linux-kernel - Re: [PATCH] mfd: intel_soc_pmic: Use CPU-id check instead of

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Date:   Tue, 09 Nov 2021 12:23:00 +0900
From:   Tsuchiya Yuto <kitakar@...il.com>
To:     Andy Shevchenko <andy.shevchenko@...il.com>,
        Hans de Goede <hdegoede@...hat.com>
Cc:     Andy Shevchenko <andy@...nel.org>,
        Lee Jones <lee.jones@...aro.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] mfd: intel_soc_pmic: Use CPU-id check instead of _HRV
 check to differentiate variants

On Sun, 2021-11-07 at 20:17 +0200, Andy Shevchenko wrote:
> On Sun, Nov 7, 2021 at 7:26 PM Hans de Goede <hdegoede@...hat.com> wrote:
> > 
> > The Intel Crystal Cove PMIC has 2 different variants, one for use with
> > Bay Trail (BYT) SoCs and one for use with Cherry Trail (CHT) SoCs.
> > 
> > So far we have been using an ACPI _HRV check to differentiate between
> > the 2, but at least on the Microsoft Surface 3, which is a CHT device,
> > the wrong _HRV value is reported by ACPI.
> > 
> > So instead switch to a CPU-ID check which avoids us relying on the
> > possibly wrong ACPI _HRV value.
> 
> Thanks, I hope Tsuchiya will test this soon, from code perspective it
> looks good to me,
> Reviewed-by: Andy Shevchenko <andy.shevchenko@...il.com>

Hi, thank you for the patch. I tried this patch (plus the patch ("ASoC:
Intel: Move soc_intel_is_foo() helpers to a generic header") [1], which
this patch needs) on my Surface 3 and can confirm it's using CHT variant
of Crystal Cove PMIC driver as expected.

Tested-by: Tsuchiya Yuto <kitakar@...il.com>

[1] https://lore.kernel.org/all/20211018143324.296961-2-hdegoede@redhat.com/

> > Reported-by: Tsuchiya Yuto <kitakar@...il.com>
> > Signed-off-by: Hans de Goede <hdegoede@...hat.com>
> > ---
> >  drivers/mfd/intel_soc_pmic_core.c | 28 +++-------------------------
> >  1 file changed, 3 insertions(+), 25 deletions(-)
> > 
> > diff --git a/drivers/mfd/intel_soc_pmic_core.c b/drivers/mfd/intel_soc_pmic_core.c
> > index ddd64f9e3341..47cb7f00dfcf 100644
> > --- a/drivers/mfd/intel_soc_pmic_core.c
> > +++ b/drivers/mfd/intel_soc_pmic_core.c
> > @@ -14,15 +14,12 @@
> >  #include <linux/module.h>
> >  #include <linux/mfd/core.h>
> >  #include <linux/mfd/intel_soc_pmic.h>
> > +#include <linux/platform_data/x86/soc.h>
> >  #include <linux/pwm.h>
> >  #include <linux/regmap.h>
> > 
> >  #include "intel_soc_pmic_core.h"
> > 
> > -/* Crystal Cove PMIC shares same ACPI ID between different platforms */
> > -#define BYT_CRC_HRV            2
> > -#define CHT_CRC_HRV            3
> > -
> >  /* PWM consumed by the Intel GFX */
> >  static struct pwm_lookup crc_pwm_lookup[] = {
> >         PWM_LOOKUP("crystal_cove_pwm", 0, "0000:00:02.0", "pwm_pmic_backlight", 0, PWM_POLARITY_NORMAL),
> > @@ -34,31 +31,12 @@ static int intel_soc_pmic_i2c_probe(struct i2c_client *i2c,
> >         struct device *dev = &i2c->dev;
> >         struct intel_soc_pmic_config *config;
> >         struct intel_soc_pmic *pmic;
> > -       unsigned long long hrv;
> > -       acpi_status status;
> >         int ret;
> > 
> > -       /*
> > -        * There are 2 different Crystal Cove PMICs a Bay Trail and Cherry
> > -        * Trail version, use _HRV to differentiate between the 2.
> > -        */
> > -       status = acpi_evaluate_integer(ACPI_HANDLE(dev), "_HRV", NULL, &hrv);
> > -       if (ACPI_FAILURE(status)) {
> > -               dev_err(dev, "Failed to get PMIC hardware revision\n");
> > -               return -ENODEV;
> > -       }
> > -
> > -       switch (hrv) {
> > -       case BYT_CRC_HRV:
> > +       if (soc_intel_is_byt())
> >                 config = &intel_soc_pmic_config_byt_crc;
> > -               break;
> > -       case CHT_CRC_HRV:
> > +       else
> >                 config = &intel_soc_pmic_config_cht_crc;
> > -               break;
> > -       default:
> > -               dev_warn(dev, "Unknown hardware rev %llu, assuming BYT\n", hrv);
> > -               config = &intel_soc_pmic_config_byt_crc;
> > -       }
> > 
> >         pmic = devm_kzalloc(dev, sizeof(*pmic), GFP_KERNEL);
> >         if (!pmic)
> > --
> > 2.31.1
> > 
> 
>