thermal: tegra: enable OC hw throttle

Parse Over Current settings from DT and program them to
generate interrupts. Also enable hw throttling whenever
there are OC events. Log the OC events as debug messages.
Signed-off-by: Wei Ni <wni@nvidia.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/tegra/soctherm.c

@@ -106,9 +106,26 @@
 #define STATS_CTL_CLR_UP			0x2
 #define STATS_CTL_EN_UP				0x1
 
+#define OC1_CFG					0x310
+#define OC1_CFG_LONG_LATENCY_MASK		BIT(6)
+#define OC1_CFG_HW_RESTORE_MASK			BIT(5)
+#define OC1_CFG_PWR_GOOD_MASK_MASK		BIT(4)
+#define OC1_CFG_THROTTLE_MODE_MASK		(0x3 << 2)
+#define OC1_CFG_ALARM_POLARITY_MASK		BIT(1)
+#define OC1_CFG_EN_THROTTLE_MASK		BIT(0)
+
+#define OC1_CNT_THRESHOLD			0x314
+#define OC1_THROTTLE_PERIOD			0x318
+#define OC1_ALARM_COUNT				0x31c
+#define OC1_FILTER				0x320
+#define OC1_STATS				0x3a8
+
 #define OC_INTR_STATUS				0x39c
 #define OC_INTR_ENABLE				0x3a0
 #define OC_INTR_DISABLE				0x3a4
+#define OC_STATS_CTL				0x3c4
+#define OC_STATS_CTL_CLR_ALL			0x2
+#define OC_STATS_CTL_EN_ALL			0x1
 
 #define OC_INTR_OC1_MASK			BIT(0)
 #define OC_INTR_OC2_MASK			BIT(1)
@@ -207,6 +224,25 @@
 #define THROT_DELAY_CTRL(throt)		(THROT_DELAY_LITE + \
 					(THROT_OFFSET * throt))
 
+#define ALARM_OFFSET			0x14
+#define ALARM_CFG(throt)		(OC1_CFG + \
+					(ALARM_OFFSET * (throt - THROTTLE_OC1)))
+
+#define ALARM_CNT_THRESHOLD(throt)	(OC1_CNT_THRESHOLD + \
+					(ALARM_OFFSET * (throt - THROTTLE_OC1)))
+
+#define ALARM_THROTTLE_PERIOD(throt)	(OC1_THROTTLE_PERIOD + \
+					(ALARM_OFFSET * (throt - THROTTLE_OC1)))
+
+#define ALARM_ALARM_COUNT(throt)	(OC1_ALARM_COUNT + \
+					(ALARM_OFFSET * (throt - THROTTLE_OC1)))
+
+#define ALARM_FILTER(throt)		(OC1_FILTER + \
+					(ALARM_OFFSET * (throt - THROTTLE_OC1)))
+
+#define ALARM_STATS(throt)		(OC1_STATS + \
+					(4 * (throt - THROTTLE_OC1)))
+
 /* get CCROC_THROT_PSKIP_xxx offset per HIGH/MED/LOW vect*/
 #define CCROC_THROT_OFFSET			0x0c
 #define CCROC_THROT_PSKIP_CTRL_CPU_REG(vect)    (CCROC_THROT_PSKIP_CTRL_CPU + \
@@ -218,6 +254,9 @@
 #define THERMCTL_LVL_REGS_SIZE		0x20
 #define THERMCTL_LVL_REG(rg, lv)	((rg) + ((lv) * THERMCTL_LVL_REGS_SIZE))
 
+#define OC_THROTTLE_MODE_DISABLED	0
+#define OC_THROTTLE_MODE_BRIEF		2
+
 static const int min_low_temp = -127000;
 static const int max_high_temp = 127000;
 
@@ -266,6 +305,15 @@ struct tegra_thermctl_zone {
 	const struct tegra_tsensor_group *sg;
 };
 
+struct soctherm_oc_cfg {
+	u32 active_low;
+	u32 throt_period;
+	u32 alarm_cnt_thresh;
+	u32 alarm_filter;
+	u32 mode;
+	bool intr_en;
+};
+
 struct soctherm_throt_cfg {
 	const char *name;
 	unsigned int id;
@@ -273,6 +321,7 @@ struct soctherm_throt_cfg {
 	u8 cpu_throt_level;
 	u32 cpu_throt_depth;
 	u32 gpu_throt_level;
+	struct soctherm_oc_cfg oc_cfg;
 	struct thermal_cooling_device *cdev;
 	bool init;
 };
@@ -747,7 +796,7 @@ static int tegra_soctherm_set_hwtrips(struct device *dev,
 		return 0;
 	}
 
-	for (i = 0; i < THROTTLE_SIZE; i++) {
+	for (i = 0; i < THROTTLE_OC1; i++) {
 		struct thermal_cooling_device *cdev;
 
 		if (!ts->throt_cfgs[i].init)
@@ -1569,6 +1618,32 @@ static int soctherm_thermtrips_parse(struct platform_device *pdev)
 	return 0;
 }
 
+static void soctherm_oc_cfg_parse(struct device *dev,
+				struct device_node *np_oc,
+				struct soctherm_throt_cfg *stc)
+{
+	u32 val;
+
+	if (of_property_read_bool(np_oc, "nvidia,polarity-active-low"))
+		stc->oc_cfg.active_low = 1;
+	else
+		stc->oc_cfg.active_low = 0;
+
+	if (!of_property_read_u32(np_oc, "nvidia,count-threshold", &val)) {
+		stc->oc_cfg.intr_en = 1;
+		stc->oc_cfg.alarm_cnt_thresh = val;
+	}
+
+	if (!of_property_read_u32(np_oc, "nvidia,throttle-period-us", &val))
+		stc->oc_cfg.throt_period = val;
+
+	if (!of_property_read_u32(np_oc, "nvidia,alarm-filter", &val))
+		stc->oc_cfg.alarm_filter = val;
+
+	/* BRIEF throttling by default, do not support STICKY */
+	stc->oc_cfg.mode = OC_THROTTLE_MODE_BRIEF;
+}
+
 static int soctherm_throt_cfg_parse(struct device *dev,
 				    struct device_node *np,
 				    struct soctherm_throt_cfg *stc)
@@ -1651,24 +1726,34 @@ static void soctherm_init_hw_throt_cdev(struct platform_device *pdev)
 			continue;
 		}
 
+		if (stc->init) {
+			dev_err(dev, "throttle-cfg: %s: redefined!\n", name);
+			of_node_put(np_stcc);
+			break;
+		}
 
 		err = soctherm_throt_cfg_parse(dev, np_stcc, stc);
 		if (err)
 			continue;
 
-		tcd = thermal_of_cooling_device_register(np_stcc,
+		if (stc->id >= THROTTLE_OC1) {
+			soctherm_oc_cfg_parse(dev, np_stcc, stc);
+			stc->init = true;
+		} else {
+
+			tcd = thermal_of_cooling_device_register(np_stcc,
 							 (char *)name, ts,
 							 &throt_cooling_ops);
-		of_node_put(np_stcc);
-		if (IS_ERR_OR_NULL(tcd)) {
-			dev_err(dev,
-				"throttle-cfg: %s: failed to register cooling device\n",
-				name);
-			continue;
+			if (IS_ERR_OR_NULL(tcd)) {
+				dev_err(dev,
+					"throttle-cfg: %s: failed to register cooling device\n",
+					name);
+				continue;
+			}
+			stc->cdev = tcd;
+			stc->init = true;
 		}
 
-		stc->cdev = tcd;
-		stc->init = true;
 	}
 
 	of_node_put(np_stc);
@@ -1819,6 +1904,28 @@ static void throttlectl_gpu_level_select(struct tegra_soctherm *ts,
 	writel(r, ts->regs + THROT_PSKIP_CTRL(throt, THROTTLE_DEV_GPU));
 }
 
+static int soctherm_oc_cfg_program(struct tegra_soctherm *ts,
+				      enum soctherm_throttle_id throt)
+{
+	u32 r;
+	struct soctherm_oc_cfg *oc = &ts->throt_cfgs[throt].oc_cfg;
+
+	if (oc->mode == OC_THROTTLE_MODE_DISABLED)
+		return -EINVAL;
+
+	r = REG_SET_MASK(0, OC1_CFG_HW_RESTORE_MASK, 1);
+	r = REG_SET_MASK(r, OC1_CFG_THROTTLE_MODE_MASK, oc->mode);
+	r = REG_SET_MASK(r, OC1_CFG_ALARM_POLARITY_MASK, oc->active_low);
+	r = REG_SET_MASK(r, OC1_CFG_EN_THROTTLE_MASK, 1);
+	writel(r, ts->regs + ALARM_CFG(throt));
+	writel(oc->throt_period, ts->regs + ALARM_THROTTLE_PERIOD(throt));
+	writel(oc->alarm_cnt_thresh, ts->regs + ALARM_CNT_THRESHOLD(throt));
+	writel(oc->alarm_filter, ts->regs + ALARM_FILTER(throt));
+	soctherm_oc_intr_enable(ts, throt, oc->intr_en);
+
+	return 0;
+}
+
 /**
  * soctherm_throttle_program() - programs pulse skippers' configuration
  * @throt: the LIGHT/HEAVY of the throttle event id.
@@ -1835,6 +1942,9 @@ static void soctherm_throttle_program(struct tegra_soctherm *ts,
 	if (!stc.init)
 		return;
 
+	if ((throt >= THROTTLE_OC1) && (soctherm_oc_cfg_program(ts, throt)))
+		return;
+
 	/* Setup PSKIP parameters */
 	if (ts->soc->use_ccroc)
 		throttlectl_cpu_level_select(ts, throt);