On Dec 12, 2007 8:23 AM, Andrew Morton <[EMAIL PROTECTED]> wrote: > On Thu, 6 Dec 2007 22:10:27 +0000 Byron Bradley <[EMAIL PROTECTED]> wrote: > > > This adds basic get/set time support for the Seiko Instruments > > S-35390A. This chip communicates using I2C and is used on the > > QNAP TS-109/TS-209 NAS devices. > > > > A nice looking little driver. > > > +static inline char reverse(char x) > > +{ > > + x = ((x >> 1) & 0x55) | ((x << 1) & 0xaa); > > + x = ((x >> 2) & 0x33) | ((x << 2) & 0xcc); > > + return (x >> 4) | (x << 4); > > +} > > Please take a peek in include/linux/bitrev.h ;)
Thanks Andrew, I knew there must have been a function to do this somewhere but all I could find were the swab functions. > Could you review and runtime test this please? > > --- a/drivers/rtc/rtc-s35390a.c~rtc-add-support-for-the-s-35390a-rtc-chip-fix > +++ a/drivers/rtc/rtc-s35390a.c > @@ -12,6 +12,7 @@ > #include <linux/module.h> > #include <linux/rtc.h> > #include <linux/i2c.h> > +#include <linux/bitrev.h> > #include <linux/bcd.h> > > #define S35390A_CMD_STATUS1 0 > @@ -121,13 +122,6 @@ static int s35390a_reg2hr(struct s35390a > return hour; > } > > -static inline char reverse(char x) > -{ > - x = ((x >> 1) & 0x55) | ((x << 1) & 0xaa); > - x = ((x >> 2) & 0x33) | ((x << 2) & 0xcc); > - return (x >> 4) | (x << 4); > -} > - > static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time > *tm) > { > struct s35390a *s35390a = i2c_get_clientdata(client); > @@ -149,7 +143,7 @@ static int s35390a_set_datetime(struct i > > /* This chip expects the bits of each byte to be in reverse order */ > for (i = 0; i < 7; ++i) > - buf[i] = reverse(buf[i]); > + buf[i] = bitrev8(buf[i]); > > err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); > > @@ -168,7 +162,7 @@ static int s35390a_get_datetime(struct i > > /* This chip returns the bits of each byte in reverse order */ > for (i = 0; i < 7; ++i) > - buf[i] = reverse(buf[i]); > + buf[i] = bitrev8(buf[i]); > > tm->tm_sec = BCD2BIN(buf[S35390A_BYTE_SECS]); > tm->tm_min = BCD2BIN(buf[S35390A_BYTE_MINS]); > _ The above patch works as expected. Thanks, -- Byron Bradley -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/