On 3 December 2012 20:10, Antoine Mathys barsa...@gmail.com wrote:
Per the datasheet, the DATE (wday) register is user defined. Implement this.
Signed-off-by: Antoine Mathys barsa...@gmail.com
---
hw/ds1338.c | 14 --
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/hw/ds1338.c b/hw/ds1338.c
index 8f85635..c502934 100644
--- a/hw/ds1338.c
+++ b/hw/ds1338.c
@@ -20,6 +20,7 @@
typedef struct {
I2CSlave i2c;
int64_t offset;
+uint8_t wday_offset;
uint8_t nvram[NVRAM_SIZE];
int32_t ptr;
bool addr_byte;
@@ -33,6 +34,7 @@ static const VMStateDescription vmstate_ds1338 = {
.fields = (VMStateField[]) {
VMSTATE_I2C_SLAVE(i2c, DS1338State),
VMSTATE_INT64(offset, DS1338State),
+VMSTATE_UINT8(wday_offset, DS1338State),
VMSTATE_UINT8_ARRAY(nvram, DS1338State, NVRAM_SIZE),
VMSTATE_INT32(ptr, DS1338State),
VMSTATE_BOOL(addr_byte, DS1338State),
This breaks migration -- you need to bump the version_id to 2 and mark
the new field as only present in the new version, like this:
VMSTATE_UINT8_V(wday_offset, DS1338State, 2),
@@ -62,7 +64,7 @@ static void write_time(DS1338State *s, const struct tm
*tm)
} else {
s-nvram[2] = to_bcd(tm-tm_hour);
}
-s-nvram[3] = to_bcd(tm-tm_wday + 1);
+s-nvram[3] = to_bcd((tm-tm_wday + s-wday_offset) % 7 + 1);
There's not much point doing a to_bcd() on a value guaranteed to
be in [0..9].
s-nvram[4] = to_bcd(tm-tm_mday);
s-nvram[5] = to_bcd(tm-tm_mon + 1);
s-nvram[6] = to_bcd(tm-tm_year - 100);
@@ -164,7 +166,12 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data)
}
break;
case 3:
-now.tm_wday = from_bcd(data 0x07) - 1;
+{
This brace should line up with the 'c' in 'case' (ditto the closing brace).
+int user_wday = from_bcd(data 0x07) - 1;
...again, from_bcd() is pointless here.
+if ((user_wday = 0) (user_wday = 6)) {
This condition is an obscure way to guard against the undefined case
of the guest writing zero to a register that's supposed to contain
values between 1 and 7. It would also be good to have a comment saying
explicitly that the datasheet says you get undefined operation here.
(for curiosity, do you happen to have real hardware to see what it
does in this case?)
+s-wday_offset = (user_wday - now.tm_wday + 7) % 7;
+}
+}
break;
case 4:
now.tm_mday = from_bcd(data 0x3f);
@@ -194,6 +201,9 @@ static int ds1338_send(I2CSlave *i2c, uint8_t data)
static int ds1338_init(I2CSlave *i2c)
{
+DS1338State *s = FROM_I2C_SLAVE(DS1338State, i2c);
+s-wday_offset = 0;
+
This doesn't belong in the device init function, you need to
create a reset function and reset it there. (ie set dc-reset
in the class init function, see eg hw/pl190.c for an example).
return 0;
}
--
1.7.10.4
thanks
-- PMM
