5d14a18d59
I had the sense of the test for when to use the old 601-style RTC registers inverted. pmac_calibrate_decr and via_calibrate_decr weren't setting ppc_tb_freq, on which all the further calculations depended. Lastly, update_gtod was losing the top 32 bits of the new tb_to_xs value. Signed-off-by: Paul Mackerras <paulus@samba.org>
311 lines
7.9 KiB
C
311 lines
7.9 KiB
C
/*
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* Support for periodic interrupts (100 per second) and for getting
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* the current time from the RTC on Power Macintoshes.
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*
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* We use the decrementer register for our periodic interrupts.
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*
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* Paul Mackerras August 1996.
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* Copyright (C) 1996 Paul Mackerras.
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* Copyright (C) 2003-2005 Benjamin Herrenschmidt.
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*
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*/
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#include <linux/config.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/time.h>
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#include <linux/adb.h>
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#include <linux/cuda.h>
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#include <linux/pmu.h>
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#include <linux/interrupt.h>
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#include <linux/hardirq.h>
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#include <linux/rtc.h>
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#include <asm/sections.h>
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#include <asm/prom.h>
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#include <asm/system.h>
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#include <asm/io.h>
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#include <asm/pgtable.h>
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#include <asm/machdep.h>
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#include <asm/time.h>
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#include <asm/nvram.h>
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#undef DEBUG
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#ifdef DEBUG
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#define DBG(x...) printk(x)
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#else
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#define DBG(x...)
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#endif
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/* Apparently the RTC stores seconds since 1 Jan 1904 */
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#define RTC_OFFSET 2082844800
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/*
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* Calibrate the decrementer frequency with the VIA timer 1.
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*/
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#define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */
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/* VIA registers */
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#define RS 0x200 /* skip between registers */
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#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
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#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
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#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
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#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
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#define ACR (11*RS) /* Auxiliary control register */
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#define IFR (13*RS) /* Interrupt flag register */
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/* Bits in ACR */
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#define T1MODE 0xc0 /* Timer 1 mode */
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#define T1MODE_CONT 0x40 /* continuous interrupts */
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/* Bits in IFR and IER */
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#define T1_INT 0x40 /* Timer 1 interrupt */
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long __init pmac_time_init(void)
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{
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#ifdef CONFIG_NVRAM
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s32 delta = 0;
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int dst;
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delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
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delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
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delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
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if (delta & 0x00800000UL)
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delta |= 0xFF000000UL;
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dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
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printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
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dst ? "on" : "off");
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return delta;
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#else
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return 0;
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#endif
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}
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unsigned long pmac_get_boot_time(void)
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{
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#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
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struct adb_request req;
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unsigned long now;
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#endif
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/* Get the time from the RTC */
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switch (sys_ctrler) {
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#ifdef CONFIG_ADB_CUDA
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case SYS_CTRLER_CUDA:
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if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
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return 0;
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while (!req.complete)
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cuda_poll();
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if (req.reply_len != 7)
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printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
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req.reply_len);
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now = (req.reply[3] << 24) + (req.reply[4] << 16)
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+ (req.reply[5] << 8) + req.reply[6];
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return now - RTC_OFFSET;
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#endif /* CONFIG_ADB_CUDA */
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#ifdef CONFIG_ADB_PMU
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case SYS_CTRLER_PMU:
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if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
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return 0;
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while (!req.complete)
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pmu_poll();
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if (req.reply_len != 4)
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printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
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req.reply_len);
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now = (req.reply[0] << 24) + (req.reply[1] << 16)
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+ (req.reply[2] << 8) + req.reply[3];
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return now - RTC_OFFSET;
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#endif /* CONFIG_ADB_PMU */
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default: ;
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}
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return 0;
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}
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void pmac_get_rtc_time(struct rtc_time *tm)
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{
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unsigned long now;
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now = pmac_get_boot_time();
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to_tm(now, tm);
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tm->tm_year -= 1900;
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tm->tm_mon -= 1; /* month is 0-based */
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}
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int pmac_set_rtc_time(struct rtc_time *tm)
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{
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unsigned long nowtime;
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#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
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struct adb_request req;
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#endif
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nowtime = mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
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tm->tm_hour, tm->tm_min, tm->tm_sec);
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nowtime += RTC_OFFSET;
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switch (sys_ctrler) {
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#ifdef CONFIG_ADB_CUDA
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case SYS_CTRLER_CUDA:
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if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
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nowtime >> 24, nowtime >> 16, nowtime >> 8,
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nowtime) < 0)
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return 0;
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while (!req.complete)
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cuda_poll();
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if ((req.reply_len != 3) && (req.reply_len != 7))
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printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
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req.reply_len);
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return 1;
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#endif /* CONFIG_ADB_CUDA */
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#ifdef CONFIG_ADB_PMU
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case SYS_CTRLER_PMU:
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if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
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nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0)
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return 0;
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while (!req.complete)
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pmu_poll();
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if (req.reply_len != 0)
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printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
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req.reply_len);
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return 1;
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#endif /* CONFIG_ADB_PMU */
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default:
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return 0;
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}
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}
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/*
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* Calibrate the decrementer register using VIA timer 1.
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* This is used both on powermacs and CHRP machines.
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*/
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int __init
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via_calibrate_decr(void)
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{
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struct device_node *vias;
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volatile unsigned char __iomem *via;
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int count = VIA_TIMER_FREQ_6 / 100;
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unsigned int dstart, dend;
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vias = find_devices("via-cuda");
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if (vias == 0)
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vias = find_devices("via-pmu");
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if (vias == 0)
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vias = find_devices("via");
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if (vias == 0 || vias->n_addrs == 0)
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return 0;
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via = ioremap(vias->addrs[0].address, vias->addrs[0].size);
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/* set timer 1 for continuous interrupts */
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out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
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/* set the counter to a small value */
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out_8(&via[T1CH], 2);
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/* set the latch to `count' */
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out_8(&via[T1LL], count);
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out_8(&via[T1LH], count >> 8);
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/* wait until it hits 0 */
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while ((in_8(&via[IFR]) & T1_INT) == 0)
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;
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dstart = get_dec();
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/* clear the interrupt & wait until it hits 0 again */
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in_8(&via[T1CL]);
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while ((in_8(&via[IFR]) & T1_INT) == 0)
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;
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dend = get_dec();
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ppc_tb_freq = (dstart - dend) * 100 / 6;
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tb_ticks_per_jiffy = (dstart - dend) / ((6 * HZ)/100);
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printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %lu (%u ticks)\n",
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tb_ticks_per_jiffy, dstart - dend);
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iounmap(via);
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return 1;
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}
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#ifdef CONFIG_PM
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/*
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* Reset the time after a sleep.
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*/
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static int
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time_sleep_notify(struct pmu_sleep_notifier *self, int when)
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{
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static unsigned long time_diff;
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unsigned long flags;
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unsigned long seq;
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struct timespec tv;
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switch (when) {
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case PBOOK_SLEEP_NOW:
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do {
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seq = read_seqbegin_irqsave(&xtime_lock, flags);
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time_diff = xtime.tv_sec - pmac_get_boot_time();
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} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
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break;
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case PBOOK_WAKE:
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tv.tv_sec = pmac_get_boot_time() + time_diff;
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tv.tv_nsec = 0;
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do_settimeofday(&tv);
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break;
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}
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return PBOOK_SLEEP_OK;
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}
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static struct pmu_sleep_notifier time_sleep_notifier = {
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time_sleep_notify, SLEEP_LEVEL_MISC,
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};
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#endif /* CONFIG_PM */
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/*
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* Query the OF and get the decr frequency.
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* This was taken from the pmac time_init() when merging the prep/pmac
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* time functions.
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*/
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void __init
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pmac_calibrate_decr(void)
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{
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struct device_node *cpu;
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unsigned int freq, *fp;
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#ifdef CONFIG_PM
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pmu_register_sleep_notifier(&time_sleep_notifier);
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#endif /* CONFIG_PM */
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/* We assume MacRISC2 machines have correct device-tree
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* calibration. That's better since the VIA itself seems
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* to be slightly off. --BenH
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*/
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if (!machine_is_compatible("MacRISC2") &&
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!machine_is_compatible("MacRISC3") &&
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!machine_is_compatible("MacRISC4"))
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if (via_calibrate_decr())
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return;
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/* Special case: QuickSilver G4s seem to have a badly calibrated
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* timebase-frequency in OF, VIA is much better on these. We should
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* probably implement calibration based on the KL timer on these
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* machines anyway... -BenH
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*/
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if (machine_is_compatible("PowerMac3,5"))
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if (via_calibrate_decr())
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return;
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/*
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* The cpu node should have a timebase-frequency property
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* to tell us the rate at which the decrementer counts.
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*/
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cpu = find_type_devices("cpu");
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if (cpu == 0)
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panic("can't find cpu node in time_init");
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fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
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if (fp == 0)
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panic("can't get cpu timebase frequency");
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freq = *fp;
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printk("time_init: decrementer frequency = %u.%.6u MHz\n",
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freq/1000000, freq%1000000);
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ppc_tb_freq = freq;
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}
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