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path: root/drivers/clocksource/acpi_pm.c
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Diffstat (limited to 'drivers/clocksource/acpi_pm.c')
-rw-r--r--drivers/clocksource/acpi_pm.c17
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index c7276a61695b..ccaa6a39cb4b 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -16,15 +16,13 @@
16 * This file is licensed under the GPL v2. 16 * This file is licensed under the GPL v2.
17 */ 17 */
18 18
19#include <linux/acpi_pmtmr.h>
19#include <linux/clocksource.h> 20#include <linux/clocksource.h>
20#include <linux/errno.h> 21#include <linux/errno.h>
21#include <linux/init.h> 22#include <linux/init.h>
22#include <linux/pci.h> 23#include <linux/pci.h>
23#include <asm/io.h> 24#include <asm/io.h>
24 25
25/* Number of PMTMR ticks expected during calibration run */
26#define PMTMR_TICKS_PER_SEC 3579545
27
28/* 26/*
29 * The I/O port the PMTMR resides at. 27 * The I/O port the PMTMR resides at.
30 * The location is detected during setup_arch(), 28 * The location is detected during setup_arch(),
@@ -32,15 +30,13 @@
32 */ 30 */
33u32 pmtmr_ioport __read_mostly; 31u32 pmtmr_ioport __read_mostly;
34 32
35#define ACPI_PM_MASK CLOCKSOURCE_MASK(24) /* limit it to 24 bits */
36
37static inline u32 read_pmtmr(void) 33static inline u32 read_pmtmr(void)
38{ 34{
39 /* mask the output to 24 bits */ 35 /* mask the output to 24 bits */
40 return inl(pmtmr_ioport) & ACPI_PM_MASK; 36 return inl(pmtmr_ioport) & ACPI_PM_MASK;
41} 37}
42 38
43static cycle_t acpi_pm_read_verified(void) 39u32 acpi_pm_read_verified(void)
44{ 40{
45 u32 v1 = 0, v2 = 0, v3 = 0; 41 u32 v1 = 0, v2 = 0, v3 = 0;
46 42
@@ -57,7 +53,12 @@ static cycle_t acpi_pm_read_verified(void)
57 } while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1) 53 } while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1)
58 || (v3 > v1 && v3 < v2))); 54 || (v3 > v1 && v3 < v2)));
59 55
60 return (cycle_t)v2; 56 return v2;
57}
58
59static cycle_t acpi_pm_read_slow(void)
60{
61 return (cycle_t)acpi_pm_read_verified();
61} 62}
62 63
63static cycle_t acpi_pm_read(void) 64static cycle_t acpi_pm_read(void)
@@ -88,7 +89,7 @@ __setup("acpi_pm_good", acpi_pm_good_setup);
88 89
89static inline void acpi_pm_need_workaround(void) 90static inline void acpi_pm_need_workaround(void)
90{ 91{
91 clocksource_acpi_pm.read = acpi_pm_read_verified; 92 clocksource_acpi_pm.read = acpi_pm_read_slow;
92 clocksource_acpi_pm.rating = 110; 93 clocksource_acpi_pm.rating = 110;
93} 94}
94 95