINVAL;
> +	}
> +
> +	*lanes = num_lanes;
> +
> +	return 0;
> +}
> +
>  static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>  {
>  	const struct rcar_csi2_format *format;
>  	u32 phycnt, vcdt = 0, vcdt2 = 0, fld = 0;
> +	unsigned int lanes;
>  	unsigned int i;
>  	int mbps, ret;
> 
> @@ -522,10 +573,18 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>  			fld |= FLD_FLD_NUM(1);
>  	}
> 
> +	/*
> +	 * Get the number of active data lanes inspecting the remote mbus
> +	 * configuration.
> +	 */
> +	ret = rcsi2_get_active_lanes(priv, &lanes);
> +	if (ret)
> +		return ret;
> +
>  	phycnt = PHYCNT_ENABLECLK;
> -	phycnt |= (1 << priv->lanes) - 1;
> +	phycnt |= (1 << lanes) - 1;
> 
> -	mbps = rcsi2_calc_mbps(priv, format->bpp);
> +	mbps = rcsi2_calc_mbps(priv, format->bpp, lanes);
>  	if (mbps < 0)
>  		return mbps;
> 
> @@ -572,7 +631,7 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>  	rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ);
>  	rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ | PHYCNT_RSTZ);
> 
> -	ret = rcsi2_wait_phy_start(priv);
> +	ret = rcsi2_wait_phy_start(priv, lanes);
>  	if (ret)
>  		return ret;
> 
> @@ -749,6 +808,7 @@ static int rcsi2_notify_bound(struct v4l2_async_notifier *notifier,
>  	}
> 
>  	priv->remote = subdev;
> +	priv->remote_pad = pad;
> 
>  	dev_dbg(priv->dev, "Bound %s pad: %d\n", subdev->name, pad);
> 
> --
> 2.27.0
>
diff mbox series

Patch

diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
index c6cc4f473a07..5dac8ea66358 100644
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c
+++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
@@ -364,6 +364,7 @@  struct rcar_csi2 {
 	struct v4l2_async_notifier notifier;
 	struct v4l2_async_subdev asd;
 	struct v4l2_subdev *remote;
+	unsigned int remote_pad;

 	struct v4l2_mbus_framefmt mf;

@@ -409,13 +410,14 @@  static void rcsi2_exit_standby(struct rcar_csi2 *priv)
 	reset_control_deassert(priv->rstc);
 }

-static int rcsi2_wait_phy_start(struct rcar_csi2 *priv)
+static int rcsi2_wait_phy_start(struct rcar_csi2 *priv,
+				unsigned int lanes)
 {
 	unsigned int timeout;

 	/* Wait for the clock and data lanes to enter LP-11 state. */
 	for (timeout = 0; timeout <= 20; timeout++) {
-		const u32 lane_mask = (1 << priv->lanes) - 1;
+		const u32 lane_mask = (1 << lanes) - 1;

 		if ((rcsi2_read(priv, PHCLM_REG) & PHCLM_STOPSTATECKL)  &&
 		    (rcsi2_read(priv, PHDLM_REG) & lane_mask) == lane_mask)
@@ -447,7 +449,8 @@  static int rcsi2_set_phypll(struct rcar_csi2 *priv, unsigned int mbps)
 	return 0;
 }

-static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
+static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp,
+			   unsigned int lanes)
 {
 	struct v4l2_subdev *source;
 	struct v4l2_ctrl *ctrl;
@@ -472,15 +475,63 @@  static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
 	 * bps = link_freq * 2
 	 */
 	mbps = v4l2_ctrl_g_ctrl_int64(ctrl) * bpp;
-	do_div(mbps, priv->lanes * 1000000);
+	do_div(mbps, lanes * 1000000);

 	return mbps;
 }

+static int rcsi2_get_active_lanes(struct rcar_csi2 *priv,
+				  unsigned int *lanes)
+{
+	struct v4l2_mbus_config mbus_config = { 0 };
+	unsigned int num_lanes = UINT_MAX;
+	int ret;
+
+	*lanes = priv->lanes;
+	ret = v4l2_subdev_call(priv->remote, pad, get_mbus_config,
+			       priv->remote_pad, &mbus_config);
+	if (ret == -ENOIOCTLCMD) {
+		dev_dbg(priv->dev, "No remote mbus configuration available\n");
+		return 0;
+	}
+
+	if (ret) {
+		dev_err(priv->dev, "Failed to get remote mbus configuration\n");
+		return ret;
+	}
+
+	if (mbus_config.type != V4L2_MBUS_CSI2_DPHY) {
+		dev_err(priv->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 > priv->lanes) {
+		dev_err(priv->dev,
+			"Unsupported mbus config: too many data lanes %u\n",
+			num_lanes);
+		return -EINVAL;
+	}
+
+	*lanes = num_lanes;
+
+	return 0;
+}
+
 static int rcsi2_start_receiver(struct rcar_csi2 *priv)
 {
 	const struct rcar_csi2_format *format;
 	u32 phycnt, vcdt = 0, vcdt2 = 0, fld = 0;
+	unsigned int lanes;
 	unsigned int i;
 	int mbps, ret;

@@ -522,10 +573,18 @@  static int rcsi2_start_receiver(struct rcar_csi2 *priv)
 			fld |= FLD_FLD_NUM(1);
 	}

+	/*
+	 * Get the number of active data lanes inspecting the remote mbus
+	 * configuration.
+	 */
+	ret = rcsi2_get_active_lanes(priv, &lanes);
+	if (ret)
+		return ret;
+
 	phycnt = PHYCNT_ENABLECLK;
-	phycnt |= (1 << priv->lanes) - 1;
+	phycnt |= (1 << lanes) - 1;

-	mbps = rcsi2_calc_mbps(priv, format->bpp);
+	mbps = rcsi2_calc_mbps(priv, format->bpp, lanes);
 	if (mbps < 0)
 		return mbps;

@@ -572,7 +631,7 @@  static int rcsi2_start_receiver(struct rcar_csi2 *priv)
 	rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ);
 	rcsi2_write(priv, PHYCNT_REG, phycnt | PHYCNT_SHUTDOWNZ | PHYCNT_RSTZ);

-	ret = rcsi2_wait_phy_start(priv);
+	ret = rcsi2_wait_phy_start(priv, lanes);
 	if (ret)
 		return ret;

@@ -749,6 +808,7 @@  static int rcsi2_notify_bound(struct v4l2_async_notifier *notifier,
 	}

 	priv->remote = subdev;
+	priv->remote_pad = pad;

 	dev_dbg(priv->dev, "Bound %s pad: %d\n", subdev->name, pad);