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>

1 files changed, 149 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 1ef83dc26de..bb3593db42e 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/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)) {