linux-kernel - Re: [PATCH] cros_ec: instantiate properly Intel ISH MCU device

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Date:   Thu, 28 Feb 2019 13:33:09 +0100
From:   Enric Balletbo Serra <eballetbo@...il.com>
To:     Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
Cc:     Lee Jones <lee.jones@...aro.org>,
        Benson Leung <bleung@...omium.org>,
        Enric Balletbo i Serra <enric.balletbo@...labora.com>,
        Guenter Roeck <groeck@...omium.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Gwendal Grignou <gwendal@...gle.com>,
        Jett Rink <jettrink@...omium.org>,
        Andy Shevchenko <andriy.shevchenko@...el.com>
Subject: Re: [PATCH] cros_ec: instantiate properly Intel ISH MCU device

Hi,

Based on the discussion we had, only some few comments.

Missatge de Rushikesh S Kadam <rushikesh.s.kadam@...el.com> del dia
dg., 24 de febr. 2019 a les 10:15:
>
> Intel Integrated Sensor Hub (ISH) is also a MCU running EC
> having feature bit EC_FEATURE_ISH. Instantiate it as a special
> CrOS EC device with device name 'cros_ish'.
>
> Signed-off-by: Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
> ---
>  drivers/mfd/cros_ec_dev.c            | 10 ++++++++++
>  include/linux/mfd/cros_ec.h          |  1 +
>  include/linux/mfd/cros_ec_commands.h |  2 ++

Better if you use the "mfd: cros_ec:" prefix in the next version so
it's clear that this should go through the MFD tree.

>  3 files changed, 13 insertions(+)
>
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index 2d0fee4..be499b8 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -414,6 +414,16 @@ static int ec_device_probe(struct platform_device *pdev)
>         device_initialize(&ec->class_dev);
>         cdev_init(&ec->cdev, &fops);
>
> +       /* check whether this is actually a Intel ISH rather than an EC */

"Check whether this is actually an Integrated Sensor Hub (ISH) rather
than an EC"?

> +       if (cros_ec_check_features(ec, EC_FEATURE_ISH)) {
> +               dev_info(dev, "Intel ISH MCU detected.\n");

 dev_info(dev, "CrOS ISH MCU detected.\n"); ?

> +               /*
> +                * Help userspace differentiating ECs from ISH MCU,
> +                * regardless of the probing order.
> +                */
> +               ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
> +       }
> +
>         /*
>          * Add the class device
>          * Link to the character device for creating the /dev entry
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index de8b588..00c5765 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -24,6 +24,7 @@
>
>  #define CROS_EC_DEV_NAME "cros_ec"
>  #define CROS_EC_DEV_PD_NAME "cros_pd"
> +#define CROS_EC_DEV_ISH_NAME "cros_ish"
>
>  /*
>   * The EC is unresponsive for a time after a reboot command.  Add a
> diff --git a/include/linux/mfd/cros_ec_commands.h b/include/linux/mfd/cros_ec_commands.h
> index fc91082..9276c3c 100644
> --- a/include/linux/mfd/cros_ec_commands.h
> +++ b/include/linux/mfd/cros_ec_commands.h
> @@ -856,6 +856,8 @@ enum ec_feature_code {
>         EC_FEATURE_RTC = 27,
>         /* EC supports CEC commands */
>         EC_FEATURE_CEC = 35,
> +       /* The MCU is an Intel Integrated Sensor Hub */
> +       EC_FEATURE_ISH = 40,

Just a note that we will have a trivial conflict to solve with
https://lkml.org/lkml/2019/2/27/723

>  };
>
>  #define EC_FEATURE_MASK_0(event_code) (1UL << (event_code % 32))
> --
> 1.9.1
>

Best regards,
Enric