diff options
| author | Deepak Saxena <dsaxena@linaro.org> | 2011-11-01 17:25:25 -0400 |
|---|---|---|
| committer | John Stultz <john.stultz@linaro.org> | 2011-11-21 22:00:59 -0500 |
| commit | 5f724e84f91550985a9ae3deb6e0dbc8d8396ed7 (patch) | |
| tree | c7c8695e1963a8f35791848727c39af41c1ffac2 /drivers/clocksource | |
| parent | cbf1599b3589c6c73999095ca25e9c3f23042e19 (diff) | |
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) | |||
| 53 | count |= inb_p(PIT_CH0) << 8; | 53 | count |= inb_p(PIT_CH0) << 8; |
| 54 | 54 | ||
| 55 | /* VIA686a test code... reset the latch if count > max + 1 */ | 55 | /* VIA686a test code... reset the latch if count > max + 1 */ |
| 56 | if (count > LATCH) { | 56 | if (count > PIT_LATCH) { |
| 57 | outb_p(0x34, PIT_MODE); | 57 | outb_p(0x34, PIT_MODE); |
| 58 | outb_p(PIT_LATCH & 0xff, PIT_CH0); | 58 | outb_p(PIT_LATCH & 0xff, PIT_CH0); |
| 59 | outb_p(PIT_LATCH >> 8, PIT_CH0); | 59 | outb_p(PIT_LATCH >> 8, PIT_CH0); |
| @@ -114,8 +114,8 @@ static void init_pit_timer(enum clock_event_mode mode, | |||
| 114 | case CLOCK_EVT_MODE_PERIODIC: | 114 | case CLOCK_EVT_MODE_PERIODIC: |
| 115 | /* binary, mode 2, LSB/MSB, ch 0 */ | 115 | /* binary, mode 2, LSB/MSB, ch 0 */ |
| 116 | outb_p(0x34, PIT_MODE); | 116 | outb_p(0x34, PIT_MODE); |
| 117 | outb_p(LATCH & 0xff , PIT_CH0); /* LSB */ | 117 | outb_p(PIT_LATCH & 0xff , PIT_CH0); /* LSB */ |
| 118 | outb_p(LATCH >> 8 , PIT_CH0); /* MSB */ | 118 | outb_p(PIT_LATCH >> 8 , PIT_CH0); /* MSB */ |
| 119 | break; | 119 | break; |
| 120 | 120 | ||
| 121 | case CLOCK_EVT_MODE_SHUTDOWN: | 121 | case CLOCK_EVT_MODE_SHUTDOWN: |
