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Magnus Dammc793c1b2010-02-05 11:14:49 +00001/*
2 * SH-Mobile Timer
3 *
4 * Copyright (C) 2010 Magnus Damm
5 * Copyright (C) 2002 - 2009 Paul Mundt
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; version 2 of the License.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
Magnus Dammc793c1b2010-02-05 11:14:49 +000015 */
16#include <linux/platform_device.h>
Rob Herring0583fe42013-04-10 18:27:51 -050017#include <linux/clocksource.h>
Magnus Damm0f2c9f22012-03-28 19:22:30 +090018#include <linux/delay.h>
Magnus Dammc39dae32014-03-06 12:28:24 +090019#include <linux/of_address.h>
Magnus Dammc793c1b2010-02-05 11:14:49 +000020
Geert Uytterhoeven2e41e5f2016-01-28 16:20:48 +010021#include "common.h"
22
Magnus Damm7dd4cfd2014-08-20 22:03:12 +090023static void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz,
24 unsigned int mult, unsigned int div)
Simon Hormanf492b812014-05-13 15:59:18 +090025{
26 /* calculate a worst-case loops-per-jiffy value
27 * based on maximum cpu core hz setting and the
28 * __delay() implementation in arch/arm/lib/delay.S
29 *
30 * this will result in a longer delay than expected
31 * when the cpu core runs on lower frequencies.
32 */
33
34 unsigned int value = HZ * div / mult;
35
36 if (!preset_lpj)
37 preset_lpj = max_cpu_core_hz / value;
38}
39
Magnus Dammc39dae32014-03-06 12:28:24 +090040void __init shmobile_init_delay(void)
41{
Laurent Pinchartedc8fb12014-05-21 15:31:05 +020042 struct device_node *np, *cpus;
Geert Uytterhoevenc531fb22016-01-11 19:41:12 +010043 unsigned int div = 0;
Magnus Damm27f3c702014-10-06 08:59:20 +090044 bool has_arch_timer = false;
Laurent Pinchartedc8fb12014-05-21 15:31:05 +020045 u32 max_freq = 0;
Magnus Dammc39dae32014-03-06 12:28:24 +090046
Laurent Pinchartedc8fb12014-05-21 15:31:05 +020047 cpus = of_find_node_by_path("/cpus");
48 if (!cpus)
49 return;
Magnus Dammc39dae32014-03-06 12:28:24 +090050
Laurent Pinchartedc8fb12014-05-21 15:31:05 +020051 for_each_child_of_node(cpus, np) {
52 u32 freq;
53
54 if (!of_property_read_u32(np, "clock-frequency", &freq))
55 max_freq = max(max_freq, freq);
56
Geert Uytterhoevenc531fb22016-01-11 19:41:12 +010057 if (of_device_is_compatible(np, "arm,cortex-a8")) {
58 div = 2;
59 } else if (of_device_is_compatible(np, "arm,cortex-a9")) {
60 div = 1;
61 } else if (of_device_is_compatible(np, "arm,cortex-a7") ||
62 of_device_is_compatible(np, "arm,cortex-a15")) {
63 div = 1;
Magnus Damm27f3c702014-10-06 08:59:20 +090064 has_arch_timer = true;
65 }
Magnus Dammc39dae32014-03-06 12:28:24 +090066 }
67
Laurent Pinchartedc8fb12014-05-21 15:31:05 +020068 of_node_put(cpus);
69
Geert Uytterhoevenc531fb22016-01-11 19:41:12 +010070 if (!max_freq || !div)
Laurent Pinchartedc8fb12014-05-21 15:31:05 +020071 return;
72
Geert Uytterhoevenc531fb22016-01-11 19:41:12 +010073 if (!has_arch_timer || !IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
74 shmobile_setup_delay_hz(max_freq, 1, div);
Magnus Dammc39dae32014-03-06 12:28:24 +090075}