drm/i915/psr: Bring back HSW/BDW PSR AUX CH registers/setup

Reintroduce the special PSR AUX CH setup for hsw/bdw. Not all
of it was even removed (BDW AUX data registers were left behind).
Update the code to use REG_BIT() & co. while at it.

v2: Define the SRD_AUX_CTL bits in terms of DP_AUX_CTL bits (Jouni)
    Add a comment explaining the hand rolled DPCD write (Jouni)

Cc: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230609141404.12729-6-ville.syrjala@linux.intel.com
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
index 197c6e8..21b50a5 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
@@ -14,7 +14,7 @@
 #include "intel_pps.h"
 #include "intel_tc.h"
 
-static u32 intel_dp_aux_pack(const u8 *src, int src_bytes)
+u32 intel_dp_aux_pack(const u8 *src, int src_bytes)
 {
        int i;
        u32 v = 0;

diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.h b/drivers/gpu/drm/i915/display/intel_dp_aux.h
index 5b608f9..8447f3e 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_aux.h
+++ b/drivers/gpu/drm/i915/display/intel_dp_aux.h
@@ -6,6 +6,8 @@
 #ifndef __INTEL_DP_AUX_H__
 #define __INTEL_DP_AUX_H__
 
+#include <linux/types.h>
+
 enum aux_ch;
 struct drm_i915_private;
 struct intel_dp;
@@ -17,5 +19,6 @@ void intel_dp_aux_init(struct intel_dp *intel_dp);
 enum aux_ch intel_dp_aux_ch(struct intel_encoder *encoder);
 
 void intel_dp_aux_irq_handler(struct drm_i915_private *i915);
+u32 intel_dp_aux_pack(const u8 *src, int src_bytes);
 
 #endif /* __INTEL_DP_AUX_H__ */

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index f592065..897d4f9 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/drivers/gpu/drm/i915/display/intel_psr.c
@@ -288,6 +288,24 @@ static i915_reg_t psr_iir_reg(struct drm_i915_private *dev_priv,
                return EDP_PSR_IIR;
 }
 
+static i915_reg_t psr_aux_ctl_reg(struct drm_i915_private *dev_priv,
+                                 enum transcoder cpu_transcoder)
+{
+       if (DISPLAY_VER(dev_priv) >= 8)
+               return EDP_PSR_AUX_CTL(cpu_transcoder);
+       else
+               return HSW_SRD_AUX_CTL;
+}
+
+static i915_reg_t psr_aux_data_reg(struct drm_i915_private *dev_priv,
+                                  enum transcoder cpu_transcoder, int i)
+{
+       if (DISPLAY_VER(dev_priv) >= 8)
+               return EDP_PSR_AUX_DATA(cpu_transcoder, i);
+       else
+               return HSW_SRD_AUX_DATA(i);
+}
+
 static void psr_irq_control(struct intel_dp *intel_dp)
 {
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
@@ -512,6 +530,43 @@ void intel_psr_init_dpcd(struct intel_dp *intel_dp)
        }
 }
 
+static void hsw_psr_setup_aux(struct intel_dp *intel_dp)
+{
+       struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
+       enum transcoder cpu_transcoder = intel_dp->psr.transcoder;
+       u32 aux_clock_divider, aux_ctl;
+       /* write DP_SET_POWER=D0 */
+       static const u8 aux_msg[] = {
+               [0] = (DP_AUX_NATIVE_WRITE << 4) | ((DP_SET_POWER >> 16) & 0xf),
+               [1] = (DP_SET_POWER >> 8) & 0xff,
+               [2] = DP_SET_POWER & 0xff,
+               [3] = 1 - 1,
+               [4] = DP_SET_POWER_D0,
+       };
+       int i;
+
+       BUILD_BUG_ON(sizeof(aux_msg) > 20);
+       for (i = 0; i < sizeof(aux_msg); i += 4)
+               intel_de_write(dev_priv,
+                              psr_aux_data_reg(dev_priv, cpu_transcoder, i >> 2),
+                              intel_dp_aux_pack(&aux_msg[i], sizeof(aux_msg) - i));
+
+       aux_clock_divider = intel_dp->get_aux_clock_divider(intel_dp, 0);
+
+       /* Start with bits set for DDI_AUX_CTL register */
+       aux_ctl = intel_dp->get_aux_send_ctl(intel_dp, sizeof(aux_msg),
+                                            aux_clock_divider);
+
+       /* Select only valid bits for SRD_AUX_CTL */
+       aux_ctl &= EDP_PSR_AUX_CTL_TIME_OUT_MASK |
+               EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK |
+               EDP_PSR_AUX_CTL_PRECHARGE_2US_MASK |
+               EDP_PSR_AUX_CTL_BIT_CLOCK_2X_MASK;
+
+       intel_de_write(dev_priv, psr_aux_ctl_reg(dev_priv, cpu_transcoder),
+                      aux_ctl);
+}
+
 static void intel_psr_enable_sink(struct intel_dp *intel_dp)
 {
        struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
@@ -1319,6 +1374,13 @@ static void intel_psr_enable_source(struct intel_dp *intel_dp,
        u32 mask;
 
        /*
+        * Only HSW and BDW have PSR AUX registers that need to be setup.
+        * SKL+ use hardcoded values PSR AUX transactions
+        */
+       if (DISPLAY_VER(dev_priv) < 9)
+               hsw_psr_setup_aux(intel_dp);
+
+       /*
         * Per Spec: Avoid continuous PSR exit by masking MEMUP and HPD also
         * mask LPSP to avoid dependency on other drivers that might block
         * runtime_pm besides preventing  other hw tracking issues now we

diff --git a/drivers/gpu/drm/i915/display/intel_psr_regs.h b/drivers/gpu/drm/i915/display/intel_psr_regs.h
index 998f638..d399513 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_psr_regs.h
+++ b/drivers/gpu/drm/i915/display/intel_psr_regs.h
@@ -7,6 +7,7 @@
 #define __INTEL_PSR_REGS_H__
 
 #include "intel_display_reg_defs.h"
+#include "intel_dp_aux_regs.h"
 
 #define TRANS_EXITLINE(trans)  _MMIO_TRANS2((trans), _TRANS_EXITLINE_A)
 #define   EXITLINE_ENABLE      REG_BIT(31)
@@ -80,6 +81,17 @@
 #define   EDP_PSR_PRE_ENTRY(trans)     (TGL_PSR_PRE_ENTRY <<           \
                                         _EDP_PSR_TRANS_SHIFT(trans))
 
+#define HSW_SRD_AUX_CTL                                _MMIO(0x64810)
+#define _SRD_AUX_CTL_A                         0x60810
+#define _SRD_AUX_CTL_EDP                       0x6f810
+#define EDP_PSR_AUX_CTL(tran)                  _MMIO_TRANS2(tran, _SRD_AUX_CTL_A)
+#define   EDP_PSR_AUX_CTL_TIME_OUT_MASK                DP_AUX_CH_CTL_TIME_OUT_MASK
+#define   EDP_PSR_AUX_CTL_MESSAGE_SIZE_MASK    DP_AUX_CH_CTL_MESSAGE_SIZE_MASK
+#define   EDP_PSR_AUX_CTL_PRECHARGE_2US_MASK   DP_AUX_CH_CTL_PRECHARGE_2US_MASK
+#define   EDP_PSR_AUX_CTL_ERROR_INTERRUPT      REG_BIT(11)
+#define   EDP_PSR_AUX_CTL_BIT_CLOCK_2X_MASK    DP_AUX_CH_CTL_BIT_CLOCK_2X_MASK
+
+#define HSW_SRD_AUX_DATA(i)                    _MMIO(0x64814 + (i) * 4) /* 5 registers */
 #define _SRD_AUX_DATA_A                                0x60814
 #define _SRD_AUX_DATA_EDP                      0x6f814
 #define EDP_PSR_AUX_DATA(tran, i)              _MMIO_TRANS2(tran, _SRD_AUX_DATA_A + (i) * 4) /* 5 registers */