media: rcar-vin: Mask VNCSI_IFMD register

The VNCSI_IFMD register controls the data expansion mode and the
channel routing between the CSI-2 receivers and VIN instances.

According to the chip manual revision 2.20 not all fields are available
for all the SoCs:
- V3M, V3H and E3 do not support the DES1 field has they do not feature
  a CSI20 receiver.
- D3 only supports parallel input, and the whole register shall always
  be written as 0.

Inspect the per-SoC channel routing table where the available CSI-2
instances are reported and configure VNCSI_IFMD accordingly.

This patch supports this BSP change commit:

https://github.com/renesas-rcar/linux-bsp/commit/f54697394457
("media: rcar-vin: Fix VnCSI_IFMD register access for r8a77990")

[hverkuil: replace BSP commit ID with BSP URL]

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Suggested-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
index 7dd91de..48280dd 100644 (file)
--- a/drivers/media/platform/rcar-vin/rcar-dma.c
+++ b/drivers/media/platform/rcar-vin/rcar-dma.c
@@ -1448,7 +1448,9 @@ error:
  */
 int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel)
 {
-       u32 ifmd, vnmc;
+       const struct rvin_group_route *route;
+       u32 ifmd = 0;
+       u32 vnmc;
        int ret;
 
        ret = pm_runtime_get_sync(vin->dev);
@@ -1461,9 +1463,26 @@ int rvin_set_channel_routing(struct rvin_dev *vin, u8 chsel)
        vnmc = rvin_read(vin, VNMC_REG);
        rvin_write(vin, vnmc & ~VNMC_VUP, VNMC_REG);
 
-       ifmd = VNCSI_IFMD_DES1 | VNCSI_IFMD_DES0 | VNCSI_IFMD_CSI_CHSEL(chsel);
+       /*
+        * Set data expansion mode to "pad with 0s" by inspecting the routes
+        * table to find out which bit fields are available in the IFMD
+        * register. IFMD_DES1 controls data expansion mode for CSI20/21,
+        * IFMD_DES0 controls data expansion mode for CSI40/41.
+        */
+       for (route = vin->info->routes; route->mask; route++) {
+               if (route->csi == RVIN_CSI20 || route->csi == RVIN_CSI21)
+                       ifmd |= VNCSI_IFMD_DES1;
+               else
+                       ifmd |= VNCSI_IFMD_DES0;
 
-       rvin_write(vin, ifmd, VNCSI_IFMD_REG);
+               if (ifmd == (VNCSI_IFMD_DES0 | VNCSI_IFMD_DES1))
+                       break;
+       }
+
+       if (ifmd) {
+               ifmd |= VNCSI_IFMD_CSI_CHSEL(chsel);
+               rvin_write(vin, ifmd, VNCSI_IFMD_REG);
+       }
 
        vin_dbg(vin, "Set IFMD 0x%x\n", ifmd);