[PATCH v2 2/2] [media] imx: ask source subdevice for number of active data lanes

From: Philipp Zabel <p.zabel@pengutronix.de>
To: linux-media@vger.kernel.org
Cc: Dave Stevenson <dave.stevenson@raspberrypi.org>,
	Hans Verkuil <hansverk@cisco.com>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Mauro Carvalho Chehab <mchehab@s-opensource.com>,
	Mats Randgaard <matrandg@cisco.com>,
	Steve Longerbeam <slongerbeam@gmail.com>,
	Philipp Zabel <p.zabel@pengutronix.de>
Subject: [PATCH v2 2/2] [media] imx: ask source subdevice for number of active data lanes
Date: Thu, 21 Sep 2017 17:30:55 +0200	[thread overview]
Message-ID: <20170921153055.16206-2-p.zabel@pengutronix.de> (raw)

Temporarily use g_mbus_config() to determine the number of active data
lanes used by the transmitter. If g_mbus_config is not supported or
does not return the number of active lines, default to using all
connected data lines.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
---
New in v2:
 - Use the active lanes reported via g_mbus_config(), if available, to
   configure the CSI2_N_LANES register correctly.
---
 drivers/staging/media/imx/imx6-mipi-csi2.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/imx/imx6-mipi-csi2.c b/drivers/staging/media/imx/imx6-mipi-csi2.c
index 5061f3f524fd5..cd19730d0159c 100644
--- a/drivers/staging/media/imx/imx6-mipi-csi2.c
+++ b/drivers/staging/media/imx/imx6-mipi-csi2.c
@@ -135,10 +135,8 @@ 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, int lanes)
 {
-	int lanes = csi2->bus.num_data_lanes;
-
 	writel(lanes - 1, csi2->base + CSI2_N_LANES);
 }
 
@@ -301,6 +299,9 @@ static void csi2ipu_gasket_init(struct csi2_dev *csi2)
 
 static int csi2_start(struct csi2_dev *csi2)
 {
+	const u32 mask = V4L2_MBUS_CSI2_LANE_MASK;
+	struct v4l2_mbus_config cfg;
+	int lanes = 0;
 	int ret;
 
 	ret = clk_prepare_enable(csi2->pix_clk);
@@ -316,7 +317,10 @@ static int csi2_start(struct csi2_dev *csi2)
 		goto err_disable_clk;
 
 	/* Step 4 */
-	csi2_set_lanes(csi2);
+	ret = v4l2_subdev_call(csi2->src_sd, video, g_mbus_config, &cfg);
+	if (ret == 0)
+		lanes = (cfg.flags & mask) >> __ffs(mask);
+	csi2_set_lanes(csi2, lanes ?: csi2->bus.num_data_lanes);
 	csi2_enable(csi2, true);
 
 	/* Step 5 */
-- 
2.11.0
