Subject: [PATCH v3 4/4] thermal: Add Tegra SOCTHERM thermal management driver

From: [email-masked] (Eduardo Valentin)
Date: Mon, 11 Aug 2014 09:32:21 -0400

Hello Mikko,

It follows more small comments.

On Wed, Aug 6, 2014 at 6:25 AM, Mikko Perttunen <[email-masked]> wrote:
> This adds support for the Tegra SOCTHERM thermal sensing and management
> system found in the Tegra124 system-on-chip. This initial driver supports
> temperature polling for four thermal zones.
>
> Signed-off-by: Mikko Perttunen <[email-masked]>
> ---
> v3:
> - changed commit message
> - changed bool to tristate
> - added text to Kconfig entry
> - added const to t124_sensor_config
> - removed .name and .config fields
> - use sign_extend32 for sign extension
>
>  drivers/thermal/Kconfig          |  10 +
>  drivers/thermal/Makefile         |   1 +
>  drivers/thermal/tegra_soctherm.c | 430 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 441 insertions(+)
>  create mode 100644 drivers/thermal/tegra_soctherm.c
>
> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
> index 693208e..fd9d049 100644
> --- a/drivers/thermal/Kconfig
> +++ b/drivers/thermal/Kconfig
> @@ -175,6 +175,16 @@ 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
> +       tristate "Tegra SOCTHERM thermal management"
> +       depends on ARCH_TEGRA
> +       help
> +         Enable this option for integrated thermal management support on NVIDIA
> +         Tegra124 systems-on-chip. The driver supports four thermal zones
> +         (CPU, GPU, MEM, PLLX). Cooling devices can be bound to the thermal
> +         zones to manage temperatures. This option is also required for the
> +         emergency thermal reset (thermtrip) feature to function.
> +

Way better now. Thanks for fixing.

>  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..2e5cd88
> --- /dev/null
> +++ b/drivers/thermal/tegra_soctherm.c
> @@ -0,0 +1,430 @@
> +/*
> + * drivers/thermal/tegra_soctherm.c
> + *
> + * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
> + *
> + * Author:
> + *     Mikko Perttunen <[email-masked]>
> + *
> + * 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)
> +#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 {
> +       u32 base;
> +       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 const 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
> +};
> +
> +static struct tegra_tsensor t124_tsensors[] = {

Shouldn't this one be const too?

> +       {
> +               .base = 0xc0,
> +               .calib_fuse_offset = 0x098,
> +               .fuse_corr_alpha = 1135400,
> +               .fuse_corr_beta = -6266900,
> +       },
> +       {
> +               .base = 0xe0,
> +               .calib_fuse_offset = 0x084,
> +               .fuse_corr_alpha = 1122220,
> +               .fuse_corr_beta = -5700700,
> +       },
> +       {
> +               .base = 0x100,
> +               .calib_fuse_offset = 0x088,
> +               .fuse_corr_alpha = 1127000,
> +               .fuse_corr_beta = -6768200,
> +       },
> +       {
> +               .base = 0x120,
> +               .calib_fuse_offset = 0x12c,
> +               .fuse_corr_alpha = 1110900,
> +               .fuse_corr_beta = -6232000,
> +       },
> +       {
> +               .base = 0x140,
> +               .calib_fuse_offset = 0x158,
> +               .fuse_corr_alpha = 1122300,
> +               .fuse_corr_beta = -5936400,
> +       },
> +       {
> +               .base = 0x160,
> +               .calib_fuse_offset = 0x15c,
> +               .fuse_corr_alpha = 1145700,
> +               .fuse_corr_beta = -7124600,
> +       },
> +       {
> +               .base = 0x180,
> +               .calib_fuse_offset = 0x154,
> +               .fuse_corr_alpha = 1120100,
> +               .fuse_corr_beta = -6000500,
> +       },
> +       {
> +               .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];

the amount of thermal zones is const here. Is there any case in which
the board would have a config that has more than 4 or less than 4 zones?

> +};
> +
> +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;

Where these shifts and masks come from?

> +
> +       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);

ditto.

> +       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;
> +
> +       actual_tsensor_cp = (shared.base_cp * 64) + sign_extend32(val, 12);
> +       val = (val & (0x1fff << 13)) >> 13;

ditto.

> +       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 = t124_tsensor_config.pdiv * t124_tsensor_config.tsample_ate;
> +       div = t124_tsensor_config.tsample * t124_tsensor_config.pdiv_ate;
> +
> +       therma = div_s64((s64) delta_temp * (1LL << 13) * mult,

ditto.

> +               (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 |= t124_tsensor_config.tall << SENSOR_CONFIG0_TALL_SHIFT;
> +       writel(val, base + SENSOR_CONFIG0);
> +
> +       val = 0;
> +       val |= (t124_tsensor_config.tsample - 1) <<
> +               SENSOR_CONFIG1_TSAMPLE_SHIFT;
> +       val |= t124_tsensor_config.tiddq_en << SENSOR_CONFIG1_TIDDQ_EN_SHIFT;
> +       val |= t124_tsensor_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)
> +{

It would be kind to have a comment explaining the transformation.

> +       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);

Why the temp_shift is not part of the 'translate_temp' ?

> +
> +       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
> +};

I still missing why the two above cannot be part of
tegra_tsensor_configuration or tegra_tsensor. Would you mind
enlightining me?

> +
> +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; 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->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,
> +       },
> +};
> +module_platform_driver(tegra_soctherm_driver);
> +
> +MODULE_AUTHOR("Mikko Perttunen <[email-masked]>");
> +MODULE_DESCRIPTION("Tegra SOCTHERM thermal management driver");
> +MODULE_LICENSE("GPL v2");
> --
> 1.8.1.5
>

-- 
Eduardo Bezerra Valentin