Re: [PATCH v3 3/3] thermal: broadcom: Add Stingray thermal driver

From: Srinath Mannam
Date: Sun Sep 16 2018 - 23:50:26 EST


Hi Daniel,

Thank you for your review comments.
I will address all your comments in next patch set.

Regards,
Srinath.

On Fri, Sep 14, 2018 at 7:50 PM, Daniel Lezcano
<daniel.lezcano@xxxxxxxxxx> wrote:
> On 09/08/2018 14:54, Srinath Mannam wrote:
>> From: Pramod Kumar <pramod.kumar@xxxxxxxxxxxx>
>>
>> Adds stingray thermal driver to monitor six
>> thermal zones temperature and trips at critical temperature.
>
> Hi Pramod,
>
> could you elaborate a bit more the description? As you are introducing a
> new driver it would be nice to give the sensor details.
>
>> Signed-off-by: Pramod Kumar <pramod.kumar@xxxxxxxxxxxx>
>> Signed-off-by: Srinath Mannam <srinath.mannam@xxxxxxxxxxxx>
>> Reviewed-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
>> Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
>> Reviewed-by: Vikram Prakash <vikram.prakash@xxxxxxxxxxxx>
>> ---
>> drivers/thermal/Kconfig | 3 +-
>> drivers/thermal/broadcom/Kconfig | 9 ++
>> drivers/thermal/broadcom/Makefile | 1 +
>> drivers/thermal/broadcom/sr-thermal.c | 216 ++++++++++++++++++++++++++++++++++
>> 4 files changed, 228 insertions(+), 1 deletion(-)
>> create mode 100644 drivers/thermal/broadcom/sr-thermal.c
>>
>> diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
>> index 8297988..26d39d4 100644
>> --- a/drivers/thermal/Kconfig
>> +++ b/drivers/thermal/Kconfig
>> @@ -416,7 +416,8 @@ config MTK_THERMAL
>> controller present in Mediatek SoCs
>>
>> menu "Broadcom thermal drivers"
>> -depends on ARCH_BCM || ARCH_BRCMSTB || ARCH_BCM2835 || COMPILE_TEST
>> +depends on ARCH_BCM || ARCH_BRCMSTB || ARCH_BCM2835 || ARCH_BCM_IPROC || \
>> + COMPILE_TEST
>> source "drivers/thermal/broadcom/Kconfig"
>> endmenu
>>
>> diff --git a/drivers/thermal/broadcom/Kconfig b/drivers/thermal/broadcom/Kconfig
>> index c106a15..dc9a9bd 100644
>> --- a/drivers/thermal/broadcom/Kconfig
>> +++ b/drivers/thermal/broadcom/Kconfig
>> @@ -22,3 +22,12 @@ config BCM_NS_THERMAL
>> BCM4708, BCM4709, BCM5301x, BCM95852X, etc). It contains DMU (Device
>> Management Unit) block with a thermal sensor that allows checking CPU
>> temperature.
>> +
>> +config BCM_SR_THERMAL
>> + tristate "Stingray thermal driver"
>> + depends on ARCH_BCM_IPROC || COMPILE_TEST
>> + default ARCH_BCM_IPROC
>> + help
>> + Support for the Stingray family of SoCs. Its different blocks like
>> + iHost, CRMU and NITRO has thermal sensor that allows checking its
>> + temperature.
>> diff --git a/drivers/thermal/broadcom/Makefile b/drivers/thermal/broadcom/Makefile
>> index fae10ec..79df69e 100644
>> --- a/drivers/thermal/broadcom/Makefile
>> +++ b/drivers/thermal/broadcom/Makefile
>> @@ -1,3 +1,4 @@
>> obj-$(CONFIG_BCM2835_THERMAL) += bcm2835_thermal.o
>> obj-$(CONFIG_BRCMSTB_THERMAL) += brcmstb_thermal.o
>> obj-$(CONFIG_BCM_NS_THERMAL) += ns-thermal.o
>> +obj-$(CONFIG_BCM_SR_THERMAL) += sr-thermal.o
>> diff --git a/drivers/thermal/broadcom/sr-thermal.c b/drivers/thermal/broadcom/sr-thermal.c
>> new file mode 100644
>> index 0000000..909f80c
>> --- /dev/null
>> +++ b/drivers/thermal/broadcom/sr-thermal.c
>> @@ -0,0 +1,216 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (C) 2018 Broadcom
>> + */
>> +
>> +#include <linux/acpi.h>
>> +#include <linux/module.h>
>> +#include <linux/of_address.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/thermal.h>
>> +
>> +#define TMON_CRIT_TEMP 105000 /* temp in millidegree C */
>
> I suggest to move this in the DT?
>
>> +#define SR_TMON_MAX_LIST 6
>> +
>> +/*
>> + * In stingray thermal IO memory,
>> + * Total Number of available TMONs MASK is at offset 0
>> + * temperature registers BASE is at 4 byte offset.
>> + * Each TMON temperature register size is 4.
>> + */
>> +#define SR_TMON_TEMP_BASE(id) ((id) * 0x4)
>> +
>> +static const char * const sr_tmon_names[SR_TMON_MAX_LIST] = {
>
> It will be more elegant to replace the macro SR_TMON_MAX_LIST by
> ARRAY_SIZE(sr_tmon_names) and declare this array as:
>
> static const char *const sr_tmon_name[] = {
> ...
> };
>
>> + "sr_tmon_ihost0",
>> + "sr_tmon_ihost1",
>> + "sr_tmon_ihost2",
>> + "sr_tmon_ihost3",
>> + "sr_tmon_crmu",
>> + "sr_tmon_nitro",
>> +};
>> +
>> +struct sr_tmon {
>> + struct thermal_zone_device *tz;
>> + unsigned int crit_temp;
>> + unsigned int tmon_id;
>> + struct sr_thermal *priv;
>> +};
>> +
>> +struct sr_thermal {
>> + struct device *dev;
>
> This field is used for dev_dbg, may be it could be removed along with
> the dev_dbg message?
>
>> + void __iomem *regs;
>> + struct sr_tmon tmon[SR_TMON_MAX_LIST];
>> +};
>> +
>> +static int sr_get_temp(struct thermal_zone_device *tz, int *temp)
>> +{
>> + struct sr_tmon *tmon = tz->devdata;
>> + struct sr_thermal *sr_thermal = tmon->priv;
>> +
>> + *temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));
>> +
>> + return 0;
>> +}
>> +
>> +static int sr_get_trip_type(struct thermal_zone_device *tz, int trip,
>> + enum thermal_trip_type *type)
>> +{
>> + struct sr_tmon *tmon = tz->devdata;
>> + struct sr_thermal *sr_thermal = tmon->priv;
>> +
>> + switch (trip) {
>> + case 0:
>> + *type = THERMAL_TRIP_CRITICAL;
>> + break;
>> + default:
>> + dev_dbg(sr_thermal->dev,
>> + "Driver does not support more than 1 trip point\n");
>> + return -EINVAL;
>> + }
>> + return 0;
>> +}
>> +
>> +static int sr_get_trip_temp(struct thermal_zone_device *tz, int trip, int *temp)
>> +{
>> + struct sr_tmon *tmon = tz->devdata;
>> + struct sr_thermal *sr_thermal = tmon->priv;
>> +
>> + switch (trip) {
>> + case 0:
>> + *temp = tmon->crit_temp;
>> + break;
>> + default:
>> + dev_dbg(sr_thermal->dev,
>> + "Driver does not support more than 1 trip point\n");
>> + return -EINVAL;
>> + }
>> + return 0;
>> +}
>> +
>> +static int sr_set_trip_temp(struct thermal_zone_device *tz, int trip, int temp)
>> +{
>> + struct sr_tmon *tmon = tz->devdata;
>> +
>> + switch (trip) {
>> + case 0:
>> + /*
>> + * Allow the user to change critical temperature
>> + * as per their requirement, could be for debug
>> + * purpose, even if it's more than the recommended
>> + * critical temperature.
>> + */
>
> Couldn't the user harm the hardware with a too high value?
>
> Why not define this value in the DT?
>
>> + tmon->crit_temp = temp;
>> + break;
>> + default:
>> + return -EINVAL;
>> + }
>> + return 0;
>> +}
>
> Is it possible to factor out these 3 functions above and remove the
> 'switch' in all of them ?
>
>> +static struct thermal_zone_device_ops sr_thermal_ops = {
>> + .get_temp = sr_get_temp,
>> + .get_trip_type = sr_get_trip_type,
>> + .get_trip_temp = sr_get_trip_temp,
>> + .set_trip_temp = sr_set_trip_temp,
>> +};
>> +
>> +static int sr_thermal_probe(struct platform_device *pdev)
>> +{
>> + struct device *dev = &pdev->dev;
>> + struct sr_thermal *sr_thermal;
>> + struct sr_tmon *tmon;
>> + struct resource *res;
>> + uint32_t sr_tmon_list = 0;
>> + unsigned int i;
>> + int ret;
>> +
>> + sr_thermal = devm_kzalloc(dev, sizeof(*sr_thermal), GFP_KERNEL);
>> + if (!sr_thermal)
>> + return -ENOMEM;
>> +
>> + sr_thermal->dev = dev;
>> +
>> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + sr_thermal->regs = (void __iomem *)devm_memremap(&pdev->dev, res->start,
>> + resource_size(res), MEMREMAP_WB);
>> + if (IS_ERR(sr_thermal->regs)) {
>> + dev_err(dev, "failed to get io address\n");
>> + return PTR_ERR(sr_thermal->regs);
>> + }
>> +
>> + ret = device_property_read_u32(dev, "brcm,tmon-mask", &sr_tmon_list);
>> + if (ret)
>> + return ret;
>> +
>> + for (i = 0; i < SR_TMON_MAX_LIST; i++) {
>> +
>> + if (!(sr_tmon_list & BIT(i)))
>> + continue;
>> +
>> + /* Flush temperature registers */
>> + writel(0, sr_thermal->regs + SR_TMON_TEMP_BASE(i));
>> + tmon = &sr_thermal->tmon[i];
>
> It is possible to initialize tmon to:
>
> tmon = &sr_thermal->tmon;
>
> and then use the pointer increment:
> tmon++;
>
>
>> + tmon->crit_temp = TMON_CRIT_TEMP;
>> + tmon->tmon_id = i;
>> + tmon->priv = sr_thermal;
>> + tmon->tz = thermal_zone_device_register(sr_tmon_names[i],
>> + 1, 1,
>> + tmon,
>> + &sr_thermal_ops,
>> + NULL, 1000, 1000);
>> + if (IS_ERR(tmon->tz))
>> + goto err_exit;
>> +
>> + dev_info(dev, "%s: registered\n", sr_tmon_names[i]);
>> + }
>> + platform_set_drvdata(pdev, sr_thermal);
>> +
>> + return 0;
>> +
>> +err_exit:
>> + while (--i >= 0) {
>> + if (sr_thermal->tmon[i].tz)
>> + thermal_zone_device_unregister(sr_thermal->tmon[i].tz);
>> + }
>> +
>> + return PTR_ERR(tmon->tz);
>> +}
>> +
>> +static int sr_thermal_remove(struct platform_device *pdev)
>> +{
>> + struct sr_thermal *sr_thermal = platform_get_drvdata(pdev);
>> + unsigned int i;
>> +
>> + for (i = 0; i < SR_TMON_MAX_LIST; i++)
>> + if (sr_thermal->tmon[i].tz)
>> + thermal_zone_device_unregister(sr_thermal->tmon[i].tz);
>> +
>> + return 0;
>> +}
>> +
>> +static const struct of_device_id sr_thermal_of_match[] = {
>> + { .compatible = "brcm,sr-thermal", },
>> + {},
>> +};
>> +MODULE_DEVICE_TABLE(of, sr_thermal_of_match);
>> +
>> +static const struct acpi_device_id sr_thermal_acpi_ids[] = {
>> + { .id = "BRCM0500" },
>> + { /* sentinel */ }
>> +};
>> +MODULE_DEVICE_TABLE(acpi, sr_thermal_acpi_ids);
>> +
>> +static struct platform_driver sr_thermal_driver = {
>> + .probe = sr_thermal_probe,
>> + .remove = sr_thermal_remove,
>> + .driver = {
>> + .name = "sr-thermal",
>> + .of_match_table = sr_thermal_of_match,
>> + .acpi_match_table = ACPI_PTR(sr_thermal_acpi_ids),
>> + },
>> +};
>> +module_platform_driver(sr_thermal_driver);
>> +
>> +MODULE_AUTHOR("Pramod Kumar <pramod.kumar@xxxxxxxxxxxx>");
>> +MODULE_DESCRIPTION("Stingray thermal driver");
>> +MODULE_LICENSE("GPL v2");
>>
>
>
> --
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