Subject: [PATCH v2 4/4] thermal: Add Tegra SOCTHERM thermal management driver

From: [email-masked] (Mikko Perttunen)
Date: Wed, 6 Aug 2014 10:30:00 +0300

On 05/08/14 16:53, Eduardo Valentin wrote:
>
> 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 <[email-masked]>
>> ---
>>   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?

Yes. I'll change this.

>
>> +     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?

I'll add some text about driver/hw capabilities.

>
>>   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 <[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)
>
> I suppose tabulation is intentional to group shits and masks per
> registers?

Yes.

>
>> +#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?

Indeed. I'll fix it.

>
>> +
>> +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?

Technically you could have differing configs for each sensor. But I 
guess if anyone ever needs it they can add that feature; better to keep 
it simple.

>
>> +             .calib_fuse_offset = 0x160,
>> +             .fuse_corr_alpha = 1106500,
>> +             .fuse_corr_beta = -6729300,
>> +     },
>> +     { .name = NULL },
>> +};
>
> Same for the above?

I'll change this one to use ARRAY_SIZE as well.

>
>> +
>> +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?

Yeah, looks like I missed this spot when making the change to use 
sign_extend32.

>
>> +
>> +     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)?

These are for the thermctl registers, while tsensor_configuration is for 
the 'raw' tsensors which are used internally by the hardware as a data 
source for the thermctl stuff.

>
>> +
>> +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?

Yes. Suspend/resume is not useful yet since we don't yet support LP0. 
The deepest suspend level we support is LP1 which doesn't reset the 
soctherm block. At runtime we should never unclock it anyway, since that
would prevent emergency thermal reset from working.

>
>> +};
>> +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
>>

Thanks, Mikko