Commit 2b1cd4c4 authored by Mike Frysinger's avatar Mike Frysinger Committed by Linus Torvalds

[PATCH] some rtc documentation updates

Fix typo when describing RTC_WKALM.  Add some helpful pointers to people
developing their own RTC driver.  Change a bunch of the error messages in the
test program to be a bit more helpful.
Signed-off-by: default avatarMike Frysinger <vapier@gentoo.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1efc5da3
......@@ -149,7 +149,7 @@ RTC class framework, but can't be supported by the older driver.
is connected to an IRQ line, it can often issue an alarm IRQ up to
24 hours in the future.
* RTC_WKALM_SET, RTC_WKALM_READ ... RTCs that can issue alarms beyond
* RTC_WKALM_SET, RTC_WKALM_RD ... RTCs that can issue alarms beyond
the next 24 hours use a slightly more powerful API, which supports
setting the longer alarm time and enabling its IRQ using a single
request (using the same model as EFI firmware).
......@@ -167,6 +167,28 @@ Linux out of a low power sleep state (or hibernation) back to a fully
operational state. For example, a system could enter a deep power saving
state until it's time to execute some scheduled tasks.
Note that many of these ioctls need not actually be implemented by your
driver. The common rtc-dev interface handles many of these nicely if your
driver returns ENOIOCTLCMD. Some common examples:
* RTC_RD_TIME, RTC_SET_TIME: the read_time/set_time functions will be
called with appropriate values.
* RTC_ALM_SET, RTC_ALM_READ, RTC_WKALM_SET, RTC_WKALM_RD: the
set_alarm/read_alarm functions will be called. To differentiate
between the ALM and WKALM, check the larger fields of the rtc_wkalrm
struct (like tm_year). These will be set to -1 when using ALM and
will be set to proper values when using WKALM.
* RTC_IRQP_SET, RTC_IRQP_READ: the irq_set_freq function will be called
to set the frequency while the framework will handle the read for you
since the frequency is stored in the irq_freq member of the rtc_device
structure. Also make sure you set the max_user_freq member in your
initialization routines so the framework can sanity check the user
input for you.
If all else fails, check out the rtc-test.c driver!
-------------------- 8< ---------------- 8< -----------------------------
......@@ -237,7 +259,7 @@ int main(int argc, char **argv)
"\n...Update IRQs not supported.\n");
goto test_READ;
}
perror("ioctl");
perror("RTC_UIE_ON ioctl");
exit(errno);
}
......@@ -284,7 +306,7 @@ int main(int argc, char **argv)
/* Turn off update interrupts */
retval = ioctl(fd, RTC_UIE_OFF, 0);
if (retval == -1) {
perror("ioctl");
perror("RTC_UIE_OFF ioctl");
exit(errno);
}
......@@ -292,7 +314,7 @@ test_READ:
/* Read the RTC time/date */
retval = ioctl(fd, RTC_RD_TIME, &rtc_tm);
if (retval == -1) {
perror("ioctl");
perror("RTC_RD_TIME ioctl");
exit(errno);
}
......@@ -320,14 +342,14 @@ test_READ:
"\n...Alarm IRQs not supported.\n");
goto test_PIE;
}
perror("ioctl");
perror("RTC_ALM_SET ioctl");
exit(errno);
}
/* Read the current alarm settings */
retval = ioctl(fd, RTC_ALM_READ, &rtc_tm);
if (retval == -1) {
perror("ioctl");
perror("RTC_ALM_READ ioctl");
exit(errno);
}
......@@ -337,7 +359,7 @@ test_READ:
/* Enable alarm interrupts */
retval = ioctl(fd, RTC_AIE_ON, 0);
if (retval == -1) {
perror("ioctl");
perror("RTC_AIE_ON ioctl");
exit(errno);
}
......@@ -355,7 +377,7 @@ test_READ:
/* Disable alarm interrupts */
retval = ioctl(fd, RTC_AIE_OFF, 0);
if (retval == -1) {
perror("ioctl");
perror("RTC_AIE_OFF ioctl");
exit(errno);
}
......@@ -368,7 +390,7 @@ test_PIE:
fprintf(stderr, "\nNo periodic IRQ support\n");
return 0;
}
perror("ioctl");
perror("RTC_IRQP_READ ioctl");
exit(errno);
}
fprintf(stderr, "\nPeriodic IRQ rate is %ldHz.\n", tmp);
......@@ -387,7 +409,7 @@ test_PIE:
"\n...Periodic IRQ rate is fixed\n");
goto done;
}
perror("ioctl");
perror("RTC_IRQP_SET ioctl");
exit(errno);
}
......@@ -397,7 +419,7 @@ test_PIE:
/* Enable periodic interrupts */
retval = ioctl(fd, RTC_PIE_ON, 0);
if (retval == -1) {
perror("ioctl");
perror("RTC_PIE_ON ioctl");
exit(errno);
}
......@@ -416,7 +438,7 @@ test_PIE:
/* Disable periodic interrupts */
retval = ioctl(fd, RTC_PIE_OFF, 0);
if (retval == -1) {
perror("ioctl");
perror("RTC_PIE_OFF ioctl");
exit(errno);
}
}
......
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