Re: [PATCH] drm/i915/bxt: edp1.4 Intermediate Freq support

Jani Nikula
2015-05-26T09:51:56Z

On Tue, 26 May 2015, Sonika Jindal <sonika.jindal@intel.com> wrote:
> BXT supports following intermediate link rates for edp:
> 2.16GHz, 2.43GHz, 3.24GHz, 4.32GHz.
> Adding support for programming the intermediate rates.
>
> v2: Adding clock in bxt_clk_div struct and then look for the entry with
> required rate (Ville)
> v3: 'clock' has the selected value, no need to use link_bw or rate_select
> for selecting pll(Ville)
> v4: Make bxt_dp_clk_val const and remove size (Ville)
> v5: Rebased
>
> Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> ---
> drivers/gpu/drm/i915/intel_ddi.c | 40 +++++++++++++++-----------------------
> drivers/gpu/drm/i915/intel_dp.c | 7 ++++++-
> 2 files changed, 22 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index cacb07b..eb3238a 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1334,6 +1334,7 @@ skl_ddi_pll_select(struct intel_crtc *intel_crtc,
>
> /* bxt clock parameters */
> struct bxt_clk_div {
> + int clock;
> uint32_t p1;
> uint32_t p2;
> uint32_t m2_int;
> @@ -1343,14 +1344,14 @@ struct bxt_clk_div {
> };
>
> /* pre-calculated values for DP linkrates */
> -static struct bxt_clk_div bxt_dp_clk_val[7] = {
> - /* 162 */ {4, 2, 32, 1677722, 1, 1},
> - /* 270 */ {4, 1, 27, 0, 0, 1},
> - /* 540 */ {2, 1, 27, 0, 0, 1},
> - /* 216 */ {3, 2, 32, 1677722, 1, 1},
> - /* 243 */ {4, 1, 24, 1258291, 1, 1},
> - /* 324 */ {4, 1, 32, 1677722, 1, 1},
> - /* 432 */ {3, 1, 32, 1677722, 1, 1}
> +static const struct bxt_clk_div bxt_dp_clk_val[] = {
> + {162000, 4, 2, 32, 1677722, 1, 1, 5, 11, 2, 9, 0xd},
> + {270000, 4, 1, 27, 0, 0, 1, 3, 8, 1, 9, 0xd},
> + {540000, 2, 1, 27, 0, 0, 1, 3, 8, 1, 9, 0x18},
> + {216000, 3, 2, 32, 1677722, 1, 1, 5, 11, 2, 9, 0xd},
> + {243000, 4, 1, 24, 1258291, 1, 1, 5, 11, 2, 9, 0xd},
> + {324000, 4, 1, 32, 1677722, 1, 1, 5, 11, 2, 9, 0xd},
> + {432000, 3, 1, 32, 1677722, 1, 1, 5, 11, 2, 9, 0x18}
> };
>
> static bool
> @@ -1390,24 +1391,15 @@ bxt_ddi_pll_select(struct intel_crtc *intel_crtc,
> vco = best_clock.vco;
> } else if (intel_encoder->type == INTEL_OUTPUT_DISPLAYPORT ||
> intel_encoder->type == INTEL_OUTPUT_EDP) {
> - struct drm_encoder *encoder = &intel_encoder->base;
> - struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> + int i;
>
> - switch (intel_dp->link_bw) {
> - case DP_LINK_BW_1_62:
> - clk_div = bxt_dp_clk_val[0];
> - break;
> - case DP_LINK_BW_2_7:
> - clk_div = bxt_dp_clk_val[1];
> - break;
> - case DP_LINK_BW_5_4:
> - clk_div = bxt_dp_clk_val[2];
> - break;
> - default:
> - clk_div = bxt_dp_clk_val[0];
> - DRM_ERROR("Unknown link rate\n");
> + clk_div = bxt_dp_clk_val[0];
> + for (i = 0; i < ARRAY_SIZE(bxt_dp_clk_val); ++i) {
> + if (bxt_dp_clk_val[i].clock == clock) {
> + clk_div = bxt_dp_clk_val[i];
> + break;
> + }
> }
> - vco = clock * 10 / 2 * clk_div.p1 * clk_div.p2;

Without vco set, won't this hit the DRM_ERROR("Invalid VCO\n"); path
right below?

BR,
Jani.

> }
>
> dco_amp = 15;
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index abd442a..bd0f958 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -91,6 +91,8 @@ static const struct dp_link_dpll chv_dpll[] = {
> { .p1 = 2, .p2 = 1, .n = 1, .m1 = 2, .m2 = 0x6c00000 } }
> };
>
> +static const int bxt_rates[] = { 162000, 216000, 243000, 270000,
> + 324000, 432000, 540000 };
> static const int skl_rates[] = { 162000, 216000, 270000,
> 324000, 432000, 540000 };
> static const int chv_rates[] = { 162000, 202500, 210000, 216000,
> @@ -1170,7 +1172,10 @@ intel_dp_sink_rates(struct intel_dp *intel_dp, const int **sink_rates)
> static int
> intel_dp_source_rates(struct drm_device *dev, const int **source_rates)
> {
> - if (IS_SKYLAKE(dev)) {
> + if (IS_BROXTON(dev)) {
> + *source_rates = bxt_rates;
> + return ARRAY_SIZE(bxt_rates);
> + } else if (IS_SKYLAKE(dev)) {
> *source_rates = skl_rates;
> return ARRAY_SIZE(skl_rates);
> } else if (IS_CHERRYVIEW(dev)) {
> --
> 1.7.10.4
>
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--
Jani Nikula, Intel Open Source Technology Center