diff options
author | Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de> | 2007-09-30 15:35:48 -0400 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-10-12 18:43:37 -0400 |
commit | cef5975d453bbc1bbf29ceb7d80749feebc22a74 (patch) | |
tree | 5a433a0d1ea7730d6dffe3f5db72c866535b7d0d /arch/arm/mach-ns9xxx | |
parent | f02e579558cf2aba06ecc7d4515661286b60f411 (diff) |
[ARM] 4592/1: ns9xxx: clocksource driver
Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-ns9xxx')
-rw-r--r-- | arch/arm/mach-ns9xxx/time.c | 68 |
1 files changed, 42 insertions, 26 deletions
diff --git a/arch/arm/mach-ns9xxx/time.c b/arch/arm/mach-ns9xxx/time.c index 3327d302618d..d29345501762 100644 --- a/arch/arm/mach-ns9xxx/time.c +++ b/arch/arm/mach-ns9xxx/time.c | |||
@@ -11,6 +11,9 @@ | |||
11 | #include <linux/jiffies.h> | 11 | #include <linux/jiffies.h> |
12 | #include <linux/interrupt.h> | 12 | #include <linux/interrupt.h> |
13 | #include <linux/irq.h> | 13 | #include <linux/irq.h> |
14 | #include <linux/stringify.h> | ||
15 | #include <linux/clocksource.h> | ||
16 | |||
14 | #include <asm/arch-ns9xxx/regs-sys.h> | 17 | #include <asm/arch-ns9xxx/regs-sys.h> |
15 | #include <asm/arch-ns9xxx/clock.h> | 18 | #include <asm/arch-ns9xxx/clock.h> |
16 | #include <asm/arch-ns9xxx/irqs.h> | 19 | #include <asm/arch-ns9xxx/irqs.h> |
@@ -18,8 +21,7 @@ | |||
18 | #include "generic.h" | 21 | #include "generic.h" |
19 | 22 | ||
20 | #define TIMERCLOCKSELECT 64 | 23 | #define TIMERCLOCKSELECT 64 |
21 | 24 | #define TIMER_CLOCKSOURCE 1 | |
22 | static u32 usecs_per_tick; | ||
23 | 25 | ||
24 | static irqreturn_t | 26 | static irqreturn_t |
25 | ns9xxx_timer_interrupt(int irq, void *dev_id) | 27 | ns9xxx_timer_interrupt(int irq, void *dev_id) |
@@ -45,39 +47,30 @@ ns9xxx_timer_interrupt(int irq, void *dev_id) | |||
45 | return IRQ_HANDLED; | 47 | return IRQ_HANDLED; |
46 | } | 48 | } |
47 | 49 | ||
48 | static unsigned long ns9xxx_timer_gettimeoffset(void) | ||
49 | { | ||
50 | /* return the microseconds which have passed since the last interrupt | ||
51 | * was _serviced_. That is, if an interrupt is pending or the counter | ||
52 | * reloads, return one period more. */ | ||
53 | |||
54 | u32 counter1 = SYS_TR(0); | ||
55 | int pending = SYS_ISR & (1 << IRQ_TIMER0); | ||
56 | u32 counter2 = SYS_TR(0); | ||
57 | u32 elapsed; | ||
58 | |||
59 | if (pending || counter2 > counter1) | ||
60 | elapsed = 2 * SYS_TRC(0) - counter2; | ||
61 | else | ||
62 | elapsed = SYS_TRC(0) - counter1; | ||
63 | |||
64 | return (elapsed * usecs_per_tick) >> 16; | ||
65 | |||
66 | } | ||
67 | |||
68 | static struct irqaction ns9xxx_timer_irq = { | 50 | static struct irqaction ns9xxx_timer_irq = { |
69 | .name = "NS9xxx Timer Tick", | 51 | .name = "NS9xxx Timer Tick", |
70 | .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, | 52 | .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, |
71 | .handler = ns9xxx_timer_interrupt, | 53 | .handler = ns9xxx_timer_interrupt, |
72 | }; | 54 | }; |
73 | 55 | ||
56 | static cycle_t ns9xxx_clocksource_read(void) | ||
57 | { | ||
58 | return SYS_TR(TIMER_CLOCKSOURCE); | ||
59 | } | ||
60 | |||
61 | static struct clocksource ns9xxx_clocksource = { | ||
62 | .name = "ns9xxx-timer" __stringify(TIMER_CLOCKSOURCE), | ||
63 | .rating = 300, | ||
64 | .read = ns9xxx_clocksource_read, | ||
65 | .mask = CLOCKSOURCE_MASK(32), | ||
66 | .shift = 20, | ||
67 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | ||
68 | }; | ||
69 | |||
74 | static void __init ns9xxx_timer_init(void) | 70 | static void __init ns9xxx_timer_init(void) |
75 | { | 71 | { |
76 | int tc; | 72 | int tc; |
77 | 73 | ||
78 | usecs_per_tick = | ||
79 | SH_DIV(1000000 * TIMERCLOCKSELECT, ns9xxx_cpuclock(), 16); | ||
80 | |||
81 | /* disable timer */ | 74 | /* disable timer */ |
82 | if ((tc = SYS_TC(0)) & SYS_TCx_TEN) | 75 | if ((tc = SYS_TC(0)) & SYS_TCx_TEN) |
83 | SYS_TC(0) = tc & ~SYS_TCx_TEN; | 76 | SYS_TC(0) = tc & ~SYS_TCx_TEN; |
@@ -94,9 +87,32 @@ static void __init ns9xxx_timer_init(void) | |||
94 | SYS_TC(0) = tc; | 87 | SYS_TC(0) = tc; |
95 | 88 | ||
96 | setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq); | 89 | setup_irq(IRQ_TIMER0, &ns9xxx_timer_irq); |
90 | |||
91 | tc = SYS_TC(TIMER_CLOCKSOURCE); | ||
92 | if (REGGET(tc, SYS_TCx, TEN)) { | ||
93 | REGSET(tc, SYS_TCx, TEN, DIS); | ||
94 | SYS_TC(TIMER_CLOCKSOURCE) = tc; | ||
95 | } | ||
96 | |||
97 | SYS_TRC(TIMER_CLOCKSOURCE) = 0; | ||
98 | |||
99 | REGSET(tc, SYS_TCx, TEN, EN); | ||
100 | REGSET(tc, SYS_TCx, TDBG, STOP); | ||
101 | REGSET(tc, SYS_TCx, TLCS, CPU); | ||
102 | REGSET(tc, SYS_TCx, TM, IEE); | ||
103 | REGSET(tc, SYS_TCx, INTS, DIS); | ||
104 | REGSET(tc, SYS_TCx, UDS, UP); | ||
105 | REGSET(tc, SYS_TCx, TSZ, 32); | ||
106 | REGSET(tc, SYS_TCx, REN, EN); | ||
107 | |||
108 | SYS_TC(TIMER_CLOCKSOURCE) = tc; | ||
109 | |||
110 | ns9xxx_clocksource.mult = clocksource_hz2mult(ns9xxx_cpuclock(), | ||
111 | ns9xxx_clocksource.shift); | ||
112 | |||
113 | clocksource_register(&ns9xxx_clocksource); | ||
97 | } | 114 | } |
98 | 115 | ||
99 | struct sys_timer ns9xxx_timer = { | 116 | struct sys_timer ns9xxx_timer = { |
100 | .init = ns9xxx_timer_init, | 117 | .init = ns9xxx_timer_init, |
101 | .offset = ns9xxx_timer_gettimeoffset, | ||
102 | }; | 118 | }; |