drivers/thermal/tegra_soctherm.c - linux - Git at Google

 /*
  * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
  *
  * Author:
  *	Mikko Perttunen <mperttunen@nvidia.com>
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * 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/bitops.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
 #include <linux/thermal.h>

 #include <soc/tegra/fuse.h>

 #define SENSOR_CONFIG0				0
 #define SENSOR_CONFIG0_STOP			BIT(0)
 #define SENSOR_CONFIG0_TALL_SHIFT		8
 #define SENSOR_CONFIG0_TCALC_OVER		BIT(4)
 #define SENSOR_CONFIG0_OVER			BIT(3)
 #define SENSOR_CONFIG0_CPTR_OVER		BIT(2)

 #define SENSOR_CONFIG1				4
 #define SENSOR_CONFIG1_TSAMPLE_SHIFT		0
 #define SENSOR_CONFIG1_TIDDQ_EN_SHIFT		15
 #define SENSOR_CONFIG1_TEN_COUNT_SHIFT		24
 #define SENSOR_CONFIG1_TEMP_ENABLE		BIT(31)

 #define SENSOR_CONFIG2				8
 #define SENSOR_CONFIG2_THERMA_SHIFT		16
 #define SENSOR_CONFIG2_THERMB_SHIFT		0

 #define SENSOR_PDIV				0x1c0
 #define SENSOR_PDIV_T124			0x8888
 #define SENSOR_HOTSPOT_OFF			0x1c4
 #define SENSOR_HOTSPOT_OFF_T124			0x00060600
 #define SENSOR_TEMP1				0x1c8
 #define SENSOR_TEMP2				0x1cc

 #define SENSOR_TEMP_MASK			0xffff
 #define READBACK_VALUE_MASK			0xff00
 #define READBACK_VALUE_SHIFT			8
 #define READBACK_ADD_HALF			BIT(7)
 #define READBACK_NEGATE				BIT(0)

 #define FUSE_TSENSOR8_CALIB			0x180
 #define FUSE_SPARE_REALIGNMENT_REG_0		0x1fc

 #define FUSE_TSENSOR_CALIB_CP_TS_BASE_MASK	0x1fff
 #define FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK	(0x1fff << 13)
 #define FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT	13

 #define FUSE_TSENSOR8_CALIB_CP_TS_BASE_MASK	0x3ff
 #define FUSE_TSENSOR8_CALIB_FT_TS_BASE_MASK	(0x7ff << 10)
 #define FUSE_TSENSOR8_CALIB_FT_TS_BASE_SHIFT	10

 #define FUSE_SPARE_REALIGNMENT_REG_SHIFT_CP_MASK 0x3f
 #define FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_MASK (0x1f << 21)
 #define FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_SHIFT 21

 #define NOMINAL_CALIB_FT_T124			105
 #define NOMINAL_CALIB_CP_T124			25

 struct tegra_tsensor_configuration {
 	u32 tall, tsample, tiddq_en, ten_count, pdiv, tsample_ate, pdiv_ate;
 };

 struct tegra_tsensor {
 	const struct tegra_tsensor_configuration *config;
 	u32 base, calib_fuse_offset;
 	/* Correction values used to modify values read from calibration fuses */
 	s32 fuse_corr_alpha, fuse_corr_beta;
 };

 struct tegra_thermctl_zone {
 	void __iomem *reg;
 	unsigned int shift;
 };

 static const struct tegra_tsensor_configuration t124_tsensor_config = {
 	.tall = 16300,
 	.tsample = 120,
 	.tiddq_en = 1,
 	.ten_count = 1,
 	.pdiv = 8,
 	.tsample_ate = 480,
 	.pdiv_ate = 8
 };

 static const struct tegra_tsensor t124_tsensors[] = {
 	{
 		.config = &t124_tsensor_config,
 		.base = 0xc0,
 		.calib_fuse_offset = 0x098,
 		.fuse_corr_alpha = 1135400,
 		.fuse_corr_beta = -6266900,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0xe0,
 		.calib_fuse_offset = 0x084,
 		.fuse_corr_alpha = 1122220,
 		.fuse_corr_beta = -5700700,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0x100,
 		.calib_fuse_offset = 0x088,
 		.fuse_corr_alpha = 1127000,
 		.fuse_corr_beta = -6768200,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0x120,
 		.calib_fuse_offset = 0x12c,
 		.fuse_corr_alpha = 1110900,
 		.fuse_corr_beta = -6232000,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0x140,
 		.calib_fuse_offset = 0x158,
 		.fuse_corr_alpha = 1122300,
 		.fuse_corr_beta = -5936400,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0x160,
 		.calib_fuse_offset = 0x15c,
 		.fuse_corr_alpha = 1145700,
 		.fuse_corr_beta = -7124600,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0x180,
 		.calib_fuse_offset = 0x154,
 		.fuse_corr_alpha = 1120100,
 		.fuse_corr_beta = -6000500,
 	},
 	{
 		.config = &t124_tsensor_config,
 		.base = 0x1a0,
 		.calib_fuse_offset = 0x160,
 		.fuse_corr_alpha = 1106500,
 		.fuse_corr_beta = -6729300,
 	},
 };

 struct tegra_soctherm {
 	struct reset_control *reset;
 	struct clk *clock_tsensor;
 	struct clk *clock_soctherm;
 	void __iomem *regs;

 	struct thermal_zone_device *thermctl_tzs[4];
 };

 struct tsensor_shared_calibration {
 	u32 base_cp, base_ft;
 	u32 actual_temp_cp, actual_temp_ft;
 };

 static int calculate_shared_calibration(struct tsensor_shared_calibration *r)
 {
 	u32 val, shifted_cp, shifted_ft;
 	int err;

 	err = tegra_fuse_readl(FUSE_TSENSOR8_CALIB, &val);
 	if (err)
 		return err;
 	r->base_cp = val & FUSE_TSENSOR8_CALIB_CP_TS_BASE_MASK;
 	r->base_ft = (val & FUSE_TSENSOR8_CALIB_FT_TS_BASE_MASK)
 		>> FUSE_TSENSOR8_CALIB_FT_TS_BASE_SHIFT;
 	val = ((val & FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_MASK)
 		>> FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_SHIFT);
 	shifted_ft = sign_extend32(val, 4);

 	err = tegra_fuse_readl(FUSE_SPARE_REALIGNMENT_REG_0, &val);
 	if (err)
 		return err;
 	shifted_cp = sign_extend32(val, 5);

 	r->actual_temp_cp = 2 * NOMINAL_CALIB_CP_T124 + shifted_cp;
 	r->actual_temp_ft = 2 * NOMINAL_CALIB_FT_T124 + shifted_ft;

 	return 0;
 }

 static s64 div64_s64_precise(s64 a, s64 b)
 {
 	s64 r, al;

 	/* Scale up for increased precision division */
 	al = a << 16;

 	r = div64_s64(al * 2 + 1, 2 * b);
 	return r >> 16;
 }

 static int
 calculate_tsensor_calibration(const struct tegra_tsensor *sensor,
 			      const struct tsensor_shared_calibration *shared,
 			      u32 *calib)
 {
 	u32 val;
 	s32 actual_tsensor_ft, actual_tsensor_cp, delta_sens, delta_temp,
 	    mult, div;
 	s16 therma, thermb;
 	s64 tmp;
 	int err;

 	err = tegra_fuse_readl(sensor->calib_fuse_offset, &val);
 	if (err)
 		return err;

 	actual_tsensor_cp = (shared->base_cp * 64) + sign_extend32(val, 12);
 	val = (val & FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK)
 		>> FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT;
 	actual_tsensor_ft = (shared->base_ft * 32) + sign_extend32(val, 12);

 	delta_sens = actual_tsensor_ft - actual_tsensor_cp;
 	delta_temp = shared->actual_temp_ft - shared->actual_temp_cp;

 	mult = sensor->config->pdiv * sensor->config->tsample_ate;
 	div = sensor->config->tsample * sensor->config->pdiv_ate;

 	therma = div64_s64_precise((s64) delta_temp * (1LL << 13) * mult,
 				   (s64) delta_sens * div);

 	tmp = (s64)actual_tsensor_ft * shared->actual_temp_cp -
 	      (s64)actual_tsensor_cp * shared->actual_temp_ft;
 	thermb = div64_s64_precise(tmp, (s64)delta_sens);

 	therma = div64_s64_precise((s64)therma * sensor->fuse_corr_alpha,
 				   (s64)1000000LL);
 	thermb = div64_s64_precise((s64)thermb * sensor->fuse_corr_alpha +
 				   sensor->fuse_corr_beta, (s64)1000000LL);

 	*calib = ((u16)therma << SENSOR_CONFIG2_THERMA_SHIFT) |
 		 ((u16)thermb << SENSOR_CONFIG2_THERMB_SHIFT);

 	return 0;
 }

 static int enable_tsensor(struct tegra_soctherm *tegra,
 			  const struct tegra_tsensor *sensor,
 			  const struct tsensor_shared_calibration *shared)
 {
 	void __iomem *base = tegra->regs + sensor->base;
 	unsigned int val;
 	u32 calib;
 	int err;

 	err = calculate_tsensor_calibration(sensor, shared, &calib);
 	if (err)
 		return err;

 	val = sensor->config->tall << SENSOR_CONFIG0_TALL_SHIFT;
 	writel(val, base + SENSOR_CONFIG0);

 	val  = (sensor->config->tsample - 1) << SENSOR_CONFIG1_TSAMPLE_SHIFT;
 	val |= sensor->config->tiddq_en << SENSOR_CONFIG1_TIDDQ_EN_SHIFT;
 	val |= sensor->config->ten_count << SENSOR_CONFIG1_TEN_COUNT_SHIFT;
 	val |= SENSOR_CONFIG1_TEMP_ENABLE;
 	writel(val, base + SENSOR_CONFIG1);

 	writel(calib, base + SENSOR_CONFIG2);

 	return 0;
 }

 /*
  * Translate from soctherm readback format to millicelsius.
  * The soctherm readback format in bits is as follows:
  *   TTTTTTTT H______N
  * where T's contain the temperature in Celsius,
  * H denotes an addition of 0.5 Celsius and N denotes negation
  * of the final value.
  */
 static int translate_temp(u16 val)
 {
 	long t;

 	t = ((val & READBACK_VALUE_MASK) >> READBACK_VALUE_SHIFT) * 1000;
 	if (val & READBACK_ADD_HALF)
 		t += 500;
 	if (val & READBACK_NEGATE)
 		t *= -1;

 	return t;
 }

 static int tegra_thermctl_get_temp(void *data, int *out_temp)
 {
 	struct tegra_thermctl_zone *zone = data;
 	u32 val;

 	val = (readl(zone->reg) >> zone->shift) & SENSOR_TEMP_MASK;
 	*out_temp = translate_temp(val);

 	return 0;
 }

 static const struct thermal_zone_of_device_ops tegra_of_thermal_ops = {
 	.get_temp = tegra_thermctl_get_temp,
 };

 static const struct of_device_id tegra_soctherm_of_match[] = {
 	{ .compatible = "nvidia,tegra124-soctherm" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, tegra_soctherm_of_match);

 struct thermctl_zone_desc {
 	unsigned int offset;
 	unsigned int shift;
 };

 static const struct thermctl_zone_desc t124_thermctl_temp_zones[] = {
 	{ SENSOR_TEMP1, 16 },
 	{ SENSOR_TEMP2, 16 },
 	{ SENSOR_TEMP1, 0 },
 	{ SENSOR_TEMP2, 0 }
 };

 static int tegra_soctherm_probe(struct platform_device *pdev)
 {
 	struct tegra_soctherm *tegra;
 	struct thermal_zone_device *tz;
 	struct tsensor_shared_calibration shared_calib;
 	struct resource *res;
 	unsigned int i;
 	int err;

 	const struct tegra_tsensor *tsensors = t124_tsensors;

 	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
 	if (!tegra)
 		return -ENOMEM;

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(tegra->regs))
 		return PTR_ERR(tegra->regs);

 	tegra->reset = devm_reset_control_get(&pdev->dev, "soctherm");
 	if (IS_ERR(tegra->reset)) {
 		dev_err(&pdev->dev, "can't get soctherm reset\n");
 		return PTR_ERR(tegra->reset);
 	}

 	tegra->clock_tsensor = devm_clk_get(&pdev->dev, "tsensor");
 	if (IS_ERR(tegra->clock_tsensor)) {
 		dev_err(&pdev->dev, "can't get tsensor clock\n");
 		return PTR_ERR(tegra->clock_tsensor);
 	}

 	tegra->clock_soctherm = devm_clk_get(&pdev->dev, "soctherm");
 	if (IS_ERR(tegra->clock_soctherm)) {
 		dev_err(&pdev->dev, "can't get soctherm clock\n");
 		return PTR_ERR(tegra->clock_soctherm);
 	}

 	reset_control_assert(tegra->reset);

 	err = clk_prepare_enable(tegra->clock_soctherm);
 	if (err)
 		return err;

 	err = clk_prepare_enable(tegra->clock_tsensor);
 	if (err) {
 		clk_disable_unprepare(tegra->clock_soctherm);
 		return err;
 	}

 	reset_control_deassert(tegra->reset);

 	/* Initialize raw sensors */

 	err = calculate_shared_calibration(&shared_calib);
 	if (err)
 		goto disable_clocks;

 	for (i = 0; i < ARRAY_SIZE(t124_tsensors); ++i) {
 		err = enable_tsensor(tegra, tsensors + i, &shared_calib);
 		if (err)
 			goto disable_clocks;
 	}

 	writel(SENSOR_PDIV_T124, tegra->regs + SENSOR_PDIV);
 	writel(SENSOR_HOTSPOT_OFF_T124, tegra->regs + SENSOR_HOTSPOT_OFF);

 	/* Initialize thermctl sensors */

 	for (i = 0; i < ARRAY_SIZE(tegra->thermctl_tzs); ++i) {
 		struct tegra_thermctl_zone *zone =
 			devm_kzalloc(&pdev->dev, sizeof(*zone), GFP_KERNEL);
 		if (!zone) {
 			err = -ENOMEM;
 			goto unregister_tzs;
 		}

 		zone->reg = tegra->regs + t124_thermctl_temp_zones[i].offset;
 		zone->shift = t124_thermctl_temp_zones[i].shift;

 		tz = thermal_zone_of_sensor_register(&pdev->dev, i, zone,
 						     &tegra_of_thermal_ops);
 		if (IS_ERR(tz)) {
 			err = PTR_ERR(tz);
 			dev_err(&pdev->dev, "failed to register sensor: %d\n",
 				err);
 			goto unregister_tzs;
 		}

 		tegra->thermctl_tzs[i] = tz;
 	}

 	return 0;

 unregister_tzs:
 	while (i--)
 		thermal_zone_of_sensor_unregister(&pdev->dev,
 						  tegra->thermctl_tzs[i]);

 disable_clocks:
 	clk_disable_unprepare(tegra->clock_tsensor);
 	clk_disable_unprepare(tegra->clock_soctherm);

 	return err;
 }

 static int tegra_soctherm_remove(struct platform_device *pdev)
 {
 	struct tegra_soctherm *tegra = platform_get_drvdata(pdev);
 	unsigned int i;

 	for (i = 0; i < ARRAY_SIZE(tegra->thermctl_tzs); ++i) {
 		thermal_zone_of_sensor_unregister(&pdev->dev,
 						  tegra->thermctl_tzs[i]);
 	}

 	clk_disable_unprepare(tegra->clock_tsensor);
 	clk_disable_unprepare(tegra->clock_soctherm);

 	return 0;
 }

 static struct platform_driver tegra_soctherm_driver = {
 	.probe = tegra_soctherm_probe,
 	.remove = tegra_soctherm_remove,
 	.driver = {
 		.name = "tegra-soctherm",
 		.of_match_table = tegra_soctherm_of_match,
 	},
 };
 module_platform_driver(tegra_soctherm_driver);

 MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
 MODULE_DESCRIPTION("NVIDIA Tegra SOCTHERM thermal management driver");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (c) 2014, NVIDIA CORPORATION. All rights reserved.
	*
	* Author:
	* Mikko Perttunen <mperttunen@nvidia.com>
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* 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/bitops.h>
	#include <linux/clk.h>
	#include <linux/delay.h>
	#include <linux/err.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/reset.h>
	#include <linux/thermal.h>

	#include <soc/tegra/fuse.h>

	#define SENSOR_CONFIG0 0
	#define SENSOR_CONFIG0_STOP BIT(0)
	#define SENSOR_CONFIG0_TALL_SHIFT 8
	#define SENSOR_CONFIG0_TCALC_OVER BIT(4)
	#define SENSOR_CONFIG0_OVER BIT(3)
	#define SENSOR_CONFIG0_CPTR_OVER BIT(2)

	#define SENSOR_CONFIG1 4
	#define SENSOR_CONFIG1_TSAMPLE_SHIFT 0
	#define SENSOR_CONFIG1_TIDDQ_EN_SHIFT 15
	#define SENSOR_CONFIG1_TEN_COUNT_SHIFT 24
	#define SENSOR_CONFIG1_TEMP_ENABLE BIT(31)

	#define SENSOR_CONFIG2 8
	#define SENSOR_CONFIG2_THERMA_SHIFT 16
	#define SENSOR_CONFIG2_THERMB_SHIFT 0

	#define SENSOR_PDIV 0x1c0
	#define SENSOR_PDIV_T124 0x8888
	#define SENSOR_HOTSPOT_OFF 0x1c4
	#define SENSOR_HOTSPOT_OFF_T124 0x00060600
	#define SENSOR_TEMP1 0x1c8
	#define SENSOR_TEMP2 0x1cc

	#define SENSOR_TEMP_MASK 0xffff
	#define READBACK_VALUE_MASK 0xff00
	#define READBACK_VALUE_SHIFT 8
	#define READBACK_ADD_HALF BIT(7)
	#define READBACK_NEGATE BIT(0)

	#define FUSE_TSENSOR8_CALIB 0x180
	#define FUSE_SPARE_REALIGNMENT_REG_0 0x1fc

	#define FUSE_TSENSOR_CALIB_CP_TS_BASE_MASK 0x1fff
	#define FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK (0x1fff << 13)
	#define FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT 13

	#define FUSE_TSENSOR8_CALIB_CP_TS_BASE_MASK 0x3ff
	#define FUSE_TSENSOR8_CALIB_FT_TS_BASE_MASK (0x7ff << 10)
	#define FUSE_TSENSOR8_CALIB_FT_TS_BASE_SHIFT 10

	#define FUSE_SPARE_REALIGNMENT_REG_SHIFT_CP_MASK 0x3f
	#define FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_MASK (0x1f << 21)
	#define FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_SHIFT 21

	#define NOMINAL_CALIB_FT_T124 105
	#define NOMINAL_CALIB_CP_T124 25

	struct tegra_tsensor_configuration {
	u32 tall, tsample, tiddq_en, ten_count, pdiv, tsample_ate, pdiv_ate;
	};

	struct tegra_tsensor {
	const struct tegra_tsensor_configuration *config;
	u32 base, calib_fuse_offset;
	/* Correction values used to modify values read from calibration fuses */
	s32 fuse_corr_alpha, fuse_corr_beta;
	};

	struct tegra_thermctl_zone {
	void __iomem *reg;
	unsigned int shift;
	};

	static const struct tegra_tsensor_configuration t124_tsensor_config = {
	.tall = 16300,
	.tsample = 120,
	.tiddq_en = 1,
	.ten_count = 1,
	.pdiv = 8,
	.tsample_ate = 480,
	.pdiv_ate = 8
	};

	static const struct tegra_tsensor t124_tsensors[] = {
	{
	.config = &t124_tsensor_config,
	.base = 0xc0,
	.calib_fuse_offset = 0x098,
	.fuse_corr_alpha = 1135400,
	.fuse_corr_beta = -6266900,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0xe0,
	.calib_fuse_offset = 0x084,
	.fuse_corr_alpha = 1122220,
	.fuse_corr_beta = -5700700,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0x100,
	.calib_fuse_offset = 0x088,
	.fuse_corr_alpha = 1127000,
	.fuse_corr_beta = -6768200,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0x120,
	.calib_fuse_offset = 0x12c,
	.fuse_corr_alpha = 1110900,
	.fuse_corr_beta = -6232000,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0x140,
	.calib_fuse_offset = 0x158,
	.fuse_corr_alpha = 1122300,
	.fuse_corr_beta = -5936400,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0x160,
	.calib_fuse_offset = 0x15c,
	.fuse_corr_alpha = 1145700,
	.fuse_corr_beta = -7124600,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0x180,
	.calib_fuse_offset = 0x154,
	.fuse_corr_alpha = 1120100,
	.fuse_corr_beta = -6000500,
	},
	{
	.config = &t124_tsensor_config,
	.base = 0x1a0,
	.calib_fuse_offset = 0x160,
	.fuse_corr_alpha = 1106500,
	.fuse_corr_beta = -6729300,
	},
	};

	struct tegra_soctherm {
	struct reset_control *reset;
	struct clk *clock_tsensor;
	struct clk *clock_soctherm;
	void __iomem *regs;

	struct thermal_zone_device *thermctl_tzs[4];
	};

	struct tsensor_shared_calibration {
	u32 base_cp, base_ft;
	u32 actual_temp_cp, actual_temp_ft;
	};

	static int calculate_shared_calibration(struct tsensor_shared_calibration *r)
	{
	u32 val, shifted_cp, shifted_ft;
	int err;

	err = tegra_fuse_readl(FUSE_TSENSOR8_CALIB, &val);
	if (err)
	return err;
	r->base_cp = val & FUSE_TSENSOR8_CALIB_CP_TS_BASE_MASK;
	r->base_ft = (val & FUSE_TSENSOR8_CALIB_FT_TS_BASE_MASK)
	>> FUSE_TSENSOR8_CALIB_FT_TS_BASE_SHIFT;
	val = ((val & FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_MASK)
	>> FUSE_SPARE_REALIGNMENT_REG_SHIFT_FT_SHIFT);
	shifted_ft = sign_extend32(val, 4);

	err = tegra_fuse_readl(FUSE_SPARE_REALIGNMENT_REG_0, &val);
	if (err)
	return err;
	shifted_cp = sign_extend32(val, 5);

	r->actual_temp_cp = 2 * NOMINAL_CALIB_CP_T124 + shifted_cp;
	r->actual_temp_ft = 2 * NOMINAL_CALIB_FT_T124 + shifted_ft;

	return 0;
	}

	static s64 div64_s64_precise(s64 a, s64 b)
	{
	s64 r, al;

	/* Scale up for increased precision division */
	al = a << 16;

	r = div64_s64(al * 2 + 1, 2 * b);
	return r >> 16;
	}

	static int
	calculate_tsensor_calibration(const struct tegra_tsensor *sensor,
	const struct tsensor_shared_calibration *shared,
	u32 *calib)
	{
	u32 val;
	s32 actual_tsensor_ft, actual_tsensor_cp, delta_sens, delta_temp,
	mult, div;
	s16 therma, thermb;
	s64 tmp;
	int err;

	err = tegra_fuse_readl(sensor->calib_fuse_offset, &val);
	if (err)
	return err;

	actual_tsensor_cp = (shared->base_cp * 64) + sign_extend32(val, 12);
	val = (val & FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK)
	>> FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT;
	actual_tsensor_ft = (shared->base_ft * 32) + sign_extend32(val, 12);

	delta_sens = actual_tsensor_ft - actual_tsensor_cp;
	delta_temp = shared->actual_temp_ft - shared->actual_temp_cp;

	mult = sensor->config->pdiv * sensor->config->tsample_ate;
	div = sensor->config->tsample * sensor->config->pdiv_ate;

	therma = div64_s64_precise((s64) delta_temp * (1LL << 13) * mult,
	(s64) delta_sens * div);

	tmp = (s64)actual_tsensor_ft * shared->actual_temp_cp -
	(s64)actual_tsensor_cp * shared->actual_temp_ft;
	thermb = div64_s64_precise(tmp, (s64)delta_sens);

	therma = div64_s64_precise((s64)therma * sensor->fuse_corr_alpha,
	(s64)1000000LL);
	thermb = div64_s64_precise((s64)thermb * sensor->fuse_corr_alpha +
	sensor->fuse_corr_beta, (s64)1000000LL);

	*calib = ((u16)therma << SENSOR_CONFIG2_THERMA_SHIFT) \|
	((u16)thermb << SENSOR_CONFIG2_THERMB_SHIFT);

	return 0;
	}

	static int enable_tsensor(struct tegra_soctherm *tegra,
	const struct tegra_tsensor *sensor,
	const struct tsensor_shared_calibration *shared)
	{
	void __iomem *base = tegra->regs + sensor->base;
	unsigned int val;
	u32 calib;
	int err;

	err = calculate_tsensor_calibration(sensor, shared, &calib);
	if (err)
	return err;

	val = sensor->config->tall << SENSOR_CONFIG0_TALL_SHIFT;
	writel(val, base + SENSOR_CONFIG0);

	val = (sensor->config->tsample - 1) << SENSOR_CONFIG1_TSAMPLE_SHIFT;
	val \|= sensor->config->tiddq_en << SENSOR_CONFIG1_TIDDQ_EN_SHIFT;
	val \|= sensor->config->ten_count << SENSOR_CONFIG1_TEN_COUNT_SHIFT;
	val \|= SENSOR_CONFIG1_TEMP_ENABLE;
	writel(val, base + SENSOR_CONFIG1);

	writel(calib, base + SENSOR_CONFIG2);

	return 0;
	}

	/*
	* Translate from soctherm readback format to millicelsius.
	* The soctherm readback format in bits is as follows:
	* TTTTTTTT H______N
	* where T's contain the temperature in Celsius,
	* H denotes an addition of 0.5 Celsius and N denotes negation
	* of the final value.
	*/
	static int translate_temp(u16 val)
	{
	long t;

	t = ((val & READBACK_VALUE_MASK) >> READBACK_VALUE_SHIFT) * 1000;
	if (val & READBACK_ADD_HALF)
	t += 500;
	if (val & READBACK_NEGATE)
	t *= -1;

	return t;
	}

	static int tegra_thermctl_get_temp(void data, int out_temp)
	{
	struct tegra_thermctl_zone *zone = data;
	u32 val;

	val = (readl(zone->reg) >> zone->shift) & SENSOR_TEMP_MASK;
	*out_temp = translate_temp(val);

	return 0;
	}

	static const struct thermal_zone_of_device_ops tegra_of_thermal_ops = {
	.get_temp = tegra_thermctl_get_temp,
	};

	static const struct of_device_id tegra_soctherm_of_match[] = {
	{ .compatible = "nvidia,tegra124-soctherm" },
	{ },
	};
	MODULE_DEVICE_TABLE(of, tegra_soctherm_of_match);

	struct thermctl_zone_desc {
	unsigned int offset;
	unsigned int shift;
	};

	static const struct thermctl_zone_desc t124_thermctl_temp_zones[] = {
	{ SENSOR_TEMP1, 16 },
	{ SENSOR_TEMP2, 16 },
	{ SENSOR_TEMP1, 0 },
	{ SENSOR_TEMP2, 0 }
	};

	static int tegra_soctherm_probe(struct platform_device *pdev)
	{
	struct tegra_soctherm *tegra;
	struct thermal_zone_device *tz;
	struct tsensor_shared_calibration shared_calib;
	struct resource *res;
	unsigned int i;
	int err;

	const struct tegra_tsensor *tsensors = t124_tsensors;

	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
	if (!tegra)
	return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	tegra->regs = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(tegra->regs))
	return PTR_ERR(tegra->regs);

	tegra->reset = devm_reset_control_get(&pdev->dev, "soctherm");
	if (IS_ERR(tegra->reset)) {
	dev_err(&pdev->dev, "can't get soctherm reset\n");
	return PTR_ERR(tegra->reset);
	}

	tegra->clock_tsensor = devm_clk_get(&pdev->dev, "tsensor");
	if (IS_ERR(tegra->clock_tsensor)) {
	dev_err(&pdev->dev, "can't get tsensor clock\n");
	return PTR_ERR(tegra->clock_tsensor);
	}

	tegra->clock_soctherm = devm_clk_get(&pdev->dev, "soctherm");
	if (IS_ERR(tegra->clock_soctherm)) {
	dev_err(&pdev->dev, "can't get soctherm clock\n");
	return PTR_ERR(tegra->clock_soctherm);
	}

	reset_control_assert(tegra->reset);

	err = clk_prepare_enable(tegra->clock_soctherm);
	if (err)
	return err;

	err = clk_prepare_enable(tegra->clock_tsensor);
	if (err) {
	clk_disable_unprepare(tegra->clock_soctherm);
	return err;
	}

	reset_control_deassert(tegra->reset);

	/* Initialize raw sensors */

	err = calculate_shared_calibration(&shared_calib);
	if (err)
	goto disable_clocks;

	for (i = 0; i < ARRAY_SIZE(t124_tsensors); ++i) {
	err = enable_tsensor(tegra, tsensors + i, &shared_calib);
	if (err)
	goto disable_clocks;
	}

	writel(SENSOR_PDIV_T124, tegra->regs + SENSOR_PDIV);
	writel(SENSOR_HOTSPOT_OFF_T124, tegra->regs + SENSOR_HOTSPOT_OFF);

	/* Initialize thermctl sensors */

	for (i = 0; i < ARRAY_SIZE(tegra->thermctl_tzs); ++i) {
	struct tegra_thermctl_zone *zone =
	devm_kzalloc(&pdev->dev, sizeof(*zone), GFP_KERNEL);
	if (!zone) {
	err = -ENOMEM;
	goto unregister_tzs;
	}

	zone->reg = tegra->regs + t124_thermctl_temp_zones[i].offset;
	zone->shift = t124_thermctl_temp_zones[i].shift;

	tz = thermal_zone_of_sensor_register(&pdev->dev, i, zone,
	&tegra_of_thermal_ops);
	if (IS_ERR(tz)) {
	err = PTR_ERR(tz);
	dev_err(&pdev->dev, "failed to register sensor: %d\n",
	err);
	goto unregister_tzs;
	}

	tegra->thermctl_tzs[i] = tz;
	}

	return 0;

	unregister_tzs:
	while (i--)
	thermal_zone_of_sensor_unregister(&pdev->dev,
	tegra->thermctl_tzs[i]);

	disable_clocks:
	clk_disable_unprepare(tegra->clock_tsensor);
	clk_disable_unprepare(tegra->clock_soctherm);

	return err;
	}

	static int tegra_soctherm_remove(struct platform_device *pdev)
	{
	struct tegra_soctherm *tegra = platform_get_drvdata(pdev);
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(tegra->thermctl_tzs); ++i) {
	thermal_zone_of_sensor_unregister(&pdev->dev,
	tegra->thermctl_tzs[i]);
	}

	clk_disable_unprepare(tegra->clock_tsensor);
	clk_disable_unprepare(tegra->clock_soctherm);

	return 0;
	}

	static struct platform_driver tegra_soctherm_driver = {
	.probe = tegra_soctherm_probe,
	.remove = tegra_soctherm_remove,
	.driver = {
	.name = "tegra-soctherm",
	.of_match_table = tegra_soctherm_of_match,
	},
	};
	module_platform_driver(tegra_soctherm_driver);

	MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
	MODULE_DESCRIPTION("NVIDIA Tegra SOCTHERM thermal management driver");
	MODULE_LICENSE("GPL v2");