| 1 | |
| 2 | * This program is free software; you can redistribute it and/or modify
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| 3 | * it under the terms of the GNU General Public License version 2 as
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| 4 | * published by the Free Software Foundation.
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| 5 | *
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| 6 | * This program is distributed in the hope that it will be useful,
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| 7 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 8 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 9 | * GNU General Public License for more details.
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| 10 | *
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| 11 | * Copyright (C) 2014 ARM Limited
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| 12 |
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| 13 |
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| 14 | #include <linux/clocksource.h>
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| 15 | #include <linux/io.h>
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| 16 | #include <linux/of_address.h>
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| 17 | #include <linux/sched_clock.h>
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| 18 |
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| 19 | #define SYS_24MHZ 0x05c
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| 20 |
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| 21 | static void __iomem *versatile_sys_24mhz;
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| 22 |
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| 23 | static u64 notrace versatile_sys_24mhz_read(void)
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| 24 | {
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| 25 | return readl(versatile_sys_24mhz);
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| 26 | }
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| 27 |
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| 28 | static void __init versatile_sched_clock_init(struct device_node *node)
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| 29 | {
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| 30 | void __iomem *base = of_iomap(node, 0);
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| 31 |
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| 32 | if (!base)
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| 33 | return;
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| 34 |
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| 35 | versatile_sys_24mhz = base + SYS_24MHZ;
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| 36 |
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| 37 | sched_clock_register(versatile_sys_24mhz_read, 32, 24000000);
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| 38 | }
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| 39 | CLOCKSOURCE_OF_DECLARE(vexpress, "arm,vexpress-sysreg",
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| 40 | versatile_sched_clock_init);
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| 41 | CLOCKSOURCE_OF_DECLARE(versatile, "arm,versatile-sysreg",
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| 42 | versatile_sched_clock_init);
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