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| author | Deepak Saxena <dsaxena@linaro.org> | 2011-11-01 22:25:25 +0100 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2011-11-22 04:00:59 +0100 |
| commit | 5f724e84f91550985a9ae3deb6e0dbc8d8396ed7 (patch) | |
| tree | c7c8695e1963a8f35791848727c39af41c1ffac2 /drivers/clocksource | |
| parent | time: x86: Remove CLOCK_TICK_RATE from acpi_pm clocksource driver (diff) | |
| download | linux-5f724e84f91550985a9ae3deb6e0dbc8d8396ed7.tar.xz linux-5f724e84f91550985a9ae3deb6e0dbc8d8396ed7.zip | |
time: x86: Replace LATCH with PIT_LATCH in i8253 clocksource driver
The i8253 clockevent & clocksource driver uses PIT_LATCH
except for two cases where it uses LATCH:
1)
/* VIA686a test code... reset the latch if count > max + 1 */
if (count > LATCH) {
LATCH is based on CLOCK_TICK_RATE which is defined as
PIT_TICK_RATE on x86 so this should just be the later.
2)
...
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* binary, mode 2, LSB/MSB, ch 0 */
outb_p(0x34, PIT_MODE);
outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
outb_p(LATCH >> 8 , PIT_CH0); /* MSB */
...
MIPS and ARM are the only other arches that use this driver. In
the MIPS case CLOCK_TICK_RATE is defined as the same value as
PIT_TICK_RATE. For ARM, the only machine that uses it is
Footbridge which has a totally bogus CLOCK_TICK_RATE according
to the comments. Furthermore, the clockevent_i8253_init()
initializes the clockevent with PIT_TIC_RATE, so there's
no reason to use the generic LATCH.
This is part of work to remove and depecrate the global
CLOCK_TICK_RATE symbol.
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/i8253.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c index 27c49e60b7d6..e7cab2da910f 100644 --- a/drivers/clocksource/i8253.c +++ b/drivers/clocksource/i8253.c @@ -53,7 +53,7 @@ static cycle_t i8253_read(struct clocksource *cs) count |= inb_p(PIT_CH0) << 8; /* VIA686a test code... reset the latch if count > max + 1 */ - if (count > LATCH) { + if (count > PIT_LATCH) { outb_p(0x34, PIT_MODE); outb_p(PIT_LATCH & 0xff, PIT_CH0); outb_p(PIT_LATCH >> 8, PIT_CH0); @@ -114,8 +114,8 @@ static void init_pit_timer(enum clock_event_mode mode, case CLOCK_EVT_MODE_PERIODIC: /* binary, mode 2, LSB/MSB, ch 0 */ outb_p(0x34, PIT_MODE); - outb_p(LATCH & 0xff , PIT_CH0); /* LSB */ - outb_p(LATCH >> 8 , PIT_CH0); /* MSB */ + outb_p(PIT_LATCH & 0xff , PIT_CH0); /* LSB */ + outb_p(PIT_LATCH >> 8 , PIT_CH0); /* MSB */ break; case CLOCK_EVT_MODE_SHUTDOWN: |