linux-kernel - Re: [PATCH 1/3] thermal: hisilicon: add new hisilicon thermal sensor driver

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Message-ID: <550BCE34.9010904@hisilicon.com>
Date:	Fri, 20 Mar 2015 15:37:24 +0800
From:	kongxinwei <kong.kongxinwei@...ilicon.com>
To:	Mark Rutland <mark.rutland@....com>
CC:	"rui.zhuang@...el.com" <rui.zhuang@...el.com>,
	"edubezval@...il.com" <edubezval@...il.com>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linuxarm@...wei.com" <linuxarm@...wei.com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"liguozhu@...ilicon.com" <liguozhu@...ilicon.com>,
	"xuwei5@...ilicon.com" <xuwei5@...ilicon.com>
Subject: Re: [PATCH 1/3] thermal: hisilicon: add new hisilicon thermal sensor
 driver



在 2015/3/19 22:17, Mark Rutland 写道:
> On Thu, Mar 19, 2015 at 07:57:27AM +0000, kongxinwei wrote:
>> This patch adds the support for hisilicon thermal sensor, within
>> hisilicon SoC. there will register sensors for thermal framework
>> and use device tree to bind cooling device.
>>
>> Signed-off-by: Leo Yan <leo.yan@...aro.org>
>> Signed-off-by: kongxinwei <kong.kongxinwei@...ilicon.com>
>> ---
>>  drivers/thermal/Kconfig        |   8 +
>>  drivers/thermal/Makefile       |   1 +
>>  drivers/thermal/hisi_thermal.c | 531 +++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 540 insertions(+)
>>  create mode 100644 drivers/thermal/hisi_thermal.c
> 
> [...]
> 
>> +       ret = of_property_read_u32(np, "hisilicon,tsensor-lag-value",
>> +                                  &sensor->lag);
> 
> This wasn't in the binding.
> 

good comment, delete it.

Xinwei

> [...]
> 
>> +       ret = of_property_read_u32(np, "hisilicon,tsensor-thres-temp",
>> +                                  &sensor->thres_temp);
>> +       if (ret) {
>> +               dev_err(&pdev->dev, "failed to get thres value %d: %d\n",
>> +                       index, ret);
>> +               return ret;
>> +       }
>> +
>> +       ret = of_property_read_u32(np, "hisilicon,tsensor-reset-temp",
>> +                                  &sensor->reset_temp);
>> +       if (ret) {
>> +               dev_err(&pdev->dev, "failed to get reset value %d: %d\n",
>> +                       index, ret);
>> +               return ret;
>> +       }
> 
> I see now that these properties result in the HW being programmed. You
> should figure out how to reconcile these with thermal-zone trip points
> rather than having parallel properties.
> 
oh,firstly,this "tsensor-thres-temp" property is threshold temperature value
which causes interrupt function by setting thermal value register. "thermal
-zone trip points" applies scanning mode to cause other function such as
cooling freq .., but this "tsensor-thres-temp" property be used by interrupt
mode. when scanning mode don't satisfies systerm demands, the interrut mode
perfectly help scanning mode to complete function. "tsensor-thres-temp" temp-
erature is higher than "thermal-zone trip points" temperature, so this "
tsensor-thres-temp" property is secondary attribute.

secondly, this "tsensor-reset-temp" property is hardware protect temperature
which is close to or is below to burn out the SoC. When SoC temperature is
"tsensor-reset-temp" temperature value, SoC will be force to reboot and ensure
SoC not to burn out. So it don't conflict thermal-zone.


>> +
>> +       if (of_property_read_bool(np, "hisilicon,tsensor-bind-irq")) {
>> +
>> +               if (data->irq_bind_sensor != -1)
>> +                       dev_warn(&pdev->dev, "irq has bound to index %d\n",
>> +                                data->irq_bind_sensor);
>> +
>> +               /* bind irq to this sensor */
>> +               data->irq_bind_sensor = index;
>> +       }
> 
> I don't see why this should be specified in the DT. Why do you believe
> it should?
> 
SoC include foure thermal sensor modules,every modules is able to cause
interrupt,so binding a module to realize interupt function and i believe
it should be specified.
> [...]
> 
>> +static int hisi_thermal_probe(struct platform_device *pdev)
>> +{
>> +       struct hisi_thermal_data *data;
>> +       struct resource *res;
>> +       int i;
>> +       int ret;
>> +
>> +       if (!cpufreq_get_current_driver()) {
>> +               dev_dbg(&pdev->dev, "no cpufreq driver!");
>> +               return -EPROBE_DEFER;
>> +       }
> 
> Surely we care about not burning out the board even if we don't have
> cpufreq?
> 
> Is there any ordering guarantee between the probing of this driver and
> cpufreq?
> 
> 
Yes! It will use thermal framework to realize cpu cooling device function.

> [...]
> 
>> +       data->clk = devm_clk_get(&pdev->dev, NULL);
> 
> You gave this clock a name in the binding. Use it or drop it.
>

Thanks comment,use it.

> Mark. 
> 

Xinwei
> .
> 

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