1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * SH-Mobile Timer
 4 *
 5 * Copyright (C) 2010  Magnus Damm
 6 * Copyright (C) 2002 - 2009  Paul Mundt
 
 
 
 
 
 
 
 
 
 7 */
 8#include <linux/platform_device.h>
 9#include <linux/clocksource.h>
10#include <linux/delay.h>
11#include <linux/of_address.h>
12
13#include "common.h"
14
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
15void __init shmobile_init_delay(void)
16{
17	struct device_node *np;
 
 
18	u32 max_freq = 0;
19
20	for_each_of_cpu_node(np) {
 
 
 
 
21		u32 freq;
22
23		if (!of_property_read_u32(np, "clock-frequency", &freq))
24			max_freq = max(max_freq, freq);
 
 
 
 
 
 
 
 
 
 
25	}
26
27	if (!max_freq)
28		return;
29
30	/*
31	 * Calculate a worst-case loops-per-jiffy value
32	 * based on maximum cpu core hz setting and the
33	 * __delay() implementation in arch/arm/lib/delay.S.
34	 *
35	 * This will result in a longer delay than expected
36	 * when the cpu core runs on lower frequencies.
37	 */
38
39	if (!preset_lpj)
40		preset_lpj = max_freq / HZ;
41}

 
 1/*
 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.
15 */
16#include <linux/platform_device.h>
17#include <linux/clocksource.h>
18#include <linux/delay.h>
19#include <linux/of_address.h>
20
21#include "common.h"
22
23static void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz,
24					   unsigned int mult, unsigned int div)
25{
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
40void __init shmobile_init_delay(void)
41{
42	struct device_node *np, *cpus;
43	unsigned int div = 0;
44	bool has_arch_timer = false;
45	u32 max_freq = 0;
46
47	cpus = of_find_node_by_path("/cpus");
48	if (!cpus)
49		return;
50
51	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
57		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;
64			has_arch_timer = true;
65		}
66	}
67
68	of_node_put(cpus);
 
69
70	if (!max_freq || !div)
71		return;
 
 
 
 
 
 
72
73	if (!has_arch_timer || !IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
74		shmobile_setup_delay_hz(max_freq, 1, div);
75}