[Intel-gfx] [PATCH 5/9] drm/i915: Setup EDP PSR AUX Registers

Paulo Zanoni przanoni at gmail.com
Thu Jan 31 22:35:40 CET 2013


Hi

In addition to Jani's comments:

2013/1/30 Rodrigo Vivi <rodrigo.vivi at gmail.com>:
> From: Shobhit Kumar <shobhit.kumar at intel.com>
>
> Signed-off-by: Shobhit Kumar <shobhit.kumar at intel.com>
>
> v2: Created aux_clock_divider function to avoid duplicated code.
>     Unfortunatelly dp_aux_ch and psr_aux_ch aren't so similar to reuse full code.
>

DDI A AUX channel transactions must not be sent while SRD is enabled.
SRD must be completely disabled before DDI A AUX channel transaction
can be sent. So I think we should put a big WARN_ON inside
intel_dp_aux_ch checking for this restriction. This WARN could maybe
go in a separate patch.

SRD AUX channel transactions must not be sent while DDI A AUX is being
used. This patch may also include a big WARN on the newly-added
function.

More below:

> Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h  | 13 ++++++
>  drivers/gpu/drm/i915/intel_dp.c  | 89 +++++++++++++++++++++++++++++++---------
>  drivers/gpu/drm/i915/intel_drv.h |  1 +
>  3 files changed, 83 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 7bb3134..10732dc 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -1563,6 +1563,19 @@
>  #define BCLRPAT(pipe) _PIPE(pipe, _BCLRPAT_A, _BCLRPAT_B)
>  #define VSYNCSHIFT(trans) _TRANSCODER(trans, _VSYNCSHIFT_A, _VSYNCSHIFT_B)
>
> +#define EDP_PSR_AUX_CTL                        0x64810
> +#define EDP_PSR_AUX_DATA1              0x64814
> +#define EDP_PSR_AUX_DATA2              0x64818
> +#define EDP_PSR_AUX_DATA3              0x6481c
> +#define EDP_PSR_AUX_DATA4              0x64820
> +#define EDP_PSR_AUX_DATA5              0x64824
> +#define EDP_PSR_STATUS_CTL             0x64840
> +#define   EDP_PSR_STATUS_MASK          (7<<29)
> +#define EDP_PSR_PERF_CNT               0x64844
> +#define EDP_PSR_DEBUG_CTL              0x64860
> +#define   EDP_PSR_DEBUG_MASK_MEMUP     (1<<26)
> +#define   EDP_PSR_DEBUG_MASK_HPD       (1<<25)
> +
>  /* VGA port control */
>  #define ADPA                   0x61100
>  #define PCH_ADPA                0xe1100
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index aeb0ef1..fe83e05 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -364,6 +364,34 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp, bool has_aux_irq)
>         return status;
>  }
>
> +static uint32_t get_aux_clock_divider(struct intel_dp *intel_dp)
> +{
> +       struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
> +       struct drm_device *dev = intel_dig_port->base.base.dev;
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +       /* The clock divider is based off the hrawclk,
> +        * and would like to run at 2MHz. So, take the
> +        * hrawclk value and divide by 2 and use that
> +        *
> +        * Note that PCH attached eDP panels should use a 125MHz input
> +        * clock divider.
> +        */
> +       if (is_cpu_edp(intel_dp)) {
> +               if (HAS_DDI(dev))
> +                       return intel_ddi_get_cdclk_freq(dev_priv) >> 1;
> +               else if (IS_VALLEYVIEW(dev))
> +                       return 100;
> +               else if (IS_GEN6(dev) || IS_GEN7(dev))
> +                       return 200; /* SNB & IVB eDP input clock at 400Mhz */
> +               else
> +                       return 225; /* eDP input clock at 450Mhz */
> +       } else if (HAS_PCH_SPLIT(dev))
> +               return DIV_ROUND_UP(intel_pch_rawclk(dev), 2);
> +       else
> +               return intel_hrawclk(dev) / 2;
> +}
> +
>  static int
>  intel_dp_aux_ch(struct intel_dp *intel_dp,
>                 uint8_t *send, int send_bytes,
> @@ -411,26 +439,7 @@ intel_dp_aux_ch(struct intel_dp *intel_dp,
>         }
>
>         intel_dp_check_edp(intel_dp);
> -       /* The clock divider is based off the hrawclk,
> -        * and would like to run at 2MHz. So, take the
> -        * hrawclk value and divide by 2 and use that
> -        *
> -        * Note that PCH attached eDP panels should use a 125MHz input
> -        * clock divider.
> -        */
> -       if (is_cpu_edp(intel_dp)) {
> -               if (HAS_DDI(dev))
> -                       aux_clock_divider = intel_ddi_get_cdclk_freq(dev_priv) >> 1;
> -               else if (IS_VALLEYVIEW(dev))
> -                       aux_clock_divider = 100;
> -               else if (IS_GEN6(dev) || IS_GEN7(dev))
> -                       aux_clock_divider = 200; /* SNB & IVB eDP input clock at 400Mhz */
> -               else
> -                       aux_clock_divider = 225; /* eDP input clock at 450Mhz */
> -       } else if (HAS_PCH_SPLIT(dev))
> -               aux_clock_divider = DIV_ROUND_UP(intel_pch_rawclk(dev), 2);
> -       else
> -               aux_clock_divider = intel_hrawclk(dev) / 2;
> +       aux_clock_divider = get_aux_clock_divider(intel_dp);
>
>         if (IS_GEN6(dev))
>                 precharge = 3;
> @@ -1440,6 +1449,46 @@ static bool is_edp_psr(struct intel_dp *intel_dp)
>         return (is_edp(intel_dp) && (intel_dp->psr_dpcd[0] & 0x1));
>  }
>
> +static void intel_edp_psr_setup(struct intel_dp *intel_dp)
> +{
> +       struct drm_device *dev = intel_dp_to_dev(intel_dp);
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +       uint32_t aux_clock_divider;
> +       int precharge = 0x3;
> +       int msg_size = 5;       /* Header(4) + Message(1) */
> +
> +       /* No need to setup if already done as these setting are persistent
> +        * until power states are entered */
> +       if (intel_dp->psr_setup)
> +               return;
> +
> +       /* Setup AUX registers */
> +       /* Write command on DPCD 0x0600 */
> +       I915_WRITE(EDP_PSR_AUX_DATA1, 0x80060000);
> +
> +       /* Set the state to normal operation D0 in DPCD 0x0600 */
> +       I915_WRITE(EDP_PSR_AUX_DATA2, 0x01000000);
> +
> +       aux_clock_divider = get_aux_clock_divider(intel_dp);
> +
> +       I915_WRITE(EDP_PSR_AUX_CTL,
> +                  DP_AUX_CH_CTL_TIME_OUT_400us |
> +                  (msg_size << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
> +                  (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
> +                  (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT));

On DP_AUX_CH the message "goes" after we write 1 to bit 31. And then
we wait for the "done" bit. How does it work here?

Also, on DP_AUX_CH we try at least 5 times. Shouldn't we do this here too?

> +
> +       /* Setup the debug register */
> +       I915_WRITE(EDP_PSR_DEBUG_CTL, I915_READ(EDP_PSR_DEBUG_CTL) |
> +                       EDP_PSR_DEBUG_MASK_MEMUP |
> +                       EDP_PSR_DEBUG_MASK_HPD);

Why?

> +
> +       /* This flag can be made to 0 from pm code so as to reinitialize the
> +        * AUX register in case of power states, returning from which will not
> +        * maintain the AUX register settings
> +        */
> +       intel_dp->psr_setup = 1;
> +}
> +
>  static void intel_enable_dp(struct intel_encoder *encoder)
>  {
>         struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index d4b3bac..3fa2dd0 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -383,6 +383,7 @@ struct intel_dp {
>         int backlight_on_delay;
>         int backlight_off_delay;
>         struct delayed_work panel_vdd_work;
> +       uint8_t psr_setup;

bool psr_setup_done ?

>         bool want_panel_vdd;
>         struct intel_connector *attached_connector;
>  };
> --
> 1.7.11.7
>
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-- 
Paulo Zanoni



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