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 23 void __init shmobile_init_delay(void) 24 { 25 struct device_node *np; 26 u32 max_freq = 0; 27 28 for_each_of_cpu_node(np) { 29 u32 freq; 30 31 if (!of_property_read_u32(np, "clock-frequency", &freq)) 32 max_freq = max(max_freq, freq); 33 } 34 35 if (!max_freq) 36 return; 37 38 /* 39 * Calculate a worst-case loops-per-jiffy value 40 * based on maximum cpu core hz setting and the 41 * __delay() implementation in arch/arm/lib/delay.S. 42 * 43 * This will result in a longer delay than expected 44 * when the cpu core runs on lower frequencies. 45 */ 46 47 if (!preset_lpj) 48 preset_lpj = max_freq / HZ; 49 } 50