1 /* ASB2305-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 #ifndef __ASSEMBLY__
15 #include <linux/irq.h>
16 #endif /* __ASSEMBLY__ */
17 
18 #include <asm/timer-regs.h>
19 #include <unit/clock.h>
20 #include <asm/param.h>
21 
22 /*
23  * jiffies counter specifications
24  */
25 
26 #define	TMJCBR_MAX		0xffff
27 #define	TMJCIRQ			TM1IRQ
28 #define	TMJCICR			TM1ICR
29 
30 #ifndef __ASSEMBLY__
31 
32 #define MN10300_SRC_IOCLK	MN10300_IOCLK
33 
34 #ifndef HZ
35 # error HZ undeclared.
36 #endif /* !HZ */
37 /* use as little prescaling as possible to avoid losing accuracy */
38 #if (MN10300_SRC_IOCLK + HZ / 2) / HZ - 1 <= TMJCBR_MAX
39 # define IOCLK_PRESCALE		1
40 # define JC_TIMER_CLKSRC	TM0MD_SRC_IOCLK
41 # define TSC_TIMER_CLKSRC	TM4MD_SRC_IOCLK
42 #elif (MN10300_SRC_IOCLK / 8 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
43 # define IOCLK_PRESCALE		8
44 # define JC_TIMER_CLKSRC	TM0MD_SRC_IOCLK_8
45 # define TSC_TIMER_CLKSRC	TM4MD_SRC_IOCLK_8
46 #elif (MN10300_SRC_IOCLK / 32 + HZ / 2) / HZ - 1 <= TMJCBR_MAX
47 # define IOCLK_PRESCALE		32
48 # define JC_TIMER_CLKSRC	TM0MD_SRC_IOCLK_32
49 # define TSC_TIMER_CLKSRC	TM4MD_SRC_IOCLK_32
50 #else
51 # error You lose.
52 #endif
53 
54 #define MN10300_JCCLK		(MN10300_SRC_IOCLK / IOCLK_PRESCALE)
55 #define MN10300_TSCCLK		(MN10300_SRC_IOCLK / IOCLK_PRESCALE)
56 
57 #define MN10300_JC_PER_HZ	((MN10300_JCCLK + HZ / 2) / HZ)
58 #define MN10300_TSC_PER_HZ	((MN10300_TSCCLK + HZ / 2) / HZ)
59 
stop_jiffies_counter(void)60 static inline void stop_jiffies_counter(void)
61 {
62 	u16 tmp;
63 	TM01MD = JC_TIMER_CLKSRC | TM1MD_SRC_TM0CASCADE << 8;
64 	tmp = TM01MD;
65 }
66 
reload_jiffies_counter(u32 cnt)67 static inline void reload_jiffies_counter(u32 cnt)
68 {
69 	u32 tmp;
70 
71 	TM01BR = cnt;
72 	tmp = TM01BR;
73 
74 	TM01MD = JC_TIMER_CLKSRC |		\
75 		 TM1MD_SRC_TM0CASCADE << 8 |	\
76 		 TM0MD_INIT_COUNTER |		\
77 		 TM1MD_INIT_COUNTER << 8;
78 
79 
80 	TM01MD = JC_TIMER_CLKSRC |		\
81 		 TM1MD_SRC_TM0CASCADE << 8 |	\
82 		 TM0MD_COUNT_ENABLE |		\
83 		 TM1MD_COUNT_ENABLE << 8;
84 
85 	tmp = TM01MD;
86 }
87 
88 #endif /* !__ASSEMBLY__ */
89 
90 
91 /*
92  * timestamp counter specifications
93  */
94 
95 #define	TMTSCBR_MAX		0xffffffff
96 #define	TMTSCBC			TM45BC
97 
98 #ifndef __ASSEMBLY__
99 
startup_timestamp_counter(void)100 static inline void startup_timestamp_counter(void)
101 {
102 	u32 t32;
103 
104 	/* set up timer 4 & 5 cascaded as a 32-bit counter to count real time
105 	 * - count down from 4Gig-1 to 0 and wrap at IOCLK rate
106 	 */
107 	TM45BR = TMTSCBR_MAX;
108 	t32 = TM45BR;
109 
110 	TM4MD = TSC_TIMER_CLKSRC;
111 	TM4MD |= TM4MD_INIT_COUNTER;
112 	TM4MD &= ~TM4MD_INIT_COUNTER;
113 	TM4ICR = 0;
114 	t32 = TM4ICR;
115 
116 	TM5MD = TM5MD_SRC_TM4CASCADE;
117 	TM5MD |= TM5MD_INIT_COUNTER;
118 	TM5MD &= ~TM5MD_INIT_COUNTER;
119 	TM5ICR = 0;
120 	t32 = TM5ICR;
121 
122 	TM5MD |= TM5MD_COUNT_ENABLE;
123 	TM4MD |= TM4MD_COUNT_ENABLE;
124 	t32 = TM5MD;
125 	t32 = TM4MD;
126 }
127 
shutdown_timestamp_counter(void)128 static inline void shutdown_timestamp_counter(void)
129 {
130 	u8 t8;
131 	TM4MD = 0;
132 	TM5MD = 0;
133 	t8 = TM4MD;
134 	t8 = TM5MD;
135 }
136 
137 /*
138  * we use a cascaded pair of 16-bit down-counting timers to count I/O
139  * clock cycles for the purposes of time keeping
140  */
141 typedef unsigned long cycles_t;
142 
read_timestamp_counter(void)143 static inline cycles_t read_timestamp_counter(void)
144 {
145 	return (cycles_t)~TMTSCBC;
146 }
147 
148 #endif /* !__ASSEMBLY__ */
149 
150 #endif /* _ASM_UNIT_TIMEX_H */
151