rtc: imxdi: when locked, do not fail silently

If the DryICE unit is locked it is impossible to set the time. Provide an
error message for this case.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Signed-off-by: Robert Schwebel <rsc@pengutronix.de>
[rsc: got NDA clearance from Freescale]
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

1 files changed, 24 insertions, 3 deletions

diff --git a/drivers/rtc/rtc-imxdi.c b/drivers/rtc/rtc-imxdi.c
index a08da4a353db..7bffd7f0e306 100644
--- a/drivers/rtc/rtc-imxdi.c
+++ b/drivers/rtc/rtc-imxdi.c
@@ -566,14 +566,35 @@ static int dryice_rtc_read_time(struct device *dev, struct rtc_time *tm)
 static int dryice_rtc_set_mmss(struct device *dev, unsigned long secs)
 {
         struct imxdi_dev *imxdi = dev_get_drvdata(dev);
+        u32 dcr, dsr;
         int rc;
 
+        dcr = readl(imxdi->ioaddr + DCR);
+        dsr = readl(imxdi->ioaddr + DSR);
+
+        if (!(dcr & DCR_TCE) || (dsr & DSR_SVF)) {
+                if (dcr & DCR_TCHL) {
+                        /* we are even more out of luck */
+                        di_what_is_to_be_done(imxdi, "battery");
+                        return -EPERM;
+                }
+                if ((dcr & DCR_TCSL) || (dsr & DSR_SVF)) {
+                        /* we are out of luck for now */
+                        di_what_is_to_be_done(imxdi, "main");
+                        return -EPERM;
+                }
+        }
+
         /* zero the fractional part first */
         rc = di_write_wait(imxdi, 0, DTCLR);
-        if (rc == 0)
-                rc = di_write_wait(imxdi, secs, DTCMR);
+        if (rc != 0)
+                return rc;
 
-        return rc;
+        rc = di_write_wait(imxdi, secs, DTCMR);
+        if (rc != 0)
+                return rc;
+
+        return di_write_wait(imxdi, readl(imxdi->ioaddr + DCR) | DCR_TCE, DCR);
 }
 
 static int dryice_rtc_alarm_irq_enable(struct device *dev,