[2/2] thermal: Add support for Airoha EN7581 thermal sensor

diff --git a/drivers/thermal/airoha_thermal.c b/drivers/thermal/airoha_thermal.c
new file mode 100644
index 000000000000..7fe2982c6a3b
--- /dev/null
+++ b/drivers/thermal/airoha_thermal.c
@@ -0,0 +1,492 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+
+/* SCU regs */
+#define EN7581_PLLRG_PROTECT			0x268
+#define EN7581_PWD_TADC				0x2ec
+#define   EN7581_MUX_TADC			GENMASK(3, 1)
+#define EN7581_DOUT_TADC			0x2f8
+#define   EN7581_DOUT_TADC_MASK			GENMASK(15, 0)
+
+/* PTP_THERMAL regs */
+#define EN7581_TEMPMONCTL0			0x800
+#define   EN7581_SENSE3_EN			BIT(3)
+#define   EN7581_SENSE2_EN			BIT(2)
+#define   EN7581_SENSE1_EN			BIT(1)
+#define   EN7581_SENSE0_EN			BIT(0)
+#define EN7581_TEMPMONCTL1			0x804
+/* period unit calculated in BUS clock * 256 scaling-up */
+#define   EN7581_PERIOD_UNIT			GENMASK(9, 0)
+#define EN7581_TEMPMONCTL2			0x808
+#define   EN7581_FILT_INTERVAL			GENMASK(25, 16)
+#define   EN7581_SEN_INTERVAL			GENMASK(9, 0)
+#define EN7581_TEMPMONINT			0x80C
+#define   EN7581_STAGE3_INT_EN			BIT(31)
+#define   EN7581_STAGE2_INT_EN			BIT(30)
+#define   EN7581_STAGE1_INT_EN			BIT(29)
+#define   EN7581_FILTER_INT_EN_3		BIT(28)
+#define   EN7581_IMMD_INT_EN3			BIT(27)
+#define   EN7581_NOHOTINTEN3			BIT(26)
+#define   EN7581_HOFSINTEN3			BIT(25)
+#define   EN7581_LOFSINTEN3			BIT(24)
+#define   EN7581_HINTEN3			BIT(23)
+#define   EN7581_CINTEN3			BIT(22)
+#define   EN7581_FILTER_INT_EN_2		BIT(21)
+#define   EN7581_FILTER_INT_EN_1		BIT(20)
+#define   EN7581_FILTER_INT_EN_0		BIT(19)
+#define   EN7581_IMMD_INT_EN2			BIT(18)
+#define   EN7581_IMMD_INT_EN1			BIT(17)
+#define   EN7581_IMMD_INT_EN0			BIT(16)
+#define   EN7581_TIME_OUT_INT_EN		BIT(15)
+#define   EN7581_NOHOTINTEN2			BIT(14)
+#define   EN7581_HOFSINTEN2			BIT(13)
+#define   EN7581_LOFSINTEN2			BIT(12)
+#define   EN7581_HINTEN2			BIT(11)
+#define   EN7581_CINTEN2			BIT(10)
+#define   EN7581_NOHOTINTEN1			BIT(9)
+#define   EN7581_HOFSINTEN1			BIT(8)
+#define   EN7581_LOFSINTEN1			BIT(7)
+#define   EN7581_HINTEN1			BIT(6)
+#define   EN7581_CINTEN1			BIT(5)
+#define   EN7581_NOHOTINTEN0			BIT(4)
+/* Similar to COLD and HOT also these seems to be swapped in documentation */
+#define   EN7581_LOFSINTEN0			BIT(3) /* In documentation: BIT(2) */
+#define   EN7581_HOFSINTEN0			BIT(2) /* In documentation: BIT(3) */
+/* It seems documentation have these swapped as the HW
+ * - Fire BIT(1) when lower than EN7581_COLD_THRE
+ * - Fire BIT(0) and BIT(5) when higher than EN7581_HOT2NORMAL_THRE or
+ *     EN7581_HOT_THRE
+ */
+#define   EN7581_CINTEN0			BIT(1) /* In documentation: BIT(0) */
+#define   EN7581_HINTEN0			BIT(0) /* In documentation: BIT(1) */
+#define EN7581_TEMPMONINTSTS			0x810
+#define   EN7581_STAGE3_INT_STAT		BIT(31)
+#define   EN7581_STAGE2_INT_STAT		BIT(30)
+#define   EN7581_STAGE1_INT_STAT		BIT(29)
+#define   EN7581_FILTER_INT_STAT_3		BIT(28)
+#define   EN7581_IMMD_INT_STS3			BIT(27)
+#define   EN7581_NOHOTINTSTS3			BIT(26)
+#define   EN7581_HOFSINTSTS3			BIT(25)
+#define   EN7581_LOFSINTSTS3			BIT(24)
+#define   EN7581_HINTSTS3			BIT(23)
+#define   EN7581_CINTSTS3			BIT(22)
+#define   EN7581_FILTER_INT_STAT_2		BIT(21)
+#define   EN7581_FILTER_INT_STAT_1		BIT(20)
+#define   EN7581_FILTER_INT_STAT_0		BIT(19)
+#define   EN7581_IMMD_INT_STS2			BIT(18)
+#define   EN7581_IMMD_INT_STS1			BIT(17)
+#define   EN7581_IMMD_INT_STS0			BIT(16)
+#define   EN7581_TIME_OUT_INT_STAT		BIT(15)
+#define   EN7581_NOHOTINTSTS2			BIT(14)
+#define   EN7581_HOFSINTSTS2			BIT(13)
+#define   EN7581_LOFSINTSTS2			BIT(12)
+#define   EN7581_HINTSTS2			BIT(11)
+#define   EN7581_CINTSTS2			BIT(10)
+#define   EN7581_NOHOTINTSTS1			BIT(9)
+#define   EN7581_HOFSINTSTS1			BIT(8)
+#define   EN7581_LOFSINTSTS1			BIT(7)
+#define   EN7581_HINTSTS1			BIT(6)
+#define   EN7581_CINTSTS1			BIT(5)
+#define   EN7581_NOHOTINTSTS0			BIT(4)
+/* Similar to COLD and HOT also these seems to be swapped in documentation */
+#define   EN7581_LOFSINTSTS0			BIT(3) /* In documentation: BIT(2) */
+#define   EN7581_HOFSINTSTS0			BIT(2) /* In documentation: BIT(3) */
+/* It seems documentation have these swapped as the HW
+ * - Fire BIT(1) when lower than EN7581_COLD_THRE
+ * - Fire BIT(0) and BIT(5) when higher than EN7581_HOT2NORMAL_THRE or
+ *     EN7581_HOT_THRE
+ *
+ * To clear things, we swap the define but we keep them documented here.
+ */
+#define   EN7581_CINTSTS0			BIT(1) /* In documentation: BIT(0) */
+#define   EN7581_HINTSTS0			BIT(0) /* In documentation: BIT(1)*/
+/* Monitor will take the bigger threshold between HOT2NORMAL and HOT
+ * and will fire both HOT2NORMAL and HOT interrupt when higher than the 2
+ *
+ * It has also been observed that not setting HOT2NORMAL makes the monitor
+ * treat COLD threshold as HOT2NORMAL.
+ */
+#define EN7581_TEMPH2NTHRE			0x824
+/* It seems HOT2NORMAL is actually NORMAL2HOT */
+#define   EN7581_HOT2NORMAL_THRE		GENMASK(11, 0)
+#define EN7581_TEMPHTHRE			0x828
+#define   EN7581_HOT_THRE			GENMASK(11, 0)
+/* Monitor will use this as HOT2NORMAL (fire interrupt when lower than...)*/
+#define EN7581_TEMPCTHRE			0x82c
+#define   EN7581_COLD_THRE			GENMASK(11, 0)
+/* Also LOW and HIGH offset register are swapped */
+#define EN7581_TEMPOFFSETL			0x830 /* In documentation: 0x834 */
+#define   EN7581_LOW_OFFSET			GENMASK(11, 0)
+#define EN7581_TEMPOFFSETH			0x834 /* In documentation: 0x830 */
+#define   EN7581_HIGH_OFFSET			GENMASK(11, 0)
+#define EN7581_TEMPMSRCTL0			0x838
+#define   EN7581_MSRCTL3			GENMASK(11, 9)
+#define   EN7581_MSRCTL2			GENMASK(8, 6)
+#define   EN7581_MSRCTL1			GENMASK(5, 3)
+#define   EN7581_MSRCTL0			GENMASK(2, 0)
+#define EN7581_TEMPADCVALIDADDR			0x878
+#define   EN7581_ADC_VALID_ADDR			GENMASK(31, 0)
+#define EN7581_TEMPADCVOLTADDR			0x87c
+#define   EN7581_ADC_VOLT_ADDR			GENMASK(31, 0)
+#define EN7581_TEMPRDCTRL			0x880
+/*
+ * NOTICE: AHB have this set to 0 by default. Means that
+ * the same addr is used for ADC volt and valid reading.
+ * In such case, VALID ADDR is used and volt addr is ignored.
+ */
+#define   EN7581_RD_CTRL_DIFF			BIT(0)
+#define EN7581_TEMPADCVALIDMASK			0x884
+#define   EN7581_ADV_RD_VALID_POLARITY		BIT(5)
+#define   EN7581_ADV_RD_VALID_POS		GENMASK(4, 0)
+#define EN7581_TEMPADCVOLTAGESHIFT		0x888
+#define   EN7581_ADC_VOLTAGE_SHIFT		GENMASK(4, 0)
+/*
+ * Same values for each CTL.
+ * Can operate in:
+ * - 1 sample
+ * - 2 sample and make average of them
+ * - 4,6,10,16 sample, drop max and min and make avgerage of them
+ */
+#define   EN7581_MSRCTL_1SAMPLE			0x0
+#define   EN7581_MSRCTL_AVG2SAMPLE		0x1
+#define   EN7581_MSRCTL_4SAMPLE_MAX_MIX_AVG2	0x2
+#define   EN7581_MSRCTL_6SAMPLE_MAX_MIX_AVG4	0x3
+#define   EN7581_MSRCTL_10SAMPLE_MAX_MIX_AVG8	0x4
+#define   EN7581_MSRCTL_18SAMPLE_MAX_MIX_AVG16	0x5
+#define EN7581_TEMPAHBPOLL			0x840
+#define   EN7581_ADC_POLL_INTVL			GENMASK(31, 0)
+/* PTPSPARE0,2 reg are used to store efuse info for calibrated temp offset */
+#define EN7581_EFUSE_TEMP_OFFSET_REG		0xf20 /* PTPSPARE0 */
+#define   EN7581_EFUSE_TEMP_OFFSET		GENMASK(31, 16)
+#define EN7581_PTPSPARE1			0xf24 /* PTPSPARE1 */
+#define EN7581_EFUSE_TEMP_CPU_SENSOR_REG	0xf28 /* PTPSPARE2 */
+
+#define EN7581_SLOPE_X100_DIO_DEFAULT		5645
+#define EN7581_SLOPE_X100_DIO_AVS		5645
+
+#define EN7581_INIT_TEMP_CPK_X10		300
+#define EN7581_INIT_TEMP_FTK_X10		620
+#define EN7581_INIT_TEMP_NONK_X10		550
+
+#define EN7581_SCU_THERMAL_PROTECT_KEY		0x12
+#define EN7581_SCU_THERMAL_MUX_DIODE1		0x7
+
+/* Start using thermal helper only after tz are init */
+#define AIROHA_GET_SLOPE(priv)			((priv)->init_done ? \
+						 thermal_zone_get_slope((priv)->tz) : \
+						 (priv)->default_slope)
+#define AIROHA_GET_OFFSET(priv)			((priv)->init_done ? \
+						 thermal_zone_get_offset((priv)->tz) : \
+						 (priv)->default_offset)
+
+/* Convert temp to raw value as read from ADC	((((temp / 100) - init) * slope) / 1000) + offset */
+#define TEMP_TO_RAW(priv, temp)			((((((temp) / 100) - (priv)->init_temp) * \
+						  AIROHA_GET_SLOPE(priv)) / 1000) + AIROHA_GET_OFFSET(priv))
+
+/* Convert raw to temp				((((temp - offset) * 1000) / slope + init) * 100) */
+#define RAW_TO_TEMP(priv, raw)			(((((raw) - AIROHA_GET_OFFSET(priv)) * 1000) / \
+						  AIROHA_GET_SLOPE(priv) + (priv)->init_temp) * 100)
+
+struct airoha_thermal_priv {
+	struct thermal_zone_device *tz;
+	void __iomem *base;
+
+	struct regmap *chip_scu;
+	struct resource scu_adc_res;
+	int init_temp;
+	int default_slope;
+	int default_offset;
+
+	bool init_done;
+};
+
+static int airoha_get_thermal_ADC(struct airoha_thermal_priv *priv)
+{
+	u32 val;
+
+	regmap_read(priv->chip_scu, EN7581_DOUT_TADC, &val);
+	return FIELD_GET(EN7581_DOUT_TADC_MASK, val);
+}
+
+static void airoha_init_thermal_ADC_mode(struct airoha_thermal_priv *priv)
+{
+	u32 adc_mux, pllrg;
+
+	/* Save PLLRG current value */
+	regmap_read(priv->chip_scu, EN7581_PLLRG_PROTECT, &pllrg);
+
+	/* Give access to thermal regs */
+	regmap_write(priv->chip_scu, EN7581_PLLRG_PROTECT, EN7581_SCU_THERMAL_PROTECT_KEY);
+	adc_mux = FIELD_PREP(EN7581_MUX_TADC, EN7581_SCU_THERMAL_MUX_DIODE1);
+	regmap_write(priv->chip_scu, EN7581_PWD_TADC, adc_mux);
+
+	/* Restore PLLRG value on exit */
+	regmap_write(priv->chip_scu, EN7581_PLLRG_PROTECT, pllrg);
+}
+
+static int airoha_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
+{
+	struct airoha_thermal_priv *priv = tz->devdata;
+	int min, max, avg_temp, temp_adc;
+	int i;
+
+	/* Get the starting temp */
+	temp_adc = airoha_get_thermal_ADC(priv);
+	min = temp_adc;
+	max = temp_adc;
+	avg_temp = temp_adc;
+
+	/* Make 5 more measurement and average the temp ADC difference */
+	for (i = 0; i < 5; i++) {
+		temp_adc = airoha_get_thermal_ADC(priv);
+		avg_temp += temp_adc;
+		if (temp_adc > max)
+			max = temp_adc;
+		if (temp_adc < min)
+			min = temp_adc;
+	}
+	avg_temp = avg_temp - max - min;
+	avg_temp /= 4;
+
+	*temp = RAW_TO_TEMP(priv, avg_temp);
+	return 0;
+}
+
+static int airoha_thermal_set_trips(struct thermal_zone_device *tz, int low,
+				    int high)
+{
+	struct airoha_thermal_priv *priv = tz->devdata;
+
+	if (high != INT_MAX) {
+		/* Validate high and clamp them a sane value */
+		if (high > RAW_TO_TEMP(priv, FIELD_MAX(EN7581_DOUT_TADC_MASK)))
+			high = 110000;
+
+		/* We offset the high temp of 1°C to trigger correct event */
+		writel(TEMP_TO_RAW(priv, high) >> 4,
+		       priv->base + EN7581_TEMPOFFSETH);
+	}
+
+	if (low != -INT_MAX) {
+		/* Validate low and clamp them to a sane value */
+		if (low < RAW_TO_TEMP(priv, 0))
+			low = -33000;
+
+		/* We offset the low temp of 1°C to trigger correct event */
+		writel(TEMP_TO_RAW(priv, low) >> 4,
+		       priv->base + EN7581_TEMPOFFSETL);
+	}
+
+	/* Enable sensor 0 monitor */
+	writel(EN7581_SENSE0_EN, priv->base + EN7581_TEMPMONCTL0);
+
+	return 0;
+}
+
+static const struct thermal_zone_device_ops thdev_ops = {
+	.get_temp = airoha_thermal_get_temp,
+	.set_trips = airoha_thermal_set_trips,
+};
+
+static irqreturn_t airoha_thermal_irq(int irq, void *data)
+{
+	struct airoha_thermal_priv *priv = data;
+	enum thermal_notify_event event;
+	u32 status;
+
+	status = readl(priv->base + EN7581_TEMPMONINTSTS);
+	switch (status & (EN7581_HOFSINTSTS0 | EN7581_LOFSINTSTS0)) {
+	case EN7581_HOFSINTSTS0:
+		event = THERMAL_TRIP_VIOLATED;
+		break;
+	case EN7581_LOFSINTSTS0:
+		event = THERMAL_EVENT_UNSPECIFIED;
+		break;
+	default:
+		goto exit;
+	}
+
+	thermal_zone_device_update(priv->tz, event);
+
+exit:
+	/* reset interrupt */
+	writel(status, priv->base + EN7581_TEMPMONINTSTS);
+
+	return IRQ_HANDLED;
+}
+
+static void airoha_thermal_setup_adc_val(struct device *dev,
+					 struct airoha_thermal_priv *priv)
+{
+	u32 efuse_calib_info, cpu_sensor;
+
+	/* Setup thermal sensor to ADC mode and setup the mux to DIODE1 */
+	airoha_init_thermal_ADC_mode(priv);
+	/* sleep 10 ms for ADC to enable */
+	usleep_range(10 * USEC_PER_MSEC, 11 * USEC_PER_MSEC);
+
+	efuse_calib_info = readl(priv->base + EN7581_EFUSE_TEMP_OFFSET_REG);
+	if (efuse_calib_info) {
+		priv->default_offset = FIELD_GET(EN7581_EFUSE_TEMP_OFFSET, efuse_calib_info);
+		/* Different slope are applied if the sensor is used for CPU or for package */
+		cpu_sensor = readl(priv->base + EN7581_EFUSE_TEMP_CPU_SENSOR_REG);
+		if (cpu_sensor) {
+			priv->default_slope = EN7581_SLOPE_X100_DIO_DEFAULT;
+			priv->init_temp = EN7581_INIT_TEMP_FTK_X10;
+		} else {
+			priv->default_slope = EN7581_SLOPE_X100_DIO_AVS;
+			priv->init_temp = EN7581_INIT_TEMP_CPK_X10;
+		}
+	} else {
+		priv->default_offset = airoha_get_thermal_ADC(priv);
+		priv->default_slope = EN7581_SLOPE_X100_DIO_DEFAULT;
+		priv->init_temp = EN7581_INIT_TEMP_NONK_X10;
+		dev_info(dev, "missing thermal calibrarion EFUSE, using non calibrated value\n");
+	}
+}
+
+static void airoha_thermal_setup_monitor(struct airoha_thermal_priv *priv)
+{
+	/* Set measure mode */
+	writel(FIELD_PREP(EN7581_MSRCTL0, EN7581_MSRCTL_6SAMPLE_MAX_MIX_AVG4),
+	       priv->base + EN7581_TEMPMSRCTL0);
+
+	/*
+	 * Configure ADC valid reading addr
+	 * The AHB temp monitor system doesn't have direct access to the
+	 * thermal sensor. It does instead work by providing all kind of
+	 * address to configure how to access and setup an ADC for the
+	 * sensor. EN7581 supports only one sensor hence the
+	 * implementation is greatly simplified but the AHB supports
+	 * up to 4 different sensor from the same ADC that can be
+	 * switched by tuning the ADC mux or wiriting address.
+	 *
+	 * We set valid instead of volt as we don't enable valid/volt
+	 * split reading and AHB read valid addr in such case.
+	 */
+	writel(priv->scu_adc_res.start + EN7581_DOUT_TADC,
+	       priv->base + EN7581_TEMPADCVALIDADDR);
+
+	/*
+	 * Configure valid bit on a fake value of bit 16. The ADC outputs
+	 * max of 2 bytes for voltage.
+	 */
+	writel(FIELD_PREP(EN7581_ADV_RD_VALID_POS, 16),
+	       priv->base + EN7581_TEMPADCVALIDMASK);
+
+	/*
+	 * AHB supports max 12 bytes for ADC voltage. Shift the read
+	 * value 4 bit to the right. Precision lost by this is minimal
+	 * in the order of half a °C and is acceptable in the context
+	 * of triggering interrupt in critical condition.
+	 */
+	writel(FIELD_PREP(EN7581_ADC_VOLTAGE_SHIFT, 4),
+	       priv->base + EN7581_TEMPADCVOLTAGESHIFT);
+
+	/* Enable LOW and HIGH interrupt */
+	writel(EN7581_HOFSINTEN0 | EN7581_LOFSINTEN0,
+	       priv->base + EN7581_TEMPMONINT);
+
+	/* BUS clock is 300MHz counting unit is 3 * 68.64 * 256 = 52.715us */
+	writel(FIELD_PREP(EN7581_PERIOD_UNIT, 3),
+	       priv->base + EN7581_TEMPMONCTL1);
+
+	/*
+	 * filt interval is 1 * 52.715us = 52.715us,
+	 * sen interval is 379 * 52.715us = 19.97ms
+	 */
+	writel(FIELD_PREP(EN7581_FILT_INTERVAL, 1) |
+	       FIELD_PREP(EN7581_FILT_INTERVAL, 379),
+	       priv->base + EN7581_TEMPMONCTL2);
+
+	/* AHB poll is set to 146 * 68.64 = 10.02us */
+	writel(FIELD_PREP(EN7581_ADC_POLL_INTVL, 146),
+	       priv->base + EN7581_TEMPAHBPOLL);
+}
+
+static int airoha_thermal_probe(struct platform_device *pdev)
+{
+	struct airoha_thermal_priv *priv;
+	struct device_node *chip_scu_np;
+	struct device *dev = &pdev->dev;
+	int irq, ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	chip_scu_np = of_parse_phandle(dev->of_node, "airoha,chip-scu", 0);
+	if (!chip_scu_np)
+		return -EINVAL;
+
+	priv->chip_scu = syscon_node_to_regmap(chip_scu_np);
+	if (IS_ERR(priv->chip_scu))
+		return PTR_ERR(priv->chip_scu);
+
+	of_address_to_resource(chip_scu_np, 0, &priv->scu_adc_res);
+	of_node_put(chip_scu_np);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+					airoha_thermal_irq, IRQF_ONESHOT,
+					pdev->name, (void *)priv);
+	if (ret) {
+		dev_err(dev, "Can't get interrupt working.\n");
+		return ret;
+	}
+
+	airoha_thermal_setup_monitor(priv);
+	airoha_thermal_setup_adc_val(dev, priv);
+
+	/* register of thermal sensor and get info from DT */
+	priv->tz = devm_thermal_of_zone_register(dev, 0, priv, &thdev_ops);
+	if (IS_ERR(priv->tz)) {
+		dev_err(dev, "register thermal zone sensor failed\n");
+		return PTR_ERR(priv->tz);
+	}
+
+	/* Fill tz slope and offset with parsed values */
+	priv->tz->tzp->offset = priv->default_offset;
+	priv->tz->tzp->slope = priv->default_slope;
+	priv->init_done = true;
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+}
+
+static const struct of_device_id airoha_thermal_match[] = {
+	{ .compatible = "airoha,en7581-thermal" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, airoha_thermal_match);
+
+static struct platform_driver airoha_thermal_driver = {
+	.driver = {
+		.name = "airoha-thermal",
+		.of_match_table = airoha_thermal_match,
+	},
+	.probe = airoha_thermal_probe,
+};
+
+module_platform_driver(airoha_thermal_driver);
+
+MODULE_AUTHOR("Christian Marangi <ansuelsmth@gmail.com>");
+MODULE_DESCRIPTION("Airoha thermal driver");
+MODULE_LICENSE("GPL");