[Intel-gfx] [PATCH 4/9] drm/i915: Pixel Clock and pixel overlap related changes for dual link Configuration
Jani Nikula
jani.nikula at linux.intel.com
Wed Sep 24 11:23:15 CEST 2014
On Wed, 24 Sep 2014, Gaurav K Singh <gaurav.k.singh at intel.com> wrote:
> Signed-off-by: Gaurav K Singh <gaurav.k.singh at intel.com>
> Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
> ---
> drivers/gpu/drm/i915/i915_reg.h | 4 ++++
> drivers/gpu/drm/i915/intel_bios.h | 3 ++-
> drivers/gpu/drm/i915/intel_dsi.c | 8 ++++++++
> drivers/gpu/drm/i915/intel_dsi.h | 6 ++++++
> drivers/gpu/drm/i915/intel_dsi_panel_vbt.c | 21 +++++++++++++++++++++
> 5 files changed, 41 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 922d807..3ed5774 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -5662,6 +5662,10 @@ enum punit_power_well {
> #define GEN8_PMINTR_REDIRECT_TO_NON_DISP (1<<31)
> #define VLV_PWRDWNUPCTL 0xA294
>
> +#define VLV_CHICKEN_3 0x7040C
> +#define PIXEL_OVERLAP_CNT_MASK (3 << 30)
> +#define PIXEL_OVERLAP_CNT_SHIFT 30
> +
> #define GEN6_PMISR 0x44020
> #define GEN6_PMIMR 0x44024 /* rps_lock */
> #define GEN6_PMIIR 0x44028
> diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
> index 7603765..39dfb65 100644
> --- a/drivers/gpu/drm/i915/intel_bios.h
> +++ b/drivers/gpu/drm/i915/intel_bios.h
> @@ -798,7 +798,8 @@ struct mipi_config {
> #define DUAL_LINK_PIXEL_ALT 2
> u16 dual_link:2;
> u16 lane_cnt:2;
> - u16 rsvd3:12;
> + u16 pixel_overlap:3;
> + u16 rsvd3:9;
>
> u16 rsvd4;
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi.c b/drivers/gpu/drm/i915/intel_dsi.c
> index 3b1890e..583c7fd 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.c
> +++ b/drivers/gpu/drm/i915/intel_dsi.c
> @@ -116,6 +116,14 @@ static void intel_dsi_port_enable(struct intel_encoder *encoder)
> << DUAL_LINK_MODE_SHIFT;
> port_control |= pipe ? LANE_CONFIGURATION_DUAL_LINK_B :
> LANE_CONFIGURATION_DUAL_LINK_A;
> +
> + if (intel_dsi->dual_link & MIPI_DUAL_LINK_FRONT_BACK) {
It's really confusing to treat ->dual_link as a bit mask when it's not.
> + temp = I915_READ(VLV_CHICKEN_3);
> + temp &= ~PIXEL_OVERLAP_CNT_MASK |
> + intel_dsi->pixel_overlap <<
> + PIXEL_OVERLAP_CNT_SHIFT;
> + I915_WRITE(VLV_CHICKEN_3, temp);
> + }
> /*For Port A */
> temp = I915_READ(MIPI_PORT_CTRL(0));
> temp = temp | port_control;
> diff --git a/drivers/gpu/drm/i915/intel_dsi.h b/drivers/gpu/drm/i915/intel_dsi.h
> index 950ab41..7fac460 100644
> --- a/drivers/gpu/drm/i915/intel_dsi.h
> +++ b/drivers/gpu/drm/i915/intel_dsi.h
> @@ -28,6 +28,11 @@
> #include <drm/drm_crtc.h>
> #include "intel_drv.h"
>
> +/* Dual Link support */
> +#define MIPI_DUAL_LINK_NONE 0
> +#define MIPI_DUAL_LINK_FRONT_BACK 1
> +#define MIPI_DUAL_LINK_PIXEL_ALT 2
> +
Spread the word, using the word "MIPI" for "DSI" feels like saying I
have an "embedded VESA" display on my laptop. Really.
> struct intel_dsi_device {
> unsigned int panel_id;
> const char *name;
> @@ -102,6 +107,7 @@ struct intel_dsi {
>
> u8 escape_clk_div;
> u8 dual_link;
> + u8 pixel_overlap;
> u32 port_bits;
> u32 bw_timer;
> u32 dphy_reg;
> diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
> index d424ebc..8bc911b 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
> +++ b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c
> @@ -284,6 +284,7 @@ static bool generic_init(struct intel_dsi_device *dsi)
> intel_dsi->pixel_format = mipi_config->videomode_color_format << 7;
> intel_dsi->port = 0;
> intel_dsi->dual_link = mipi_config->dual_link;
> + intel_dsi->pixel_overlap = mipi_config->pixel_overlap;
>
> if (intel_dsi->pixel_format == VID_MODE_FORMAT_RGB666)
> bits_per_pixel = 18;
> @@ -303,6 +304,20 @@ static bool generic_init(struct intel_dsi_device *dsi)
>
> pclk = mode->clock;
>
> + /* In dual link mode each port needs half of pixel clock */
> + if (intel_dsi->dual_link) {
> + pclk = pclk / 2;
> +
> + /* we can enable pixel_overlap if needed by panel. In this
> + * case we need to increase the pixelclock for extra pixels
> + */
> + if (intel_dsi->dual_link & MIPI_DUAL_LINK_FRONT_BACK) {
> + pclk += DIV_ROUND_UP(mode->vtotal *
> + intel_dsi->pixel_overlap *
> + 60, 1000);
> + }
> + }
> +
> /* Burst Mode Ratio
> * Target ddr frequency from VBT / non burst ddr freq
> * multiply by 100 to preserve remainder
> @@ -497,6 +512,12 @@ static bool generic_init(struct intel_dsi_device *dsi)
> DRM_DEBUG_KMS("Clockstop %s\n", intel_dsi->clock_stop ?
> "disabled" : "enabled");
> DRM_DEBUG_KMS("Mode %s\n", intel_dsi->operation_mode ? "command" : "video");
> + if (intel_dsi->dual_link == MIPI_DUAL_LINK_FRONT_BACK)
> + DRM_DEBUG_KMS("Dual link: MIPI_DUAL_LINK_FRONT_BACK\n");
> + else if (intel_dsi->dual_link == MIPI_DUAL_LINK_PIXEL_ALT)
> + DRM_DEBUG_KMS("Dual link: MIPI_DUAL_LINK_PIXEL_ALT\n");
> + else
> + DRM_DEBUG_KMS("Dual link: NONE\n");
> DRM_DEBUG_KMS("Pixel Format %d\n", intel_dsi->pixel_format);
> DRM_DEBUG_KMS("TLPX %d\n", intel_dsi->escape_clk_div);
> DRM_DEBUG_KMS("LP RX Timeout 0x%x\n", intel_dsi->lp_rx_timeout);
> --
> 1.7.9.5
>
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--
Jani Nikula, Intel Open Source Technology Center
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