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authorAndrew Victor <andrew@sanpeople.com>2007-02-05 05:42:07 -0500
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-02-08 09:50:56 -0500
commit9d0412680e6c7b685ee466842047bcfb924d6dc5 (patch)
treec79300964ef1aca5d24571696f95e76b37c14679 /arch/arm/mach-at91rm9200/at91rm9200_time.c
parenta93d48cc6019f84394b31d10c0d830a3b71696be (diff)
[ARM] 4124/1: Rename mach-at91rm9200 and arch-at91rm9200 directories
Now that Linux includes support for the Atmel AT91SAM9260 and AT91SAM9261 processors in addition to the original Atmel AT91RM9200 (with support for more AT91 processors pending), the "mach-at91rm9200" and "arch-at91rm9200" directories should be renamed to indicate their more generic nature. The following git commands should be run BEFORE applying this patch: git-mv arch/arm/mach-at91rm9200 arch/arm/mach-at91 git-mv include/asm-arm/arch-at91rm9200 include/asm-arm/arch-at91 Signed-off-by: Andrew Victor <andrew@sanpeople.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-at91rm9200/at91rm9200_time.c')
-rw-r--r--arch/arm/mach-at91rm9200/at91rm9200_time.c146
1 files changed, 0 insertions, 146 deletions
diff --git a/arch/arm/mach-at91rm9200/at91rm9200_time.c b/arch/arm/mach-at91rm9200/at91rm9200_time.c
deleted file mode 100644
index b999e192a7e9..000000000000
--- a/arch/arm/mach-at91rm9200/at91rm9200_time.c
+++ /dev/null
@@ -1,146 +0,0 @@
1/*
2 * linux/arch/arm/mach-at91rm9200/at91rm9200_time.c
3 *
4 * Copyright (C) 2003 SAN People
5 * Copyright (C) 2003 ATMEL
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/init.h>
23#include <linux/interrupt.h>
24#include <linux/irq.h>
25#include <linux/kernel.h>
26#include <linux/sched.h>
27#include <linux/time.h>
28
29#include <asm/hardware.h>
30#include <asm/io.h>
31#include <asm/mach/time.h>
32
33#include <asm/arch/at91_st.h>
34
35static unsigned long last_crtr;
36
37/*
38 * The ST_CRTR is updated asynchronously to the master clock. It is therefore
39 * necessary to read it twice (with the same value) to ensure accuracy.
40 */
41static inline unsigned long read_CRTR(void) {
42 unsigned long x1, x2;
43
44 do {
45 x1 = at91_sys_read(AT91_ST_CRTR);
46 x2 = at91_sys_read(AT91_ST_CRTR);
47 } while (x1 != x2);
48
49 return x1;
50}
51
52/*
53 * Returns number of microseconds since last timer interrupt. Note that interrupts
54 * will have been disabled by do_gettimeofday()
55 * 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy.
56 * 'tick' is usecs per jiffy (linux/timex.h).
57 */
58static unsigned long at91rm9200_gettimeoffset(void)
59{
60 unsigned long elapsed;
61
62 elapsed = (read_CRTR() - last_crtr) & AT91_ST_ALMV;
63
64 return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH;
65}
66
67/*
68 * IRQ handler for the timer.
69 */
70static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
71{
72 if (at91_sys_read(AT91_ST_SR) & AT91_ST_PITS) { /* This is a shared interrupt */
73 write_seqlock(&xtime_lock);
74
75 while (((read_CRTR() - last_crtr) & AT91_ST_ALMV) >= LATCH) {
76 timer_tick();
77 last_crtr = (last_crtr + LATCH) & AT91_ST_ALMV;
78 }
79
80 write_sequnlock(&xtime_lock);
81
82 return IRQ_HANDLED;
83 }
84 else
85 return IRQ_NONE; /* not handled */
86}
87
88static struct irqaction at91rm9200_timer_irq = {
89 .name = "at91_tick",
90 .flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER,
91 .handler = at91rm9200_timer_interrupt
92};
93
94void at91rm9200_timer_reset(void)
95{
96 last_crtr = 0;
97
98 /* Real time counter incremented every 30.51758 microseconds */
99 at91_sys_write(AT91_ST_RTMR, 1);
100
101 /* Set Period Interval timer */
102 at91_sys_write(AT91_ST_PIMR, LATCH);
103
104 /* Clear any pending interrupts */
105 (void) at91_sys_read(AT91_ST_SR);
106
107 /* Enable Period Interval Timer interrupt */
108 at91_sys_write(AT91_ST_IER, AT91_ST_PITS);
109}
110
111/*
112 * Set up timer interrupt.
113 */
114void __init at91rm9200_timer_init(void)
115{
116 /* Disable all timer interrupts */
117 at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS);
118 (void) at91_sys_read(AT91_ST_SR); /* Clear any pending interrupts */
119
120 /* Make IRQs happen for the system timer */
121 setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq);
122
123 /* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */
124 tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE;
125
126 /* Initialize and enable the timer interrupt */
127 at91rm9200_timer_reset();
128}
129
130#ifdef CONFIG_PM
131static void at91rm9200_timer_suspend(void)
132{
133 /* disable Period Interval Timer interrupt */
134 at91_sys_write(AT91_ST_IDR, AT91_ST_PITS);
135}
136#else
137#define at91rm9200_timer_suspend NULL
138#endif
139
140struct sys_timer at91rm9200_timer = {
141 .init = at91rm9200_timer_init,
142 .offset = at91rm9200_gettimeoffset,
143 .suspend = at91rm9200_timer_suspend,
144 .resume = at91rm9200_timer_reset,
145};
146