drm/i915: clock readout support for DDI v3
Read out and calculate the port and pixel clocks on DDI configs as well.
This means we have to grab the DP divider values and look at the port
mapping to figure out which clock select reg to read out.
v2: do the work from ddi_get_config (Ville)
v3: check WRPLL reference clock (Ville)
add additional SPLL freqs (Ville)
clean up port/crtc clock calc (Ville)
fix up crtc_clock conditionals (Ville)
drop superfluous dp_get_m_n from get_config (Ville)
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index f6485a8..fe2967e 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -633,6 +633,96 @@
/* Otherwise a < c && b >= d, do nothing */
}
+static int intel_ddi_calc_wrpll_link(struct drm_i915_private *dev_priv,
+ int reg)
+{
+ int refclk = LC_FREQ;
+ int n, p, r;
+ u32 wrpll;
+
+ wrpll = I915_READ(reg);
+ switch (wrpll & SPLL_PLL_REF_MASK) {
+ case SPLL_PLL_SSC:
+ case SPLL_PLL_NON_SSC:
+ /*
+ * We could calculate spread here, but our checking
+ * code only cares about 5% accuracy, and spread is a max of
+ * 0.5% downspread.
+ */
+ refclk = 135;
+ break;
+ case SPLL_PLL_LCPLL:
+ refclk = LC_FREQ;
+ break;
+ default:
+ WARN(1, "bad wrpll refclk\n");
+ return 0;
+ }
+
+ r = wrpll & WRPLL_DIVIDER_REF_MASK;
+ p = (wrpll & WRPLL_DIVIDER_POST_MASK) >> WRPLL_DIVIDER_POST_SHIFT;
+ n = (wrpll & WRPLL_DIVIDER_FB_MASK) >> WRPLL_DIVIDER_FB_SHIFT;
+
+ return (LC_FREQ * n) / (p * r);
+}
+
+static void intel_ddi_clock_get(struct intel_encoder *encoder,
+ struct intel_crtc_config *pipe_config)
+{
+ struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+ enum port port = intel_ddi_get_encoder_port(encoder);
+ int link_clock = 0;
+ u32 val, pll;
+
+ val = I915_READ(PORT_CLK_SEL(port));
+ switch (val & PORT_CLK_SEL_MASK) {
+ case PORT_CLK_SEL_LCPLL_810:
+ link_clock = 81000;
+ break;
+ case PORT_CLK_SEL_LCPLL_1350:
+ link_clock = 135000;
+ break;
+ case PORT_CLK_SEL_LCPLL_2700:
+ link_clock = 270000;
+ break;
+ case PORT_CLK_SEL_WRPLL1:
+ link_clock = intel_ddi_calc_wrpll_link(dev_priv, WRPLL_CTL1);
+ break;
+ case PORT_CLK_SEL_WRPLL2:
+ link_clock = intel_ddi_calc_wrpll_link(dev_priv, WRPLL_CTL2);
+ break;
+ case PORT_CLK_SEL_SPLL:
+ pll = I915_READ(SPLL_CTL) & SPLL_PLL_FREQ_MASK;
+ if (pll == SPLL_PLL_FREQ_810MHz)
+ link_clock = 81000;
+ else if (pll == SPLL_PLL_FREQ_1350MHz)
+ link_clock = 135000;
+ else if (pll == SPLL_PLL_FREQ_2700MHz)
+ link_clock = 270000;
+ else {
+ WARN(1, "bad spll freq\n");
+ return;
+ }
+ break;
+ default:
+ WARN(1, "bad port clock sel\n");
+ return;
+ }
+
+ pipe_config->port_clock = link_clock * 2;
+
+ if (pipe_config->has_pch_encoder)
+ pipe_config->adjusted_mode.crtc_clock =
+ intel_dotclock_calculate(pipe_config->port_clock,
+ &pipe_config->fdi_m_n);
+ else if (pipe_config->has_dp_encoder)
+ pipe_config->adjusted_mode.crtc_clock =
+ intel_dotclock_calculate(pipe_config->port_clock,
+ &pipe_config->dp_m_n);
+ else
+ pipe_config->adjusted_mode.crtc_clock = pipe_config->port_clock;
+}
+
static void
intel_ddi_calculate_wrpll(int clock /* in Hz */,
unsigned *r2_out, unsigned *n2_out, unsigned *p_out)
@@ -1509,6 +1599,8 @@
pipe_config->pipe_bpp, dev_priv->vbt.edp_bpp);
dev_priv->vbt.edp_bpp = pipe_config->pipe_bpp;
}
+
+ intel_ddi_clock_get(encoder, pipe_config);
}
static void intel_ddi_destroy(struct drm_encoder *encoder)