/arch/ppc64/kernel/pmac_time.c

  1/*
  2 * Support for periodic interrupts (100 per second) and for getting
  3 * the current time from the RTC on Power Macintoshes.
  4 *
  5 * We use the decrementer register for our periodic interrupts.
  6 *
  7 * Paul Mackerras	August 1996.
  8 * Copyright (C) 1996 Paul Mackerras.
  9 * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
 10 *
 11 */
 12#include <linux/config.h>
 13#include <linux/errno.h>
 14#include <linux/sched.h>
 15#include <linux/kernel.h>
 16#include <linux/param.h>
 17#include <linux/string.h>
 18#include <linux/mm.h>
 19#include <linux/init.h>
 20#include <linux/time.h>
 21#include <linux/adb.h>
 22#include <linux/pmu.h>
 23#include <linux/interrupt.h>
 24
 25#include <asm/sections.h>
 26#include <asm/prom.h>
 27#include <asm/system.h>
 28#include <asm/io.h>
 29#include <asm/pgtable.h>
 30#include <asm/machdep.h>
 31#include <asm/time.h>
 32#include <asm/nvram.h>
 33#include <asm/smu.h>
 34
 35#undef DEBUG
 36
 37#ifdef DEBUG
 38#define DBG(x...) printk(x)
 39#else
 40#define DBG(x...)
 41#endif
 42
 43extern void setup_default_decr(void);
 44
 45extern unsigned long ppc_tb_freq;
 46extern unsigned long ppc_proc_freq;
 47
 48/* Apparently the RTC stores seconds since 1 Jan 1904 */
 49#define RTC_OFFSET	2082844800
 50
 51/*
 52 * Calibrate the decrementer frequency with the VIA timer 1.
 53 */
 54#define VIA_TIMER_FREQ_6	4700000	/* time 1 frequency * 6 */
 55
 56extern struct timezone sys_tz;
 57extern void to_tm(int tim, struct rtc_time * tm);
 58
 59void __pmac pmac_get_rtc_time(struct rtc_time *tm)
 60{
 61	switch(sys_ctrler) {
 62#ifdef CONFIG_ADB_PMU
 63	case SYS_CTRLER_PMU: {
 64		/* TODO: Move that to a function in the PMU driver */
 65		struct adb_request req;
 66		unsigned int now;
 67
 68		if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
 69			return;
 70		pmu_wait_complete(&req);
 71		if (req.reply_len != 4)
 72			printk(KERN_ERR "pmac_get_rtc_time: PMU returned a %d"
 73			       " bytes reply\n", req.reply_len);
 74		now = (req.reply[0] << 24) + (req.reply[1] << 16)
 75			+ (req.reply[2] << 8) + req.reply[3];
 76		DBG("get: %u -> %u\n", (int)now, (int)(now - RTC_OFFSET));
 77		now -= RTC_OFFSET;
 78
 79		to_tm(now, tm);
 80		tm->tm_year -= 1900;
 81		tm->tm_mon -= 1;
 82	
 83		DBG("-> tm_mday: %d, tm_mon: %d, tm_year: %d, %d:%02d:%02d\n",
 84		    tm->tm_mday, tm->tm_mon, tm->tm_year,
 85		    tm->tm_hour, tm->tm_min, tm->tm_sec);
 86		break;
 87	}
 88#endif /* CONFIG_ADB_PMU */
 89
 90#ifdef CONFIG_PMAC_SMU
 91	case SYS_CTRLER_SMU:
 92		smu_get_rtc_time(tm);
 93		break;
 94#endif /* CONFIG_PMAC_SMU */
 95	default:
 96		;
 97	}
 98}
 99
100int __pmac pmac_set_rtc_time(struct rtc_time *tm)
101{
102	switch(sys_ctrler) {
103#ifdef CONFIG_ADB_PMU
104	case SYS_CTRLER_PMU: {
105		/* TODO: Move that to a function in the PMU driver */
106		struct adb_request req;
107		unsigned int nowtime;
108
109		DBG("set: tm_mday: %d, tm_mon: %d, tm_year: %d,"
110		    " %d:%02d:%02d\n",
111		    tm->tm_mday, tm->tm_mon, tm->tm_year,
112		    tm->tm_hour, tm->tm_min, tm->tm_sec);
113
114		nowtime = mktime(tm->tm_year + 1900, tm->tm_mon + 1,
115				 tm->tm_mday, tm->tm_hour, tm->tm_min,
116				 tm->tm_sec);
117
118		DBG("-> %u -> %u\n", (int)nowtime,
119		    (int)(nowtime + RTC_OFFSET));
120		nowtime += RTC_OFFSET;
121
122		if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
123				nowtime >> 24, nowtime >> 16,
124				nowtime >> 8, nowtime) < 0)
125			return -ENXIO;
126		pmu_wait_complete(&req);
127		if (req.reply_len != 0)
128			printk(KERN_ERR "pmac_set_rtc_time: PMU returned a %d"
129			       " bytes reply\n", req.reply_len);
130		return 0;
131	}
132#endif /* CONFIG_ADB_PMU */
133
134#ifdef CONFIG_PMAC_SMU
135	case SYS_CTRLER_SMU:
136		return smu_set_rtc_time(tm);
137#endif /* CONFIG_PMAC_SMU */
138	default:
139		return -ENODEV;
140	}
141}
142
143void __init pmac_get_boot_time(struct rtc_time *tm)
144{
145	pmac_get_rtc_time(tm);
146
147#ifdef disabled__CONFIG_NVRAM
148	s32 delta = 0;
149	int dst;
150	
151	delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
152	delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
153	delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
154	if (delta & 0x00800000UL)
155		delta |= 0xFF000000UL;
156	dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
157	printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
158		dst ? "on" : "off");
159#endif
160}
161
162/*
163 * Query the OF and get the decr frequency.
164 * This was taken from the pmac time_init() when merging the prep/pmac
165 * time functions.
166 */
167void __init pmac_calibrate_decr(void)
168{
169	struct device_node *cpu;
170	unsigned int freq, *fp;
171	struct div_result divres;
172
173	/*
174	 * The cpu node should have a timebase-frequency property
175	 * to tell us the rate at which the decrementer counts.
176	 */
177	cpu = find_type_devices("cpu");
178	if (cpu == 0)
179		panic("can't find cpu node in time_init");
180	fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
181	if (fp == 0)
182		panic("can't get cpu timebase frequency");
183	freq = *fp;
184	printk("time_init: decrementer frequency = %u.%.6u MHz\n",
185	       freq/1000000, freq%1000000);
186	tb_ticks_per_jiffy = freq / HZ;
187	tb_ticks_per_sec = tb_ticks_per_jiffy * HZ;
188	tb_ticks_per_usec = freq / 1000000;
189	tb_to_us = mulhwu_scale_factor(freq, 1000000);
190	div128_by_32( 1024*1024, 0, tb_ticks_per_sec, &divres );
191	tb_to_xs = divres.result_low;
192	ppc_tb_freq = freq;
193
194	fp = (unsigned int *)get_property(cpu, "clock-frequency", NULL);
195	if (fp == 0)
196		panic("can't get cpu processor frequency");
197	ppc_proc_freq = *fp;
198
199	setup_default_decr();
200}
201