drm/i915: make DP work on LPT-LP machines

We need to enable a special bit, otherwise none of the DP functions
requiring the PCH will work.

Version 2: store the PCH ID inside dev_priv, as suggested by Daniel
Vetter.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index f7aef97..d5d8f2f 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -396,13 +396,6 @@ static const struct pci_device_id pciidlist[] = {          /* aka */
 MODULE_DEVICE_TABLE(pci, pciidlist);
 #endif
 
-#define INTEL_PCH_DEVICE_ID_MASK       0xff00
-#define INTEL_PCH_IBX_DEVICE_ID_TYPE   0x3b00
-#define INTEL_PCH_CPT_DEVICE_ID_TYPE   0x1c00
-#define INTEL_PCH_PPT_DEVICE_ID_TYPE   0x1e00
-#define INTEL_PCH_LPT_DEVICE_ID_TYPE   0x8c00
-#define INTEL_PCH_LPT_LP_DEVICE_ID_TYPE        0x9c00
-
 void intel_detect_pch(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
@@ -417,8 +410,9 @@ void intel_detect_pch(struct drm_device *dev)
        pch = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
        if (pch) {
                if (pch->vendor == PCI_VENDOR_ID_INTEL) {
-                       int id;
+                       unsigned short id;
                        id = pch->device & INTEL_PCH_DEVICE_ID_MASK;
+                       dev_priv->pch_id = id;
 
                        if (id == INTEL_PCH_IBX_DEVICE_ID_TYPE) {
                                dev_priv->pch_type = PCH_IBX;

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b25df10..669afca 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -737,6 +737,7 @@ typedef struct drm_i915_private {
 
        /* PCH chipset type */
        enum intel_pch pch_type;
+       unsigned short pch_id;
 
        unsigned long quirks;
 
@@ -1205,6 +1206,13 @@ struct drm_i915_file_private {
 
 #define HAS_PIPE_CONTROL(dev) (INTEL_INFO(dev)->gen >= 5)
 
+#define INTEL_PCH_DEVICE_ID_MASK               0xff00
+#define INTEL_PCH_IBX_DEVICE_ID_TYPE           0x3b00
+#define INTEL_PCH_CPT_DEVICE_ID_TYPE           0x1c00
+#define INTEL_PCH_PPT_DEVICE_ID_TYPE           0x1e00
+#define INTEL_PCH_LPT_DEVICE_ID_TYPE           0x8c00
+#define INTEL_PCH_LPT_LP_DEVICE_ID_TYPE                0x9c00
+
 #define INTEL_PCH_TYPE(dev) (((struct drm_i915_private *)(dev)->dev_private)->pch_type)
 #define HAS_PCH_LPT(dev) (INTEL_PCH_TYPE(dev) == PCH_LPT)
 #define HAS_PCH_CPT(dev) (INTEL_PCH_TYPE(dev) == PCH_CPT)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 9118bd1..2d83876 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3851,6 +3851,7 @@
 
 #define SOUTH_DSPCLK_GATE_D    0xc2020
 #define  PCH_DPLSUNIT_CLOCK_GATE_DISABLE (1<<29)
+#define  PCH_LP_PARTITION_LEVEL_DISABLE  (1<<12)
 
 /* CPU: FDI_TX */
 #define _FDI_TXA_CTL             0x60100

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 0edb549..647dfcc 100644 (file)
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3549,6 +3549,20 @@ static void gen7_setup_fixed_func_scheduler(struct drm_i915_private *dev_priv)
        I915_WRITE(GEN7_FF_THREAD_MODE, reg);
 }
 
+static void lpt_init_clock_gating(struct drm_device *dev)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+
+       /*
+        * TODO: this bit should only be enabled when really needed, then
+        * disabled when not needed anymore in order to save power.
+        */
+       if (dev_priv->pch_id == INTEL_PCH_LPT_LP_DEVICE_ID_TYPE)
+               I915_WRITE(SOUTH_DSPCLK_GATE_D,
+                          I915_READ(SOUTH_DSPCLK_GATE_D) |
+                          PCH_LP_PARTITION_LEVEL_DISABLE);
+}
+
 static void haswell_init_clock_gating(struct drm_device *dev)
 {
        struct drm_i915_private *dev_priv = dev->dev_private;
@@ -3600,6 +3614,7 @@ static void haswell_init_clock_gating(struct drm_device *dev)
                        WM_DBG_DISALLOW_SPRITE |
                        WM_DBG_DISALLOW_MAXFIFO);
 
+       lpt_init_clock_gating(dev);
 }
 
 static void ivybridge_init_clock_gating(struct drm_device *dev)