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1 /* ASB2303-specific timer specifications
2  *
3  * Copyright (C) 2007, 2010 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public Licence
8  * as published by the Free Software Foundation; either version
9  * 2 of the Licence, or (at your option) any later version.
10  */
11 #ifndef _ASM_UNIT_TIMEX_H
12 #define _ASM_UNIT_TIMEX_H
13 
14 #include <asm/timer-regs.h>
15 #include <unit/clock.h>
16 #include <asm/param.h>
17 
18 /*
19  * jiffies counter specifications
20  */
21 
22 #define	TMJCBR_MAX		0xffff
23 #define	TMJCIRQ			TM1IRQ
24 #define	TMJCICR			TM1ICR
25 
26 #ifndef __ASSEMBLY__
27 
28 #define MN10300_SRC_IOCLK	MN10300_IOCLK
29 
30 #ifndef HZ
31 # error HZ undeclared.
32 #endif /* !HZ */
33 /* use as little prescaling as possible to avoid losing accuracy */
34 #if (MN10300_SRC_IOCLK + HZ / 2) / HZ - 1 <= TMJCBR_MAX
35 # define IOCLK_PRESCALE		1
36 # define JC_TIMER_CLKSRC	TM0MD_SRC_IOCLK
37 # define TSC_TIMER_CLKSRC	TM4MD_SRC_IOCLK
38 #elif (MN10300_SRC_IOCLK / 8 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
39 # define IOCLK_PRESCALE		8
40 # define JC_TIMER_CLKSRC	TM0MD_SRC_IOCLK_8
41 # define TSC_TIMER_CLKSRC	TM4MD_SRC_IOCLK_8
42 #elif (MN10300_SRC_IOCLK / 32 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
43 # define IOCLK_PRESCALE		32
44 # define JC_TIMER_CLKSRC	TM0MD_SRC_IOCLK_32
45 # define TSC_TIMER_CLKSRC	TM4MD_SRC_IOCLK_32
46 #else
47 # error You lose.
48 #endif
49 
50 #define MN10300_JCCLK		(MN10300_SRC_IOCLK / IOCLK_PRESCALE)
51 #define MN10300_TSCCLK		(MN10300_SRC_IOCLK / IOCLK_PRESCALE)
52 
53 #define MN10300_JC_PER_HZ	((MN10300_JCCLK + HZ / 2) / HZ)
54 #define MN10300_TSC_PER_HZ	((MN10300_TSCCLK + HZ / 2) / HZ)
55 
stop_jiffies_counter(void)56 static inline void stop_jiffies_counter(void)
57 {
58 	u16 tmp;
59 	TM01MD = JC_TIMER_CLKSRC | TM1MD_SRC_TM0CASCADE << 8;
60 	tmp = TM01MD;
61 }
62 
reload_jiffies_counter(u32 cnt)63 static inline void reload_jiffies_counter(u32 cnt)
64 {
65 	u32 tmp;
66 
67 	TM01BR = cnt;
68 	tmp = TM01BR;
69 
70 	TM01MD = JC_TIMER_CLKSRC |		\
71 		 TM1MD_SRC_TM0CASCADE << 8 |	\
72 		 TM0MD_INIT_COUNTER |		\
73 		 TM1MD_INIT_COUNTER << 8;
74 
75 
76 	TM01MD = JC_TIMER_CLKSRC |		\
77 		 TM1MD_SRC_TM0CASCADE << 8 |	\
78 		 TM0MD_COUNT_ENABLE |		\
79 		 TM1MD_COUNT_ENABLE << 8;
80 
81 	tmp = TM01MD;
82 }
83 
84 #endif /* !__ASSEMBLY__ */
85 
86 
87 /*
88  * timestamp counter specifications
89  */
90 
91 #define	TMTSCBR_MAX		0xffffffff
92 #define	TMTSCBC			TM45BC
93 
94 #ifndef __ASSEMBLY__
95 
startup_timestamp_counter(void)96 static inline void startup_timestamp_counter(void)
97 {
98 	u32 t32;
99 
100 	/* set up timer 4 & 5 cascaded as a 32-bit counter to count real time
101 	 * - count down from 4Gig-1 to 0 and wrap at IOCLK rate
102 	 */
103 	TM45BR = TMTSCBR_MAX;
104 	t32 = TM45BR;
105 
106 	TM4MD = TSC_TIMER_CLKSRC;
107 	TM4MD |= TM4MD_INIT_COUNTER;
108 	TM4MD &= ~TM4MD_INIT_COUNTER;
109 	TM4ICR = 0;
110 	t32 = TM4ICR;
111 
112 	TM5MD = TM5MD_SRC_TM4CASCADE;
113 	TM5MD |= TM5MD_INIT_COUNTER;
114 	TM5MD &= ~TM5MD_INIT_COUNTER;
115 	TM5ICR = 0;
116 	t32 = TM5ICR;
117 
118 	TM5MD |= TM5MD_COUNT_ENABLE;
119 	TM4MD |= TM4MD_COUNT_ENABLE;
120 	t32 = TM5MD;
121 	t32 = TM4MD;
122 }
123 
shutdown_timestamp_counter(void)124 static inline void shutdown_timestamp_counter(void)
125 {
126 	u8 t8;
127 	TM4MD = 0;
128 	TM5MD = 0;
129 	t8 = TM4MD;
130 	t8 = TM5MD;
131 }
132 
133 /*
134  * we use a cascaded pair of 16-bit down-counting timers to count I/O
135  * clock cycles for the purposes of time keeping
136  */
137 typedef unsigned long cycles_t;
138 
read_timestamp_counter(void)139 static inline cycles_t read_timestamp_counter(void)
140 {
141 	return (cycles_t)~TMTSCBC;
142 }
143 
144 #endif /* !__ASSEMBLY__ */
145 
146 #endif /* _ASM_UNIT_TIMEX_H */
147