Re: [PATCH 2/3] thermal: Add Mediatek thermal controller support

[Punit Agrawal]

Hi Sascha,

One comment below -

Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> writes:

> This adds support for the Mediatek thermal controller found on MT8173
> and likely other SoCs.
> The controller is a bit special. It does not have its own ADC, instead
> it controls the on-SoC AUXADC via AHB bus accesses. For this reason
> we need the physical address of the AUXADC. Also it controls a mux
> using AHB bus accesses, so we need the APMIXEDSYS physical address aswell.
>
> Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Reviewed-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
> ---
>  drivers/thermal/Kconfig       |   8 +
>  drivers/thermal/Makefile      |   1 +
>  drivers/thermal/mtk_thermal.c | 528 ++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 537 insertions(+)
>  create mode 100644 drivers/thermal/mtk_thermal.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 118938e..07ad114 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -340,6 +340,14 @@ config ACPI_THERMAL_REL
>  	tristate
>  	depends on ACPI
>  
> +config MTK_THERMAL
> +	tristate "Temperature sensor driver for mediatek SoCs"
> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	default y
> +	help
> +	  Enable this option if you want to have support for thermal management
> +	  controller present in Mediatek SoCs
> +
>  menu "Texas Instruments thermal drivers"
>  source "drivers/thermal/ti-soc-thermal/Kconfig"
>  endmenu
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 535dfee..cc1cab3 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -44,3 +44,4 @@ obj-$(CONFIG_INT340X_THERMAL)  += int340x_thermal/
>  obj-$(CONFIG_ST_THERMAL)	+= st/
>  obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
>  obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
> +obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
> diff --git a/drivers/thermal/mtk_thermal.c b/drivers/thermal/mtk_thermal.c
> new file mode 100644
> index 0000000..4f8cd34
> --- /dev/null
> +++ b/drivers/thermal/mtk_thermal.c
> @@ -0,0 +1,528 @@
> +/*
> + * Copyright (c) 2015 MediaTek Inc.
> + * Author: Hanyi Wu <hanyi.wu@xxxxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/thermal.h>
> +#include <linux/reset.h>
> +#include <linux/time.h>
> +#include <linux/types.h>
> +
> +/* AUXADC Registers */
> +#define AUXADC_CON0_V		0x000
> +#define AUXADC_CON1_V		0x004
> +#define AUXADC_CON1_SET_V	0x008
> +#define AUXADC_CON1_CLR_V	0x00c
> +#define AUXADC_CON2_V		0x010
> +#define AUXADC_DATA(channel)	(0x14 + (channel) * 4)
> +#define AUXADC_MISC_V		0x094
> +
> +#define AUXADC_CON1_CHANNEL(x)	BIT(x)
> +
> +#define APMIXED_SYS_TS_CON1	0x604
> +
> +/* Thermal Controller Registers */
> +#define TEMP_MONCTL0		0x000
> +#define TEMP_MONCTL1		0x004
> +#define TEMP_MONCTL2		0x008
> +#define TEMP_MSRCTL0		0x038
> +#define TEMP_AHBPOLL		0x040
> +#define TEMP_AHBTO		0x044
> +#define TEMP_ADCPNP0		0x048
> +#define TEMP_ADCPNP1		0x04c
> +#define TEMP_ADCPNP2		0x050
> +#define TEMP_ADCPNP3		0x0b4
> +
> +#define TEMP_ADCMUX		0x054
> +#define TEMP_ADCEN		0x060
> +#define TEMP_PNPMUXADDR		0x064
> +#define TEMP_ADCMUXADDR		0x068
> +#define TEMP_ADCENADDR		0x074
> +#define TEMP_ADCVALIDADDR	0x078
> +#define TEMP_ADCVOLTADDR	0x07c
> +#define TEMP_RDCTRL		0x080
> +#define TEMP_ADCVALIDMASK	0x084
> +#define TEMP_ADCVOLTAGESHIFT	0x088
> +#define TEMP_ADCWRITECTRL	0x08c
> +#define TEMP_MSR0		0x090
> +#define TEMP_MSR1		0x094
> +#define TEMP_MSR2		0x098
> +#define TEMP_MSR3		0x0B8
> +
> +#define TEMP_SPARE0		0x0f0
> +
> +#define PTPCORESEL		0x400
> +
> +#define TEMP_MONCTL1_PERIOD_UNIT(x)	((x) & 0x3ff)
> +
> +#define TEMP_MONCTL2_FILTER_INTERVAL(x)	(((x) & 0x3ff)) << 16
> +#define TEMP_MONCTL2_SENSOR_INTERVAL(x)	((x) & 0x3ff)
> +
> +#define TEMP_AHBPOLL_ADC_POLL_INTERVAL(x)	(x)
> +
> +#define TEMP_ADCWRITECTRL_ADC_PNP_WRITE		BIT(0)
> +#define TEMP_ADCWRITECTRL_ADC_MUX_WRITE		BIT(1)
> +
> +#define TEMP_ADCVALIDMASK_VALID_HIGH		BIT(5)
> +#define TEMP_ADCVALIDMASK_VALID_POS(bit)	(bit)
> +
> +#define MT8173_TS1	0
> +#define MT8173_TS2	1
> +#define MT8173_TS3	2
> +#define MT8173_TS4	3
> +#define MT8173_TSABB	4
> +
> +/* AUXADC channel 11 is used for the temperature sensors */
> +#define MT8173_TEMP_AUXADC_CHANNEL	11
> +
> +/* The total number of temperature sensors in the MT8173 */
> +#define MT8173_NUM_SENSORS		5
> +
> +/* The number of banks in the MT8173 */
> +#define MT8173_NUM_ZONES		4
> +
> +/* The number of sensing points per bank */
> +#define MT8173_NUM_SENSORS_PER_ZONE	4
> +
> +#define THERMAL_NAME    "mtk-thermal"
> +
> +struct mtk_thermal;
> +
> +struct mtk_thermal_bank {
> +	struct mtk_thermal *mt;
> +	struct thermal_zone_device *tzd;
> +	int id;
> +};
> +
> +struct mtk_thermal {
> +	struct device *dev;
> +	void __iomem *thermal_base;
> +
> +	struct clk *clk_peri_therm;
> +	struct clk *clk_auxadc;
> +
> +	struct mtk_thermal_bank banks[MT8173_NUM_ZONES];
> +
> +	struct mutex lock;
> +
> +	/* Calibration values */
> +	int calib_slope;
> +	int calib_offset;
> +};
> +
> +struct mtk_thermal_bank_cfg {
> +	unsigned int num_sensors;
> +	unsigned int sensors[MT8173_NUM_SENSORS_PER_ZONE];
> +};
> +
> +static const int sensor_mux_values[MT8173_NUM_SENSORS] = { 0, 1, 2, 3, 16 };
> +
> +/*
> + * The MT8173 thermal controller has four banks. Each bank can read up to
> + * four temperature sensors simultaneously. The MT8173 has a total of 5
> + * temperature sensors. We use each bank to measure a certain area of the
> + * SoC. Since TS2 is located centrally in the SoC it is influenced by multiple
> + * areas, hence is used in different banks.
> + */
> +static const struct mtk_thermal_bank_cfg bank_data[] = {
> +	{
> +		.num_sensors = 2,
> +		.sensors = { MT8173_TS2, MT8173_TS3 },
> +	}, {
> +		.num_sensors = 2,
> +		.sensors = { MT8173_TS2, MT8173_TS4 },
> +	}, {
> +		.num_sensors = 3,
> +		.sensors = { MT8173_TS1, MT8173_TS2, MT8173_TSABB },
> +	}, {
> +		.num_sensors = 1,
> +		.sensors = { MT8173_TS2 },
> +	},
> +};
> +
> +struct mtk_thermal_sense_point {
> +	int msr;
> +	int adcpnp;
> +};
> +
> +static const struct mtk_thermal_sense_point
> +		sensing_points[MT8173_NUM_SENSORS_PER_ZONE] = {
> +	{
> +		.msr = TEMP_MSR0,
> +		.adcpnp = TEMP_ADCPNP0,
> +	}, {
> +		.msr = TEMP_MSR1,
> +		.adcpnp = TEMP_ADCPNP1,
> +	}, {
> +		.msr = TEMP_MSR2,
> +		.adcpnp = TEMP_ADCPNP2,
> +	}, {
> +		.msr = TEMP_MSR3,
> +		.adcpnp = TEMP_ADCPNP3,
> +	},
> +};
> +
> +/**
> + * raw_to_mcelsius - convert a raw ADC value to mcelsius
> + * @mt:		The thermal controller
> + * @raw:	raw ADC value
> + *
> + * This converts the raw ADC value to mcelsius using the SoC specific
> + * calibration constants
> + */
> +static int raw_to_mcelsius(struct mtk_thermal *mt, u32 raw)
> +{
> +	return mt->calib_offset + mt->calib_slope * (raw & 0xfff);
> +}
> +
> +/**
> + * mtk_thermal_get_bank - get bank
> + * @bank:	The bank
> + *
> + * The bank registers are banked, we have to select a bank in the
> + * PTPCORESEL register to access it.
> + */
> +static void mtk_thermal_get_bank(struct mtk_thermal_bank *bank)
> +{
> +	struct mtk_thermal *mt = bank->mt;
> +	u32 val;
> +
> +	mutex_lock(&mt->lock);
> +
> +	val = readl(mt->thermal_base + PTPCORESEL);
> +	val &= ~0xf;
> +	val |= bank->id;
> +	writel(val, mt->thermal_base + PTPCORESEL);
> +}
> +
> +/**
> + * mtk_thermal_put_bank - release bank
> + * @bank:	The bank
> + *
> + * release a bank previously taken with mtk_thermal_get_bank,
> + */
> +static void mtk_thermal_put_bank(struct mtk_thermal_bank *bank)
> +{
> +	struct mtk_thermal *mt = bank->mt;
> +
> +	mutex_unlock(&mt->lock);
> +}
> +
> +/**
> + * mtk_thermal_bank_temperature - get the temperature of a bank
> + * @bank:	The bank
> + *
> + * The temperature of a bank is considered the maximum temperature of
> + * the sensors associated to the bank.
> + */
> +static int mtk_thermal_bank_temperature(struct mtk_thermal_bank *bank)
> +{
> +	struct mtk_thermal *mt = bank->mt;
> +	int temp, i, max;
> +	u32 raw;
> +
> +	temp = max = INT_MIN;
> +
> +	for (i = 0; i < bank_data[bank->id].num_sensors; i++) {
> +		raw = readl(mt->thermal_base + sensing_points[i].msr);
> +
> +		temp = raw_to_mcelsius(mt, raw);
> +
> +		/*
> +		 * The first read of a sensor often contains very high bogus
> +		 * temperature value. Filter these out so that the system does
> +		 * not immediately shut down.
> +		 */
> +		if (temp > 200000)
> +			temp = 0;
> +

If the bogus value is one time, Instead of filtering here, you could
sanitise the sensor values at probe time when you are initialising the
banks.

Thanks,
Punit

> +		if (temp > max)
> +			max = temp;
> +	}
> +
> +	return max;
> +}
> +
> +static int mtk_read_temp(void *data, long *temp)
> +{
> +	struct mtk_thermal_bank *bank = data;
> +
> +	mtk_thermal_get_bank(bank);
> +
> +	*temp = mtk_thermal_bank_temperature(bank);
> +
> +	mtk_thermal_put_bank(bank);
> +
> +	return 0;
> +}
> +
> +static const struct thermal_zone_of_device_ops mtk_thermal_ops = {
> +	.get_temp = mtk_read_temp,
> +};
> +
> +static void mtk_thermal_init_bank(struct mtk_thermal *mt, int num,
> +		u32 apmixed_phys_base, u32 auxadc_phys_base)
> +{
> +	struct mtk_thermal_bank *bank = &mt->banks[num];
> +	const struct mtk_thermal_bank_cfg *cfg = &bank_data[num];
> +	int i;
> +
> +	bank->id = num;
> +	bank->mt = mt;
> +
> +	mtk_thermal_get_bank(bank);
> +
> +	/* bus clock 66M counting unit is 12 * 15.15ns * 256 = 46.540us */
> +	writel(TEMP_MONCTL1_PERIOD_UNIT(12), mt->thermal_base + TEMP_MONCTL1);
> +
> +	/*
> +	 * filt interval is 1 * 46.540us = 46.54us,
> +	 * sen interval is 429 * 46.540us = 19.96ms
> +	 */
> +	writel(TEMP_MONCTL2_FILTER_INTERVAL(1) |
> +			TEMP_MONCTL2_SENSOR_INTERVAL(429),
> +			mt->thermal_base + TEMP_MONCTL2);
> +
> +	/* poll is set to 10u */
> +	writel(TEMP_AHBPOLL_ADC_POLL_INTERVAL(768),
> +			mt->thermal_base + TEMP_AHBPOLL);
> +
> +	/* temperature sampling control, 1 sample */
> +	writel(0x00000000, mt->thermal_base + TEMP_MSRCTL0);
> +
> +	/* exceed this polling time, IRQ would be inserted */
> +	writel(0xffffffff, mt->thermal_base + TEMP_AHBTO);
> +
> +	/* number of interrupts per event, 1 is enough */
> +	writel(0x0, mt->thermal_base + TEMP_MONIDET0);
> +	writel(0x0, mt->thermal_base + TEMP_MONIDET1);
> +
> +	/*
> +	 * The MT8173 thermal controller does not have its own ADC. Instead it
> +	 * uses AHB bus accesses to control the AUXADC. To do this the thermal
> +	 * controller has to be programmed with the physical addresses of the
> +	 * AUXADC registers and with the various bit positions in the AUXADC.
> +	 * Also the thermal controller controls a mux in the APMIXEDSYS register
> +	 * space.
> +	 */
> +
> +	/*
> +	 * this value will be stored to TEMP_PNPMUXADDR (TEMP_SPARE0)
> +	 * automatically by hw
> +	 */
> +	writel(BIT(MT8173_TEMP_AUXADC_CHANNEL), mt->thermal_base + TEMP_ADCMUX);
> +
> +	/* AHB address for auxadc mux selection */
> +	writel(auxadc_phys_base + AUXADC_CON1_CLR_V,
> +			mt->thermal_base + TEMP_ADCMUXADDR);
> +
> +	/* AHB address for pnp sensor mux selection */
> +	writel(apmixed_phys_base + APMIXED_SYS_TS_CON1,
> +			mt->thermal_base + TEMP_PNPMUXADDR);
> +
> +	/* AHB value for auxadc enable */
> +	writel(BIT(MT8173_TEMP_AUXADC_CHANNEL), mt->thermal_base + TEMP_ADCEN);
> +
> +	/* AHB address for auxadc enable (channel 0 immediate mode selected) */
> +	writel(auxadc_phys_base + AUXADC_CON1_SET_V,
> +			mt->thermal_base + TEMP_ADCENADDR);
> +
> +	/* AHB address for auxadc valid bit */
> +	writel(auxadc_phys_base + AUXADC_DATA(MT8173_TEMP_AUXADC_CHANNEL),
> +			mt->thermal_base + TEMP_ADCVALIDADDR);
> +
> +	/* AHB address for auxadc voltage output */
> +	writel(auxadc_phys_base + AUXADC_DATA(MT8173_TEMP_AUXADC_CHANNEL),
> +			mt->thermal_base + TEMP_ADCVOLTADDR);
> +
> +	/* read valid & voltage are at the same register */
> +	writel(0x0, mt->thermal_base + TEMP_RDCTRL);
> +
> +	/* indicate where the valid bit is */
> +	writel(TEMP_ADCVALIDMASK_VALID_HIGH | TEMP_ADCVALIDMASK_VALID_POS(12),
> +			mt->thermal_base + TEMP_ADCVALIDMASK);
> +
> +	/* no shift */
> +	writel(0x0, mt->thermal_base + TEMP_ADCVOLTAGESHIFT);
> +
> +	/* enable auxadc mux write transaction */
> +	writel(TEMP_ADCWRITECTRL_ADC_MUX_WRITE,
> +			mt->thermal_base + TEMP_ADCWRITECTRL);
> +
> +	for (i = 0; i < cfg->num_sensors; i++)
> +		writel(sensor_mux_values[cfg->sensors[i]],
> +				mt->thermal_base + sensing_points[i].adcpnp);
> +
> +	writel((1 << cfg->num_sensors) - 1, mt->thermal_base + TEMP_MONCTL0);
> +
> +	writel(TEMP_ADCWRITECTRL_ADC_PNP_WRITE | TEMP_ADCWRITECTRL_ADC_MUX_WRITE,
> +			mt->thermal_base + TEMP_ADCWRITECTRL);
> +
> +	mtk_thermal_put_bank(bank);
> +}
> +
> +static u64 of_get_phys_base(struct device_node *np)
> +{
> +	u64 size64;
> +	const __be32 *regaddr_p;
> +
> +	regaddr_p = of_get_address(np, 0, &size64, NULL);
> +	if (!regaddr_p)
> +		return OF_BAD_ADDR;
> +
> +	return of_translate_address(np, regaddr_p);
> +}
> +
> +static int mtk_thermal_probe(struct platform_device *pdev)
> +{
> +	int ret, i;
> +	struct device_node *auxadc, *apmixedsys, *np = pdev->dev.of_node;
> +	struct mtk_thermal *mt;
> +	struct resource *res;
> +	u64 auxadc_phys_base, apmixed_phys_base;
> +
> +	mt = devm_kzalloc(&pdev->dev, sizeof(*mt), GFP_KERNEL);
> +	if (!mt)
> +		return -ENOMEM;
> +
> +	mt->clk_peri_therm = devm_clk_get(&pdev->dev, "therm");
> +	if (IS_ERR(mt->clk_peri_therm))
> +		return PTR_ERR(mt->clk_peri_therm);
> +
> +	mt->clk_auxadc = devm_clk_get(&pdev->dev, "auxadc");
> +	if (IS_ERR(mt->clk_auxadc))
> +		return PTR_ERR(mt->clk_auxadc);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	mt->thermal_base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(mt->thermal_base))
> +		return PTR_ERR(mt->thermal_base);
> +
> +	mutex_init(&mt->lock);
> +
> +	mt->dev = &pdev->dev;
> +
> +	auxadc = of_parse_phandle(np, "mediatek,auxadc", 0);
> +	if (!auxadc) {
> +		dev_err(&pdev->dev, "missing auxadc node\n");
> +		return -ENODEV;
> +	}
> +
> +	auxadc_phys_base = of_get_phys_base(auxadc);
> +	if (auxadc_phys_base == OF_BAD_ADDR) {
> +		dev_err(&pdev->dev, "Can't get auxadc phys address\n");
> +		return -EINVAL;
> +	}
> +
> +	apmixedsys = of_parse_phandle(np, "mediatek,apmixedsys", 0);
> +	if (!apmixedsys) {
> +		dev_err(&pdev->dev, "missing apmixedsys node\n");
> +		return -ENODEV;
> +	}
> +
> +	apmixed_phys_base = of_get_phys_base(apmixedsys);
> +	if (apmixed_phys_base == OF_BAD_ADDR) {
> +		dev_err(&pdev->dev, "Can't get auxadc phys address\n");
> +		return -EINVAL;
> +	}
> +
> +	ret = clk_prepare_enable(mt->clk_auxadc);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Can't enable auxadc clk: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = device_reset(&pdev->dev);
> +	if (ret)
> +		goto err_disable_clk_auxadc;
> +
> +	ret = clk_prepare_enable(mt->clk_peri_therm);
> +	if (ret) {
> +		dev_err(&pdev->dev, "Can't enable peri clk: %d\n", ret);
> +		goto err_disable_clk_auxadc;
> +	}
> +
> +	/*
> +	 * These calibration values should finally be provided by the
> +	 * firmware or fuses. For now use default values.
> +	 */
> +	mt->calib_slope = -123;
> +	mt->calib_offset = 465124;
> +
> +	for (i = 0; i < MT8173_NUM_ZONES; i++)
> +		mtk_thermal_init_bank(mt, i, apmixed_phys_base, auxadc_phys_base);
> +
> +	platform_set_drvdata(pdev, mt);
> +
> +	for (i = 0; i < MT8173_NUM_ZONES; i++) {
> +		struct mtk_thermal_bank *bank = &mt->banks[i];
> +
> +		bank->tzd = thermal_zone_of_sensor_register(&pdev->dev, i, bank,
> +				&mtk_thermal_ops);
> +	}
> +
> +	return 0;
> +
> +err_disable_clk_auxadc:
> +	clk_disable_unprepare(mt->clk_auxadc);
> +
> +	return ret;
> +}
> +
> +static int mtk_thermal_remove(struct platform_device *pdev)
> +{
> +	struct mtk_thermal *mt = platform_get_drvdata(pdev);
> +	int i;
> +
> +	for (i = 0; i < MT8173_NUM_ZONES; i++) {
> +		struct mtk_thermal_bank *bank = &mt->banks[i];
> +
> +		thermal_zone_of_sensor_unregister(&pdev->dev, bank->tzd);
> +	}
> +
> +	clk_disable_unprepare(mt->clk_peri_therm);
> +	clk_disable_unprepare(mt->clk_auxadc);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id mtk_thermal_of_match[] = {
> +	{
> +		.compatible = "mediatek,mt8173-thermal",
> +	}, {
> +	},
> +};
> +
> +static struct platform_driver mtk_thermal_driver = {
> +	.probe = mtk_thermal_probe,
> +	.remove = mtk_thermal_remove,
> +	.driver = {
> +		.name = THERMAL_NAME,
> +		.of_match_table = mtk_thermal_of_match,
> +	},
> +};
> +
> +module_platform_driver(mtk_thermal_driver);
> +
> +MODULE_AUTHOR("Sascha Hauer <s.hauer@xxxxxxxxxxxxxx");
> +MODULE_DESCRIPTION("Mediatek thermal driver");
> +MODULE_LICENSE("GPL v2");
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