RTC: rtc-cmos: Fix binary mode support

As a follow-up to the thread about RTC support for some Loongson 2E/2F
boards, this patch tries to address the "REVISIT"/"FIXME" comments about
rtc binary mode handling and allow rtc to work with rtc in binary mode.
I've also raised the message about 24-h mode not supported to warning
otherwise, one may end up with no rtc without any message in the kernel
log.

Signed-off-by: Arnaud Patard <apatard@mandriva.com>
To: linux-mips@linux-mips.org
To: rtc-linux@googlegroups.com
Cc: david-b@pacbell.net
Cc: a.zummo@towertech.it
Cc: akpm@linux-foundation.org
Patchwork: http://patchwork.linux-mips.org/patch/1158/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 40 insertions, 43 deletions

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index ece4dbddc0ea..96e8e70fbf1e 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -238,31 +238,32 @@ static int cmos_read_alarm(struct device *dev, struct rtc_wkalrm *t)
         rtc_control = CMOS_READ(RTC_CONTROL);
         spin_unlock_irq(&rtc_lock);
 
-        /* REVISIT this assumes PC style usage:  always BCD */
-
-        if (((unsigned)t->time.tm_sec) < 0x60)
-                t->time.tm_sec = bcd2bin(t->time.tm_sec);
-        else
-                t->time.tm_sec = -1;
-        if (((unsigned)t->time.tm_min) < 0x60)
-                t->time.tm_min = bcd2bin(t->time.tm_min);
-        else
-                t->time.tm_min = -1;
-        if (((unsigned)t->time.tm_hour) < 0x24)
-                t->time.tm_hour = bcd2bin(t->time.tm_hour);
-        else
-                t->time.tm_hour = -1;
-
-        if (cmos->day_alrm) {
-                if (((unsigned)t->time.tm_mday) <= 0x31)
-                        t->time.tm_mday = bcd2bin(t->time.tm_mday);
+        if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+                if (((unsigned)t->time.tm_sec) < 0x60)
+                        t->time.tm_sec = bcd2bin(t->time.tm_sec);
                 else
-                        t->time.tm_mday = -1;
-                if (cmos->mon_alrm) {
-                        if (((unsigned)t->time.tm_mon) <= 0x12)
-                                t->time.tm_mon = bcd2bin(t->time.tm_mon) - 1;
+                        t->time.tm_sec = -1;
+                if (((unsigned)t->time.tm_min) < 0x60)
+                        t->time.tm_min = bcd2bin(t->time.tm_min);
+                else
+                        t->time.tm_min = -1;
+                if (((unsigned)t->time.tm_hour) < 0x24)
+                        t->time.tm_hour = bcd2bin(t->time.tm_hour);
+                else
+                        t->time.tm_hour = -1;
+
+                if (cmos->day_alrm) {
+                        if (((unsigned)t->time.tm_mday) <= 0x31)
+                                t->time.tm_mday = bcd2bin(t->time.tm_mday);
                         else
-                                t->time.tm_mon = -1;
+                                t->time.tm_mday = -1;
+
+                        if (cmos->mon_alrm) {
+                                if (((unsigned)t->time.tm_mon) <= 0x12)
+                                        t->time.tm_mon = bcd2bin(t->time.tm_mon)-1;
+                                else
+                                        t->time.tm_mon = -1;
+                        }
                 }
         }
         t->time.tm_year = -1;
@@ -322,29 +323,26 @@ static void cmos_irq_disable(struct cmos_rtc *cmos, unsigned char mask)
 static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t)
 {
         struct cmos_rtc *cmos = dev_get_drvdata(dev);
-        unsigned char   mon, mday, hrs, min, sec;
+       unsigned char   mon, mday, hrs, min, sec, rtc_control;
 
         if (!is_valid_irq(cmos->irq))
                 return -EIO;
 
-        /* REVISIT this assumes PC style usage:  always BCD */
-
-        /* Writing 0xff means "don't care" or "match all".  */
-
         mon = t->time.tm_mon + 1;
-        mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
-
         mday = t->time.tm_mday;
-        mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
-
         hrs = t->time.tm_hour;
-        hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
-
         min = t->time.tm_min;
-        min = (min < 60) ? bin2bcd(min) : 0xff;
-
         sec = t->time.tm_sec;
-        sec = (sec < 60) ? bin2bcd(sec) : 0xff;
+
+        rtc_control = CMOS_READ(RTC_CONTROL);
+        if (!(rtc_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+                /* Writing 0xff means "don't care" or "match all".  */
+                mon = (mon <= 12) ? bin2bcd(mon) : 0xff;
+                mday = (mday >= 1 && mday <= 31) ? bin2bcd(mday) : 0xff;
+                hrs = (hrs < 24) ? bin2bcd(hrs) : 0xff;
+                min = (min < 60) ? bin2bcd(min) : 0xff;
+                sec = (sec < 60) ? bin2bcd(sec) : 0xff;
+        }
 
         spin_lock_irq(&rtc_lock);
 
@@ -478,7 +476,7 @@ static int cmos_procfs(struct device *dev, struct seq_file *seq)
                         "update_IRQ\t: %s\n"
                         "HPET_emulated\t: %s\n"
                         // "square_wave\t: %s\n"
-                        // "BCD\t\t: %s\n"
+                        "BCD\t\t: %s\n"
                         "DST_enable\t: %s\n"
                         "periodic_freq\t: %d\n"
                         "batt_status\t: %s\n",
@@ -486,7 +484,7 @@ static int cmos_procfs(struct device *dev, struct seq_file *seq)
                         (rtc_control & RTC_UIE) ? "yes" : "no",
                         is_hpet_enabled() ? "yes" : "no",
                         // (rtc_control & RTC_SQWE) ? "yes" : "no",
-                        // (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
+                        (rtc_control & RTC_DM_BINARY) ? "no" : "yes",
                         (rtc_control & RTC_DST_EN) ? "yes" : "no",
                         cmos->rtc->irq_freq,
                         (valid & RTC_VRT) ? "okay" : "dead");
@@ -751,12 +749,11 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
 
         spin_unlock_irq(&rtc_lock);
 
-        /* FIXME teach the alarm code how to handle binary mode;
+        /* FIXME:
          * <asm-generic/rtc.h> doesn't know 12-hour mode either.
          */
-        if (is_valid_irq(rtc_irq) &&
-            (!(rtc_control & RTC_24H) || (rtc_control & (RTC_DM_BINARY)))) {
-                dev_dbg(dev, "only 24-hr BCD mode supported\n");
+       if (is_valid_irq(rtc_irq) && !(rtc_control & RTC_24H)) {
+                dev_warn(dev, "only 24-hr supported\n");
                 retval = -ENXIO;
                 goto cleanup1;
         }