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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2006-06-20 14:48:18 -0400 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2006-06-20 14:48:18 -0400 |
commit | 695a9d236a6fd5a60557a02eff612880c37fe731 (patch) | |
tree | 0ca809031f5f7139568914fe73ab5e244532aaf8 /arch/arm/mach-at91rm9200/time.c | |
parent | c322e24b40b83bbdfa7c269bc0105e76a39e627f (diff) | |
parent | 55c20c0af7fe7d5d09af4addfafcfe3bdc500f5d (diff) |
Merge AT91 branch
Diffstat (limited to 'arch/arm/mach-at91rm9200/time.c')
-rw-r--r-- | arch/arm/mach-at91rm9200/time.c | 57 |
1 files changed, 36 insertions, 21 deletions
diff --git a/arch/arm/mach-at91rm9200/time.c b/arch/arm/mach-at91rm9200/time.c index 7ffcf443b99f..fc2d7d5e4637 100644 --- a/arch/arm/mach-at91rm9200/time.c +++ b/arch/arm/mach-at91rm9200/time.c | |||
@@ -31,6 +31,8 @@ | |||
31 | #include <asm/irq.h> | 31 | #include <asm/irq.h> |
32 | #include <asm/mach/time.h> | 32 | #include <asm/mach/time.h> |
33 | 33 | ||
34 | static unsigned long last_crtr; | ||
35 | |||
34 | /* | 36 | /* |
35 | * The ST_CRTR is updated asynchronously to the master clock. It is therefore | 37 | * The ST_CRTR is updated asynchronously to the master clock. It is therefore |
36 | * necessary to read it twice (with the same value) to ensure accuracy. | 38 | * necessary to read it twice (with the same value) to ensure accuracy. |
@@ -56,7 +58,7 @@ static unsigned long at91rm9200_gettimeoffset(void) | |||
56 | { | 58 | { |
57 | unsigned long elapsed; | 59 | unsigned long elapsed; |
58 | 60 | ||
59 | elapsed = (read_CRTR() - at91_sys_read(AT91_ST_RTAR)) & AT91_ST_ALMV; | 61 | elapsed = (read_CRTR() - last_crtr) & AT91_ST_ALMV; |
60 | 62 | ||
61 | return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH; | 63 | return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH; |
62 | } | 64 | } |
@@ -66,15 +68,12 @@ static unsigned long at91rm9200_gettimeoffset(void) | |||
66 | */ | 68 | */ |
67 | static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) | 69 | static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) |
68 | { | 70 | { |
69 | unsigned long rtar; | ||
70 | |||
71 | if (at91_sys_read(AT91_ST_SR) & AT91_ST_PITS) { /* This is a shared interrupt */ | 71 | if (at91_sys_read(AT91_ST_SR) & AT91_ST_PITS) { /* This is a shared interrupt */ |
72 | write_seqlock(&xtime_lock); | 72 | write_seqlock(&xtime_lock); |
73 | 73 | ||
74 | while (((read_CRTR() - at91_sys_read(AT91_ST_RTAR)) & AT91_ST_ALMV) >= LATCH) { | 74 | while (((read_CRTR() - last_crtr) & AT91_ST_ALMV) >= LATCH) { |
75 | timer_tick(regs); | 75 | timer_tick(regs); |
76 | rtar = (at91_sys_read(AT91_ST_RTAR) + LATCH) & AT91_ST_ALMV; | 76 | last_crtr = (last_crtr + LATCH) & AT91_ST_ALMV; |
77 | at91_sys_write(AT91_ST_RTAR, rtar); | ||
78 | } | 77 | } |
79 | 78 | ||
80 | write_sequnlock(&xtime_lock); | 79 | write_sequnlock(&xtime_lock); |
@@ -87,10 +86,24 @@ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id, struct pt_r | |||
87 | 86 | ||
88 | static struct irqaction at91rm9200_timer_irq = { | 87 | static struct irqaction at91rm9200_timer_irq = { |
89 | .name = "at91_tick", | 88 | .name = "at91_tick", |
90 | .flags = SA_SHIRQ | SA_INTERRUPT, | 89 | .flags = SA_SHIRQ | SA_INTERRUPT | SA_TIMER, |
91 | .handler = at91rm9200_timer_interrupt | 90 | .handler = at91rm9200_timer_interrupt |
92 | }; | 91 | }; |
93 | 92 | ||
93 | void at91rm9200_timer_reset(void) | ||
94 | { | ||
95 | last_crtr = 0; | ||
96 | |||
97 | /* Real time counter incremented every 30.51758 microseconds */ | ||
98 | at91_sys_write(AT91_ST_RTMR, 1); | ||
99 | |||
100 | /* Set Period Interval timer */ | ||
101 | at91_sys_write(AT91_ST_PIMR, LATCH); | ||
102 | |||
103 | /* Enable Period Interval Timer interrupt */ | ||
104 | at91_sys_write(AT91_ST_IER, AT91_ST_PITS); | ||
105 | } | ||
106 | |||
94 | /* | 107 | /* |
95 | * Set up timer interrupt. | 108 | * Set up timer interrupt. |
96 | */ | 109 | */ |
@@ -100,28 +113,30 @@ void __init at91rm9200_timer_init(void) | |||
100 | at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS); | 113 | at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS); |
101 | (void) at91_sys_read(AT91_ST_SR); /* Clear any pending interrupts */ | 114 | (void) at91_sys_read(AT91_ST_SR); /* Clear any pending interrupts */ |
102 | 115 | ||
103 | /* | 116 | /* Make IRQs happen for the system timer */ |
104 | * Make IRQs happen for the system timer. | ||
105 | */ | ||
106 | setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq); | 117 | setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq); |
107 | 118 | ||
108 | /* Set initial alarm to 0 */ | ||
109 | at91_sys_write(AT91_ST_RTAR, 0); | ||
110 | |||
111 | /* Real time counter incremented every 30.51758 microseconds */ | ||
112 | at91_sys_write(AT91_ST_RTMR, 1); | ||
113 | |||
114 | /* Set Period Interval timer */ | ||
115 | at91_sys_write(AT91_ST_PIMR, LATCH); | ||
116 | |||
117 | /* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */ | 119 | /* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */ |
118 | tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE; | 120 | tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE; |
119 | 121 | ||
120 | /* Enable Period Interval Timer interrupt */ | 122 | /* Initialize and enable the timer interrupt */ |
121 | at91_sys_write(AT91_ST_IER, AT91_ST_PITS); | 123 | at91rm9200_timer_reset(); |
124 | } | ||
125 | |||
126 | #ifdef CONFIG_PM | ||
127 | static void at91rm9200_timer_suspend(void) | ||
128 | { | ||
129 | /* disable Period Interval Timer interrupt */ | ||
130 | at91_sys_write(AT91_ST_IDR, AT91_ST_PITS); | ||
122 | } | 131 | } |
132 | #else | ||
133 | #define at91rm9200_timer_suspend NULL | ||
134 | #endif | ||
123 | 135 | ||
124 | struct sys_timer at91rm9200_timer = { | 136 | struct sys_timer at91rm9200_timer = { |
125 | .init = at91rm9200_timer_init, | 137 | .init = at91rm9200_timer_init, |
126 | .offset = at91rm9200_gettimeoffset, | 138 | .offset = at91rm9200_gettimeoffset, |
139 | .suspend = at91rm9200_timer_suspend, | ||
140 | .resume = at91rm9200_timer_reset, | ||
127 | }; | 141 | }; |
142 | |||