[Intel-gfx] [PATCH 4/8] drm/i915/icl: implement the tc/legacy HPD {dis, }connect flow for DP

[Srivatsa, Anusha]

>-----Original Message-----
>From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On Behalf Of
>Paulo Zanoni
>Sent: Wednesday, July 11, 2018 2:59 PM
>To: intel-gfx at lists.freedesktop.org
>Cc: Zanoni, Paulo R <paulo.r.zanoni at intel.com>
>Subject: [Intel-gfx] [PATCH 4/8] drm/i915/icl: implement the tc/legacy HPD {dis,
>}connect flow for DP
>
>Implement the DFLEXDPPMS/DFLEXDPCSSS dance for DisplayPort. These
>functions need to be called during HPD assert/deassert, but due to how our driver
>works it's much simpler if we always call them when
>icl_digital_port_connected() is called, which means we won't call them exactly
>once per HPD event. This should also cover the connected boot case, whatever
>the BIOS does.
>
>We're still missing the HDMI case, which should be implemented in the next
>patch.
>
>Also notice that, today, the BSpec pages for the DFLEXDPPMS and DFLEXDPCSSS
>registers are wrong, so you should only trust the flows described by the "Gen11
>TypeC Programming" page in our spec.
>
>Cc: Animesh Manna <animesh.manna at intel.com>
>Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>

Reviewed-by: Anusha Srivatsa <anusha.srivatsa at intel.com>

>---
> drivers/gpu/drm/i915/i915_reg.h |  6 +++++  drivers/gpu/drm/i915/intel_dp.c |
>57 ++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 62 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>index c1f350469ff6..96f590a22b26 100644
>--- a/drivers/gpu/drm/i915/i915_reg.h
>+++ b/drivers/gpu/drm/i915/i915_reg.h
>@@ -10223,4 +10223,10 @@ enum skl_power_gate {
> 						 _ICL_PHY_MISC_B)
> #define  ICL_PHY_MISC_DE_IO_COMP_PWR_DOWN	(1 << 23)
>
>+#define PORT_TX_DFLEXDPPMS
>	_MMIO(0x163890)
>+#define   DP_PHY_MODE_STATUS_COMPLETED(tc_port)		(1 <<
>(tc_port))
>+
>+#define PORT_TX_DFLEXDPCSSS
>	_MMIO(0x163894)
>+#define   DP_PHY_MODE_STATUS_NOT_SAFE(tc_port)		(1 << (tc_port))
>+
> #endif /* _I915_REG_H_ */
>diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>index 486b879cdef7..0ebce7e4c538 100644
>--- a/drivers/gpu/drm/i915/intel_dp.c
>+++ b/drivers/gpu/drm/i915/intel_dp.c
>@@ -4784,6 +4784,56 @@ static void icl_update_tc_port_type(struct
>drm_i915_private *dev_priv,
> 			      type_str);
> }
>
>+static bool icl_tc_phy_mode_status_connect(struct drm_i915_private *dev_priv,
>+					   struct intel_digital_port *dig_port) {
>+	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
>+	u32 val;
>+
>+	if (dig_port->tc_type != TC_PORT_LEGACY &&
>+	    dig_port->tc_type != TC_PORT_TYPEC)
>+		return true;
>+
>+	val = I915_READ(PORT_TX_DFLEXDPPMS);
>+	if (!(val & DP_PHY_MODE_STATUS_COMPLETED(tc_port))) {
>+		DRM_ERROR("DP PHY for TC port %d not ready\n", tc_port);
>+		return false;
>+	}
>+
>+	/*
>+	 * This function may be called many times in a row without an HPD event
>+	 * in between, so try to avoid the write when we can.
>+	 */
>+	val = I915_READ(PORT_TX_DFLEXDPCSSS);
>+	if (!(val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port))) {
>+		val |= DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
>+		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
>+	}
>+
>+	return true;
>+}
>+
>+static void icl_tc_phy_mode_status_disconnect(struct drm_i915_private
>*dev_priv,
>+					      struct intel_digital_port *dig_port) {
>+	enum tc_port tc_port = intel_port_to_tc(dev_priv, dig_port->base.port);
>+	u32 val;
>+
>+	if (dig_port->tc_type != TC_PORT_LEGACY &&
>+	    dig_port->tc_type != TC_PORT_TYPEC)
>+		return;
>+
>+	/*
>+	 * This function may be called many times in a row without an HPD event
>+	 * in between, so try to avoid the write when we can.
>+	 */
>+	val = I915_READ(PORT_TX_DFLEXDPCSSS);
>+	if (val & DP_PHY_MODE_STATUS_NOT_SAFE(tc_port)) {
>+		val &= ~DP_PHY_MODE_STATUS_NOT_SAFE(tc_port);
>+		I915_WRITE(PORT_TX_DFLEXDPCSSS, val);
>+	}
>+}
>+
> static bool icl_tc_port_connected(struct drm_i915_private *dev_priv,
> 				  struct intel_digital_port *intel_dig_port)  { @@
>-4804,12 +4854,17 @@ static bool icl_tc_port_connected(struct
>drm_i915_private *dev_priv,
> 	if (cpu_isr & tbt_bit)
> 		is_tbt = true;
>
>-	if (!is_legacy && !is_typec && !is_tbt)
>+	if (!is_legacy && !is_typec && !is_tbt) {
>+		icl_tc_phy_mode_status_disconnect(dev_priv, intel_dig_port);
> 		return false;
>+	}
>
> 	icl_update_tc_port_type(dev_priv, intel_dig_port, is_legacy, is_typec,
> 				is_tbt);
>
>+	if (!icl_tc_phy_mode_status_connect(dev_priv, intel_dig_port))
>+		return false;
>+
> 	return true;
> }
>
>--
>2.14.4
>
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