Date:   Fri, 20 Jan 2017 11:35:19 +0100
From:   Marek Vasut <marex@...x.de>
To:     Matt Ranostay <matt.ranostay@...sulko.com>,
        Josef Gajdusek <atx@....name>
Cc:     linux-iio@...r.kernel.org, Jonathan Cameron <jic23@...nel.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        maitysanchayan@...il.com, gregor.boirie@...rot.com,
        linux-kernel@...r.kernel.org, rui.zhang@...el.com,
        marxin.liska@...il.com, Corentin Chary <corentin.chary@...il.com>,
        acpi4asus-user@...ts.sourceforge.net
Subject: Re: [PATCH v3] iio: light: acpi-als: Properly enable on ASUS Zenbooks

On 01/20/2017 03:53 AM, Matt Ranostay wrote:
> On Thu, Jan 19, 2017 at 11:01 AM, Josef Gajdusek <atx@....name> wrote:
>> ASUS Zenbooks need several special ACPI calls to enable the ALS peripheral.
>> Otherwise, reads just return 0.
>>
>> Signed-off-by: Josef Gajdusek <atx@....name>
>> ---
>>  drivers/iio/light/acpi-als.c | 60 ++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 60 insertions(+)
>>
>> diff --git a/drivers/iio/light/acpi-als.c b/drivers/iio/light/acpi-als.c
>> index f0b47c5..43417c9 100644
>> --- a/drivers/iio/light/acpi-als.c
>> +++ b/drivers/iio/light/acpi-als.c
>> @@ -30,6 +30,7 @@
>>  #include <linux/acpi.h>
>>  #include <linux/err.h>
>>  #include <linux/mutex.h>
>> +#include <linux/dmi.h>
>>
>>  #include <linux/iio/iio.h>
>>  #include <linux/iio/buffer.h>
>> @@ -39,6 +40,9 @@
>>  #define ACPI_ALS_DEVICE_NAME           "acpi-als"
>>  #define ACPI_ALS_NOTIFY_ILLUMINANCE    0x80
>>
>> +#define ACPI_ALS_ASUS_TALS             "\\_SB.PCI0.LPCB.EC0.TALS"
>> +#define ACPI_ALS_ASUS_ALSC             "\\_SB.ATKD.ALSC"
> 
> Not sure I like these one off defines... this could easily get out of hand.
> Also too lazy to pop out the ACPI spec what does TALS and ALSC mean?

Well it is better than hard-coding those directly into the code, on the
other hand, it seems like these are unrelated to ALS and maybe should go
into some ASUS ACPI driver instead or something ... maybe into
drivers/platform/x86/asus-laptop.c ?

CCing the ASUS folks.

>> +
>>  ACPI_MODULE_NAME("acpi-als");
>>
>>  /*
>> @@ -170,6 +174,46 @@ static int acpi_als_read_raw(struct iio_dev *indio_dev,
>>         return IIO_VAL_INT;
>>  }
>>
>> +static int acpi_als_quirk_asus_zenbook_add(struct acpi_als *als)
>> +{
>> +       acpi_status status;
>> +
>> +       status = acpi_execute_simple_method(NULL, ACPI_ALS_ASUS_TALS, 1);
>> +       if (ACPI_FAILURE(status)) {
>> +               ACPI_EXCEPTION((AE_INFO, status, "Error enabling ALS by %s",
>> +                               ACPI_ALS_ASUS_TALS));
>> +               return -EIO;
>> +       }
>> +       status = acpi_execute_simple_method(NULL, ACPI_ALS_ASUS_ALSC, 1);
>> +       if (ACPI_FAILURE(status)) {
>> +               ACPI_EXCEPTION((AE_INFO, status, "Error enabling ALS by %s",
>> +                               ACPI_ALS_ASUS_ALSC));
>> +               return -EIO;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>> +struct quirk_entry {
>> +       int (*add)(struct acpi_als *als);
> 
> Maybe put the defines above in here.
> 
>      .tals  = "\\_SB.PCI0.LPCB.EC0.TALS",
>      .alsc = ""\\_SB.ATKD.ALSC"
> .

I don't think this'd make much good as they are not standard ACPI
functions IMO, the next platform will have different ad-hoc ones.

>> +};
>> +
>> +static struct quirk_entry acpi_als_quirk_asus_zenbook = {
>> +       .add = acpi_als_quirk_asus_zenbook_add
>> +};
>> +
>> +static const struct dmi_system_id acpi_als_quirks[] = {
>> +       {
>> +               .ident = "ASUSTeK COMPUTER INC. UX",
>> +               .matches = {
>> +                       DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
>> +                       DMI_MATCH(DMI_PRODUCT_NAME, "UX"),
> 
> Really is the DMI_PRODUCT_NAME only two characters? You are likely
> going to need another DMI property to match on.

Agreed

> Thanks,
> 
> Matt
> 
>> +               },
>> +               .driver_data = &acpi_als_quirk_asus_zenbook,
>> +       },
>> +       {},
>> +};
>> +
>>  static const struct iio_info acpi_als_info = {
>>         .driver_module          = THIS_MODULE,
>>         .read_raw               = acpi_als_read_raw,
>> @@ -180,6 +224,9 @@ static int acpi_als_add(struct acpi_device *device)
>>         struct acpi_als *als;
>>         struct iio_dev *indio_dev;
>>         struct iio_buffer *buffer;
>> +       const struct dmi_system_id *dmiid;
>> +       struct quirk_entry *quirk;
>> +       int ret;
>>
>>         indio_dev = devm_iio_device_alloc(&device->dev, sizeof(*als));
>>         if (!indio_dev)
>> @@ -191,6 +238,19 @@ static int acpi_als_add(struct acpi_device *device)
>>         als->device = device;
>>         mutex_init(&als->lock);
>>
>> +       dmiid = dmi_first_match(acpi_als_quirks);
>> +       if (dmiid) {
>> +               dev_dbg(&device->dev, "Detected quirk for %s\n", dmiid->ident);
>> +               quirk = dmiid->driver_data;
>> +               ret = quirk->add(als);
>> +               if (ret) {
>> +                       dev_err(&device->dev,
>> +                               "Executing quirk for %s failed - %d",
>> +                               dmiid->ident, ret);
>> +                       return ret;
>> +               }
>> +       }
>> +
>>         indio_dev->name = ACPI_ALS_DEVICE_NAME;
>>         indio_dev->dev.parent = &device->dev;
>>         indio_dev->info = &acpi_als_info;
>> --
>> 2.10.2
>>
>> --
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-- 
Best regards,
Marek Vasut

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