Commit-ID: 5f724e84f91550985a9ae3deb6e0dbc8d8396ed7
Gitweb: http://git.kernel.org/tip/5f724e84f91550985a9ae3deb6e0dbc8d8396ed7
Author: Deepak Saxena <dsaxena@xxxxxxxxxx>
AuthorDate: Tue, 1 Nov 2011 14:25:25 -0700
Committer: John Stultz <john.stultz@xxxxxxxxxx>
CommitDate: Mon, 21 Nov 2011 19:00:59 -0800
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@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
---
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 27c49e6..e7cab2d 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:
--
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