Re: [PATCH v5 3/6] mfd: cros_ec: Add cros_ec_get_host_event

From: Benson Leung <bleung@chromium.org>
To: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"Sameer Nanda" <snanda@chromium.org>,
	"Javier Martinez Canillas" <javier@osg.samsung.com>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Enric Balletbò" <enric.balletbo@collabora.co.uk>,
	"Vic Yang" <victoryang@chromium.org>,
	"Stephen Boyd" <sboyd@codeaurora.org>,
	"Vincent Palatin" <vpalatin@chromium.org>,
	"Randall Spangler" <rspangler@chromium.org>,
	"Todd Broch" <tbroch@chromium.org>,
	"Gwendal Grignou" <gwendal@chromium.org>,
	"Olof Johansson" <olof@lixom.net>
Subject: Re: [PATCH v5 3/6] mfd: cros_ec: Add cros_ec_get_host_event
Date: Mon, 14 Mar 2016 12:23:00 -0700	[thread overview]
Message-ID: <CANLzEkv2nd-X=h3EgM8Z8JxbJN1MnazaxqzYWVbMVXEkoytJ=g@mail.gmail.com> (raw)
In-Reply-To: <1457970301-24616-4-git-send-email-tomeu.vizoso@collabora.com>

On Mon, Mar 14, 2016 at 8:44 AM, Tomeu Vizoso
<tomeu.vizoso@collabora.com> wrote:
> This function returns the code for the host event that triggered the
> interrupt that is being currently handled.
>
> Is to be used by observers of the event_notifier in the EC device.
>
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
> ---
>
> Changes in v5: None
> Changes in v4: None
> Changes in v3: None
> Changes in v2: None
>
>  drivers/platform/chrome/cros_ec_proto.c | 23 +++++++++++++++++++++++
>  include/linux/mfd/cros_ec.h             | 10 ++++++++++
>  2 files changed, 33 insertions(+)
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index aaccdde1c9d5..97c287cfd0c0 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -486,3 +486,26 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
>         return ret;
>  }
>  EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
> +
> +u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
> +{
> +       u32 host_event;
> +
> +       if (!ec_dev->mkbp_event_supported) {
> +               dev_warn(ec_dev->dev,
> +                        "This EC does not support EC_MKBP_EVENT_HOST_EVENT");
> +               return -EPROTONOSUPPORT;

Return value of this function is u32, so this probably isn't the right
thing to do here. The kerneldoc mentions that errors are return 0.

> +       }
> +
> +       if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
> +               return 0;
> +
> +       if (ec_dev->event_size != sizeof(host_event)) {
> +               dev_warn(ec_dev->dev, "Invalid host event size\n");
> +               return 0;
> +       }
> +
> +       host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);
> +       return host_event;
> +}
> +EXPORT_SYMBOL(cros_ec_get_host_event);
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index b6961c717209..1ef98d41870b 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -304,6 +304,16 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev);
>   */
>  int cros_ec_get_next_event(struct cros_ec_device *ec_dev);
>
> +/**
> + * cros_ec_get_host_event - Return a mask of event set by the EC.
> + *
> + * Returns the mask of the event that caused the last interrupt to be raised.
> + *
> + * @ec_dev: Device to fetch event from
> + * @return event mask, 0 on error
> + */
> +uint32_t cros_ec_get_host_event(struct cros_ec_device *ec_dev);
> +
>  /* sysfs stuff */
>  extern struct attribute_group cros_ec_attr_group;
>  extern struct attribute_group cros_ec_lightbar_attr_group;
> --
> 2.5.0
>

-- 
Benson Leung
Senior Software Engineer, Chrom* OS
bleung@chromium.org