From: Suresh Udipi sudipi@jp.adit-jv.com
[ Upstream commit cee44d4fbacbbdfe62697ec94e76c6e4f726c5df ]
hsfreqrange should be chosen based on the calculated mbps which is closer to the default bit rate and within the range as per table[1]. But current calculation always selects first value which is greater than or equal to the calculated mbps which may lead to chosing a wrong range in some cases.
For example for 360 mbps for H3/M3N Existing logic selects Calculated value 360Mbps : Default 400Mbps Range [368.125 -433.125 mbps]
This hsfreqrange is out of range.
The logic is changed to get the default value which is closest to the calculated value [1]
Calculated value 360Mbps : Default 350Mbps Range [320.625 -380.625 mpbs]
[1] specs r19uh0105ej0200-r-car-3rd-generation.pdf [Table 25.9]
Please note that According to Renesas in Table 25.9 the range for 220 default value is corrected as below
|Range (Mbps) | Default Bit rate (Mbps) | ----------------------------------------------- | 197.125-244.125 | 220 | -----------------------------------------------
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: Kazuyoshi Akiyama akiyama@nds-osk.co.jp 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: Sasha Levin sashal@kernel.org --- 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 23f55514b002a..bdcddc48e2f08 100644 --- a/drivers/media/platform/rcar-vin/rcar-csi2.c +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c @@ -416,16 +416,23 @@ static int rcsi2_wait_phy_start(struct rcar_csi2 *priv) static int rcsi2_set_phypll(struct rcar_csi2 *priv, unsigned int mbps) { const struct rcsi2_mbps_reg *hsfreq; + const struct rcsi2_mbps_reg *hsfreq_prev = NULL;
- for (hsfreq = priv->info->hsfreqrange; hsfreq->mbps != 0; hsfreq++) + for (hsfreq = priv->info->hsfreqrange; hsfreq->mbps != 0; hsfreq++) { if (hsfreq->mbps >= mbps) break; + hsfreq_prev = hsfreq; + }
if (!hsfreq->mbps) { dev_err(priv->dev, "Unsupported PHY speed (%u Mbps)", mbps); return -ERANGE; }
+ if (hsfreq_prev && + ((mbps - hsfreq_prev->mbps) <= (hsfreq->mbps - mbps))) + hsfreq = hsfreq_prev; + rcsi2_write(priv, PHYPLL_REG, PHYPLL_HSFREQRANGE(hsfreq->reg));
return 0;