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 /***************************************************************************/ 29 30 #if defined(CONFIG_DRAGEN2) 31 /* with a 33.16 MHz clock, this will give usec resolution to the time functions */ 32 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK 33 #define CLOCK_PRE 7 34 #define TICKS_PER_JIFFY 41450 35 36 #elif defined(CONFIG_XCOPILOT_BUGS) 37 /* 38 * The only thing I know is that CLK32 is not available on Xcopilot 39 * I have little idea about what frequency SYSCLK has on Xcopilot. 40 * The values for prescaler and compare registers were simply 41 * taken from the original source 42 */ 43 #define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK 44 #define CLOCK_PRE 2 45 #define TICKS_PER_JIFFY 0xd7e4 46 47 #else 48 /* default to using the 32Khz clock */ 49 #define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ 50 #define CLOCK_PRE 31 51 #define TICKS_PER_JIFFY 10 52 #endif 53 54 static u32 m68328_tick_cnt; 55 static irq_handler_t timer_interrupt; 56 57 /***************************************************************************/ 58 59 static irqreturn_t hw_tick(int irq, void *dummy) 60 { 61 /* Reset Timer1 */ 62 TSTAT &= 0; 63 64 m68328_tick_cnt += TICKS_PER_JIFFY; 65 return timer_interrupt(irq, dummy); 66 } 67 68 /***************************************************************************/ 69 70 static u64 m68328_read_clk(struct clocksource *cs) 71 { 72 unsigned long flags; 73 u32 cycles; 74 75 local_irq_save(flags); 76 cycles = m68328_tick_cnt + TCN; 77 local_irq_restore(flags); 78 79 return cycles; 80 } 81 82 /***************************************************************************/ 83 84 static struct clocksource m68328_clk = { 85 .name = "timer", 86 .rating = 250, 87 .read = m68328_read_clk, 88 .mask = CLOCKSOURCE_MASK(32), 89 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 90 }; 91 92 /***************************************************************************/ 93 94 void hw_timer_init(irq_handler_t handler) 95 { 96 int ret; 97 98 /* disable timer 1 */ 99 TCTL = 0; 100 101 /* set ISR */ 102 ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL); 103 if (ret) { 104 pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM, 105 ERR_PTR(ret)); 106 } 107 108 /* Restart mode, Enable int, Set clock source */ 109 TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE; 110 TPRER = CLOCK_PRE; 111 TCMP = TICKS_PER_JIFFY; 112 113 /* Enable timer 1 */ 114 TCTL |= TCTL_TEN; 115 clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ); 116 timer_interrupt = handler; 117 } 118 119 /***************************************************************************/ 120 121 int m68328_hwclk(int set, struct rtc_time *t) 122 { 123 if (!set) { 124 long now = RTCTIME; 125 t->tm_year = 1; 126 t->tm_mon = 0; 127 t->tm_mday = 1; 128 t->tm_hour = (now >> 24) % 24; 129 t->tm_min = (now >> 16) % 60; 130 t->tm_sec = now % 60; 131 } 132 133 return 0; 134 } 135 136 /***************************************************************************/ 137