The patch titled
rtc-x1205: Fix alarm set
has been added to the -mm tree. Its filename is
rtc-x1205-fix-alarm-set.patch
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------------------------------------------------------
Subject: rtc-x1205: Fix alarm set
From: Michael Hamel <mhamel@xxxxxxxxx>
I have discovered that the current version of rtc-x1205.c does not work
correctly when asked to set the alarm time by the RTC_WKALM_SET ioctl()
call. This happens because the alarm registers do not behave like the
current-time registers. They are non-volatile. Two things go wrong:
- the X1205 requires a 10 msec delay after any attempt to write to the
non-volatile registers. The x1205_set_datetime() routine does the write
as 8 single-byte writes without any delay. Only the first write
succeeds. The second is NAKed because the chip is busy.
- the X1205 resets the RWEL bit after any write to the non-volatile
registers. This would lock out any further writes after the first even
with a 10msec delay.
I fix this by doing a single 8-byte write and then waiting 10msec for the
chip to be ready. A side effect of this change is that it will speed up
x1205_rtc_set_time() which uses the same code.
I have also implemented the 'enable' bit in the rtc_wkalm structure, which
the existing driver does not attempt to do. I have modified both
x1205_rtc_set_alarm() to set the AL0E bit, and x1205_rtc_read_alarm() to
return it.
I have tested this patch on a LinkSys NSLU2 under OpenWRT, but on no other
hardware. On the NSLU2 the X1205 correctly asserts its IRQ pin when the
alarm time matches the current time.
Signed-off-by: Michael Hamel <mhamel@xxxxxxxxx>
Signed-off-by: Alessandro Zummo <a.zummo@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/rtc/rtc-x1205.c | 103 ++++++++++++++++++++++++++++++++------
1 file changed, 87 insertions(+), 16 deletions(-)
diff -puN drivers/rtc/rtc-x1205.c~rtc-x1205-fix-alarm-set drivers/rtc/rtc-x1205.c
--- a/drivers/rtc/rtc-x1205.c~rtc-x1205-fix-alarm-set
+++ a/drivers/rtc/rtc-x1205.c
@@ -71,6 +71,7 @@
#define X1205_SR_RTCF 0x01 /* Clock failure */
#define X1205_SR_WEL 0x02 /* Write Enable Latch */
#define X1205_SR_RWEL 0x04 /* Register Write Enable */
+#define X1205_SR_AL0 0x20 /* Alarm 0 match */
#define X1205_DTR_DTR0 0x01
#define X1205_DTR_DTR1 0x02
@@ -78,6 +79,8 @@
#define X1205_HR_MIL 0x80 /* Set in ccr.hour for 24 hr mode */
+#define X1205_INT_AL0E 0x20 /* Alarm 0 enable */
+
static struct i2c_driver x1205_driver;
/*
@@ -89,8 +92,8 @@ static int x1205_get_datetime(struct i2c
unsigned char reg_base)
{
unsigned char dt_addr[2] = { 0, reg_base };
-
unsigned char buf[8];
+ int i;
struct i2c_msg msgs[] = {
{ client->addr, 0, 2, dt_addr }, /* setup read ptr */
@@ -110,6 +113,11 @@ static int x1205_get_datetime(struct i2c
buf[0], buf[1], buf[2], buf[3],
buf[4], buf[5], buf[6], buf[7]);
+ /* Mask out the enable bits if these are alarm registers */
+ if (reg_base < X1205_CCR_BASE)
+ for (i = 0; i <= 4; i++)
+ buf[i] &= 0x7F;
+
tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
tm->tm_min = BCD2BIN(buf[CCR_MIN]);
tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
@@ -147,10 +155,11 @@ static int x1205_get_status(struct i2c_c
}
static int x1205_set_datetime(struct i2c_client *client, struct rtc_time *tm,
- int datetoo, u8 reg_base)
+ int datetoo, u8 reg_base, unsigned char alm_enable)
{
- int i, xfer;
+ int i, xfer, nbytes;
unsigned char buf[8];
+ unsigned char rdata[10] = { 0, reg_base };
static const unsigned char wel[3] = { 0, X1205_REG_SR,
X1205_SR_WEL };
@@ -189,6 +198,11 @@ static int x1205_set_datetime(struct i2c
buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
}
+ /* If writing alarm registers, set compare bits on registers 0-4 */
+ if (reg_base < X1205_CCR_BASE)
+ for (i = 0; i <= 4; i++)
+ buf[i] |= 0x80;
+
/* this sequence is required to unlock the chip */
if ((xfer = i2c_master_send(client, wel, 3)) != 3) {
dev_err(&client->dev, "%s: wel - %d\n", __func__, xfer);
@@ -200,19 +214,57 @@ static int x1205_set_datetime(struct i2c
return -EIO;
}
+
/* write register's data */
- for (i = 0; i < (datetoo ? 8 : 3); i++) {
- unsigned char rdata[3] = { 0, reg_base + i, buf[i] };
+ if (datetoo)
+ nbytes = 8;
+ else
+ nbytes = 3;
+ for (i = 0; i < nbytes; i++)
+ rdata[2+i] = buf[i];
- xfer = i2c_master_send(client, rdata, 3);
+ xfer = i2c_master_send(client, rdata, nbytes+2);
+ if (xfer != nbytes+2) {
+ dev_err(&client->dev,
+ "%s: result=%d addr=%02x, data=%02x\n",
+ __func__,
+ xfer, rdata[1], rdata[2]);
+ return -EIO;
+ }
+
+ /* If we wrote to the nonvolatile region, wait 10msec for write cycle*/
+ if (reg_base < X1205_CCR_BASE) {
+ unsigned char al0e[3] = { 0, X1205_REG_INT, 0 };
+
+ msleep(10);
+
+ /* ...and set or clear the AL0E bit in the INT register */
+
+ /* Need to set RWEL again as the write has cleared it */
+ xfer = i2c_master_send(client, rwel, 3);
if (xfer != 3) {
dev_err(&client->dev,
- "%s: xfer=%d addr=%02x, data=%02x\n",
+ "%s: aloe rwel - %d\n",
__func__,
- xfer, rdata[1], rdata[2]);
+ xfer);
return -EIO;
}
- };
+
+ if (alm_enable)
+ al0e[2] = X1205_INT_AL0E;
+
+ xfer = i2c_master_send(client, al0e, 3);
+ if (xfer != 3) {
+ dev_err(&client->dev,
+ "%s: al0e - %d\n",
+ __func__,
+ xfer);
+ return -EIO;
+ }
+
+ /* and wait 10msec again for this write to complete */
+ msleep(10);
+ }
/* disable further writes */
if ((xfer = i2c_master_send(client, diswe, 3)) != 3) {
@@ -230,9 +282,9 @@ static int x1205_fix_osc(struct i2c_clie
tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
- if ((err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE)) < 0)
- dev_err(&client->dev,
- "unable to restart the oscillator\n");
+ err = x1205_set_datetime(client, &tm, 0, X1205_CCR_BASE, 0);
+ if (err < 0)
+ dev_err(&client->dev, "unable to restart the oscillator\n");
return err;
}
@@ -403,14 +455,33 @@ static int x1205_validate_client(struct
static int x1205_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
- return x1205_get_datetime(to_i2c_client(dev),
- &alrm->time, X1205_ALM0_BASE);
+ int err;
+ unsigned char intreg, status;
+ static unsigned char int_addr[2] = { 0, X1205_REG_INT };
+ struct i2c_client *client = to_i2c_client(dev);
+ struct i2c_msg msgs[] = {
+ { client->addr, 0, 2, int_addr }, /* setup read ptr */
+ { client->addr, I2C_M_RD, 1, &intreg }, /* read INT register */
+ };
+
+ /* read interrupt register and status register */
+ if ((i2c_transfer(client->adapter, &msgs[0], 2)) != 2) {
+ dev_err(&client->dev, "%s: read error\n", __func__);
+ return -EIO;
+ }
+ err = x1205_get_status(client, &status);
+ if (err == 0) {
+ alrm->pending = (status & X1205_SR_AL0) ? 1 : 0;
+ alrm->enabled = (intreg & X1205_INT_AL0E) ? 1 : 0;
+ err = x1205_get_datetime(client, &alrm->time, X1205_ALM0_BASE);
+ }
+ return err;
}
static int x1205_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
return x1205_set_datetime(to_i2c_client(dev),
- &alrm->time, 1, X1205_ALM0_BASE);
+ &alrm->time, 1, X1205_ALM0_BASE, alrm->enabled);
}
static int x1205_rtc_read_time(struct device *dev, struct rtc_time *tm)
@@ -422,7 +493,7 @@ static int x1205_rtc_read_time(struct de
static int x1205_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
return x1205_set_datetime(to_i2c_client(dev),
- tm, 1, X1205_CCR_BASE);
+ tm, 1, X1205_CCR_BASE, 0);
}
static int x1205_rtc_proc(struct device *dev, struct seq_file *seq)
_
Patches currently in -mm which might be from mhamel@xxxxxxxxx are
rtc-x1205-fix-alarm-set.patch
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