1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /***************************************************************************/ |
3 | |
4 | /* |
5 | * timers.c -- generic ColdFire hardware timer support. |
6 | * |
7 | * Copyright (C) 1999-2008, Greg Ungerer <gerg@snapgear.com> |
8 | */ |
9 | |
10 | /***************************************************************************/ |
11 | |
12 | #include <linux/kernel.h> |
13 | #include <linux/init.h> |
14 | #include <linux/sched.h> |
15 | #include <linux/interrupt.h> |
16 | #include <linux/irq.h> |
17 | #include <linux/profile.h> |
18 | #include <linux/clocksource.h> |
19 | #include <asm/io.h> |
20 | #include <asm/traps.h> |
21 | #include <asm/machdep.h> |
22 | #include <asm/coldfire.h> |
23 | #include <asm/mcftimer.h> |
24 | #include <asm/mcfsim.h> |
25 | |
26 | /***************************************************************************/ |
27 | |
28 | /* |
29 | * By default use timer1 as the system clock timer. |
30 | */ |
31 | #define FREQ (MCF_BUSCLK / 16) |
32 | #define TA(a) (MCFTIMER_BASE1 + (a)) |
33 | |
34 | /* |
35 | * These provide the underlying interrupt vector support. |
36 | * Unfortunately it is a little different on each ColdFire. |
37 | */ |
38 | void coldfire_profile_init(void); |
39 | |
40 | #if defined(CONFIG_M53xx) || defined(CONFIG_M5441x) |
41 | #define __raw_readtrr __raw_readl |
42 | #define __raw_writetrr __raw_writel |
43 | #else |
44 | #define __raw_readtrr __raw_readw |
45 | #define __raw_writetrr __raw_writew |
46 | #endif |
47 | |
48 | static u32 mcftmr_cycles_per_jiffy; |
49 | static u32 mcftmr_cnt; |
50 | |
51 | /***************************************************************************/ |
52 | |
53 | static void init_timer_irq(void) |
54 | { |
55 | #ifdef MCFSIM_ICR_AUTOVEC |
56 | /* Timer1 is always used as system timer */ |
57 | writeb(MCFSIM_ICR_AUTOVEC | MCFSIM_ICR_LEVEL6 | MCFSIM_ICR_PRI3, |
58 | MCFSIM_TIMER1ICR); |
59 | mcf_mapirq2imr(MCF_IRQ_TIMER, MCFINTC_TIMER1); |
60 | |
61 | #ifdef CONFIG_HIGHPROFILE |
62 | /* Timer2 is to be used as a high speed profile timer */ |
63 | writeb(MCFSIM_ICR_AUTOVEC | MCFSIM_ICR_LEVEL7 | MCFSIM_ICR_PRI3, |
64 | MCFSIM_TIMER2ICR); |
65 | mcf_mapirq2imr(MCF_IRQ_PROFILER, MCFINTC_TIMER2); |
66 | #endif |
67 | #endif /* MCFSIM_ICR_AUTOVEC */ |
68 | } |
69 | |
70 | /***************************************************************************/ |
71 | |
72 | static irqreturn_t mcftmr_tick(int irq, void *dummy) |
73 | { |
74 | /* Reset the ColdFire timer */ |
75 | __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, TA(MCFTIMER_TER)); |
76 | |
77 | mcftmr_cnt += mcftmr_cycles_per_jiffy; |
78 | legacy_timer_tick(ticks: 1); |
79 | return IRQ_HANDLED; |
80 | } |
81 | |
82 | /***************************************************************************/ |
83 | |
84 | static u64 mcftmr_read_clk(struct clocksource *cs) |
85 | { |
86 | unsigned long flags; |
87 | u32 cycles; |
88 | u16 tcn; |
89 | |
90 | local_irq_save(flags); |
91 | tcn = __raw_readw(TA(MCFTIMER_TCN)); |
92 | cycles = mcftmr_cnt; |
93 | local_irq_restore(flags); |
94 | |
95 | return cycles + tcn; |
96 | } |
97 | |
98 | /***************************************************************************/ |
99 | |
100 | static struct clocksource mcftmr_clk = { |
101 | .name = "tmr" , |
102 | .rating = 250, |
103 | .read = mcftmr_read_clk, |
104 | .mask = CLOCKSOURCE_MASK(32), |
105 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
106 | }; |
107 | |
108 | /***************************************************************************/ |
109 | |
110 | void hw_timer_init(void) |
111 | { |
112 | int r; |
113 | |
114 | __raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR)); |
115 | mcftmr_cycles_per_jiffy = FREQ / HZ; |
116 | /* |
117 | * The coldfire timer runs from 0 to TRR included, then 0 |
118 | * again and so on. It counts thus actually TRR + 1 steps |
119 | * for 1 tick, not TRR. So if you want n cycles, |
120 | * initialize TRR with n - 1. |
121 | */ |
122 | __raw_writetrr(mcftmr_cycles_per_jiffy - 1, TA(MCFTIMER_TRR)); |
123 | __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | |
124 | MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR)); |
125 | |
126 | clocksource_register_hz(&mcftmr_clk, FREQ); |
127 | |
128 | init_timer_irq(); |
129 | r = request_irq(irq: MCF_IRQ_TIMER, handler: mcftmr_tick, IRQF_TIMER, name: "timer" , NULL); |
130 | if (r) { |
131 | pr_err("Failed to request irq %d (timer): %pe\n" , MCF_IRQ_TIMER, |
132 | ERR_PTR(r)); |
133 | } |
134 | |
135 | #ifdef CONFIG_HIGHPROFILE |
136 | coldfire_profile_init(); |
137 | #endif |
138 | } |
139 | |
140 | /***************************************************************************/ |
141 | #ifdef CONFIG_HIGHPROFILE |
142 | /***************************************************************************/ |
143 | |
144 | /* |
145 | * By default use timer2 as the profiler clock timer. |
146 | */ |
147 | #define PA(a) (MCFTIMER_BASE2 + (a)) |
148 | |
149 | /* |
150 | * Choose a reasonably fast profile timer. Make it an odd value to |
151 | * try and get good coverage of kernel operations. |
152 | */ |
153 | #define PROFILEHZ 1013 |
154 | |
155 | /* |
156 | * Use the other timer to provide high accuracy profiling info. |
157 | */ |
158 | irqreturn_t coldfire_profile_tick(int irq, void *dummy) |
159 | { |
160 | /* Reset ColdFire timer2 */ |
161 | __raw_writeb(MCFTIMER_TER_CAP | MCFTIMER_TER_REF, PA(MCFTIMER_TER)); |
162 | if (current->pid) |
163 | profile_tick(CPU_PROFILING); |
164 | return IRQ_HANDLED; |
165 | } |
166 | |
167 | /***************************************************************************/ |
168 | |
169 | void coldfire_profile_init(void) |
170 | { |
171 | int ret; |
172 | |
173 | printk(KERN_INFO "PROFILE: lodging TIMER2 @ %dHz as profile timer\n" , |
174 | PROFILEHZ); |
175 | |
176 | /* Set up TIMER 2 as high speed profile clock */ |
177 | __raw_writew(MCFTIMER_TMR_DISABLE, PA(MCFTIMER_TMR)); |
178 | |
179 | __raw_writetrr(((MCF_BUSCLK / 16) / PROFILEHZ), PA(MCFTIMER_TRR)); |
180 | __raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 | |
181 | MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, PA(MCFTIMER_TMR)); |
182 | |
183 | ret = request_irq(MCF_IRQ_PROFILER, coldfire_profile_tick, IRQF_TIMER, |
184 | "profile timer" , NULL); |
185 | if (ret) { |
186 | pr_err("Failed to request irq %d (profile timer): %pe\n" , |
187 | MCF_IRQ_PROFILER, ERR_PTR(ret)); |
188 | } |
189 | } |
190 | |
191 | /***************************************************************************/ |
192 | #endif /* CONFIG_HIGHPROFILE */ |
193 | /***************************************************************************/ |
194 | |