From 05594394dc27ff8846a5d3beae50c020c4352516 Mon Sep 17 00:00:00 2001 From: Suresh Udipi Date: Fri, 13 Aug 2021 17:07:56 +0200 Subject: [PATCH] media: rcar-csi2: Optimize the selection PHTW register MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Michael Rodin Reviewed-by: Niklas Söderlund Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- drivers/media/platform/rcar-vin/rcar-csi2.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c index 99b28611eb12..db3d5d463f53 100644 --- a/drivers/media/platform/rcar-vin/rcar-csi2.c +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c @@ -911,10 +911,17 @@ static int rcsi2_phtw_write_mbps(struct rcar_csi2 *priv, unsigned int mbps, 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);