Message-ID: <20140805135357.GA20458@developer>
Date:	Tue, 5 Aug 2014 09:53:57 -0400
From:	Eduardo Valentin <edubezval@...il.com>
To:	Mikko Perttunen <mperttunen@...dia.com>
Cc:	rui.zhang@...el.com, swarren@...dotorg.org,
	thierry.reding@...il.com, linux-pm@...r.kernel.org,
	linux-tegra@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v2 4/4] thermal: Add Tegra SOCTHERM thermal management
 driver


Hello Mikko,

On Tue, Aug 05, 2014 at 03:18:57PM +0300, Mikko Perttunen wrote:
> This adds support for the Tegra SOCTHERM thermal sensing and management
> system found in the Tegra124 system-on-chip. This initial driver supports
> the four thermal zones with hardware-tracked trip points.
> 
> Signed-off-by: Mikko Perttunen <mperttunen@...dia.com>
> ---
>  drivers/thermal/Kconfig          |   7 +
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/tegra_soctherm.c | 452 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 460 insertions(+)
>  create mode 100644 drivers/thermal/tegra_soctherm.c
> 
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 693208e..6c03119 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -175,6 +175,13 @@ config ARMADA_THERMAL
>  	  Enable this option if you want to have support for thermal management
>  	  controller present in Armada 370 and Armada XP SoC.
>  
> +config TEGRA_SOCTHERM
> +	bool "Tegra SOCTHERM thermal management"

Is it possible to be a tristate?

> +	depends on ARCH_TEGRA
> +	help
> +	  Enable this option for integrated thermal management support on NVIDIA
> +	  Tegra124 systems-on-chip.
> +

Could you please improve the Kconfig help here?

>  config DB8500_CPUFREQ_COOLING
>  	tristate "DB8500 cpufreq cooling"
>  	depends on ARCH_U8500
> diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
> index 31e232f..f0b94d5 100644
> --- a/drivers/thermal/Makefile
> +++ b/drivers/thermal/Makefile
> @@ -33,3 +33,4 @@ obj-$(CONFIG_INTEL_SOC_DTS_THERMAL)	+= intel_soc_dts_thermal.o
>  obj-$(CONFIG_TI_SOC_THERMAL)	+= ti-soc-thermal/
>  obj-$(CONFIG_ACPI_INT3403_THERMAL)	+= int3403_thermal.o
>  obj-$(CONFIG_ST_THERMAL)	+= st/
> +obj-$(CONFIG_TEGRA_SOCTHERM)	+= tegra_soctherm.o
> diff --git a/drivers/thermal/tegra_soctherm.c b/drivers/thermal/tegra_soctherm.c
> new file mode 100644
> index 0000000..962972d
> --- /dev/null
> +++ b/drivers/thermal/tegra_soctherm.c
> @@ -0,0 +1,452 @@
> +/*
> + * drivers/thermal/tegra_soctherm.c
> + *
> + * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
> + *
> + * Author:
> + *	Mikko Perttunen <mperttunen@...dia.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/clk.h>
> +#include <linux/err.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 <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/bitops.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)

I suppose tabulation is intentional to group shits and masks per
registers?

> +#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 FUSE_TSENSOR8_CALIB			0x180
> +#define FUSE_SPARE_REALIGNMENT_REG_0		0x1fc
> +
> +#define NOMINAL_CALIB_FT_T124			105
> +#define NOMINAL_CALIB_CP_T124			25
> +
> +struct tegra_tsensor_configuration {
> +	u32 tall, tsample, tiddq_en, ten_count;
> +	u32 pdiv, tsample_ate, pdiv_ate;
> +};
> +
> +struct tegra_tsensor {
> +	const char *name;
> +	u32 base;
> +	struct tegra_tsensor_configuration *config;
> +	u32 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 *temp_reg;
> +	int temp_shift;
> +};
> +
> +static struct tegra_tsensor_configuration t124_tsensor_config = {
> +	.tall = 16300,
> +	.tsample = 120,
> +	.tiddq_en = 1,
> +	.ten_count = 1,
> +	.pdiv = 8,
> +	.tsample_ate = 481,
> +	.pdiv_ate = 8
> +};

The above struct is probably a const?

> +
> +static struct tegra_tsensor t124_tsensors[] = {
> +	{
> +		.base = 0xc0,
> +		.name = "cpu0",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x098,
> +		.fuse_corr_alpha = 1135400,
> +		.fuse_corr_beta = -6266900,
> +	},
> +	{
> +		.base = 0xe0,
> +		.name = "cpu1",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x084,
> +		.fuse_corr_alpha = 1122220,
> +		.fuse_corr_beta = -5700700,
> +	},
> +	{
> +		.base = 0x100,
> +		.name = "cpu2",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x088,
> +		.fuse_corr_alpha = 1127000,
> +		.fuse_corr_beta = -6768200,
> +	},
> +	{
> +		.base = 0x120,
> +		.name = "cpu3",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x12c,
> +		.fuse_corr_alpha = 1110900,
> +		.fuse_corr_beta = -6232000,
> +	},
> +	{
> +		.base = 0x140,
> +		.name = "mem0",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x158,
> +		.fuse_corr_alpha = 1122300,
> +		.fuse_corr_beta = -5936400,
> +	},
> +	{
> +		.base = 0x160,
> +		.name = "mem1",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x15c,
> +		.fuse_corr_alpha = 1145700,
> +		.fuse_corr_beta = -7124600,
> +	},
> +	{
> +		.base = 0x180,
> +		.name = "gpu",
> +		.config = &t124_tsensor_config,
> +		.calib_fuse_offset = 0x154,
> +		.fuse_corr_alpha = 1120100,
> +		.fuse_corr_beta = -6000500,
> +	},
> +	{
> +		.base = 0x1a0,
> +		.name = "pllx",
> +		.config = &t124_tsensor_config,

The same config is used in all sensors. Why bother creating a pointer to
same struct for every sensor then?

> +		.calib_fuse_offset = 0x160,
> +		.fuse_corr_alpha = 1106500,
> +		.fuse_corr_beta = -6729300,
> +	},
> +	{ .name = NULL },
> +};

Same for the above?

> +
> +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;
> +	u32 shifted_cp, shifted_ft;
> +	int err;
> +
> +	err = tegra_fuse_readl(FUSE_TSENSOR8_CALIB, &val);
> +	if (err)
> +		return err;
> +	r->base_cp = val & 0x3ff;
> +	r->base_ft = (val & (0x7ff << 10)) >> 10;
> +
> +	err = tegra_fuse_readl(FUSE_SPARE_REALIGNMENT_REG_0, &val);
> +	if (err)
> +		return err;
> +	shifted_cp = sign_extend32(val, 5);
> +	val = ((val & (0x1f << 21)) >> 21);
> +	shifted_ft = sign_extend32(val, 4);
> +
> +	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 int calculate_tsensor_calibration(
> +	struct tegra_tsensor *sensor,
> +	struct tsensor_shared_calibration shared,
> +	u32 *calib
> +)
> +{
> +	u32 val;
> +	s32 actual_tsensor_ft, actual_tsensor_cp;
> +	s32 delta_sens, delta_temp;
> +	s32 mult, div;
> +	s16 therma, thermb;
> +	int err;
> +
> +	err = tegra_fuse_readl(sensor->calib_fuse_offset, &val);
> +	if (err)
> +		return err;
> +
> +	/* Sign extend from 13 bits to 32 bits */
> +	actual_tsensor_cp = (shared.base_cp * 64) +
> +		(s32)((val & 0xfff) | ((val & 0x1000) ? 0xfffff000 : 0x0));
> +	val = (val & (0x1fff << 13)) >> 13;
> +	/* Sign extend from 13 bits to 32 bits */
> +	actual_tsensor_ft = (shared.base_ft * 32) +
> +		(s32)((val & 0xfff) | ((val & 0x1000) ? 0xfffff000 : 0x0));

How about having a macro for the above operation?

> +
> +	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 = div_s64((s64) delta_temp * (1LL << 13) * mult,
> +		(s64) delta_sens * div);
> +	thermb = div_s64(((s64) actual_tsensor_ft * shared.actual_temp_cp) -
> +		((s64) actual_tsensor_cp * shared.actual_temp_ft),
> +		(s64) delta_sens);
> +
> +	therma = div_s64((s64) therma * sensor->fuse_corr_alpha,
> +		(s64) 1000000LL);
> +	thermb = div_s64((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,
> +			  struct tegra_tsensor *sensor,
> +			  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 = 0;
> +	val |= sensor->config->tall << SENSOR_CONFIG0_TALL_SHIFT;
> +	writel(val, base + SENSOR_CONFIG0);
> +
> +	val = 0;
> +	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;
> +}
> +
> +static inline long translate_temp(u32 val)
> +{
> +	long t;
> +
> +	t = ((val & 0xff00) >> 8) * 1000;
> +	if (val & 0x80)
> +		t += 500;
> +	if (val & 0x01)
> +		t *= -1;
> +
> +	return t;
> +}
> +
> +static int tegra_thermctl_get_temp(void *data, long *out_temp)
> +{
> +	struct tegra_thermctl_zone *zone = data;
> +	u32 val;
> +
> +	val = (readl(zone->temp_reg) >> zone->temp_shift) & 0xffff;
> +	*out_temp = translate_temp(val);
> +
> +	return 0;
> +}
> +
> +static struct of_device_id tegra_soctherm_of_match[] = {
> +	{ .compatible = "nvidia,tegra124-soctherm" },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, tegra_soctherm_of_match);
> +
> +static int thermctl_temp_offsets[] = {
> +	SENSOR_TEMP1, SENSOR_TEMP2, SENSOR_TEMP1, SENSOR_TEMP2
> +};
> +
> +static int thermctl_temp_shifts[] = {
> +	16, 16, 0, 0
> +};

What are the above offsets and shifts? Are they per sensor? Can they be
part of your sensor data structure (tegra_tsensor_configuration)?

> +
> +static int tegra_soctherm_probe(struct platform_device *pdev)
> +{
> +	struct tegra_soctherm *tegra;
> +	struct thermal_zone_device *tz;
> +	struct tsensor_shared_calibration shared_calib;
> +	int i;
> +	int err = 0;
> +
> +	struct tegra_tsensor *tsensors = t124_tsensors;
> +
> +	tegra = devm_kzalloc(&pdev->dev, sizeof(*tegra), GFP_KERNEL);
> +	if (!tegra)
> +		return -ENOMEM;
> +
> +	tegra->regs = devm_ioremap_resource(&pdev->dev,
> +		platform_get_resource(pdev, IORESOURCE_MEM, 0));
> +	if (IS_ERR(tegra->regs)) {
> +		dev_err(&pdev->dev, "can't get registers");
> +		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 clock tsensor\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 clock soctherm\n");
> +		return PTR_ERR(tegra->clock_soctherm);
> +	}
> +
> +	reset_control_assert(tegra->reset);
> +
> +	err = clk_prepare_enable(tegra->clock_soctherm);
> +	if (err) {
> +		reset_control_deassert(tegra->reset);
> +		return err;
> +	}
> +
> +	err = clk_prepare_enable(tegra->clock_tsensor);
> +	if (err) {
> +		clk_disable_unprepare(tegra->clock_soctherm);
> +		reset_control_deassert(tegra->reset);
> +		return err;
> +	}
> +
> +	reset_control_deassert(tegra->reset);
> +
> +	/* Initialize raw sensors */
> +
> +	err = calculate_shared_calibration(&shared_calib);
> +	if (err)
> +		goto disable_clocks;
> +
> +	for (i = 0; tsensors[i].name; ++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->temp_reg = tegra->regs + thermctl_temp_offsets[i];
> +		zone->temp_shift = thermctl_temp_shifts[i];
> +
> +		tz = thermal_zone_of_sensor_register(
> +			&pdev->dev, i, zone, tegra_thermctl_get_temp, NULL);
> +		if (IS_ERR(tz)) {
> +			err = PTR_ERR(tz);
> +			dev_err(&pdev->dev, "failed to register sensor: %d\n",
> +				err);
> +			--i;
> +			goto unregister_tzs;
> +		}
> +
> +		tegra->thermctl_tzs[i] = tz;
> +	}
> +
> +	return 0;
> +
> +unregister_tzs:
> +	for (; i >= 0; 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);
> +	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,
> +	},


No suspend/resume or pm_runtime support this time?

> +};
> +module_platform_driver(tegra_soctherm_driver);
> +
> +MODULE_AUTHOR("Mikko Perttunen <mperttunen@...dia.com>");
> +MODULE_DESCRIPTION("Tegra SOCTHERM thermal management driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.8.1.5
> 
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