video: tegra: dsi: fix DSI_PAD_CONTROL reg wr value on resume

In panel resume path DSI_PAD_CONTROL value gets calibrated,
however later on values are overwritten with bit settings
for ulpm mode.

refactor value for reg write to only change ulpm related bits.

Change-Id: I9f9713bdf376c06b0e1b9f43b3e6c9f719bbd855
Signed-off-by: Boris Suvorov <bsuvorov@nvidia.com>
Reviewed-on: http://git-master/r/85873
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>

Rebase-Id: R192c61a086759bf4a5e76fec91907fbf3fa0756d

1 files changed, 16 insertions, 5 deletions

diff --git a/drivers/video/tegra/dc/dsi.c b/drivers/video/tegra/dc/dsi.c
index fb197c9bb..982b10daf 100644
--- a/drivers/video/tegra/dc/dsi.c
+++ b/drivers/video/tegra/dc/dsi.c
@@ -2419,10 +2419,18 @@ static void tegra_dc_dsi_enable(struct tegra_dc *dc)
                                         "DSI failed to enter ulpm\n");
                                 goto fail;
                         }
-                        val = DSI_PAD_CONTROL_PAD_PDIO(0) |
+
+                        val = tegra_dsi_readl(dsi, DSI_PAD_CONTROL);
+
+                        /* erase bits we're about to set */
+                        val &= ~(DSI_PAD_CONTROL_PAD_PDIO(0x3) |
+                                DSI_PAD_CONTROL_PAD_PDIO_CLK(0x1) |
+                                DSI_PAD_CONTROL_PAD_PULLDN_ENAB(TEGRA_DSI_ENABLE));
+
+                        val |= (DSI_PAD_CONTROL_PAD_PDIO(0) |
                                 DSI_PAD_CONTROL_PAD_PDIO_CLK(0) |
-                                DSI_PAD_CONTROL_PAD_PULLDN_ENAB
-                                                (TEGRA_DSI_DISABLE);
+                                DSI_PAD_CONTROL_PAD_PULLDN_ENAB(TEGRA_DSI_DISABLE));
+
                         tegra_dsi_writel(dsi, val, DSI_PAD_CONTROL);
                         if (tegra_dsi_exit_ulpm(dsi) < 0) {
                                 dev_err(&dc->ndev->dev,
@@ -2792,8 +2800,11 @@ static int tegra_dsi_deep_sleep(struct tegra_dc *dc,
                 }
         }
 
-        /* Suspend pad */
-        val = tegra_dsi_readl(dsi, DSI_PAD_CONTROL);
+        /*
+         * Suspend pad
+         * It is ok to overwrite previous value of DSI_PAD_CONTROL reg
+         * because it will be restored properly in resume sequence
+         */
         val = DSI_PAD_CONTROL_PAD_PDIO(0x3) |
                 DSI_PAD_CONTROL_PAD_PDIO_CLK(0x1) |
                 DSI_PAD_CONTROL_PAD_PULLDN_ENAB(TEGRA_DSI_ENABLE);