[PATCH v4 1/5] drm/msm/mdp4: add lcdc-align-lsb flag to control lane alignment

From: Jonathan Marek
Date: Tue Dec 04 2018 - 10:20:02 EST


This allows controlling which of the 8 lanes are used for 6 bit color.

Signed-off-by: Jonathan Marek <jonathan@xxxxxxxx>
---
v3: removed empty line and added documentation

.../devicetree/bindings/display/msm/mdp4.txt | 2 ++
.../gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c | 21 ++++++++++++-------
2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/msm/mdp4.txt b/Documentation/devicetree/bindings/display/msm/mdp4.txt
index 3c341a15c..b07eeb38f 100644
--- a/Documentation/devicetree/bindings/display/msm/mdp4.txt
+++ b/Documentation/devicetree/bindings/display/msm/mdp4.txt
@@ -38,6 +38,8 @@ Required properties:
Optional properties:
- clock-names: the following clocks are optional:
* "lut_clk"
+- qcom,lcdc-align-lsb: Boolean value indicating that LSB alignment should be
+ used for LCDC. This is only valid for 18bpp panels.

Example:

diff --git a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
index 9e08c2efa..c9e34501a 100644
--- a/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
+++ b/drivers/gpu/drm/msm/disp/mdp4/mdp4_lcdc_encoder.c
@@ -377,20 +377,25 @@ static void mdp4_lcdc_encoder_enable(struct drm_encoder *encoder)
unsigned long pc = mdp4_lcdc_encoder->pixclock;
struct mdp4_kms *mdp4_kms = get_kms(encoder);
struct drm_panel *panel;
+ uint32_t config;
int i, ret;

if (WARN_ON(mdp4_lcdc_encoder->enabled))
return;

/* TODO: hard-coded for 18bpp: */
- mdp4_crtc_set_config(encoder->crtc,
- MDP4_DMA_CONFIG_R_BPC(BPC6) |
- MDP4_DMA_CONFIG_G_BPC(BPC6) |
- MDP4_DMA_CONFIG_B_BPC(BPC6) |
- MDP4_DMA_CONFIG_PACK_ALIGN_MSB |
- MDP4_DMA_CONFIG_PACK(0x21) |
- MDP4_DMA_CONFIG_DEFLKR_EN |
- MDP4_DMA_CONFIG_DITHER_EN);
+ config =
+ MDP4_DMA_CONFIG_R_BPC(BPC6) |
+ MDP4_DMA_CONFIG_G_BPC(BPC6) |
+ MDP4_DMA_CONFIG_B_BPC(BPC6) |
+ MDP4_DMA_CONFIG_PACK(0x21) |
+ MDP4_DMA_CONFIG_DEFLKR_EN |
+ MDP4_DMA_CONFIG_DITHER_EN;
+
+ if (!of_property_read_bool(dev->dev->of_node, "qcom,lcdc-align-lsb"))
+ config |= MDP4_DMA_CONFIG_PACK_ALIGN_MSB;
+
+ mdp4_crtc_set_config(encoder->crtc, config);
mdp4_crtc_set_intf(encoder->crtc, INTF_LCDC_DTV, 0);

bs_set(mdp4_lcdc_encoder, 1);
--
2.17.1