Re: [PATCH 3/9] drm/i915: MIPI Port Ctrl related changes for dual link configuration

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Oct 21, 2014 at 12:00:30PM +0530, Singh, Gaurav K wrote:
> 
> On 9/24/2014 2:57 PM, Jani Nikula wrote:
> >On Wed, 24 Sep 2014, Gaurav K Singh <gaurav.k.singh@intel.com> wrote:
> >>Signed-off-by: Gaurav K Singh <gaurav.k.singh@intel.com>
> >>Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
> >>---
> >>  drivers/gpu/drm/i915/i915_reg.h            |    1 +
> >>  drivers/gpu/drm/i915/intel_dsi.c           |   53 ++++++++++++++++++++++------
> >>  drivers/gpu/drm/i915/intel_dsi.h           |    1 +
> >>  drivers/gpu/drm/i915/intel_dsi_panel_vbt.c |    1 +
> >>  4 files changed, 45 insertions(+), 11 deletions(-)
> >>
> >>diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> >>index ad8179b..922d807 100644
> >>--- a/drivers/gpu/drm/i915/i915_reg.h
> >>+++ b/drivers/gpu/drm/i915/i915_reg.h
> >>@@ -6215,6 +6215,7 @@ enum punit_power_well {
> >>  #define  DPI_ENABLE					(1 << 31) /* A + B */
> >>  #define  MIPIA_MIPI4DPHY_DELAY_COUNT_SHIFT		27
> >>  #define  MIPIA_MIPI4DPHY_DELAY_COUNT_MASK		(0xf << 27)
> >>+#define  DUAL_LINK_MODE_SHIFT				26
> >>  #define  DUAL_LINK_MODE_MASK				(1 << 26)
> >>  #define  DUAL_LINK_MODE_FRONT_BACK			(0 << 26)
> >>  #define  DUAL_LINK_MODE_PIXEL_ALTERNATIVE		(1 << 26)
> >>diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> >>index e456ca9..3b1890e 100644
> >>--- a/drivers/gpu/drm/i915/intel_dsi.c
> >>+++ b/drivers/gpu/drm/i915/intel_dsi.c
> >>@@ -109,13 +109,31 @@ static void intel_dsi_port_enable(struct intel_encoder *encoder)
> >>  	struct intel_crtc *intel_crtc = to_intel_crtc(encoder->base.crtc);
> >>  	struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
> >>  	enum pipe pipe = intel_crtc->pipe;
> >>-	u32 temp;
> >>-
> >>-	/* assert ip_tg_enable signal */
> >>-	temp = I915_READ(MIPI_PORT_CTRL(pipe)) & ~LANE_CONFIGURATION_MASK;
> >>-	temp = temp | intel_dsi->port_bits;
> >>-	I915_WRITE(MIPI_PORT_CTRL(pipe), temp | DPI_ENABLE);
> >>-	POSTING_READ(MIPI_PORT_CTRL(pipe));
> >>+	u32 temp, port_control = 0;
> >>+
> >>+	if (intel_dsi->dual_link) {
> >>+		port_control = (intel_dsi->dual_link - 1)
> >>+					<< DUAL_LINK_MODE_SHIFT;
> >>+		port_control |= pipe ? LANE_CONFIGURATION_DUAL_LINK_B :
> >>+					LANE_CONFIGURATION_DUAL_LINK_A;
> >>+		/*For Port A */
> >>+		temp = I915_READ(MIPI_PORT_CTRL(0));
> >>+		temp = temp | port_control;
> >>+		I915_WRITE(MIPI_PORT_CTRL(0), temp | DPI_ENABLE);
> >>+		POSTING_READ(MIPI_PORT_CTRL(0));
> >>+
> >>+		/* For Port C */
> >>+		temp = I915_READ(MIPI_PORT_CTRL(1));
> >>+		I915_WRITE(MIPI_PORT_CTRL(1), temp | DPI_ENABLE);
> >>+		POSTING_READ(MIPI_PORT_CTRL(1));
> >This calls for a cleanup in i915_reg.h for per port vs. per transcoder
> >registers. MIPI_PORT_CTRL(1) uses _TRANSCODER macro. We also have enum
> >port with PORT_C == 2. This gets confusing.
> 
> Are you suggesting to use _PORT macro instead of _TRANSCODER macro?

I think so, and given that we already have some offenders the existing
code should be converted with a prep patch first.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch