drm/i915/bdw: Support eDP PSR

Broadwell PSR support is a superset of Haswell. With this simple
register base calculation, everything that worked on HSW for eDP PSR
should work on BDW.

Note that Broadwell provides additional PSR support. This is not
addressed at this time.

v2: Make the HAS_PSR include BDW

v3: Use the correct offset (I had incorrectly used one from my faulty
brain) (Art!)

v4: It helps if you git add

v5: Be explicit about not setting min link entry time for BDW. This
should be no functional change over v4 (Jani)

Reviewed-by: Art Runyan <arthur.j.runyan@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1810,7 +1810,7 @@ struct drm_i915_file_private {
 #define HAS_DDI(dev)		(INTEL_INFO(dev)->has_ddi)
 #define HAS_POWER_WELL(dev)	(IS_HASWELL(dev) || IS_BROADWELL(dev))
 #define HAS_FPGA_DBG_UNCLAIMED(dev)	(INTEL_INFO(dev)->has_fpga_dbg)
-#define HAS_PSR(dev)		(IS_HASWELL(dev))
+#define HAS_PSR(dev)		(IS_HASWELL(dev) || IS_BROADWELL(dev))
 
 #define INTEL_PCH_DEVICE_ID_MASK		0xff00
 #define INTEL_PCH_IBX_DEVICE_ID_TYPE		0x3b00

drivers/gpu/drm/i915/i915_reg.h

@@ -1961,8 +1961,8 @@
 #define BCLRPAT(pipe) _PIPE(pipe, _BCLRPAT_A, _BCLRPAT_B)
 #define VSYNCSHIFT(trans) _TRANSCODER(trans, _VSYNCSHIFT_A, _VSYNCSHIFT_B)
 
-/* HSW eDP PSR registers */
-#define EDP_PSR_BASE(dev)			0x64800
+/* HSW+ eDP PSR registers */
+#define EDP_PSR_BASE(dev)                       (IS_HASWELL(dev) ? 0x64800 : 0x6f800)
 #define EDP_PSR_CTL(dev)			(EDP_PSR_BASE(dev) + 0)
 #define   EDP_PSR_ENABLE			(1<<31)
 #define   EDP_PSR_LINK_DISABLE			(0<<27)

drivers/gpu/drm/i915/intel_dp.c

@@ -1611,6 +1611,7 @@ static void intel_edp_psr_enable_source(struct intel_dp *intel_dp)
 	uint32_t max_sleep_time = 0x1f;
 	uint32_t idle_frames = 1;
 	uint32_t val = 0x0;
+	const uint32_t link_entry_time = EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES;
 
 	if (intel_dp->psr_dpcd[1] & DP_PSR_NO_TRAIN_ON_EXIT) {
 		val |= EDP_PSR_LINK_STANDBY;
@@ -1621,7 +1622,7 @@ static void intel_edp_psr_enable_source(struct intel_dp *intel_dp)
 		val |= EDP_PSR_LINK_DISABLE;
 
 	I915_WRITE(EDP_PSR_CTL(dev), val |
-		   EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES |
+		   IS_BROADWELL(dev) ? 0 : link_entry_time |
 		   max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT |
 		   idle_frames << EDP_PSR_IDLE_FRAME_SHIFT |
 		   EDP_PSR_ENABLE);