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/machdep.h> 26 #include <asm/MC68VZ328.h> 27 28 #include "m68328.h" 29 30 /***************************************************************************/ 31 32 #if defined(CONFIG_DRAGEN2) 33 /* with a 33.16 MHz clock, this will give usec resolution to the time functions */ 34 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK 35 #define CLOCK_PRE 7 36 #define TICKS_PER_JIFFY 41450 37 38 #elif defined(CONFIG_XCOPILOT_BUGS) 39 /* 40 * The only thing I know is that CLK32 is not available on Xcopilot 41 * I have little idea about what frequency SYSCLK has on Xcopilot. 42 * The values for prescaler and compare registers were simply 43 * taken from the original source 44 */ 45 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK 46 #define CLOCK_PRE 2 47 #define TICKS_PER_JIFFY 0xd7e4 48 49 #else 50 /* default to using the 32Khz clock */ 51 #define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ 52 #define CLOCK_PRE 31 53 #define TICKS_PER_JIFFY 10 54 #endif 55 56 static u32 m68328_tick_cnt; 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 legacy_timer_tick(1); 67 return IRQ_HANDLED; 68 } 69 70 /***************************************************************************/ 71 72 static u64 m68328_read_clk(struct clocksource *cs) 73 { 74 unsigned long flags; 75 u32 cycles; 76 77 local_irq_save(flags); 78 cycles = m68328_tick_cnt + TCN; 79 local_irq_restore(flags); 80 81 return cycles; 82 } 83 84 /***************************************************************************/ 85 86 static struct clocksource m68328_clk = { 87 .name = "timer", 88 .rating = 250, 89 .read = m68328_read_clk, 90 .mask = CLOCKSOURCE_MASK(32), 91 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 92 }; 93 94 /***************************************************************************/ 95 96 void hw_timer_init(void) 97 { 98 int ret; 99 100 /* disable timer 1 */ 101 TCTL = 0; 102 103 /* set ISR */ 104 ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL); 105 if (ret) { 106 pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM, 107 ERR_PTR(ret)); 108 } 109 110 /* Restart mode, Enable int, Set clock source */ 111 TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE; 112 TPRER = CLOCK_PRE; 113 TCMP = TICKS_PER_JIFFY; 114 115 /* Enable timer 1 */ 116 TCTL |= TCTL_TEN; 117 clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ); 118 } 119 120 /***************************************************************************/ 121 122 int m68328_hwclk(int set, struct rtc_time *t) 123 { 124 if (!set) { 125 long now = RTCTIME; 126 t->tm_year = 1; 127 t->tm_mon = 0; 128 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