Message-ID: <ea30d169-2ae6-2744-fbfd-01bbbba36554@linaro.org>
Date:   Mon, 6 Feb 2023 15:38:15 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.4.2
Subject: Re: [PATCH v12] thermal: drivers: mediatek: Add the Low Voltage
 Thermal Sensor driver
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc:     bchihi@baylibre.com, angelogioacchino.delregno@collabora.com,
        rafael@kernel.org, amitk@kernel.org, rui.zhang@intel.com,
        matthias.bgg@gmail.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, rdunlap@infradead.org,
        ye.xingchen@zte.com.cn, p.zabel@pengutronix.de,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org,
        khilman@baylibre.com, james.lo@mediatek.com,
        rex-bc.chen@mediatek.com
References: <20230124131717.128660-5-bchihi@baylibre.com>
 <20230131153816.21709-1-bchihi@baylibre.com>
 <ab1e4822-d5f4-79f6-ea38-47e2342ebe49@linaro.org>
 <20230206140713.GB15176@linaro.org>
 <b6a24ff7-4154-f2b4-88b1-a8a87c30d30a@linaro.org>
From:   Daniel Lezcano <daniel.lezcano@linaro.org>
In-Reply-To: <b6a24ff7-4154-f2b4-88b1-a8a87c30d30a@linaro.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 06/02/2023 15:30, Krzysztof Kozlowski wrote:
> On 06/02/2023 15:07, Daniel Lezcano wrote:
>> On Wed, Feb 01, 2023 at 08:55:07AM +0100, Krzysztof Kozlowski wrote:
>>> On 31/01/2023 16:38, bchihi@baylibre.com wrote:
>>>> From: Balsam CHIHI <bchihi@baylibre.com>
>>>>
>>>> The Low Voltage Thermal Sensor (LVTS) is a multiple sensors, multi
>>>> controllers contained in a thermal domain.
>>>>
>>>> A thermal domains can be the MCU or the AP.
>>>>
>>>> Each thermal domains contain up to seven controllers, each thermal
>>>> controller handle up to four thermal sensors.
>>>>
>>>> The LVTS has two Finite State Machines (FSM), one to handle the
>>>> functionin temperatures range like hot or cold temperature and another
>>>> one to handle monitoring trip point. The FSM notifies via interrupts
>>>> when a trip point is crossed.
>>>>
>>>
>>> (...)
>>>
>>>> +
>>>> +struct lvts_domain {
>>>> +	struct lvts_ctrl *lvts_ctrl;
>>>> +	struct reset_control *reset;
>>>> +	struct clk *clk;
>>>> +	int num_lvts_ctrl;
>>>> +	void __iomem *base;
>>>> +	size_t calib_len;
>>>> +	u8 *calib;
>>>> +};
>>>> +
>>>> +#ifdef CONFIG_MTK_LVTS_THERMAL_DEBUGFS
>>>> +
>>>> +static struct dentry *root;
>>>
>>> How do you handle two instances of driver?
>>
>> For now, we can put the entry in /sys/kernel/debug/<dev_name>
>>
>> I'm preparing a debugfs series for the thermal framework and that will provide
>> an entry to hook in for the sensors debugfs if available
> 
> The code looked like it does not support it at all. I think it would
> remove entries from second instance, while unbinding the first (or the
> opposite).

Yes, and you are right.

So instead of having:

/sys/kernel/debugfs/lvts/lvts@mcu

We will have:

/sys/kernel/debugfs/lvts@mcu

Later, when the other domain is added, we will have:

/sys/kernel/debugfs/lvts@mcu
/sys/kernel/debugfs/lvts@ap

Each instance takes care of removing its own entry

When I'll introduce thermal debugfs, I'll take care of massaging the 
driver to have them like:

/sys/kernel/debugfs/thermal/thermal_zone/0/sensors/lvts@mcu,0
/sys/kernel/debugfs/thermal/thermal_zone/1/sensors/lvts@ap,1


-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog