1 /***************************************************************************/ 2 3 /* 4 * timers.c - Generic hardware timer support. 5 * 6 * Copyright (C) 1993 Hamish Macdonald 7 * Copyright (C) 1999 D. Jeff Dionne 8 * Copyright (C) 2001 Georges Menie, Ken Desmet 9 * 10 * This file is subject to the terms and conditions of the GNU General Public 11 * License. See the file COPYING in the main directory of this archive 12 * for more details. 13 */ 14 15 /***************************************************************************/ 16 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/mm.h> 20 #include <linux/interrupt.h> 21 #include <linux/irq.h> 22 #include <linux/clocksource.h> 23 #include <linux/rtc.h> 24 #include <asm/setup.h> 25 #include <asm/pgtable.h> 26 #include <asm/machdep.h> 27 #include <asm/MC68VZ328.h> 28 29 /***************************************************************************/ 30 31 #if defined(CONFIG_DRAGEN2) 32 /* with a 33.16 MHz clock, this will give usec resolution to the time functions */ 33 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK 34 #define CLOCK_PRE 7 35 #define TICKS_PER_JIFFY 41450 36 37 #elif defined(CONFIG_XCOPILOT_BUGS) 38 /* 39 * The only thing I know is that CLK32 is not available on Xcopilot 40 * I have little idea about what frequency SYSCLK has on Xcopilot. 41 * The values for prescaler and compare registers were simply 42 * taken from the original source 43 */ 44 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK 45 #define CLOCK_PRE 2 46 #define TICKS_PER_JIFFY 0xd7e4 47 48 #else 49 /* default to using the 32Khz clock */ 50 #define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ 51 #define CLOCK_PRE 31 52 #define TICKS_PER_JIFFY 10 53 #endif 54 55 static u32 m68328_tick_cnt; 56 static irq_handler_t timer_interrupt; 57 58 /***************************************************************************/ 59 60 static irqreturn_t hw_tick(int irq, void *dummy) 61 { 62 /* Reset Timer1 */ 63 TSTAT &= 0; 64 65 m68328_tick_cnt += TICKS_PER_JIFFY; 66 return timer_interrupt(irq, dummy); 67 } 68 69 /***************************************************************************/ 70 71 static struct irqaction m68328_timer_irq = { 72 .name = "timer", 73 .flags = IRQF_TIMER, 74 .handler = hw_tick, 75 }; 76 77 /***************************************************************************/ 78 79 static u64 m68328_read_clk(struct clocksource *cs) 80 { 81 unsigned long flags; 82 u32 cycles; 83 84 local_irq_save(flags); 85 cycles = m68328_tick_cnt + TCN; 86 local_irq_restore(flags); 87 88 return cycles; 89 } 90 91 /***************************************************************************/ 92 93 static struct clocksource m68328_clk = { 94 .name = "timer", 95 .rating = 250, 96 .read = m68328_read_clk, 97 .mask = CLOCKSOURCE_MASK(32), 98 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 99 }; 100 101 /***************************************************************************/ 102 103 void hw_timer_init(irq_handler_t handler) 104 { 105 /* disable timer 1 */ 106 TCTL = 0; 107 108 /* set ISR */ 109 setup_irq(TMR_IRQ_NUM, &m68328_timer_irq); 110 111 /* Restart mode, Enable int, Set clock source */ 112 TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE; 113 TPRER = CLOCK_PRE; 114 TCMP = TICKS_PER_JIFFY; 115 116 /* Enable timer 1 */ 117 TCTL |= TCTL_TEN; 118 clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ); 119 timer_interrupt = handler; 120 } 121 122 /***************************************************************************/ 123 124 int m68328_hwclk(int set, struct rtc_time *t) 125 { 126 if (!set) { 127 long now = RTCTIME; 128 t->tm_year = t->tm_mon = t->tm_mday = 1; 129 t->tm_hour = (now >> 24) % 24; 130 t->tm_min = (now >> 16) % 60; 131 t->tm_sec = now % 60; 132 } 133 134 return 0; 135 } 136 137 /***************************************************************************/ 138