linux/drivers/thermal/airoha_thermal.c

// SPDX-License-Identifier: GPL-2.0-or-later

#include <linux/module.h>
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/of_address.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 average 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

/* 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) * \
						  (priv)->default_slope) / 1000) + \
						 (priv)->default_offset)

/* Convert raw to temp				((((temp - offset) * 1000) / slope + init) * 100) */
#define RAW_TO_TEMP(priv, raw)			(((((raw) - (priv)->default_offset) * 1000) / \
						  (priv)->default_slope + \
						  (priv)->init_temp) * 100)

#define AIROHA_MAX_SAMPLES			6

struct airoha_thermal_priv {
	void __iomem *base;
	struct regmap *chip_scu;
	struct resource scu_adc_res;

	struct thermal_zone_device *tz;
	int init_temp;
	int default_slope;
	int default_offset;
};

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 = thermal_zone_device_priv(tz);
	int min_value, max_value, avg_value, value;
	int i;

	avg_value = 0;
	min_value = INT_MAX;
	max_value = INT_MIN;

	for (i = 0; i < AIROHA_MAX_SAMPLES; i++) {
		value = airoha_get_thermal_ADC(priv);
		min_value = min(value, min_value);
		max_value = max(value, max_value);
		avg_value += value;
	}

	/* Drop min and max and average for the remaining sample */
	avg_value -= (min_value + max_value);
	avg_value /= AIROHA_MAX_SAMPLES - 2;

	*temp = RAW_TO_TEMP(priv, avg_value);
	return 0;
}

static int airoha_thermal_set_trips(struct thermal_zone_device *tz, int low,
				    int high)
{
	struct airoha_thermal_priv *priv = thermal_zone_device_priv(tz);
	bool enable_monitor = false;

	if (high != INT_MAX) {
		/* Validate high and clamp it a supported value */
		high = clamp_t(int, high, RAW_TO_TEMP(priv, 0),
			       RAW_TO_TEMP(priv, FIELD_MAX(EN7581_DOUT_TADC_MASK)));

		/* We offset the high temp of 1°C to trigger correct event */
		writel(TEMP_TO_RAW(priv, high) >> 4,
		       priv->base + EN7581_TEMPOFFSETH);

		enable_monitor = true;
	}

	if (low != -INT_MAX) {
		/* Validate low and clamp it to a supported value */
		low = clamp_t(int, high, RAW_TO_TEMP(priv, 0),
			      RAW_TO_TEMP(priv, FIELD_MAX(EN7581_DOUT_TADC_MASK)));

		/* We offset the low temp of 1°C to trigger correct event */
		writel(TEMP_TO_RAW(priv, low) >> 4,
		       priv->base + EN7581_TEMPOFFSETL);

		enable_monitor = true;
	}

	/* Enable sensor 0 monitor after trip are set */
	if (enable_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;
	bool update = false;
	u32 status;

	status = readl(priv->base + EN7581_TEMPMONINTSTS);
	switch (status & (EN7581_HOFSINTSTS0 | EN7581_LOFSINTSTS0)) {
	case EN7581_HOFSINTSTS0:
		event = THERMAL_TRIP_VIOLATED;
		update = true;
		break;
	case EN7581_LOFSINTSTS0:
		event = THERMAL_EVENT_UNSPECIFIED;
		update = true;
		break;
	default:
		/* Should be impossible as we enable only these Interrupt */
		break;
	}

	/* Reset Interrupt */
	writel(status, priv->base + EN7581_TEMPMONINTSTS);

	if (update)
		thermal_zone_device_update(priv->tz, event);

	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 calibration 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 various
	 * addresses 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 sensors from the same ADC that can be
	 * switched by tuning the ADC mux or writing 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);

	/* 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, 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);
	}

	platform_set_drvdata(pdev, priv);

	/* Enable LOW and HIGH interrupt */
	writel(EN7581_HOFSINTEN0 | EN7581_LOFSINTEN0,
	       priv->base + EN7581_TEMPMONINT);

	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");