1 /* 2 * Copyright (C) 2009 Samsung Electronics 3 * Heungjun Kim <riverful.kim@samsung.com> 4 * Inki Dae <inki.dae@samsung.com> 5 * Minkyu Kang <mk7.kang@samsung.com> 6 * 7 * See file CREDITS for list of people who contributed to this 8 * project. 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation; either version 2 of 13 * the License, or (at your option) any later version. 14 * 15 * This program is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU General Public License for more details. 19 * 20 * You should have received a copy of the GNU General Public License 21 * along with this program; if not, write to the Free Software 22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 23 * MA 02111-1307 USA 24 */ 25 26 #include <common.h> 27 #include <asm/io.h> 28 #include <asm/arch/pwm.h> 29 #include <asm/arch/clk.h> 30 #include <pwm.h> 31 32 DECLARE_GLOBAL_DATA_PTR; 33 34 /* macro to read the 16 bit timer */ 35 static inline struct s5p_timer *s5p_get_base_timer(void) 36 { 37 return (struct s5p_timer *)samsung_get_base_timer(); 38 } 39 40 int timer_init(void) 41 { 42 /* PWM Timer 4 */ 43 pwm_init(4, MUX_DIV_2, 0); 44 pwm_config(4, 0, 0); 45 pwm_enable(4); 46 47 return 0; 48 } 49 50 /* 51 * timer without interrupts 52 */ 53 void reset_timer(void) 54 { 55 reset_timer_masked(); 56 } 57 58 unsigned long get_timer(unsigned long base) 59 { 60 return get_timer_masked() - base; 61 } 62 63 /* delay x useconds */ 64 void __udelay(unsigned long usec) 65 { 66 struct s5p_timer *const timer = s5p_get_base_timer(); 67 unsigned long tmo, tmp, count_value; 68 69 count_value = readl(&timer->tcntb4); 70 71 if (usec >= 1000) { 72 /* 73 * if "big" number, spread normalization 74 * to seconds 75 * 1. start to normalize for usec to ticks per sec 76 * 2. find number of "ticks" to wait to achieve target 77 * 3. finish normalize. 78 */ 79 tmo = usec / 1000; 80 tmo *= (CONFIG_SYS_HZ * count_value / 10); 81 tmo /= 1000; 82 } else { 83 /* else small number, don't kill it prior to HZ multiply */ 84 tmo = usec * CONFIG_SYS_HZ * count_value / 10; 85 tmo /= (1000 * 1000); 86 } 87 88 /* get current timestamp */ 89 tmp = get_timer(0); 90 91 /* if setting this fordward will roll time stamp */ 92 /* reset "advancing" timestamp to 0, set lastinc value */ 93 /* else, set advancing stamp wake up time */ 94 if ((tmo + tmp + 1) < tmp) 95 reset_timer_masked(); 96 else 97 tmo += tmp; 98 99 /* loop till event */ 100 while (get_timer_masked() < tmo) 101 ; /* nop */ 102 } 103 104 void reset_timer_masked(void) 105 { 106 struct s5p_timer *const timer = s5p_get_base_timer(); 107 108 /* reset time */ 109 gd->lastinc = readl(&timer->tcnto4); 110 gd->tbl = 0; 111 } 112 113 unsigned long get_timer_masked(void) 114 { 115 struct s5p_timer *const timer = s5p_get_base_timer(); 116 unsigned long now = readl(&timer->tcnto4); 117 unsigned long count_value = readl(&timer->tcntb4); 118 119 if (gd->lastinc >= now) 120 gd->tbl += gd->lastinc - now; 121 else 122 gd->tbl += gd->lastinc + count_value - now; 123 124 gd->lastinc = now; 125 126 return gd->tbl; 127 } 128 129 /* 130 * This function is derived from PowerPC code (read timebase as long long). 131 * On ARM it just returns the timer value. 132 */ 133 unsigned long long get_ticks(void) 134 { 135 return get_timer(0); 136 } 137 138 /* 139 * This function is derived from PowerPC code (timebase clock frequency). 140 * On ARM it returns the number of timer ticks per second. 141 */ 142 unsigned long get_tbclk(void) 143 { 144 return CONFIG_SYS_HZ; 145 } 146