Re: [PATCH v2 1/4] mfd: cros_ec: Add cros_ec_cmd_xfer_status helper

[Enric Balletbo i Serra <enric.balletbo@collabora.com>]

On 16/06/16 17:30, Lee Jones wrote:
> On Thu, 02 Jun 2016, Brian Norris wrote:
> 
>> From: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>>
>> So that callers of cros_ec_cmd_xfer don't have to repeat boilerplate
>> code when checking for errors from the EC side.
>>
>> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
>> Reviewed-by: Benson Leung <bleung@chromium.org>
>> Signed-off-by: Brian Norris <briannorris@chromium.org>
>> ---
>> v2: no change
>>
>>  drivers/platform/chrome/cros_ec_proto.c | 15 +++++++++++++++
>>  include/linux/mfd/cros_ec.h             | 18 ++++++++++++++++++
>>  2 files changed, 33 insertions(+)
>>
>> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
>> index b6e161f71b26..ecc544c728f0 100644
>> --- a/drivers/platform/chrome/cros_ec_proto.c
>> +++ b/drivers/platform/chrome/cros_ec_proto.c
>> @@ -380,3 +380,18 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
>>  	return ret;
>>  }
>>  EXPORT_SYMBOL(cros_ec_cmd_xfer);
>> +
>> +int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
>> +			    struct cros_ec_command *msg)
>> +{
>> +	int ret;
>> +
>> +	ret = cros_ec_cmd_xfer(ec_dev, msg);
>> +	if (ret < 0)
>> +		dev_err(ec_dev->dev, "Command xfer error (err:%d)\n", ret);
>> +	else if (msg->result != EC_RES_SUCCESS)
>> +		return -EECRESULT - msg->result;
>> +
>> +	return ret;
>> +}
>> +EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
>> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
>> index 64184d27e3cd..b1e48dfbf50a 100644
>> --- a/include/linux/mfd/cros_ec.h
>> +++ b/include/linux/mfd/cros_ec.h
>> @@ -40,6 +40,9 @@
>>  #define EC_MAX_REQUEST_OVERHEAD		1
>>  #define EC_MAX_RESPONSE_OVERHEAD	2
>>  
>> +/* ec_command return value for non-success result from EC */
>> +#define EECRESULT 1000
>> +
>>  /*
>>   * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
>>   */
>> @@ -226,6 +229,21 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
>>  		     struct cros_ec_command *msg);
>>  
>>  /**
>> + * cros_ec_cmd_xfer_status - Send a command to the ChromeOS EC
>> + *
>> + * This function is identical to cros_ec_cmd_xfer, except it returns succes
> 
> s/succes/success/
> 
> I guess whoever takes this patch can do a quick fix-up job on it, so:
> 
> Acked-by: Lee Jones <lee.jones@linaro.org>
> 
>> + * status only if both the command was transmitted successfully and the EC
>> + * replied with success status. It's not necessary to check msg->result when
>> + * using this function.
>> + *
>> + * @ec_dev: EC device
>> + * @msg: Message to write
>> + * @return: Num. of bytes transferred on success, <0 on failure
>> + */
>> +int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
>> +			    struct cros_ec_command *msg);
>> +
>> +/**
>>   * cros_ec_remove - Remove a ChromeOS EC
>>   *
>>   * Call this to deregister a ChromeOS EC, then clean up any private data.
> 

This patch is also useful for other drivers like the cros-ec sensors that we plan to upstream soon, so will be good have it merged.

Tested-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>