summaryrefslogtreecommitdiff
path: root/drivers/gpu/drm/i915/intel_dsi_pll.c
diff options
context:
space:
mode:
authorShashank Sharma <shashank.sharma@intel.com>2015-09-01 17:11:38 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2015-09-23 11:08:48 +0300
commitcfe01a5eba1ff5723f3a47895fb7e9d890edf157 (patch)
treeae8741c7a9258f1aa98cf9e069558ca920d6bf11 /drivers/gpu/drm/i915/intel_dsi_pll.c
parent83e3337204b2385d20e149c8fe91bb2719978df2 (diff)
downloadlinux-cfe01a5eba1ff5723f3a47895fb7e9d890edf157.tar.xz
drm/i915/bxt: Enable BXT DSI PLL
This patch adds new functions for BXT clock and PLL programming. They are: 1. configure_dsi_pll for BXT. This function does the basic math and generates the divider ratio based on requested pixclock, and program clock registers. 2. enable_dsi_pll function. This function programs the calculated clock values on the PLL. 3. intel_enable_dsi_pll Wrapper function to use same code for multiple platforms. It checks the platform and calls appropriate core pll enable function. v2: Fixed Jani's review comments. Macros are adjusted as per convention. v3: Removed a redundant change wrt code comment. Signed-off-by: Shashank Sharma <shashank.sharma@intel.com> Signed-off-by: Uma Shankar <uma.shankar@intel.com> Reviewed-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_dsi_pll.c')
-rw-r--r--drivers/gpu/drm/i915/intel_dsi_pll.c95
1 files changed, 94 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/intel_dsi_pll.c b/drivers/gpu/drm/i915/intel_dsi_pll.c
index c6a8975b128f..b07483beded0 100644
--- a/drivers/gpu/drm/i915/intel_dsi_pll.c
+++ b/drivers/gpu/drm/i915/intel_dsi_pll.c
@@ -246,7 +246,7 @@ static void vlv_configure_dsi_pll(struct intel_encoder *encoder)
vlv_cck_write(dev_priv, CCK_REG_DSI_PLL_CONTROL, dsi_mnp.dsi_pll_ctrl);
}
-void vlv_enable_dsi_pll(struct intel_encoder *encoder)
+static void vlv_enable_dsi_pll(struct intel_encoder *encoder)
{
struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
u32 tmp;
@@ -363,3 +363,96 @@ u32 vlv_get_dsi_pclk(struct intel_encoder *encoder, int pipe_bpp)
return pclk;
}
+
+static bool bxt_configure_dsi_pll(struct intel_encoder *encoder)
+{
+ struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+ struct intel_dsi *intel_dsi = enc_to_intel_dsi(&encoder->base);
+ u8 dsi_ratio;
+ u32 dsi_clk;
+ u32 val;
+
+ dsi_clk = dsi_clk_from_pclk(intel_dsi->pclk, intel_dsi->pixel_format,
+ intel_dsi->lane_count);
+
+ /*
+ * From clock diagram, to get PLL ratio divider, divide double of DSI
+ * link rate (i.e., 2*8x=16x frequency value) by ref clock. Make sure to
+ * round 'up' the result
+ */
+ dsi_ratio = DIV_ROUND_UP(dsi_clk * 2, BXT_REF_CLOCK_KHZ);
+ if (dsi_ratio < BXT_DSI_PLL_RATIO_MIN ||
+ dsi_ratio > BXT_DSI_PLL_RATIO_MAX) {
+ DRM_ERROR("Cant get a suitable ratio from DSI PLL ratios\n");
+ return false;
+ }
+
+ /*
+ * Program DSI ratio and Select MIPIC and MIPIA PLL output as 8x
+ * Spec says both have to be programmed, even if one is not getting
+ * used. Configure MIPI_CLOCK_CTL dividers in modeset
+ */
+ val = I915_READ(BXT_DSI_PLL_CTL);
+ val &= ~BXT_DSI_PLL_PVD_RATIO_MASK;
+ val &= ~BXT_DSI_FREQ_SEL_MASK;
+ val &= ~BXT_DSI_PLL_RATIO_MASK;
+ val |= (dsi_ratio | BXT_DSIA_16X_BY2 | BXT_DSIC_16X_BY2);
+
+ /* As per recommendation from hardware team,
+ * Prog PVD ratio =1 if dsi ratio <= 50
+ */
+ if (dsi_ratio <= 50) {
+ val &= ~BXT_DSI_PLL_PVD_RATIO_MASK;
+ val |= BXT_DSI_PLL_PVD_RATIO_1;
+ }
+
+ I915_WRITE(BXT_DSI_PLL_CTL, val);
+ POSTING_READ(BXT_DSI_PLL_CTL);
+
+ return true;
+}
+
+static void bxt_enable_dsi_pll(struct intel_encoder *encoder)
+{
+ struct drm_i915_private *dev_priv = encoder->base.dev->dev_private;
+ u32 val;
+
+ DRM_DEBUG_KMS("\n");
+
+ val = I915_READ(BXT_DSI_PLL_ENABLE);
+
+ if (val & BXT_DSI_PLL_DO_ENABLE) {
+ WARN(1, "DSI PLL already enabled. Disabling it.\n");
+ val &= ~BXT_DSI_PLL_DO_ENABLE;
+ I915_WRITE(BXT_DSI_PLL_ENABLE, val);
+ }
+
+ /* Configure PLL vales */
+ if (!bxt_configure_dsi_pll(encoder)) {
+ DRM_ERROR("Configure DSI PLL failed, abort PLL enable\n");
+ return;
+ }
+
+ /* Enable DSI PLL */
+ val = I915_READ(BXT_DSI_PLL_ENABLE);
+ val |= BXT_DSI_PLL_DO_ENABLE;
+ I915_WRITE(BXT_DSI_PLL_ENABLE, val);
+
+ /* Timeout and fail if PLL not locked */
+ if (wait_for(I915_READ(BXT_DSI_PLL_ENABLE) & BXT_DSI_PLL_LOCKED, 1)) {
+ DRM_ERROR("Timed out waiting for DSI PLL to lock\n");
+ return;
+ }
+
+ DRM_DEBUG_KMS("DSI PLL locked\n");
+}
+
+void intel_enable_dsi_pll(struct intel_encoder *encoder)
+{
+ struct drm_device *dev = encoder->base.dev;
+
+ if (IS_VALLEYVIEW(dev))
+ vlv_enable_dsi_pll(encoder);
+ else if (IS_BROXTON(dev))
+ bxt_enable_dsi_pll(encoder);
+}