[Intel-gfx] [PATCH 15/19] drm/i915: HSW cdclk support

Sivakumar Thulasimani sivakumar.thulasimani at intel.com
Tue Apr 7 00:03:40 PDT 2015


sorry if i am missing something, HSW and BDW requires display audio 
controller to be updated with new values once CD clock is modified. how 
is this accomplished here ?

regards,
Sivakumar
On 4/7/2015 11:57 AM, Sivakumar Thulasimani wrote:
>
>
> On 3/31/2015 4:44 PM, Mika Kahola wrote:
>> Implement support for changing the cdclk frequency during runtime on
>> HSW. VLV/CHV already have support for this, so we can follow their
>> example for the most part. Only the actual hardware programming differs,
>> the rest is pretty much the same.
>>
>> The pipe pixel rate stuff is handled a bit differently for now due to
>> the difference in pch vs. gmch pfit handling. Eventually we should unify
>> that part to eliminate what is essentially duplicated code.
>>
>> v2: Grab rps.hw_lock around sandybridge_pcode_write()
>> v3: Rebase due to power well vs. .global_resources() reordering
>> v4: Rebase due to .global_resources() reordering for Haswell
>>
>> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>> Signed-off-by: Mika Kahola <mika.kahola at intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_reg.h      |   3 +
>>   drivers/gpu/drm/i915/intel_display.c | 161 
>> ++++++++++++++++++++++++++++++++++-
>>   2 files changed, 161 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h 
>> b/drivers/gpu/drm/i915/i915_reg.h
>> index f26ebd2..b25f712 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -6244,6 +6244,7 @@ enum skl_disp_power_wells {
>>   #define   GEN6_PCODE_WRITE_D_COMP        0x11
>>   #define   GEN6_ENCODE_RC6_VID(mv)        (((mv) - 245) / 5)
>>   #define   GEN6_DECODE_RC6_VID(vids)        (((vids) * 5) + 245)
>> +#define   HSW_PCODE_DE_WRITE_FREQ_REQ        0x17
>>   #define   DISPLAY_IPS_CONTROL            0x19
>>   #define      HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL    0x1A
>>   #define GEN6_PCODE_DATA                0x138128
>> @@ -6698,10 +6699,12 @@ enum skl_disp_power_wells {
>>   #define  LCPLL_PLL_LOCK            (1<<30)
>>   #define  LCPLL_CLK_FREQ_MASK        (3<<26)
>>   #define  LCPLL_CLK_FREQ_450        (0<<26)
>> +#define  LCPLL_CLK_FREQ_ALT_HSW        (1<<26) /* 337.5 (ULX) or 540 */
>>   #define  LCPLL_CLK_FREQ_54O_BDW        (1<<26)
>>   #define  LCPLL_CLK_FREQ_337_5_BDW    (2<<26)
>>   #define  LCPLL_CLK_FREQ_675_BDW        (3<<26)
>>   #define  LCPLL_CD_CLOCK_DISABLE        (1<<25)
>> +#define  LCPLL_ROOT_CD_CLOCK_DISABLE    (1<<24)
>>   #define  LCPLL_CD2X_CLOCK_DISABLE    (1<<23)
>>   #define  LCPLL_POWER_DOWN_ALLOW        (1<<22)
>>   #define  LCPLL_CD_SOURCE_FCLK        (1<<21)
>> diff --git a/drivers/gpu/drm/i915/intel_display.c 
>> b/drivers/gpu/drm/i915/intel_display.c
>> index 3752d5e..cce7103 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -5012,7 +5012,16 @@ static void intel_update_max_cdclk(struct 
>> drm_device *dev)
>>   {
>>       struct drm_i915_private *dev_priv = dev->dev_private;
>>   -    if (IS_VALLEYVIEW(dev)) {
>> +    if (IS_HASWELL(dev)) {
>> +        if (I915_READ(FUSE_STRAP) & HSW_CDCLK_LIMIT)
>> +            dev_priv->max_cdclk_freq = 450000;
>> +        else if (IS_HSW_ULX(dev))
>> +            dev_priv->max_cdclk_freq = 337500;
>> +        else if (IS_HSW_ULT(dev))
>> +            dev_priv->max_cdclk_freq = 450000;
>> +        else
>> +            dev_priv->max_cdclk_freq = 540000;
>> +    } else if (IS_VALLEYVIEW(dev)) {
>>           dev_priv->max_cdclk_freq = 400000;
>>       } else {
>>           /* otherwise assume cdclk is fixed */
>> @@ -8773,6 +8782,144 @@ void hsw_enable_pc8(struct drm_i915_private 
>> *dev_priv)
>>       hsw_disable_lcpll(dev_priv, true, true);
>>   }
>>   +/* compute the max rate for new configuration */
>> +static int ilk_max_pixel_rate(struct drm_i915_private *dev_priv)
>> +{
>> +    struct drm_device *dev = dev_priv->dev;
>> +    struct intel_crtc *crtc;
>> +    int max_pixel_rate = 0;
>> +
>> +    for_each_intel_crtc(dev, crtc) {
>> +        if (crtc->new_enabled)
>> +            max_pixel_rate = max(max_pixel_rate,
>> + ilk_pipe_pixel_rate(crtc->new_config));
>> +    }
>> +
>> +    return max_pixel_rate;
>> +}
>> +
>> +static int haswell_calc_cdclk(struct drm_i915_private *dev_priv,
>> +                  int max_pixel_rate)
>> +{
>> +    int cdclk;
>> +
>> +    /*
>> +     * FIXME should also account for plane ratio
>> +     * once 64bpp pixel formats are supported.
>> +     */
>> +    if (max_pixel_rate > 450000)
>> +        cdclk = 540000;
>> +    else if (max_pixel_rate > 337500 || !IS_HSW_ULX(dev_priv))
>> +        cdclk = 450000;
>> +    else
>> +        cdclk = 337500;
>> +
>> +    /*
>> +     * FIXME move the cdclk caclulation to
>> +     * compute_config() so we can fail gracegully.
>> +     */
>> +    if (cdclk > dev_priv->max_cdclk_freq) {
>> +        DRM_ERROR("requested cdclk (%d kHz) exceeds max (%d kHz)\n",
>> +              cdclk, dev_priv->max_cdclk_freq);
>> +        cdclk = dev_priv->max_cdclk_freq;
>> +    }
>> +
>> +    return cdclk;
>> +}
> won't this return 337MHz even for platforms that have HSW_CDCLK_LIMIT 
> is set ? this should return 450MHz if this fuse is set
>
>> +
>> +static void haswell_set_cdclk(struct drm_device *dev, int cdclk)
>> +{
>> +    struct drm_i915_private *dev_priv = dev->dev_private;
>> +    uint32_t val;
>> +
>> +    if (WARN((I915_READ(LCPLL_CTL) &
>> +          (LCPLL_PLL_DISABLE | LCPLL_PLL_LOCK |
>> +           LCPLL_CD_CLOCK_DISABLE | LCPLL_ROOT_CD_CLOCK_DISABLE |
>> +           LCPLL_CD2X_CLOCK_DISABLE | LCPLL_POWER_DOWN_ALLOW |
>> +           LCPLL_CD_SOURCE_FCLK)) != LCPLL_PLL_LOCK,
>> +         "trying to change cdclk frequency with cdclk not enabled\n"))
>> +        return;
>> +
>> +    val = I915_READ(LCPLL_CTL);
>> +    val &= ~LCPLL_CLK_FREQ_MASK;
>> +
>> +    switch (cdclk) {
>> +    case 450000:
>> +        val |= LCPLL_CLK_FREQ_450;
>> +        break;
>> +    case 337500:
>> +    case 540000:
>> +        val |= LCPLL_CLK_FREQ_ALT_HSW;
>> +        break;
>> +    default:
>> +        WARN(1, "invalid cdclk frequency\n");
>> +        return;
>> +    }
>> +
>> +    I915_WRITE(LCPLL_CTL, val);
>> +
>> +    if (IS_HSW_ULX(dev)) {
>> +        mutex_lock(&dev_priv->rps.hw_lock);
>> +        sandybridge_pcode_write(dev_priv, HSW_PCODE_DE_WRITE_FREQ_REQ,
>> +                    cdclk == 337500);
>> +        mutex_unlock(&dev_priv->rps.hw_lock);
>> +    }
>> +
>> +    intel_update_cdclk(dev);
>> +
>> +    WARN(cdclk != dev_priv->cdclk_freq,
>> +         "cdclk requested %d kHz but got %d kHz\n",
>> +         cdclk, dev_priv->cdclk_freq);
>> +}
>> +
>> +static void haswell_modeset_global_pipes(struct drm_device *dev,
>> +                     unsigned *prepare_pipes)
>> +{
>> +    struct drm_i915_private *dev_priv = dev->dev_private;
>> +    struct intel_crtc *crtc;
>> +    int max_pixel_rate = ilk_max_pixel_rate(dev_priv);
>> +
>> +    if (haswell_calc_cdclk(dev_priv, max_pixel_rate) ==
>> +        dev_priv->cdclk_freq)
>> +        return;
>> +
>> +    /* disable/enable all currently active pipes while we change 
>> cdclk */
>> +    for_each_intel_crtc(dev, crtc)
>> +        if (crtc->base.enabled)
>> +            *prepare_pipes |= 1 << crtc->pipe;
>> +}
>> +
>> +static void haswell_modeset_global_resources(struct drm_atomic_state 
>> *state)
>> +{
>> +    struct drm_device *dev = state->dev;
>> +    struct drm_i915_private *dev_priv = dev->dev_private;
>> +    int max_pixel_rate = ilk_max_pixel_rate(dev_priv);
>> +    int req_cdclk = haswell_calc_cdclk(dev_priv, max_pixel_rate);
>> +
>> +    if (req_cdclk != dev_priv->cdclk_freq)
>> +        haswell_set_cdclk(dev, req_cdclk);
>> +
>> +    if (req_cdclk != dev_priv->cdclk_freq) {
>> +        /*
>> +         * FIXME: We can end up here with all power domains off, yet
>> +         * with a CDCLK frequency other than the minimum. To account
>> +         * for this take the PIPE-A power domain, which covers the HW
>> +         * blocks needed for the following programming. This can be
>> +         * removed once it's guaranteed that we get here either with
>> +         * the minimum CDCLK set, or the required power domains
>> +         * enabled.
>> +         */
>> +        intel_display_power_get(dev_priv, POWER_DOMAIN_PIPE_A);
>> +
>> +        haswell_set_cdclk(dev, req_cdclk);
>> +
>> +        vlv_program_pfi_credits(dev_priv);
>> +
>> +        intel_display_power_put(dev_priv, POWER_DOMAIN_PIPE_A);
>> +    }
>> +
>> +}
>> +
>>   void hsw_disable_pc8(struct drm_i915_private *dev_priv)
>>   {
>>       struct drm_device *dev = dev_priv->dev;
>> @@ -8792,6 +8939,8 @@ void hsw_disable_pc8(struct drm_i915_private 
>> *dev_priv)
>>       intel_prepare_ddi(dev);
>>   }
>>   +
>> +
>>   static int haswell_crtc_compute_clock(struct intel_crtc *crtc,
>>                         struct intel_crtc_state *crtc_state)
>>   {
>> @@ -11866,8 +12015,11 @@ static int __intel_set_mode(struct drm_crtc 
>> *crtc,
>>        * mode set on this crtc.  For other crtcs we need to use the
>>        * adjusted_mode bits in the crtc directly.
>>        */
>> -    if (IS_VALLEYVIEW(dev)) {
>> -        valleyview_modeset_global_pipes(dev, &prepare_pipes);
>> +    if (IS_VALLEYVIEW(dev) || IS_HASWELL(dev)) {
>> +        if (IS_VALLEYVIEW(dev))
>> +            valleyview_modeset_global_pipes(dev, &prepare_pipes);
>> +        else
>> +            haswell_modeset_global_pipes(dev, &prepare_pipes);
>>             /* may have added more to prepare_pipes than we should */
>>           prepare_pipes &= ~disable_pipes;
>> @@ -13892,6 +14044,9 @@ static void intel_init_display(struct 
>> drm_device *dev)
>>           dev_priv->display.fdi_link_train = ivb_manual_fdi_link_train;
>>       } else if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
>>           dev_priv->display.fdi_link_train = hsw_fdi_link_train;
>> +        if (IS_HASWELL(dev))
>> +            dev_priv->display.modeset_global_resources =
>> +                haswell_modeset_global_resources;
>>       } else if (IS_VALLEYVIEW(dev)) {
>>           dev_priv->display.modeset_global_resources =
>>               valleyview_modeset_global_resources;
>
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