Commit | Line | Data |
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1da177e4 | 1 | /* |
78814465 | 2 | * Copyright (C) 2008-2009 Manuel Lauss <manuel.lauss@gmail.com> |
1da177e4 | 3 | * |
0c694de1 | 4 | * Previous incarnations were: |
01675095 | 5 | * Copyright (C) 2001, 2006, 2008 MontaVista Software, <source@mvista.com> |
1da177e4 LT |
6 | * Copied and modified Carsten Langgaard's time.c |
7 | * | |
8 | * Carsten Langgaard, carstenl@mips.com | |
9 | * Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved. | |
10 | * | |
11 | * ######################################################################## | |
12 | * | |
13 | * This program is free software; you can distribute it and/or modify it | |
14 | * under the terms of the GNU General Public License (Version 2) as | |
15 | * published by the Free Software Foundation. | |
16 | * | |
17 | * This program is distributed in the hope it will be useful, but WITHOUT | |
18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
20 | * for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License along | |
23 | * with this program; if not, write to the Free Software Foundation, Inc., | |
24 | * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. | |
25 | * | |
26 | * ######################################################################## | |
27 | * | |
0c694de1 ML |
28 | * Clocksource/event using the 32.768kHz-clocked Counter1 ('RTC' in the |
29 | * databooks). Firmware/Board init code must enable the counters in the | |
30 | * counter control register, otherwise the CP0 counter clocksource/event | |
31 | * will be installed instead (and use of 'wait' instruction is prohibited). | |
1da177e4 LT |
32 | */ |
33 | ||
0c694de1 ML |
34 | #include <linux/clockchips.h> |
35 | #include <linux/clocksource.h> | |
36 | #include <linux/interrupt.h> | |
1da177e4 | 37 | #include <linux/spinlock.h> |
1da177e4 | 38 | |
bdc92d74 | 39 | #include <asm/idle.h> |
2882b0c6 | 40 | #include <asm/processor.h> |
1da177e4 | 41 | #include <asm/time.h> |
1da177e4 LT |
42 | #include <asm/mach-au1x00/au1000.h> |
43 | ||
0c694de1 ML |
44 | /* 32kHz clock enabled and detected */ |
45 | #define CNTR_OK (SYS_CNTRL_E0 | SYS_CNTRL_32S) | |
1da177e4 | 46 | |
ad058e95 | 47 | static cycle_t au1x_counter1_read(struct clocksource *cs) |
0c694de1 | 48 | { |
1d09de7d | 49 | return alchemy_rdsys(AU1000_SYS_RTCREAD); |
0c694de1 ML |
50 | } |
51 | ||
52 | static struct clocksource au1x_counter1_clocksource = { | |
53 | .name = "alchemy-counter1", | |
54 | .read = au1x_counter1_read, | |
55 | .mask = CLOCKSOURCE_MASK(32), | |
56 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, | |
8e0d7372 | 57 | .rating = 1500, |
0c694de1 ML |
58 | }; |
59 | ||
60 | static int au1x_rtcmatch2_set_next_event(unsigned long delta, | |
61 | struct clock_event_device *cd) | |
62 | { | |
1d09de7d | 63 | delta += alchemy_rdsys(AU1000_SYS_RTCREAD); |
0c694de1 | 64 | /* wait for register access */ |
1d09de7d | 65 | while (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_M21) |
0c694de1 | 66 | ; |
1d09de7d | 67 | alchemy_wrsys(delta, AU1000_SYS_RTCMATCH2); |
0c694de1 ML |
68 | |
69 | return 0; | |
70 | } | |
71 | ||
0c694de1 ML |
72 | static irqreturn_t au1x_rtcmatch2_irq(int irq, void *dev_id) |
73 | { | |
74 | struct clock_event_device *cd = dev_id; | |
75 | cd->event_handler(cd); | |
76 | return IRQ_HANDLED; | |
77 | } | |
78 | ||
79 | static struct clock_event_device au1x_rtcmatch2_clockdev = { | |
80 | .name = "rtcmatch2", | |
81 | .features = CLOCK_EVT_FEAT_ONESHOT, | |
8e0d7372 | 82 | .rating = 1500, |
70342287 | 83 | .set_next_event = au1x_rtcmatch2_set_next_event, |
51c870a2 | 84 | .cpumask = cpu_all_mask, |
0c694de1 ML |
85 | }; |
86 | ||
87 | static struct irqaction au1x_rtcmatch2_irqaction = { | |
88 | .handler = au1x_rtcmatch2_irq, | |
8b5690f8 | 89 | .flags = IRQF_TIMER, |
0c694de1 ML |
90 | .name = "timer", |
91 | .dev_id = &au1x_rtcmatch2_clockdev, | |
92 | }; | |
93 | ||
78814465 | 94 | static int __init alchemy_time_init(unsigned int m2int) |
1da177e4 | 95 | { |
0c694de1 ML |
96 | struct clock_event_device *cd = &au1x_rtcmatch2_clockdev; |
97 | unsigned long t; | |
1da177e4 | 98 | |
78814465 ML |
99 | au1x_rtcmatch2_clockdev.irq = m2int; |
100 | ||
0c694de1 ML |
101 | /* Check if firmware (YAMON, ...) has enabled 32kHz and clock |
102 | * has been detected. If so install the rtcmatch2 clocksource, | |
103 | * otherwise don't bother. Note that both bits being set is by | |
104 | * no means a definite guarantee that the counters actually work | |
105 | * (the 32S bit seems to be stuck set to 1 once a single clock- | |
106 | * edge is detected, hence the timeouts). | |
1da177e4 | 107 | */ |
1d09de7d | 108 | if (CNTR_OK != (alchemy_rdsys(AU1000_SYS_CNTRCTRL) & CNTR_OK)) |
0c694de1 | 109 | goto cntr_err; |
1da177e4 | 110 | |
0c694de1 ML |
111 | /* |
112 | * setup counter 1 (RTC) to tick at full speed | |
113 | */ | |
114 | t = 0xffffff; | |
1d09de7d | 115 | while ((alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_T1S) && --t) |
0c694de1 ML |
116 | asm volatile ("nop"); |
117 | if (!t) | |
118 | goto cntr_err; | |
1da177e4 | 119 | |
1d09de7d | 120 | alchemy_wrsys(0, AU1000_SYS_RTCTRIM); /* 32.768 kHz */ |
1da177e4 | 121 | |
0c694de1 | 122 | t = 0xffffff; |
1d09de7d | 123 | while ((alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_C1S) && --t) |
0c694de1 ML |
124 | asm volatile ("nop"); |
125 | if (!t) | |
126 | goto cntr_err; | |
1d09de7d | 127 | alchemy_wrsys(0, AU1000_SYS_RTCWRITE); |
1da177e4 | 128 | |
0c694de1 | 129 | t = 0xffffff; |
1d09de7d | 130 | while ((alchemy_rdsys(AU1000_SYS_CNTRCTRL) & SYS_CNTRL_C1S) && --t) |
0c694de1 ML |
131 | asm volatile ("nop"); |
132 | if (!t) | |
133 | goto cntr_err; | |
134 | ||
135 | /* register counter1 clocksource and event device */ | |
75c4fd8c | 136 | clocksource_register_hz(&au1x_counter1_clocksource, 32768); |
0c694de1 ML |
137 | |
138 | cd->shift = 32; | |
139 | cd->mult = div_sc(32768, NSEC_PER_SEC, cd->shift); | |
140 | cd->max_delta_ns = clockevent_delta2ns(0xffffffff, cd); | |
8e365790 | 141 | cd->min_delta_ns = clockevent_delta2ns(9, cd); /* ~0.28ms */ |
0c694de1 | 142 | clockevents_register_device(cd); |
78814465 | 143 | setup_irq(m2int, &au1x_rtcmatch2_irqaction); |
0c694de1 ML |
144 | |
145 | printk(KERN_INFO "Alchemy clocksource installed\n"); | |
146 | ||
78814465 | 147 | return 0; |
0c694de1 ML |
148 | |
149 | cntr_err: | |
78814465 ML |
150 | return -1; |
151 | } | |
152 | ||
78814465 ML |
153 | static int alchemy_m2inttab[] __initdata = { |
154 | AU1000_RTC_MATCH2_INT, | |
155 | AU1500_RTC_MATCH2_INT, | |
156 | AU1100_RTC_MATCH2_INT, | |
157 | AU1550_RTC_MATCH2_INT, | |
158 | AU1200_RTC_MATCH2_INT, | |
809f36c6 | 159 | AU1300_RTC_MATCH2_INT, |
78814465 ML |
160 | }; |
161 | ||
162 | void __init plat_time_init(void) | |
163 | { | |
164 | int t; | |
165 | ||
166 | t = alchemy_get_cputype(); | |
8e0d7372 ML |
167 | if (t == ALCHEMY_CPU_UNKNOWN || |
168 | alchemy_time_init(alchemy_m2inttab[t])) | |
169 | cpu_wait = NULL; /* wait doesn't work with r4k timer */ | |
78814465 | 170 | } |