change system file

hc

2024-10-09 244b2c5ca8b14627e4a17755e5922221e121c771

 kernel/arch/arm/mach-rpc/time.c
..
..
@@ -1,11 +1,8 @@
1
+// SPDX-License-Identifier: GPL-2.0-only
1
2
 /*
2
3
  *  linux/arch/arm/common/time-acorn.c
3
4
  *
4
5
  *  Copyright (c) 1996-2000 Russell King.
5
- *
6
- * This program is free software; you can redistribute it and/or modify
7
- * it under the terms of the GNU General Public License version 2 as
8
- * published by the Free Software Foundation.
9
6
  *
10
7
  *  Changelog:
11
8
  *   24-Sep-1996	RMK	Created
..
..
@@ -13,7 +10,7 @@
13
10
  *   04-Dec-1997	RMK	Updated for new arch/arm/time.c
14
11
  *   13=Jun-2004	DS	Moved to arch/arm/common b/c shared w/CLPS7500
15
12
  */
16
-#include <linux/timex.h>
13
+#include <linux/clocksource.h>
17
14
 #include <linux/init.h>
18
15
 #include <linux/interrupt.h>
19
16
 #include <linux/irq.h>
..
..
@@ -27,11 +24,15 @@
27
24
 #define RPC_CLOCK_FREQ 2000000
28
25
 #define RPC_LATCH DIV_ROUND_CLOSEST(RPC_CLOCK_FREQ, HZ)
29
26
 
30
-static u32 ioc_timer_gettimeoffset(void)
27
+static u32 ioc_time;
28
+
29
+static u64 ioc_timer_read(struct clocksource *cs)
31
30
 {
32
31
 	unsigned int count1, count2, status;
33
-	long offset;
32
+	unsigned long flags;
33
+	u32 ticks;
34
34
 
35
+	local_irq_save(flags);
35
36
 	ioc_writeb (0, IOC_T0LATCH);
36
37
 	barrier ();
37
38
 	count1 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
..
..
@@ -41,26 +42,33 @@
41
42
 	ioc_writeb (0, IOC_T0LATCH);
42
43
 	barrier ();
43
44
 	count2 = ioc_readb(IOC_T0CNTL) | (ioc_readb(IOC_T0CNTH) << 8);
45
+	ticks = ioc_time + RPC_LATCH - count2;
46
+	local_irq_restore(flags);
44
47
 
45
-	offset = count2;
46
48
 	if (count2 < count1) {
47
49
 		/*
48
-		 * We have not had an interrupt between reading count1
49
-		 * and count2.
50
+		 * The timer has not reloaded between reading count1 and
51
+		 * count2, check whether an interrupt was actually pending.
50
52
 		 */
51
53
 		if (status & (1 << 5))
52
-			offset -= RPC_LATCH;
54
+			ticks += RPC_LATCH;
53
55
 	} else if (count2 > count1) {
54
56
 		/*
55
-		 * We have just had another interrupt between reading
56
-		 * count1 and count2.
57
+		 * The timer has reloaded, so count2 indicates the new
58
+		 * count since the wrap.  The interrupt would not have
59
+		 * been processed, so add the missed ticks.
57
60
 		 */
58
-		offset -= RPC_LATCH;
61
+		ticks += RPC_LATCH;
59
62
 	}
60
63
 
61
-	offset = (RPC_LATCH - offset) * (tick_nsec / 1000);
62
-	return DIV_ROUND_CLOSEST(offset, RPC_LATCH) * 1000;
64
+	return ticks;
63
65
 }
66
+
67
+static struct clocksource ioctime_clocksource = {
68
+	.read = ioc_timer_read,
69
+	.mask = CLOCKSOURCE_MASK(32),
70
+	.rating = 100,
71
+};
64
72
 
65
73
 void __init ioctime_init(void)
66
74
 {
..
..
@@ -72,21 +80,18 @@
72
80
 static irqreturn_t
73
81
 ioc_timer_interrupt(int irq, void *dev_id)
74
82
 {
83
+	ioc_time += RPC_LATCH;
75
84
 	timer_tick();
76
85
 	return IRQ_HANDLED;
77
86
 }
78
-
79
-static struct irqaction ioc_timer_irq = {
80
-	.name		= "timer",
81
-	.handler	= ioc_timer_interrupt
82
-};
83
87
 
84
88
 /*
85
89
  * Set up timer interrupt.
86
90
  */
87
91
 void __init ioc_timer_init(void)
88
92
 {
89
-	arch_gettimeoffset = ioc_timer_gettimeoffset;
93
+	WARN_ON(clocksource_register_hz(&ioctime_clocksource, RPC_CLOCK_FREQ));
90
94
 	ioctime_init();
91
-	setup_irq(IRQ_TIMER0, &ioc_timer_irq);
95
+	if (request_irq(IRQ_TIMER0, ioc_timer_interrupt, 0, "timer", NULL))
96
+		pr_err("Failed to request irq %d (timer)\n", IRQ_TIMER0);
92
97
 }