| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Support for periodic interrupts (100 per second) and for getting |
| * the current time from the RTC on Power Macintoshes. |
| * |
| * We use the decrementer register for our periodic interrupts. |
| * |
| * Paul Mackerras August 1996. |
| * Copyright (C) 1996 Paul Mackerras. |
| * Copyright (C) 2003-2005 Benjamin Herrenschmidt. |
| * |
| */ |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/kernel.h> |
| #include <linux/param.h> |
| #include <linux/string.h> |
| #include <linux/mm.h> |
| #include <linux/init.h> |
| #include <linux/time.h> |
| #include <linux/adb.h> |
| #include <linux/cuda.h> |
| #include <linux/pmu.h> |
| #include <linux/interrupt.h> |
| #include <linux/hardirq.h> |
| #include <linux/rtc.h> |
| |
| #include <asm/sections.h> |
| #include <asm/prom.h> |
| #include <asm/io.h> |
| #include <asm/pgtable.h> |
| #include <asm/machdep.h> |
| #include <asm/time.h> |
| #include <asm/nvram.h> |
| #include <asm/smu.h> |
| |
| #include "pmac.h" |
| |
| #undef DEBUG |
| |
| #ifdef DEBUG |
| #define DBG(x...) printk(x) |
| #else |
| #define DBG(x...) |
| #endif |
| |
| /* |
| * Calibrate the decrementer frequency with the VIA timer 1. |
| */ |
| #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */ |
| |
| /* VIA registers */ |
| #define RS 0x200 /* skip between registers */ |
| #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ |
| #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ |
| #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ |
| #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ |
| #define ACR (11*RS) /* Auxiliary control register */ |
| #define IFR (13*RS) /* Interrupt flag register */ |
| |
| /* Bits in ACR */ |
| #define T1MODE 0xc0 /* Timer 1 mode */ |
| #define T1MODE_CONT 0x40 /* continuous interrupts */ |
| |
| /* Bits in IFR and IER */ |
| #define T1_INT 0x40 /* Timer 1 interrupt */ |
| |
| long __init pmac_time_init(void) |
| { |
| s32 delta = 0; |
| #if defined(CONFIG_NVRAM) && defined(CONFIG_PPC32) |
| int dst; |
| |
| delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16; |
| delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8; |
| delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb); |
| if (delta & 0x00800000UL) |
| delta |= 0xFF000000UL; |
| dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0); |
| printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60, |
| dst ? "on" : "off"); |
| #endif |
| return delta; |
| } |
| |
| #ifdef CONFIG_PMAC_SMU |
| static time64_t smu_get_time(void) |
| { |
| struct rtc_time tm; |
| |
| if (smu_get_rtc_time(&tm, 1)) |
| return 0; |
| return rtc_tm_to_time64(&tm); |
| } |
| #endif |
| |
| /* Can't be __init, it's called when suspending and resuming */ |
| time64_t pmac_get_boot_time(void) |
| { |
| /* Get the time from the RTC, used only at boot time */ |
| switch (sys_ctrler) { |
| #ifdef CONFIG_ADB_CUDA |
| case SYS_CTRLER_CUDA: |
| return cuda_get_time(); |
| #endif |
| #ifdef CONFIG_ADB_PMU |
| case SYS_CTRLER_PMU: |
| return pmu_get_time(); |
| #endif |
| #ifdef CONFIG_PMAC_SMU |
| case SYS_CTRLER_SMU: |
| return smu_get_time(); |
| #endif |
| default: |
| return 0; |
| } |
| } |
| |
| void pmac_get_rtc_time(struct rtc_time *tm) |
| { |
| /* Get the time from the RTC, used only at boot time */ |
| switch (sys_ctrler) { |
| #ifdef CONFIG_ADB_CUDA |
| case SYS_CTRLER_CUDA: |
| rtc_time64_to_tm(cuda_get_time(), tm); |
| break; |
| #endif |
| #ifdef CONFIG_ADB_PMU |
| case SYS_CTRLER_PMU: |
| rtc_time64_to_tm(pmu_get_time(), tm); |
| break; |
| #endif |
| #ifdef CONFIG_PMAC_SMU |
| case SYS_CTRLER_SMU: |
| smu_get_rtc_time(tm, 1); |
| break; |
| #endif |
| default: |
| ; |
| } |
| } |
| |
| int pmac_set_rtc_time(struct rtc_time *tm) |
| { |
| switch (sys_ctrler) { |
| #ifdef CONFIG_ADB_CUDA |
| case SYS_CTRLER_CUDA: |
| return cuda_set_rtc_time(tm); |
| #endif |
| #ifdef CONFIG_ADB_PMU |
| case SYS_CTRLER_PMU: |
| return pmu_set_rtc_time(tm); |
| #endif |
| #ifdef CONFIG_PMAC_SMU |
| case SYS_CTRLER_SMU: |
| return smu_set_rtc_time(tm, 1); |
| #endif |
| default: |
| return -ENODEV; |
| } |
| } |
| |
| #ifdef CONFIG_PPC32 |
| /* |
| * Calibrate the decrementer register using VIA timer 1. |
| * This is used both on powermacs and CHRP machines. |
| */ |
| static int __init via_calibrate_decr(void) |
| { |
| struct device_node *vias; |
| volatile unsigned char __iomem *via; |
| int count = VIA_TIMER_FREQ_6 / 100; |
| unsigned int dstart, dend; |
| struct resource rsrc; |
| |
| vias = of_find_node_by_name(NULL, "via-cuda"); |
| if (vias == NULL) |
| vias = of_find_node_by_name(NULL, "via-pmu"); |
| if (vias == NULL) |
| vias = of_find_node_by_name(NULL, "via"); |
| if (vias == NULL || of_address_to_resource(vias, 0, &rsrc)) { |
| of_node_put(vias); |
| return 0; |
| } |
| of_node_put(vias); |
| via = ioremap(rsrc.start, resource_size(&rsrc)); |
| if (via == NULL) { |
| printk(KERN_ERR "Failed to map VIA for timer calibration !\n"); |
| return 0; |
| } |
| |
| /* set timer 1 for continuous interrupts */ |
| out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT); |
| /* set the counter to a small value */ |
| out_8(&via[T1CH], 2); |
| /* set the latch to `count' */ |
| out_8(&via[T1LL], count); |
| out_8(&via[T1LH], count >> 8); |
| /* wait until it hits 0 */ |
| while ((in_8(&via[IFR]) & T1_INT) == 0) |
| ; |
| dstart = get_dec(); |
| /* clear the interrupt & wait until it hits 0 again */ |
| in_8(&via[T1CL]); |
| while ((in_8(&via[IFR]) & T1_INT) == 0) |
| ; |
| dend = get_dec(); |
| |
| ppc_tb_freq = (dstart - dend) * 100 / 6; |
| |
| iounmap(via); |
| |
| return 1; |
| } |
| #endif |
| |
| /* |
| * Query the OF and get the decr frequency. |
| */ |
| void __init pmac_calibrate_decr(void) |
| { |
| generic_calibrate_decr(); |
| |
| #ifdef CONFIG_PPC32 |
| /* We assume MacRISC2 machines have correct device-tree |
| * calibration. That's better since the VIA itself seems |
| * to be slightly off. --BenH |
| */ |
| if (!of_machine_is_compatible("MacRISC2") && |
| !of_machine_is_compatible("MacRISC3") && |
| !of_machine_is_compatible("MacRISC4")) |
| if (via_calibrate_decr()) |
| return; |
| |
| /* Special case: QuickSilver G4s seem to have a badly calibrated |
| * timebase-frequency in OF, VIA is much better on these. We should |
| * probably implement calibration based on the KL timer on these |
| * machines anyway... -BenH |
| */ |
| if (of_machine_is_compatible("PowerMac3,5")) |
| if (via_calibrate_decr()) |
| return; |
| #endif |
| } |