From f1ab20a9584c97eddf07d4f8937f0aff42bd1038 Mon Sep 17 00:00:00 2001 From: Dave Stevenson Date: Tue, 23 Jun 2020 14:32:51 +0100 Subject: [PATCH] media: bcm2835-unicam: Add support for get_mbus_config to set num lanes Use the get_mbus_config pad subdev call to allow a source to use fewer than the number of CSI2 lanes defined in device tree. Signed-off-by: Dave Stevenson --- .../media/platform/bcm2835/bcm2835-unicam.c | 31 ++++++++++++++++--- 1 file changed, 27 insertions(+), 4 deletions(-) --- a/drivers/media/platform/bcm2835/bcm2835-unicam.c +++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c @@ -1639,12 +1639,35 @@ static int unicam_start_streaming(struct goto err_streaming; } - /* - * TODO: Retrieve the number of active data lanes from the connected - * subdevice. - */ dev->active_data_lanes = dev->max_data_lanes; + if (dev->bus_type == V4L2_MBUS_CSI2_DPHY) { + struct v4l2_mbus_config mbus_config = { 0 }; + + ret = v4l2_subdev_call(dev->sensor, pad, get_mbus_config, + 0, &mbus_config); + if (ret < 0 && ret != -ENOIOCTLCMD) { + unicam_dbg(3, dev, "g_mbus_config failed\n"); + goto err_pm_put; + } + + dev->active_data_lanes = + (mbus_config.flags & V4L2_MBUS_CSI2_LANE_MASK) >> + __ffs(V4L2_MBUS_CSI2_LANE_MASK); + if (!dev->active_data_lanes) + dev->active_data_lanes = dev->max_data_lanes; + if (dev->active_data_lanes > dev->max_data_lanes) { + unicam_err(dev, "Device has requested %u data lanes, which is >%u configured in DT\n", + dev->active_data_lanes, + dev->max_data_lanes); + ret = -EINVAL; + goto err_pm_put; + } + } + + unicam_dbg(1, dev, "Running with %u data lanes\n", + dev->active_data_lanes); + ret = clk_set_rate(dev->clock, 100 * 1000 * 1000); if (ret) { unicam_err(dev, "failed to set up clock\n");