drm/i915: Add the support of memory self-refresh on Ironlake
authorZhenyu Wang <zhenyuw@linux.intel.com>
Thu, 1 Apr 2010 05:07:53 +0000 (13:07 +0800)
committerEric Anholt <eric@anholt.net>
Mon, 12 Apr 2010 16:30:43 +0000 (09:30 -0700)
Update the self-refresh watermark for display plane/cursor and enable
the memory self-refresh on Ironlake. The watermark is also updated for
the active display plane.

More than 1W idle power is saved on one Ironlake laptop after enabling
memory self-refresh.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
drivers/gpu/drm/i915/i915_reg.h
drivers/gpu/drm/i915/intel_display.c

index 6d8bf62..527d30a 100644 (file)
 #define PINEVIEW_CURSOR_DFT_WM 0
 #define PINEVIEW_CURSOR_GUARD_WM       5
 
+
+/* define the Watermark register on Ironlake */
+#define WM0_PIPEA_ILK          0x45100
+#define  WM0_PIPE_PLANE_MASK   (0x7f<<16)
+#define  WM0_PIPE_PLANE_SHIFT  16
+#define  WM0_PIPE_SPRITE_MASK  (0x3f<<8)
+#define  WM0_PIPE_SPRITE_SHIFT 8
+#define  WM0_PIPE_CURSOR_MASK  (0x1f)
+
+#define WM0_PIPEB_ILK          0x45104
+#define WM1_LP_ILK             0x45108
+#define  WM1_LP_SR_EN          (1<<31)
+#define  WM1_LP_LATENCY_SHIFT  24
+#define  WM1_LP_LATENCY_MASK   (0x7f<<24)
+#define  WM1_LP_SR_MASK                (0x1ff<<8)
+#define  WM1_LP_SR_SHIFT       8
+#define  WM1_LP_CURSOR_MASK    (0x3f)
+
+/* Memory latency timer register */
+#define MLTR_ILK               0x11222
+/* the unit of memory self-refresh latency time is 0.5us */
+#define  ILK_SRLT_MASK         0x3f
+
+/* define the fifo size on Ironlake */
+#define ILK_DISPLAY_FIFO       128
+#define ILK_DISPLAY_MAXWM      64
+#define ILK_DISPLAY_DFTWM      8
+
+#define ILK_DISPLAY_SR_FIFO    512
+#define ILK_DISPLAY_MAX_SRWM   0x1ff
+#define ILK_DISPLAY_DFT_SRWM   0x3f
+#define ILK_CURSOR_SR_FIFO     64
+#define ILK_CURSOR_MAX_SRWM    0x3f
+#define ILK_CURSOR_DFT_SRWM    8
+
+#define ILK_FIFO_LINE_SIZE     64
+
 /*
  * The two pipe frame counter registers are not synchronized, so
  * reading a stable value is somewhat tricky. The following code
 #define GTIIR   0x44018
 #define GTIER   0x4401c
 
+#define ILK_DISPLAY_CHICKEN2   0x42004
+#define  ILK_DPARB_GATE        (1<<22)
+#define  ILK_VSDPFD_FULL       (1<<21)
+#define ILK_DSPCLK_GATE                0x42020
+#define  ILK_DPARB_CLK_GATE    (1<<5)
+
 #define DISP_ARB_CTL   0x45000
 #define  DISP_TILE_SURFACE_SWIZZLING   (1<<13)
+#define  DISP_FBC_WM_DIS               (1<<15)
 
 /* PCH */
 
index e38c906..9fdea06 100644 (file)
@@ -2527,6 +2527,30 @@ static struct intel_watermark_params i830_wm_info = {
        I830_FIFO_LINE_SIZE
 };
 
+static struct intel_watermark_params ironlake_display_wm_info = {
+       ILK_DISPLAY_FIFO,
+       ILK_DISPLAY_MAXWM,
+       ILK_DISPLAY_DFTWM,
+       2,
+       ILK_FIFO_LINE_SIZE
+};
+
+static struct intel_watermark_params ironlake_display_srwm_info = {
+       ILK_DISPLAY_SR_FIFO,
+       ILK_DISPLAY_MAX_SRWM,
+       ILK_DISPLAY_DFT_SRWM,
+       2,
+       ILK_FIFO_LINE_SIZE
+};
+
+static struct intel_watermark_params ironlake_cursor_srwm_info = {
+       ILK_CURSOR_SR_FIFO,
+       ILK_CURSOR_MAX_SRWM,
+       ILK_CURSOR_DFT_SRWM,
+       2,
+       ILK_FIFO_LINE_SIZE
+};
+
 /**
  * intel_calculate_wm - calculate watermark level
  * @clock_in_khz: pixel clock
@@ -3014,6 +3038,108 @@ static void i830_update_wm(struct drm_device *dev, int planea_clock, int unused,
        I915_WRITE(FW_BLC, fwater_lo);
 }
 
+#define ILK_LP0_PLANE_LATENCY          700
+
+static void ironlake_update_wm(struct drm_device *dev,  int planea_clock,
+                      int planeb_clock, int sr_hdisplay, int pixel_size)
+{
+       struct drm_i915_private *dev_priv = dev->dev_private;
+       int planea_wm, planeb_wm, cursora_wm, cursorb_wm;
+       int sr_wm, cursor_wm;
+       unsigned long line_time_us;
+       int sr_clock, entries_required;
+       u32 reg_value;
+
+       /* Calculate and update the watermark for plane A */
+       if (planea_clock) {
+               entries_required = ((planea_clock / 1000) * pixel_size *
+                                    ILK_LP0_PLANE_LATENCY) / 1000;
+               entries_required = DIV_ROUND_UP(entries_required,
+                                  ironlake_display_wm_info.cacheline_size);
+               planea_wm = entries_required +
+                           ironlake_display_wm_info.guard_size;
+
+               if (planea_wm > (int)ironlake_display_wm_info.max_wm)
+                       planea_wm = ironlake_display_wm_info.max_wm;
+
+               cursora_wm = 16;
+               reg_value = I915_READ(WM0_PIPEA_ILK);
+               reg_value &= ~(WM0_PIPE_PLANE_MASK | WM0_PIPE_CURSOR_MASK);
+               reg_value |= (planea_wm << WM0_PIPE_PLANE_SHIFT) |
+                            (cursora_wm & WM0_PIPE_CURSOR_MASK);
+               I915_WRITE(WM0_PIPEA_ILK, reg_value);
+               DRM_DEBUG_KMS("FIFO watermarks For pipe A - plane %d, "
+                               "cursor: %d\n", planea_wm, cursora_wm);
+       }
+       /* Calculate and update the watermark for plane B */
+       if (planeb_clock) {
+               entries_required = ((planeb_clock / 1000) * pixel_size *
+                                    ILK_LP0_PLANE_LATENCY) / 1000;
+               entries_required = DIV_ROUND_UP(entries_required,
+                                  ironlake_display_wm_info.cacheline_size);
+               planeb_wm = entries_required +
+                           ironlake_display_wm_info.guard_size;
+
+               if (planeb_wm > (int)ironlake_display_wm_info.max_wm)
+                       planeb_wm = ironlake_display_wm_info.max_wm;
+
+               cursorb_wm = 16;
+               reg_value = I915_READ(WM0_PIPEB_ILK);
+               reg_value &= ~(WM0_PIPE_PLANE_MASK | WM0_PIPE_CURSOR_MASK);
+               reg_value |= (planeb_wm << WM0_PIPE_PLANE_SHIFT) |
+                            (cursorb_wm & WM0_PIPE_CURSOR_MASK);
+               I915_WRITE(WM0_PIPEB_ILK, reg_value);
+               DRM_DEBUG_KMS("FIFO watermarks For pipe B - plane %d, "
+                               "cursor: %d\n", planeb_wm, cursorb_wm);
+       }
+
+       /*
+        * Calculate and update the self-refresh watermark only when one
+        * display plane is used.
+        */
+       if (!planea_clock || !planeb_clock) {
+               int line_count;
+               /* Read the self-refresh latency. The unit is 0.5us */
+               int ilk_sr_latency = I915_READ(MLTR_ILK) & ILK_SRLT_MASK;
+
+               sr_clock = planea_clock ? planea_clock : planeb_clock;
+               line_time_us = ((sr_hdisplay * 1000) / sr_clock);
+
+               /* Use ns/us then divide to preserve precision */
+               line_count = ((ilk_sr_latency * 500) / line_time_us + 1000)
+                              / 1000;
+
+               /* calculate the self-refresh watermark for display plane */
+               entries_required = line_count * sr_hdisplay * pixel_size;
+               entries_required = DIV_ROUND_UP(entries_required,
+                                  ironlake_display_srwm_info.cacheline_size);
+               sr_wm = entries_required +
+                       ironlake_display_srwm_info.guard_size;
+
+               /* calculate the self-refresh watermark for display cursor */
+               entries_required = line_count * pixel_size * 64;
+               entries_required = DIV_ROUND_UP(entries_required,
+                                  ironlake_cursor_srwm_info.cacheline_size);
+               cursor_wm = entries_required +
+                           ironlake_cursor_srwm_info.guard_size;
+
+               /* configure watermark and enable self-refresh */
+               reg_value = I915_READ(WM1_LP_ILK);
+               reg_value &= ~(WM1_LP_LATENCY_MASK | WM1_LP_SR_MASK |
+                              WM1_LP_CURSOR_MASK);
+               reg_value |= WM1_LP_SR_EN |
+                            (ilk_sr_latency << WM1_LP_LATENCY_SHIFT) |
+                            (sr_wm << WM1_LP_SR_SHIFT) | cursor_wm;
+
+               I915_WRITE(WM1_LP_ILK, reg_value);
+               DRM_DEBUG_KMS("self-refresh watermark: display plane %d "
+                               "cursor %d\n", sr_wm, cursor_wm);
+
+       } else {
+               /* Turn off self refresh if both pipes are enabled */
+               I915_WRITE(WM1_LP_ILK, I915_READ(WM1_LP_ILK) & ~WM1_LP_SR_EN);
+       }
+}
 /**
  * intel_update_watermarks - update FIFO watermark values based on current modes
  *
@@ -4973,6 +5099,25 @@ void intel_init_clock_gating(struct drm_device *dev)
                }
 
                I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);
+
+               /*
+                * According to the spec the following bits should be set in
+                * order to enable memory self-refresh
+                * The bit 22/21 of 0x42004
+                * The bit 5 of 0x42020
+                * The bit 15 of 0x45000
+                */
+               if (IS_IRONLAKE(dev)) {
+                       I915_WRITE(ILK_DISPLAY_CHICKEN2,
+                                       (I915_READ(ILK_DISPLAY_CHICKEN2) |
+                                       ILK_DPARB_GATE | ILK_VSDPFD_FULL));
+                       I915_WRITE(ILK_DSPCLK_GATE,
+                                       (I915_READ(ILK_DSPCLK_GATE) |
+                                               ILK_DPARB_CLK_GATE));
+                       I915_WRITE(DISP_ARB_CTL,
+                                       (I915_READ(DISP_ARB_CTL) |
+                                               DISP_FBC_WM_DIS));
+               }
                return;
        } else if (IS_G4X(dev)) {
                uint32_t dspclk_gate;
@@ -5088,9 +5233,18 @@ static void intel_init_display(struct drm_device *dev)
                        i830_get_display_clock_speed;
 
        /* For FIFO watermark updates */
-       if (HAS_PCH_SPLIT(dev))
-               dev_priv->display.update_wm = NULL;
-       else if (IS_PINEVIEW(dev)) {
+       if (HAS_PCH_SPLIT(dev)) {
+               if (IS_IRONLAKE(dev)) {
+                       if (I915_READ(MLTR_ILK) & ILK_SRLT_MASK)
+                               dev_priv->display.update_wm = ironlake_update_wm;
+                       else {
+                               DRM_DEBUG_KMS("Failed to get proper latency. "
+                                             "Disable CxSR\n");
+                               dev_priv->display.update_wm = NULL;
+                       }
+               } else
+                       dev_priv->display.update_wm = NULL;
+       } else if (IS_PINEVIEW(dev)) {
                if (!intel_get_cxsr_latency(IS_PINEVIEW_G(dev),
                                            dev_priv->fsb_freq,
                                            dev_priv->mem_freq)) {