Re: [PATCH v2 2/2] mfd: tps65215: Remove regmap_read check

[Shree Ramamoorthy]

Hi,


On 1/7/25 6:47 AM, Roger Quadros wrote:
> On 07/01/2025 00:18, Shree Ramamoorthy wrote:
> > Hi,
> >
> > On 1/4/2025 12:16 PM, Roger Quadros wrote:
> > > On 04/01/2025 00:57, Shree Ramamoorthy wrote:
> > > > The chipid macro/variable and regmap_read function call is not needed
> > > > because the TPS65219_REG_TI_DEV_ID register value is not a consistent value
> > > > across TPS65219 PMIC config versions. Reading from the DEV_ID register
> > > > without a consistent value to compare it to isn't useful. There isn't a
> > > > way to verify the match data ID is the same ID read from the DEV_ID device
> > > > register. 0xF0 isn't a DEV_ID value consistent across TPS65219 NVM
> > > > configurations.
> > > >
> > > > For TPS65215, there is a consistent value in bits 5-0 of the DEV_ID
> > > > register. However, there are other error checks in place within probe()
> > > > that apply to both PMICs rather than keeping this isolated check for one
> > > > PMIC.
> > > >
> > > > Signed-off-by: Shree Ramamoorthy <s-ramamoorthy@xxxxxx>
> > > In that case this could be squashed with 1?
> > Since this change does not have to do with TPS65215 support directly
> > and is a different type of change, I wanted to keep this patch separate.
> > I can instead have this patch be first, then the MFD add TPS65215 support
> > will follow this to avoid any confusion about regmap_read being modified then removed.
> OK thanks.
>
> > > > ---
> > > >   drivers/mfd/tps65219.c       | 6 ------
> > > >   include/linux/mfd/tps65219.h | 2 --
> > > >   2 files changed, 8 deletions(-)
> > > >
> > > > diff --git a/drivers/mfd/tps65219.c b/drivers/mfd/tps65219.c
> > > > index 816b271990a2..d3267bf7cd77 100644
> > > > --- a/drivers/mfd/tps65219.c
> > > > +++ b/drivers/mfd/tps65219.c
> > > > @@ -382,12 +382,6 @@ static int tps65219_probe(struct i2c_client *client)
> > > >   	if (ret)
> > > >   		return ret;
> > > >   
> > > > -	ret = regmap_read(tps->regmap, TPS65219_REG_TI_DEV_ID, &tps->chip_id);
> > > > -	if (ret) {
> > > > -		dev_err(tps->dev, "Failed to read device ID: %d\n", ret);
> > > > -		return ret;
> > > > -	}
> > > > -
> > > >   	ret = devm_mfd_add_devices(tps->dev, PLATFORM_DEVID_AUTO,
> > > >   				   pmic->cells, pmic->n_cells,
> > > >   				   NULL, 0, regmap_irq_get_domain(tps->irq_data));
> > > > diff --git a/include/linux/mfd/tps65219.h b/include/linux/mfd/tps65219.h
> > > > index 9892b6e4c85c..535115bfa4a4 100644
> > > > --- a/include/linux/mfd/tps65219.h
> > > > +++ b/include/linux/mfd/tps65219.h
> > > > @@ -15,8 +15,6 @@
> > > >   #include <linux/regmap.h>
> > > >   #include <linux/regulator/driver.h>
> > > >   
> > > > -/* TPS chip id list */
> > > > -#define TPS65219					0xF0
> > > >   /* Chip id list*/
> > > >   enum pmic_id {
> > > >   	TPS65215,
> > > Looking at TRM, TPS65215 device_id is 0x15 and TPS6521901 device_id is 0x00.
> > >
> > > shouldn't we use that here as well?
> > The device_id value set varies across TPS65219 hardware versions.
> Do you foresee any software quirks being applied for specific versions of
> TPS65219? If not then probably not worth the effort to keep track of all the
> versions.

I don't foresee any sw quirks that would need to be support for TPS65219,
since there haven't been any since the driver was released.

> > Having the device_id as the chip_id differentiator will fail for TPS65219,
> > even though the system engineers have now kept the TPS65215 device_id value
> > consistent across all hardware versions.

--
Best,
Shree Ramamoorthy
PMIC Software Engineer