On Wed, 10 Dec 2014, Gaurav K Singh <gaurav.k.singh@xxxxxxxxx> wrote:
> For CHT changes are required for calculating the correct m,n & p with
> minimal error +/- for the required DSI clock, so that the correct dividor
> & ctrl values are written in cck regs for DSI. This patch has been tested
> on CHT RVP with 1200 x 1920 panel.
>
> Signed-off-by: Gaurav K Singh <gaurav.k.singh@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/intel_dsi_pll.c | 43 ++++++++++++++++++++++++++--------
> 1 file changed, 33 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
> index 8957f10..9236b66 100644
> --- a/drivers/gpu/drm/i915/intel_dsi_pll.c
> +++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
> @@ -162,7 +162,8 @@ static u32 dsi_clk_from_pclk(u32 pclk, int pixel_format, int lane_count)
>
> #endif
>
> -static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
> +static int dsi_calc_mnp(struct drm_i915_private *dev_priv,
> + u32 dsi_clk, struct dsi_mnp *dsi_mnp)
> {
> u32 m, n, p;
> u32 ref_clk;
> @@ -173,6 +174,10 @@ static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
> u32 calc_m;
> u32 calc_p;
> u32 m_seed;
> + u32 m_start;
> + u32 m_limit;
> + u32 n_limit;
> + u32 p_limit;
>
> /* dsi_clk is expected in KHZ */
> if (dsi_clk < 300000 || dsi_clk > 1150000) {
> @@ -180,18 +185,33 @@ static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
> return -ECHRNG;
> }
>
> - ref_clk = 25000;
> + if (IS_CHERRYVIEW(dev_priv->dev)) {
You can use IS_CHERRYVIEW(dev_priv) directly. It's magic.
> + ref_clk = 100000;
> + m_start = 70;
> + m_limit = 96;
> + n_limit = 4;
> + p_limit = 6;
> + } else if (IS_VALLEYVIEW(dev_priv->dev)) {
Same.
> + ref_clk = 25000;
> + m_start = 62;
> + m_limit = 92;
> + n_limit = 1;
> + p_limit = 6;
> + } else {
> + DRM_ERROR("Unsupported device\n");
> + return -ENODEV;
> + }
We don't really do this kind of else branches, otherwise the driver
would be full of it.
Otherwise,
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> target_dsi_clk = dsi_clk;
> error = 0xFFFFFFFF;
> tmp_error = 0xFFFFFFFF;
> calc_m = 0;
> calc_p = 0;
>
> - for (m = 62; m <= 92; m++) {
> - for (p = 2; p <= 6; p++) {
> + for (m = m_start; m <= m_limit; m++) {
> + for (p = 2; p <= p_limit; p++) {
> /* Find the optimal m and p divisors
> with minimal error +/- the required clock */
> - calc_dsi_clk = (m * ref_clk) / p;
> + calc_dsi_clk = (m * ref_clk) / (p * n_limit);
> if (calc_dsi_clk == target_dsi_clk) {
> calc_m = m;
> calc_p = p;
> @@ -212,11 +232,14 @@ static int dsi_calc_mnp(u32 dsi_clk, struct dsi_mnp *dsi_mnp)
> }
>
> m_seed = lfsr_converts[calc_m - 62];
> - n = 1;
> + n = n_limit;
> dsi_mnp->dsi_pll_ctrl = 1 << (DSI_PLL_P1_POST_DIV_SHIFT + calc_p - 2);
> - dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT |
> - m_seed << DSI_PLL_M1_DIV_SHIFT;
> -
> + if (IS_CHERRYVIEW(dev_priv->dev))
> + dsi_mnp->dsi_pll_div = (n/2) << DSI_PLL_N1_DIV_SHIFT |
> + m_seed << DSI_PLL_M1_DIV_SHIFT;
> + else
> + dsi_mnp->dsi_pll_div = (n - 1) << DSI_PLL_N1_DIV_SHIFT |
> + m_seed << DSI_PLL_M1_DIV_SHIFT;
> return 0;
> }
>
> @@ -235,7 +258,7 @@ static void vlv_configure_dsi_pll(struct intel_encoder *encoder)
> dsi_clk = dsi_clk_from_pclk(intel_dsi->pclk, intel_dsi->pixel_format,
> intel_dsi->lane_count);
>
> - ret = dsi_calc_mnp(dsi_clk, &dsi_mnp);
> + ret = dsi_calc_mnp(dev_priv, dsi_clk, &dsi_mnp);
> if (ret) {
> DRM_DEBUG_KMS("dsi_calc_mnp failed\n");
> return;
> --
> 1.7.9.5
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Jani Nikula, Intel Open Source Technology Center
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