[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@pengutronix.de>
Reviewed-by: Daniel Kurtz <redacted>
---
 drivers/thermal/Kconfig       |   8 +
 drivers/thermal/Makefile      |   1 +
 drivers/thermal/mtk_thermal.c | 537 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 546 insertions(+)
 create mode 100644 drivers/thermal/mtk_thermal.c

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 0390044..dadd1eb 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig

@@ -348,6 +348,14 @@ config INTEL_PCH_THERMAL
 	  Thermal reporting device will provide temperature reading,
 	  programmable trip points and other information.
 
+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 26f1608..5f979e7 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile

@@ -45,3 +45,4 @@ obj-$(CONFIG_INTEL_PCH_THERMAL)	+= intel_pch_thermal.o
 obj-$(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..6be1a6c
--- /dev/null
+++ b/drivers/thermal/mtk_thermal.c

@@ -0,0 +1,537 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author: Hanyi Wu <hanyi.wu@mediatek.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>
+#include <dt-bindings/thermal/mt8173.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_MONIDET0		0x014
+#define TEMP_MONIDET1		0x018
+#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[] = {
+	[MT8173_THERMAL_ZONE_CA53] = {
+		.num_sensors = 2,
+		.sensors = { MT8173_TS2, MT8173_TS3 },
+	},
+
+	[MT8173_THERMAL_ZONE_CA57] = {
+		.num_sensors = 2,
+		.sensors = { MT8173_TS2, MT8173_TS4 },
+	},
+
+	[MT8173_THERMAL_ZONE_GPU] = {
+		.num_sensors = 3,
+		.sensors = { MT8173_TS1, MT8173_TS2, MT8173_TSABB },
+	},
+
+	[MT8173_THERMAL_ZONE_CORE] = {
+		.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;
+