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

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

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,

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);
 }
 

drivers/gpu/drm/i915/i915_reg.h

@@ -9111,6 +9111,10 @@ enum {
 #define   ICL_PCODE_EXIT_TCCOLD			0x12
 #define   HSW_PCODE_DE_WRITE_FREQ_REQ		0x17
 #define   DISPLAY_IPS_CONTROL			0x19
+#define   TGL_PCODE_TCCOLD			0x26
+#define     TGL_PCODE_EXIT_TCCOLD_DATA_L_EXIT_FAILED	REG_BIT(0)
+#define     TGL_PCODE_EXIT_TCCOLD_DATA_H_BLOCK_REQ	0
+#define     TGL_PCODE_EXIT_TCCOLD_DATA_H_UNBLOCK_REQ	REG_BIT(0)
             /* See also IPS_CTL */
 #define     IPS_PCODE_CONTROL			(1 << 30)
 #define   HSW_PCODE_DYNAMIC_DUTY_CYCLE_CONTROL	0x1A