Re: [PATCH] power:bq27xxx: 27000/10 read FLAGS register as single

From: Andrew F. Davis
Date: Tue Jul 26 2016 - 09:05:08 EST


On 07/18/2016 11:12 AM, H. Nikolaus Schaller wrote:
> The bq27000 and bq27010 have a single byte FLAGS register.
> Other gauges have 16 bit FLAGS registers.
>
> For reading the FLAGS register it is sufficient to read the single
> register instead of reading RSOC at the next higher address as
> well and then ignore the high byte.
>
> This does not change functionality but optimizes i2c and hdq
> traffic.
>
> Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
> ---

Matches the datasheet,

Acked-by: Andrew F. Davis <afd@xxxxxx>

> drivers/power/bq27xxx_battery.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/power/bq27xxx_battery.c b/drivers/power/bq27xxx_battery.c
> index 45f6ebf..56712b2 100644
> --- a/drivers/power/bq27xxx_battery.c
> +++ b/drivers/power/bq27xxx_battery.c
> @@ -656,8 +656,9 @@ static bool bq27xxx_battery_dead(struct bq27xxx_device_info *di, u16 flags)
> static int bq27xxx_battery_read_health(struct bq27xxx_device_info *di)
> {
> int flags;
> + bool has_singe_flag = di->chip == BQ27000 || di->chip == BQ27010;
>
> - flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, false);
> + flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, has_singe_flag);
> if (flags < 0) {
> dev_err(di->dev, "error reading flag register:%d\n", flags);
> return flags;
> @@ -760,7 +761,7 @@ static int bq27xxx_battery_current(struct bq27xxx_device_info *di,
> }
>
> if (di->chip == BQ27000 || di->chip == BQ27010) {
> - flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, false);
> + flags = bq27xxx_read(di, BQ27XXX_REG_FLAGS, true);
> if (flags & BQ27000_FLAG_CHGS) {
> dev_dbg(di->dev, "negative current!\n");
> curr = -curr;
>