Message-Id: <1440657677-2890-3-git-send-email-s.hauer@pengutronix.de>
Date:	Thu, 27 Aug 2015 08:41:16 +0200
From:	Sascha Hauer <s.hauer@...gutronix.de>
To:	linux-pm@...r.kernel.org, Zhang Rui <rui.zhang@...el.com>,
	Eduardo Valentin <edubezval@...il.com>
Cc:	linux-kernel@...r.kernel.org, linux-mediatek@...ts.infradead.org,
	Daniel Kurtz <djkurtz@...omium.org>, kernel@...gutronix.de,
	Matthias Brugger <matthias.bgg@...il.com>,
	Sascha Hauer <s.hauer@...gutronix.de>
Subject: [PATCH 2/3] thermal: Add Mediatek thermal controller support

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@...gutronix.de>
Reviewed-by: Daniel Kurtz <djkurtz@...omium.org>
---
 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@...iatek.com>
+ *
+ * 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 (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@...gutronix.de");
+MODULE_DESCRIPTION("Mediatek thermal driver");
+MODULE_LICENSE("GPL v2");
-- 
2.5.0

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