Subject: Re: [PATCH V3] thermal: qoriq: Add thermal management support

From: Eduardo Valentin <[email-masked]>
Date: Wed, 4 Nov 2015 11:24:46 -0800

On Fri, Sep 25, 2015 at 03:09:42AM +0000, Hongtao Jia wrote:
> 
> > -----Original Message-----
> > From: Wood Scott-B07421
> > Sent: Friday, September 25, 2015 6:10 AM
> > To: Jia Hongtao-B38951
> > Cc: [email-masked]; [email-masked]; linuxppc-
> > [email-masked]
> > Subject: Re: [PATCH V3] thermal: qoriq: Add thermal management support
> > 
> > On Wed, 2015-09-23 at 16:28 +0800, Jia Hongtao wrote:
> > > This driver add thermal management support by enabling TMU (Thermal
> > > Monitoring Unit) on QorIQ platform.
> > >
> > > It's based on thermal of framework:
> > > - Trip points defined in device tree.
> > > - Cpufreq as cooling device registered in qoriq cpufreq driver.
> > 
> > I don't see any cooling device registered in the qoriq cpufreq driver.
> > Is this dependent on some other patch?
> 
> It's not depend on any patch. But I saw your patch below:
> [PATCH v3 5/5] cpufreq: qoriq: Don't look at clock implementation details
> So I hold my patch waiting for your patch merged or there will be conflict.
> 
> I could send it out too if you are fine with it.

Would you guys benefit of cpufreq-cpu0?

> 
> > 
> > >
> > > Signed-off-by: Jia Hongtao <[email-masked]>
> > > ---
> > > V3: Using thermal of framework.
> > >
> > >  drivers/thermal/Kconfig         |  11 ++
> > >  drivers/thermal/Makefile        |   1 +
> > >  drivers/thermal/qoriq_thermal.c | 267

Please include a binding description in your next version. Also,
remember to include an example of your binding.

> > > ++++++++++++++++++++++++++++++++++++++++
> > >  3 files changed, 279 insertions(+)
> > >  create mode 100644 drivers/thermal/qoriq_thermal.c
> > >
> > > diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig index
> > > 0390044..c91041b 100644
> > > --- a/drivers/thermal/Kconfig
> > > +++ b/drivers/thermal/Kconfig
> > > @@ -180,6 +180,17 @@ config IMX_THERMAL
> > >         cpufreq is used as the cooling device to throttle CPUs when the
> > >         passive trip is crossed.
> > >
> > > +config QORIQ_THERMAL

It would be really great if you could consolidate this driver with
IMX_THERMAL. Do you think it is doable?

> > > +     tristate "Freescale QorIQ Thermal Monitoring Unit"
> > > +     depends on CPU_THERMAL
> > > +     depends on THERMAL_OF
> > > +     default n
> > > +     help
> > > +       Enable thermal management based on Freescale QorIQ Thermal
> > Monitoring
> > > +       Unit (TMU). It supports one critical trip point and one passive
> > trip
> > > +       point. The cpufreq is used as the cooling device to throttle
> > CPUs when
> > > +       the passive trip is crossed.
> > 
> > "default n" is unnecessary -- n is already the default.
> 
> Right.
> 
> > 
> > Where is the interaction between this driver and cpufreq?
> 
> It's all in cpufreq patch I mentioned above.
> 
> > 
> > > config SPEAR_THERMAL
> > >       bool "SPEAr thermal sensor driver"
> > >       depends on PLAT_SPEAR
> > > diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile index
> > > 26f1608..e55d703 100644
> > > --- a/drivers/thermal/Makefile
> > > +++ b/drivers/thermal/Makefile
> > > @@ -33,6 +33,7 @@ obj-$(CONFIG_DOVE_THERMAL)          += dove_thermal.o
> > >  obj-$(CONFIG_DB8500_THERMAL) += db8500_thermal.o
> > >  obj-$(CONFIG_ARMADA_THERMAL) += armada_thermal.o
> > >  obj-$(CONFIG_IMX_THERMAL)    += imx_thermal.o
> > > +obj-$(CONFIG_QORIQ_THERMAL)  += qoriq_thermal.o
> > >  obj-$(CONFIG_DB8500_CPUFREQ_COOLING) += db8500_cpufreq_cooling.o
> > >  obj-$(CONFIG_INTEL_POWERCLAMP)       += intel_powerclamp.o
> > >  obj-$(CONFIG_X86_PKG_TEMP_THERMAL)   += x86_pkg_temp_thermal.o
> > > diff --git a/drivers/thermal/qoriq_thermal.c
> > > b/drivers/thermal/qoriq_thermal.c new file mode 100644 index
> > > 0000000..7c2a3261
> > > --- /dev/null
> > > +++ b/drivers/thermal/qoriq_thermal.c
> > > @@ -0,0 +1,267 @@
> > > +/*
> > > + * Copyright 2015 Freescale Semiconductor, Inc.
> > > + *
> > > + * This program is free software; you can redistribute it and/or
> > > +modify it
> > > + * under the terms and conditions of the GNU General Public License,
> > > + * version 2, as published by the Free Software Foundation.
> > > + *
> > > + * This program is distributed in the hope 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.
> > > + *
> > > + */
> > > +
> > > +/*
> > > + * Based on Freescale QorIQ Thermal Monitoring Unit (TMU)  */
> > 
> > What does this comment mean?  This *is* the "Freescale QorIQ Thermal
> > Monitoring Unit" driver.
> 
> I mean thermal management based on the monitor TMU.
> I could remove this comment though.
> 
> > 
> > > +#include <linux/cpufreq.h>
> > 
> > What do you use from this header?
> 
> Sorry, forget to remove it from last version in which cooling devices are
> registered in thermal driver instead of cpufreq driver.
> 
> > 
> > > +#include <linux/module.h>
> > > +#include <linux/platform_device.h>
> > > +#include <linux/err.h>
> > > +#include <linux/io.h>
> > > +#include <linux/of.h>
> > > +#include <linux/of_address.h>
> > > +#include <linux/thermal.h>
> > > +
> > > +#include "thermal_core.h"
> > > +
> > > +#define SITES_MAX    16
> > > +
> > > +/*
> > > + * QorIQ TMU Registers
> > > + */
> > > +struct qoriq_tmu_site_regs {
> > > +     __be32 tritsr;          /* Immediate Temperature Site Register */
> > > +     __be32 tratsr;          /* Average Temperature Site Register */
> > > +     u8 res0[0x8];
> > > +} __packed;
> > > +
> > > +struct qoriq_tmu_regs {
> > > +     __be32 tmr;             /* Mode Register */
> > > +#define TMR_DISABLE  0x0
> > > +#define TMR_ME               0x80000000
> > > +#define TMR_ALPF     0x0c000000
> > > +#define TMR_MSITE    0x00008000      /* Core temperature site */
> > > +#define TMR_ALL              (TMR_ME | TMR_ALPF | TMR_MSITE)
> > > +     __be32 tsr;             /* Status Register */
> > > +     __be32 tmtmir;          /* Temperature measurement interval
> > Register */
> > > +#define TMTMIR_DEFAULT       0x00000007
> > > +     u8 res0[0x14];
> > > +     __be32 tier;            /* Interrupt Enable Register */
> > > +#define TIER_DISABLE 0x0
> > > +     __be32 tidr;            /* Interrupt Detect Register */
> > > +     __be32 tiscr;           /* Interrupt Site Capture Register */
> > > +     __be32 ticscr;          /* Interrupt Critical Site Capture
> > Register */
> > > +     u8 res1[0x10];
> > > +     __be32 tmhtcrh;         /* High Temperature Capture Register */
> > > +     __be32 tmhtcrl;         /* Low Temperature Capture Register */
> > > +     u8 res2[0x8];
> > > +     __be32 tmhtitr;         /* High Temperature Immediate Threshold
> > */
> > > +     __be32 tmhtatr;         /* High Temperature Average Threshold */
> > > +     __be32 tmhtactr;        /* High Temperature Average Crit
> > Threshold */
> > > +     u8 res3[0x24];
> > > +     __be32 ttcfgr;          /* Temperature Configuration Register */
> > > +     __be32 tscfgr;          /* Sensor Configuration Register */
> > > +     u8 res4[0x78];
> > > +     struct qoriq_tmu_site_regs site[SITES_MAX];
> > > +     u8 res5[0x9f8];
> > > +     __be32 ipbrr0;          /* IP Block Revision Register 0 */
> > > +     __be32 ipbrr1;          /* IP Block Revision Register 1 */
> > > +     u8 res6[0x310];
> > > +     __be32 ttr0cr;          /* Temperature Range 0 Control Register
> > */
> > > +     __be32 ttr1cr;          /* Temperature Range 1 Control Register
> > */
> > > +     __be32 ttr2cr;          /* Temperature Range 2 Control Register
> > */
> > > +     __be32 ttr3cr;          /* Temperature Range 3 Control Register
> > */
> > > +};
> > > +
> > > +/*
> > > + * Thermal zone data
> > > + */
> > > +struct qoriq_tmu_data {
> > > +     struct thermal_zone_device *tz;
> > > +     struct qoriq_tmu_regs __iomem *regs; };
> > > +
> > 
> > > +static int tmu_get_temp(void *p, int *temp) {
> > > +     u8 val;
> > > +     struct qoriq_tmu_data *data = p;
> > > +
> > > +     val = ioread32be(&data->regs->site[0].tritsr);
> > > +     *temp = (int)val * 1000;
> > 
> > Why don't you declare val as int in the first place?
> 
> It's a 32bit register.
> Only the least significant 8 bits represent the temperature.
> The most significant bit shows the validness of the value.
> I use u8 type to remove the rest 24bits influence.
> 
> > 
> > > +     for (i = 0; i < len; i += 8, calibration += 2) {
> > > +             val = (int)of_read_number(calibration, 1);
> > > +             iowrite32be(val, &data->regs->ttcfgr);
> > > +             val = (int)of_read_number(calibration + 1, 1);
> > > +             iowrite32be(val, &data->regs->tscfgr);
> > 
> > Unnecessary casts.
> 
> Ok.
> 
> > 
> > > +     }
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static void qoriq_tmu_init_device(struct qoriq_tmu_data *data) {
> > > +     /* Disable interrupt, using polling instead */
> > > +     iowrite32be(TIER_DISABLE, &data->regs->tier);
> > > +
> > > +     /* Set update_interval */
> > > +     iowrite32be(TMTMIR_DEFAULT, &data->regs->tmtmir);
> > > +
> > > +     /* Enable monitoring */
> > > +     iowrite32be(TMR_ALL, &data->regs->tmr); }
> > > +
> > > +static struct thermal_zone_of_device_ops tmu_tz_ops = {
> > > +     .get_temp = tmu_get_temp,
> > > +};
> > > +
> > > +static int qoriq_tmu_probe(struct platform_device *pdev) {
> > > +     int ret;
> > > +     const struct thermal_trip *trip;
> > > +     struct qoriq_tmu_data *data;
> > > +
> > > +     if (!pdev->dev.of_node) {
> > > +             dev_err(&pdev->dev, "Device OF-Node is NULL");
> > > +             return -EFAULT;
> > > +     }
> > 
> > EFAULT is for bad user addresses and is not appropriate here.
> 
> I will change it to ENODEV.
> 
> > 
> > > +
> > > +     data = devm_kzalloc(&pdev->dev, sizeof(struct qoriq_tmu_data),
> > > +                         GFP_KERNEL);
> > > +     if (!data)
> > > +             return -ENOMEM;
> > > +
> > > +     platform_set_drvdata(pdev, data);
> > > +     data->regs = of_iomap(pdev->dev.of_node, 0);
> > > +
> > > +     if (!data->regs) {
> > > +             dev_err(&pdev->dev, "Failed to get memory region\n");
> > > +             ret = -ENODEV;
> > > +             goto err_iomap;
> > > +     }
> > > +
> > > +     ret = qoriq_tmu_calibration(pdev);      /* TMU calibration */
> > > +     if (ret < 0) {
> > > +             dev_err(&pdev->dev, "TMU calibration failed.\n");
> > > +             ret = -ENODEV;
> > > +             goto err_iomap;
> > > +     }
> > 
> > That function returns negative when device tree properties are missing,
> > not when a calibration procedure fails.
> 
> What's your suggestion here to return then?
> 
> > 
> > > +
> > > +     qoriq_tmu_init_device(data);    /* TMU initialization */
> > > +
> > > +     data->tz = thermal_zone_of_sensor_register(&pdev->dev, 0,
> > > +                             data, &tmu_tz_ops);
> > > +     if (IS_ERR(data->tz)) {
> > > +             ret = PTR_ERR(data->tz);
> > > +             dev_err(&pdev->dev,
> > > +                     "Failed to register thermal zone device %d\n",
> > ret);
> > > +             goto err_thermal;
> > > +     }
> > > +
> > > +     trip = of_thermal_get_trip_points(data->tz);
> > > +
> > > +     data->tz->ops->set_mode(data->tz, THERMAL_DEVICE_ENABLED);
> > 
> > Doesn't thermal_zone_of_sensor_register() already call ops->set_mode with
> > TERMAL_DEVICE_ENABLED?
> 
> You are right.
> I referenced the code from other platform and did not notice this.
> Thanks.
> 
> > 
> > > +
> > > +     return 0;
> > > +
> > > +err_thermal:
> > > +     iounmap(data->regs);
> > > +
> > > +err_iomap:
> > > +     platform_set_drvdata(pdev, NULL);
> > > +     devm_kfree(&pdev->dev, data);
> > > +
> > > +     return ret;
> > > +}
> > > +
> > > +static int qoriq_tmu_remove(struct platform_device *pdev) {
> > > +     struct qoriq_tmu_data *data = platform_get_drvdata(pdev);
> > > +
> > > +     /* Disable monitoring */
> > > +     iowrite32be(TMR_DISABLE, &data->regs->tmr);
> > > +
> > > +     thermal_zone_of_sensor_unregister(&pdev->dev, data->tz);
> > > +     iounmap(data->regs);
> > > +
> > > +     platform_set_drvdata(pdev, NULL);
> > > +     devm_kfree(&pdev->dev, data);
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +#ifdef CONFIG_PM_SLEEP
> > > +static int qoriq_tmu_suspend(struct device *dev) {
> > > +     struct qoriq_tmu_data *data = dev_get_drvdata(dev);
> > > +
> > > +     /* Disable monitoring */
> > > +     iowrite32be(TMR_DISABLE, &data->regs->tmr);
> > > +     data->tz->ops->set_mode(data->tz, THERMAL_DEVICE_DISABLED);
> > > +
> > > +     return 0;
> > > +}
> > > +
> > > +static int qoriq_tmu_resume(struct device *dev) {
> > > +     struct qoriq_tmu_data *data = dev_get_drvdata(dev);
> > > +
> > > +     /* Enable monitoring */
> > > +     iowrite32be(TMR_ALL, &data->regs->tmr);
> > > +     data->tz->ops->set_mode(data->tz, THERMAL_DEVICE_ENABLED);
> > > +
> > > +     return 0;
> > > +}
> > > +#endif
> > > +
> > > +static SIMPLE_DEV_PM_OPS(qoriq_tmu_pm_ops,
> > > +                      qoriq_tmu_suspend, qoriq_tmu_resume);
> > > +
> > 
> > 
> > > +static const struct of_device_id qoriq_tmu_match[] = {
> > > +     { .compatible = "fsl,qoriq-tmu", },
> > > +     {},
> > > +};
> > 
> > Binding?
> 
> Not send out yet.
> I planned to send the patch with device tree patchset including
> adding TMU node to T1040/T1024/LS1021A platform.
> 
> It's depending on the device tree files moving patch I sent out
> not long ago.
> 
> > 
> > > +
> > > +static struct platform_driver qoriq_tmu = {
> > > +     .driver = {
> > > +             .name           = "qoriq_thermal",
> > > +             .pm = &qoriq_tmu_pm_ops,
> > > +             .of_match_table = qoriq_tmu_match,
> > > +     },
> > 
> > Why the tabs after ".name"?
> 
> Will indent the other two.
> 
> > 
> > -Scott
>