drm/i915/tc/tgl: Implement TC cold sequences

TC ports can enter in TCCOLD to save power and is required to request
to PCODE to exit this state before use or read to TC registers.

For TGL there is a new MBOX command to do that with a parameter to ask
PCODE to exit and block TCCOLD entry or unblock TCCOLD entry.

So adding a new power domain to reuse the refcount and only allow
TC cold when all TC ports are not in use.

v2:
- fixed missing case in intel_display_power_domain_str()
- moved tgl_tc_cold_request to intel_display_power.c
- renamed TGL_TC_COLD_OFF to TGL_TC_COLD_OFF_POWER_DOMAINS
- added all TC and TBT aux power domains to
TGL_TC_COLD_OFF_POWER_DOMAINS

v3:
- added one msec sleep when PCODE returns -EAGAIN
- added timeout of 5msec to not loop forever if
sandybridge_pcode_write_timeout() keeps returning -EAGAIN

v4:
- Made failure to block or unblock TC cold a error
- removed 5msec timeout, instead giving PCODE 1msec by up 3 times to
recover from the internal error

v5:
- only sleeping 1msec when ret is -EAGAIN

BSpec: 49294
Cc: Imre Deak <imre.deak@intel.com>
Cc: Cooper Chiou <cooper.chiou@intel.com>
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200414194956.164323-6-jose.souza@intel.com

3 files changed, 123 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_display_power.c b/drivers/gpu/drm/i915/display/intel_display_power.c
index 3a4a378792f2..ff76a5fdbdbe 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.c
+++ b/drivers/gpu/drm/i915/display/intel_display_power.c
@@ -151,6 +151,8 @@ intel_display_power_domain_str(enum intel_display_power_domain domain)
 		return "GT_IRQ";
 	case POWER_DOMAIN_DPLL_DC_OFF:
 		return "DPLL_DC_OFF";
+	case POWER_DOMAIN_TC_COLD_OFF:
+		return "TC_COLD_OFF";
 	default:
 		MISSING_CASE(domain);
 		return "?";
@@ -2861,6 +2863,21 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 #define TGL_AUX_I_TBT6_IO_POWER_DOMAINS (	\
 	BIT_ULL(POWER_DOMAIN_AUX_I_TBT))
 
+#define TGL_TC_COLD_OFF_POWER_DOMAINS (		\
+	BIT_ULL(POWER_DOMAIN_AUX_D)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_E)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_F)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_G)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_H)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_I)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_D_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_E_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_F_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_G_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_H_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_AUX_I_TBT)	|	\
+	BIT_ULL(POWER_DOMAIN_TC_COLD_OFF))
+
 static const struct i915_power_well_ops i9xx_always_on_power_well_ops = {
 	.sync_hw = i9xx_power_well_sync_hw_noop,
 	.enable = i9xx_always_on_power_well_noop,
@@ -3963,6 +3980,91 @@ static const struct i915_power_well_desc ehl_power_wells[] = {
 	},
 };
 
+static void
+tgl_tc_cold_request(struct drm_i915_private *i915, bool block)
+{
+	u8 tries = 0;
+	int ret;
+
+	while (1) {
+		u32 low_val = 0, high_val;
+
+		if (block)
+			high_val = TGL_PCODE_EXIT_TCCOLD_DATA_H_BLOCK_REQ;
+		else
+			high_val = TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ;
+
+		/*
+		 * Spec states that we should timeout the request after 200us
+		 * but the function below will timeout after 500us
+		 */
+		ret = sandybridge_pcode_read(i915, TGL_PCODE_TCCOLD, &low_val,
+					     &high_val);
+		if (ret == 0) {
+			if (block &&
+			    (low_val & TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED))
+				ret = -EIO;
+			else
+				break;
+		}
+
+		if (++tries == 3)
+			break;
+
+		if (ret == -EAGAIN)
+			msleep(1);
+	}
+
+	if (ret)
+		drm_err(&i915->drm, "TC cold %sblock failed\n",
+			block ? "" : "un");
+	else
+		drm_dbg_kms(&i915->drm, "TC cold %sblock succeeded\n",
+			    block ? "" : "un");
+}
+
+static void
+tgl_tc_cold_off_power_well_enable(struct drm_i915_private *i915,
+				  struct i915_power_well *power_well)
+{
+	tgl_tc_cold_request(i915, true);
+}
+
+static void
+tgl_tc_cold_off_power_well_disable(struct drm_i915_private *i915,
+				   struct i915_power_well *power_well)
+{
+	tgl_tc_cold_request(i915, false);
+}
+
+static void
+tgl_tc_cold_off_power_well_sync_hw(struct drm_i915_private *i915,
+				   struct i915_power_well *power_well)
+{
+	if (power_well->count > 0)
+		tgl_tc_cold_off_power_well_enable(i915, power_well);
+	else
+		tgl_tc_cold_off_power_well_disable(i915, power_well);
+}
+
+static bool
+tgl_tc_cold_off_power_well_is_enabled(struct drm_i915_private *dev_priv,
+				      struct i915_power_well *power_well)
+{
+	/*
+	 * Not the correctly implementation but there is no way to just read it
+	 * from PCODE, so returning count to avoid state mismatch errors
+	 */
+	return power_well->count;
+}
+
+static const struct i915_power_well_ops tgl_tc_cold_off_ops = {
+	.sync_hw = tgl_tc_cold_off_power_well_sync_hw,
+	.enable = tgl_tc_cold_off_power_well_enable,
+	.disable = tgl_tc_cold_off_power_well_disable,
+	.is_enabled = tgl_tc_cold_off_power_well_is_enabled,
+};
+
 static const struct i915_power_well_desc tgl_power_wells[] = {
 	{
 		.name = "always-on",
@@ -4290,6 +4392,12 @@ static const struct i915_power_well_desc tgl_power_wells[] = {
 			.hsw.irq_pipe_mask = BIT(PIPE_D),
 		},
 	},
+	{
+		.name = "TC cold off",
+		.domains = TGL_TC_COLD_OFF_POWER_DOMAINS,
+		.ops = &tgl_tc_cold_off_ops,
+		.id = DISP_PW_ID_NONE,
+	},
 };
 
 static int
diff --git a/drivers/gpu/drm/i915/display/intel_display_power.h b/drivers/gpu/drm/i915/display/intel_display_power.h
index 14c5ad20287f..6c917699293b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_power.h
+++ b/drivers/gpu/drm/i915/display/intel_display_power.h
@@ -76,6 +76,7 @@ enum intel_display_power_domain {
 	POWER_DOMAIN_MODESET,
 	POWER_DOMAIN_GT_IRQ,
 	POWER_DOMAIN_DPLL_DC_OFF,
+	POWER_DOMAIN_TC_COLD_OFF,
 	POWER_DOMAIN_INIT,
 
 	POWER_DOMAIN_NUM,
diff --git a/drivers/gpu/drm/i915/display/intel_tc.c b/drivers/gpu/drm/i915/display/intel_tc.c
index 0cf33d4d21c3..521a94c63640 100644
--- a/drivers/gpu/drm/i915/display/intel_tc.c
+++ b/drivers/gpu/drm/i915/display/intel_tc.c
@@ -53,16 +53,27 @@ tc_port_load_fia_params(struct drm_i915_private *i915,
 	}
 }
 
+static enum intel_display_power_domain
+tc_cold_get_power_domain(struct intel_digital_port *dig_port)
+{
+	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
+
+	if (INTEL_GEN(i915) == 11)
+		return intel_legacy_aux_to_power_domain(dig_port->aux_ch);
+	else
+		return POWER_DOMAIN_TC_COLD_OFF;
+}
+
 static intel_wakeref_t
 tc_cold_block(struct intel_digital_port *dig_port)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
 	enum intel_display_power_domain domain;
 
-	if (INTEL_GEN(i915) != 11 || !dig_port->tc_legacy_port)
+	if (INTEL_GEN(i915) == 11 && !dig_port->tc_legacy_port)
 		return 0;
 
-	domain = intel_legacy_aux_to_power_domain(dig_port->aux_ch);
+	domain = tc_cold_get_power_domain(dig_port);
 	return intel_display_power_get(i915, domain);
 }
 
@@ -80,7 +91,7 @@ tc_cold_unblock(struct intel_digital_port *dig_port, intel_wakeref_t wakeref)
 	if (wakeref == 0)
 		return;
 
-	domain = intel_legacy_aux_to_power_domain(dig_port->aux_ch);
+	domain = tc_cold_get_power_domain(dig_port);
 	intel_display_power_put_async(i915, domain, wakeref);
 }