Re: [PATCH 1/3] platform/chrome: cros_ec_proto: Add peripheral charger count API

[Prashant Malani <pmalani@chromium.org>]

Hey Stephen,

On Apr 14 17:32, Stephen Boyd wrote:
> Add a peripheral charger count API similar to the one implemented in the
> ChromeOS PCHG driver so we can use it to decide whether or not to
> register the PCHG device in the cros_ec MFD driver.
> 
> Cc: Lee Jones <lee.jones@linaro.org>
> Cc: Daisuke Nojiri <dnojiri@chromium.org>
> Cc: Benson Leung <bleung@chromium.org>
> Cc: Guenter Roeck <groeck@chromium.org>
> Cc: <chrome-platform@lists.linux.dev>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>  drivers/platform/chrome/cros_ec_proto.c     | 31 +++++++++++++++++++++
>  include/linux/platform_data/cros_ec_proto.h |  1 +
>  2 files changed, 32 insertions(+)
> 
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index c4caf2e2de82..42269703ca6c 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -832,6 +832,37 @@ bool cros_ec_check_features(struct cros_ec_dev *ec, int feature)
>  }
>  EXPORT_SYMBOL_GPL(cros_ec_check_features);
>  
> +/**
> + * cros_ec_pchg_port_count() - Return the number of peripheral charger ports.
> + * @ec: EC device.
> + *
> + * Return: Number of peripheral charger ports, or 0 in case of error.
> + */
> +unsigned int cros_ec_pchg_port_count(struct cros_ec_dev *ec)
> +{
> +	struct cros_ec_command *msg;
> +	const struct ec_response_pchg_count *rsp;
> +	struct cros_ec_device *ec_dev = ec->ec_dev;
> +	int ret, count = 0;
> +
> +	msg = kzalloc(sizeof(*msg) + sizeof(*rsp), GFP_KERNEL);
> +	if (!msg)
> +		return 0;
> +
> +	msg->command = EC_CMD_PCHG_COUNT + ec->cmd_offset;
> +	msg->insize = sizeof(*rsp);
> +
> +	ret = cros_ec_cmd_xfer_status(ec_dev, msg);
> +	if (ret >= 0) {
> +		rsp = (const struct ec_response_pchg_count *)msg->data;
> +		count = rsp->port_count;
> +	}
> +	kfree(msg);

Can we use the wrapper function cros_ec_command() [1] here, which does
the kzalloc and msg construction?

Best regards,

-Prashant

[1] https://elixir.bootlin.com/linux/latest/source/drivers/platform/chrome/cros_ec_proto.c#L914