Re: [PATCH v12] thermal: drivers: mediatek: Add the Low Voltage Thermal Sensor driver

[Daniel Lezcano]

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@xxxxxxxxxxxx wrote:
> > > > From: Balsam CHIHI <bchihi@xxxxxxxxxxxx>
> > > >
> > > > 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




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