Re: [PATCH 03/14] POWER: bq27x00: Fix current now property

[Rodolfo Giometti]

On Sun, Feb 06, 2011 at 01:48:00AM +0100, Lars-Peter Clausen wrote:
> From: Pali Rohár <pali.rohar@xxxxxxxxx>
> 
> According to the bq27000 datasheet to obtain the current value in Micro-ampere
> from the AI register it has to be transformed by the following formula:
>     current = AI * 3570 / 20
> 
> This patch adjust the drivers code accordingly.
> 
> Signed-off-by: Pali Rohár <pali.rohar@xxxxxxxxx>
> Signed-off-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> ---
>  drivers/power/bq27x00_battery.c |    7 +++++--
>  1 files changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/power/bq27x00_battery.c b/drivers/power/bq27x00_battery.c
> index 4f74659..1b06134 100644
> --- a/drivers/power/bq27x00_battery.c
> +++ b/drivers/power/bq27x00_battery.c
> @@ -44,6 +44,8 @@
>  #define BQ27500_FLAG_DSC		BIT(0)
>  #define BQ27500_FLAG_FC			BIT(9)
>  
> +#define BQ27000_RS			20 /* Resistor sense */
> +
>  /* If the system has several batteries we need a different name for each
>   * of them...
>   */
> @@ -149,7 +151,7 @@ static int bq27x00_battery_current(struct bq27x00_device_info *di)
>  
>  	if (di->chip == BQ27500) {
>  		/* bq27500 returns signed value */
> -		curr = (int)(s16)curr;
> +		curr = (int)((s16)curr) * 1000;
>  	} else {
>  		ret = bq27x00_read(BQ27x00_REG_FLAGS, &flags, 0, di);
>  		if (ret < 0) {
> @@ -160,9 +162,10 @@ static int bq27x00_battery_current(struct bq27x00_device_info *di)
>  			dev_dbg(di->dev, "negative current!\n");
>  			curr = -curr;
>  		}
> +		curr = curr * 3570 / BQ27000_RS;
>  	}
>  
> -	return curr * 1000;
> +	return curr;
>  }
>  
>  /*
> -- 
> 1.7.2.3
> 

Acked-by: Rodolfo Giometti <giometti@xxxxxxxx>

-- 

GNU/Linux Solutions                  e-mail: giometti@xxxxxxxxxxxx
Linux Device Driver                          giometti@xxxxxxxx
Embedded Systems                     phone:  +39 349 2432127
UNIX programming                     skype:  rodolfo.giometti
Freelance ICT Italia - Consulente ICT Italia - www.consulenti-ict.it
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