From: Suresh Udipi sudipi@jp.adit-jv.com
commit 549cc89cd09a85aaa16dc07ef3db811d5cf9bcb1 upstream.
PHTW register is selected based on default bit rate from Table[1]. for the bit rates less than or equal to 250. Currently first value of default bit rate which is greater than or equal to the caculated mbps is selected. This selection can be further improved by selecting the default bit rate which is nearest to the calculated value.
[1] specs r19uh0105ej0200-r-car-3rd-generation.pdf [Table 25.12]
Fixes: 769afd212b16 ("media: rcar-csi2: add Renesas R-Car MIPI CSI-2 receiver driver") Signed-off-by: Suresh Udipi sudipi@jp.adit-jv.com Signed-off-by: Michael Rodin mrodin@de.adit-jv.com Reviewed-by: Niklas Söderlund niklas.soderlund+renesas@ragnatech.se Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/media/platform/rcar-vin/rcar-csi2.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
--- a/drivers/media/platform/rcar-vin/rcar-csi2.c +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c @@ -976,10 +976,17 @@ static int rcsi2_phtw_write_mbps(struct const struct rcsi2_mbps_reg *values, u16 code) { const struct rcsi2_mbps_reg *value; + const struct rcsi2_mbps_reg *prev_value = NULL;
- for (value = values; value->mbps; value++) + for (value = values; value->mbps; value++) { if (value->mbps >= mbps) break; + prev_value = value; + } + + if (prev_value && + ((mbps - prev_value->mbps) <= (value->mbps - mbps))) + value = prev_value;
if (!value->mbps) { dev_err(priv->dev, "Unsupported PHY speed (%u Mbps)", mbps);