drm/i915: Enable/Disable PSR

Adding Enable and Disable PSR functionalities. This includes setting the
PSR configuration over AUX, sending SDP VSC DIP over the eDP PIPE config,
enabling PSR in the sink via DPCD register and finally enabling PSR on
the host.

This patch is based on initial PSR code by Sateesh Kavuri and Kumar Shobhit
but in a different implementation.

v2: * moved functions around and changed its names.
    * removed VSC DIP unset from disable.
    * remove FBC wa.
    * don't mask LSPS anymore.
    * incorporate new crtc usage after a rebase.
v3: Make a clear separation between Sink (Panel) and Source (HW) enabling.
v4: Fix identation and other style issues raised by checkpatch (by Paulo).
v5: Changes according to Paulo's review:
    static on write_vsc;
    avoid using dp_to_dev when already calling dp_to_dig_port;
    remove unecessary TP default time setting;
    remove unecessary interrupts disabling;
    remove unecessary wait_for_vblank when disabling psr;
v6: remove unecessary wait_for_vblank when writing vsc;
v7: adding setup once function to avoid unnecessarily write to vsc
    and set debug_ctl every time we enable or disable psr.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Credits-by: Sateesh Kavuri <sateesh.kavuri@intel.com>
Credits-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Shobhit Kumar <shobhit.kumar@intel.com>
[danvet: Apply Paulo's suggestion for unconditionally clearing the
control register when writing the DIP.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -1779,6 +1779,47 @@
 #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_CTL				0x64800
+#define   EDP_PSR_ENABLE			(1<<31)
+#define   EDP_PSR_LINK_DISABLE			(0<<27)
+#define   EDP_PSR_LINK_STANDBY			(1<<27)
+#define   EDP_PSR_MIN_LINK_ENTRY_TIME_MASK	(3<<25)
+#define   EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES	(0<<25)
+#define   EDP_PSR_MIN_LINK_ENTRY_TIME_4_LINES	(1<<25)
+#define   EDP_PSR_MIN_LINK_ENTRY_TIME_2_LINES	(2<<25)
+#define   EDP_PSR_MIN_LINK_ENTRY_TIME_0_LINES	(3<<25)
+#define   EDP_PSR_MAX_SLEEP_TIME_SHIFT		20
+#define   EDP_PSR_SKIP_AUX_EXIT			(1<<12)
+#define   EDP_PSR_TP1_TP2_SEL			(0<<11)
+#define   EDP_PSR_TP1_TP3_SEL			(1<<11)
+#define   EDP_PSR_TP2_TP3_TIME_500us		(0<<8)
+#define   EDP_PSR_TP2_TP3_TIME_100us		(1<<8)
+#define   EDP_PSR_TP2_TP3_TIME_2500us		(2<<8)
+#define   EDP_PSR_TP2_TP3_TIME_0us		(3<<8)
+#define   EDP_PSR_TP1_TIME_500us		(0<<4)
+#define   EDP_PSR_TP1_TIME_100us		(1<<4)
+#define   EDP_PSR_TP1_TIME_2500us		(2<<4)
+#define   EDP_PSR_TP1_TIME_0us			(3<<4)
+#define   EDP_PSR_IDLE_FRAME_SHIFT		0
+
+#define EDP_PSR_AUX_CTL			0x64810
+#define EDP_PSR_AUX_DATA1		0x64814
+#define   EDP_PSR_DPCD_COMMAND		0x80060000
+#define EDP_PSR_AUX_DATA2		0x64818
+#define   EDP_PSR_DPCD_NORMAL_OPERATION	(1<<24)
+#define EDP_PSR_AUX_DATA3		0x6481c
+#define EDP_PSR_AUX_DATA4		0x64820
+#define EDP_PSR_AUX_DATA5		0x64824
+
+#define EDP_PSR_STATUS_CTL			0x64840
+#define   EDP_PSR_STATUS_STATE_MASK		(7<<29)
+
+#define EDP_PSR_DEBUG_CTL		0x64860
+#define   EDP_PSR_DEBUG_MASK_LPSP	(1<<27)
+#define   EDP_PSR_DEBUG_MASK_MEMUP	(1<<26)
+#define   EDP_PSR_DEBUG_MASK_HPD	(1<<25)
+
 /* VGA port control */
 #define ADPA			0x61100
 #define PCH_ADPA                0xe1100
@@ -2048,6 +2089,7 @@
  * (Haswell and newer) to see which VIDEO_DIP_DATA byte corresponds to each byte
  * of the infoframe structure specified by CEA-861. */
 #define   VIDEO_DIP_DATA_SIZE	32
+#define   VIDEO_DIP_VSC_DATA_SIZE	36
 #define VIDEO_DIP_CTL		0x61170
 /* Pre HSW: */
 #define   VIDEO_DIP_ENABLE		(1 << 31)

drivers/gpu/drm/i915/intel_dp.c

@@ -1378,6 +1378,153 @@ static bool is_edp_psr(struct intel_dp *intel_dp)
 		intel_dp->psr_dpcd[0] & DP_PSR_IS_SUPPORTED;
 }
 
+static bool intel_edp_is_psr_enabled(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (!IS_HASWELL(dev))
+		return false;
+
+	return I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE;
+}
+
+static void intel_edp_psr_write_vsc(struct intel_dp *intel_dp,
+				    struct edp_vsc_psr *vsc_psr)
+{
+	struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp);
+	struct drm_device *dev = dig_port->base.base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *crtc = to_intel_crtc(dig_port->base.base.crtc);
+	u32 ctl_reg = HSW_TVIDEO_DIP_CTL(crtc->config.cpu_transcoder);
+	u32 data_reg = HSW_TVIDEO_DIP_VSC_DATA(crtc->config.cpu_transcoder);
+	uint32_t *data = (uint32_t *) vsc_psr;
+	unsigned int i;
+
+	/* As per BSPec (Pipe Video Data Island Packet), we need to disable
+	   the video DIP being updated before program video DIP data buffer
+	   registers for DIP being updated. */
+	I915_WRITE(ctl_reg, 0);
+	POSTING_READ(ctl_reg);
+
+	for (i = 0; i < VIDEO_DIP_VSC_DATA_SIZE; i += 4) {
+		if (i < sizeof(struct edp_vsc_psr))
+			I915_WRITE(data_reg + i, *data++);
+		else
+			I915_WRITE(data_reg + i, 0);
+	}
+
+	I915_WRITE(ctl_reg, VIDEO_DIP_ENABLE_VSC_HSW);
+	POSTING_READ(ctl_reg);
+}
+
+static void intel_edp_psr_setup(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct edp_vsc_psr psr_vsc;
+
+	if (intel_dp->psr_setup_done)
+		return;
+
+	/* Prepare VSC packet as per EDP 1.3 spec, Table 3.10 */
+	memset(&psr_vsc, 0, sizeof(psr_vsc));
+	psr_vsc.sdp_header.HB0 = 0;
+	psr_vsc.sdp_header.HB1 = 0x7;
+	psr_vsc.sdp_header.HB2 = 0x2;
+	psr_vsc.sdp_header.HB3 = 0x8;
+	intel_edp_psr_write_vsc(intel_dp, &psr_vsc);
+
+	/* Avoid continuous PSR exit by masking memup and hpd */
+	I915_WRITE(EDP_PSR_DEBUG_CTL, EDP_PSR_DEBUG_MASK_MEMUP |
+		   EDP_PSR_DEBUG_MASK_HPD);
+
+	intel_dp->psr_setup_done = true;
+}
+
+static void intel_edp_psr_enable_sink(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t aux_clock_divider = get_aux_clock_divider(intel_dp);
+	int precharge = 0x3;
+	int msg_size = 5;       /* Header(4) + Message(1) */
+
+	/* Enable PSR in sink */
+	if (intel_dp->psr_dpcd[1] & DP_PSR_NO_TRAIN_ON_EXIT)
+		intel_dp_aux_native_write_1(intel_dp, DP_PSR_EN_CFG,
+					    DP_PSR_ENABLE &
+					    ~DP_PSR_MAIN_LINK_ACTIVE);
+	else
+		intel_dp_aux_native_write_1(intel_dp, DP_PSR_EN_CFG,
+					    DP_PSR_ENABLE |
+					    DP_PSR_MAIN_LINK_ACTIVE);
+
+	/* Setup AUX registers */
+	I915_WRITE(EDP_PSR_AUX_DATA1, EDP_PSR_DPCD_COMMAND);
+	I915_WRITE(EDP_PSR_AUX_DATA2, EDP_PSR_DPCD_NORMAL_OPERATION);
+	I915_WRITE(EDP_PSR_AUX_CTL,
+		   DP_AUX_CH_CTL_TIME_OUT_400us |
+		   (msg_size << DP_AUX_CH_CTL_MESSAGE_SIZE_SHIFT) |
+		   (precharge << DP_AUX_CH_CTL_PRECHARGE_2US_SHIFT) |
+		   (aux_clock_divider << DP_AUX_CH_CTL_BIT_CLOCK_2X_SHIFT));
+}
+
+static void intel_edp_psr_enable_source(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	uint32_t max_sleep_time = 0x1f;
+	uint32_t idle_frames = 1;
+	uint32_t val = 0x0;
+
+	if (intel_dp->psr_dpcd[1] & DP_PSR_NO_TRAIN_ON_EXIT) {
+		val |= EDP_PSR_LINK_STANDBY;
+		val |= EDP_PSR_TP2_TP3_TIME_0us;
+		val |= EDP_PSR_TP1_TIME_0us;
+		val |= EDP_PSR_SKIP_AUX_EXIT;
+	} else
+		val |= EDP_PSR_LINK_DISABLE;
+
+	I915_WRITE(EDP_PSR_CTL, val |
+		   EDP_PSR_MIN_LINK_ENTRY_TIME_8_LINES |
+		   max_sleep_time << EDP_PSR_MAX_SLEEP_TIME_SHIFT |
+		   idle_frames << EDP_PSR_IDLE_FRAME_SHIFT |
+		   EDP_PSR_ENABLE);
+}
+
+void intel_edp_psr_enable(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+
+	if (!is_edp_psr(intel_dp) || intel_edp_is_psr_enabled(dev))
+		return;
+
+	/* Setup PSR once */
+	intel_edp_psr_setup(intel_dp);
+
+	/* Enable PSR on the panel */
+	intel_edp_psr_enable_sink(intel_dp);
+
+	/* Enable PSR on the host */
+	intel_edp_psr_enable_source(intel_dp);
+}
+
+void intel_edp_psr_disable(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (!intel_edp_is_psr_enabled(dev))
+		return;
+
+	I915_WRITE(EDP_PSR_CTL, I915_READ(EDP_PSR_CTL) & ~EDP_PSR_ENABLE);
+
+	/* Wait till PSR is idle */
+	if (_wait_for((I915_READ(EDP_PSR_STATUS_CTL) &
+		       EDP_PSR_STATUS_STATE_MASK) == 0, 2000, 10))
+		DRM_ERROR("Timed out waiting for PSR Idle State\n");
+}
+
 static void intel_disable_dp(struct intel_encoder *encoder)
 {
 	struct intel_dp *intel_dp = enc_to_intel_dp(&encoder->base);
@@ -3189,6 +3336,8 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 	WARN(error, "intel_dp_i2c_init failed with error %d for port %c\n",
 	     error, port_name(port));
 
+	intel_dp->psr_setup_done = false;
+
 	if (!intel_edp_init_connector(intel_dp, intel_connector)) {
 		i2c_del_adapter(&intel_dp->adapter);
 		if (is_edp(intel_dp)) {

drivers/gpu/drm/i915/intel_drv.h

@@ -499,6 +499,7 @@ struct intel_dp {
 	int backlight_off_delay;
 	struct delayed_work panel_vdd_work;
 	bool want_panel_vdd;
+	bool psr_setup_done;
 	struct intel_connector *attached_connector;
 };
 
@@ -834,4 +835,7 @@ extern bool intel_set_pch_fifo_underrun_reporting(struct drm_device *dev,
 						 enum transcoder pch_transcoder,
 						 bool enable);
 
+extern void intel_edp_psr_enable(struct intel_dp *intel_dp);
+extern void intel_edp_psr_disable(struct intel_dp *intel_dp);
+
 #endif /* __INTEL_DRV_H__ */