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

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Message-ID: <57d8356c-e5f7-b23b-7efe-0be831f3d8c2@redhat.com>
Date:   Tue, 9 Nov 2021 09:36:18 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Tsuchiya Yuto <kitakar@...il.com>,
        Andy Shevchenko <andy.shevchenko@...il.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

Hi,

On 11/9/21 04:23, Tsuchiya Yuto wrote:
> 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],

Right, this patch needs to be applie don top of the upcoming v5.16-rc1
which has that patch, I wanted to mention that but I forgot.

> 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>

Thank you.

Regards,

Hans



> 
> [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
>>>
>>
>>
> 
>