@@ -8,6 +8,7 @@
#ifndef __ASM_MACH_PS2_SCMD_H
#define __ASM_MACH_PS2_SCMD_H
+#include <linux/time64.h>
#include <linux/types.h>
#define SCMD_COMMAND 0x1f402016
@@ -20,10 +21,12 @@
/**
* enum scmd_cmd - system commands
+ * @scmd_cmd_read_rtc: read the real-time clock (RTC)
* @scmd_cmd_power_off: power off the system
* @scmd_cmd_read_machine_name: read machine name
*/
enum scmd_cmd {
+ scmd_cmd_read_rtc = 8,
scmd_cmd_power_off = 15,
scmd_cmd_read_machine_name = 23,
};
@@ -44,4 +47,6 @@ struct scmd_machine_name {
struct scmd_machine_name scmd_read_machine_name(void);
+int scmd_read_rtc(time64_t *t);
+
#endif /* __ASM_MACH_PS2_SCMD_H */
@@ -13,8 +13,14 @@
#include <linux/sched.h>
#include <linux/sched/signal.h>
+#include <linux/bcd.h>
+#include <linux/rtc.h>
+
#include <asm/mach-ps2/scmd.h>
+#define UTC_TO_JST (9*60*60) /* UTC to Japan standard time */
+#define JST_TO_UTC (-UTC_TO_JST) /* Japan standard time to UTC */
+
/**
* completed - poll for condition to happen, or timeout
* @condition: function to poll for condition
@@ -266,6 +272,55 @@ struct scmd_machine_name scmd_read_machine_name(void)
}
EXPORT_SYMBOL_GPL(scmd_read_machine_name);
+/**
+ * scmd_read_rtc - system command to read the real-time clock (RTC)
+ * @t: pointer to store the time on a successful reading
+ *
+ * The hardware clock is designed to keep Japan standard time (JST), regardless
+ * of the region of the machine. This is adjusted in the driver so that the
+ * clock to the kernel appears to be kept in coordinated universal time (UTC).
+ * Tools such as hwclock should therefore read the clock in the UTC timescale.
+ *
+ * Context: sleep
+ * Return: 0 on success, else a negative error number
+ */
+int scmd_read_rtc(time64_t *t)
+{
+ struct __attribute__ ((packed)) {
+ u8 status;
+ u8 second;
+ u8 minute;
+ u8 hour;
+ u8 pad;
+ u8 day;
+ u8 month;
+ u8 year;
+ } rtc;
+ int err;
+
+ BUILD_BUG_ON(sizeof(rtc) != 8);
+ err = scmd(scmd_cmd_read_rtc, NULL, 0, &rtc, sizeof(rtc));
+ if (err < 0) {
+ pr_debug("%s: Read failed with %d at 0\n", __func__, err);
+ return err;
+ }
+ if (rtc.status != 0) {
+ pr_debug("%s: Invalid result with status 0x%x\n",
+ __func__, rtc.status);
+ return -EIO;
+ }
+
+ *t = mktime64(bcd2bin(rtc.year) + 2000,
+ bcd2bin(rtc.month),
+ bcd2bin(rtc.day),
+ bcd2bin(rtc.hour),
+ bcd2bin(rtc.minute),
+ bcd2bin(rtc.second)) + JST_TO_UTC;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(scmd_read_rtc);
+
MODULE_DESCRIPTION("PlayStation 2 system commands");
MODULE_AUTHOR("Fredrik Noring");
MODULE_LICENSE("GPL");
The hardware clock is designed to keep Japan standard time (JST), regardless of the region of the machine. This is adjusted in the driver so that the clock to the kernel appears to be kept in coordinated universal time (UTC). Tools such as hwclock should therefore read the clock in the UTC timescale. Signed-off-by: Fredrik Noring <noring@nocrew.org> --- arch/mips/include/asm/mach-ps2/scmd.h | 5 +++ arch/mips/ps2/scmd.c | 55 +++++++++++++++++++++++++++ 2 files changed, 60 insertions(+)