Re: [PATCH 1/3] rtc: s35390a: clarify INT2 pin output modes

From: Alexandre Belloni
Date: Tue May 21 2019 - 11:57:05 EST


Hello,

This seems good to me but...

On 21/05/2019 16:20:22+0200, Richard Leitner wrote:
> Fix the INT2 mode mask to not include the "TEST" flag. Furthermore
> remove the not needed reversion of bits when parsing the INT2 modes.
> Instead reverse the INT2_MODE defines.
>
> Additionally mention the flag names from the datasheet for the different
> modes in the comments.
>
> Signed-off-by: Richard Leitner <richard.leitner@xxxxxxxxxxx>
> ---
> drivers/rtc/rtc-s35390a.c | 16 +++++++---------
> 1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/rtc/rtc-s35390a.c b/drivers/rtc/rtc-s35390a.c
> index 3c64dbb08109..6fb6d835b178 100644
> --- a/drivers/rtc/rtc-s35390a.c
> +++ b/drivers/rtc/rtc-s35390a.c
> @@ -45,12 +45,13 @@
> /* flag for STATUS2 */
> #define S35390A_FLAG_TEST 0x01
>
> -#define S35390A_INT2_MODE_MASK 0xF0
> -
> +/* INT2 pin output mode */
> +#define S35390A_INT2_MODE_MASK 0x0E
> #define S35390A_INT2_MODE_NOINTR 0x00
> -#define S35390A_INT2_MODE_FREQ 0x10
> -#define S35390A_INT2_MODE_ALARM 0x40
> -#define S35390A_INT2_MODE_PMIN_EDG 0x20
> +#define S35390A_INT2_MODE_ALARM 0x02 /* INT2AE */
> +#define S35390A_INT2_MODE_PMIN_EDG 0x04 /* INT2ME */
> +#define S35390A_INT2_MODE_FREQ 0x08 /* INT2FE */
> +#define S35390A_INT2_MODE_PMIN 0x0C /* INT2ME | INT2FE */
>

While you are at it you may as well use BIT().

> static const struct i2c_device_id s35390a_id[] = {
> { "s35390a", 0 },
> @@ -303,9 +304,6 @@ static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
> else
> sts = S35390A_INT2_MODE_NOINTR;
>
> - /* This chip expects the bits of each byte to be in reverse order */
> - sts = bitrev8(sts);
> -
> /* set interupt mode*/
> err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts));
> if (err < 0)
> @@ -343,7 +341,7 @@ static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
> if (err < 0)
> return err;
>
> - if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
> + if ((sts & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) {
> /*
> * When the alarm isn't enabled, the register to configure
> * the alarm time isn't accessible.
> --
> 2.20.1
>

--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com