Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 330 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
new file mode 100644
index 000000000..f92c1918f
--- /dev/null
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -0,0 +1,330 @@
+// 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
+
+/*
+ * Offset between Unix time (1970-based) and Mac time (1904-based). Cuda and PMU
+ * times wrap in 2040. If we need to handle later times, the read_time functions
+ * need to be changed to interpret wrapped times as post-2040.
+ */
+#define RTC_OFFSET	2082844800
+
+/*
+ * 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;
+#ifdef CONFIG_NVRAM
+	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_ADB_CUDA
+static time64_t cuda_get_time(void)
+{
+	struct adb_request req;
+	time64_t now;
+
+	if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
+		return 0;
+	while (!req.complete)
+		cuda_poll();
+	if (req.reply_len != 7)
+		printk(KERN_ERR "cuda_get_time: got %d byte reply\n",
+		       req.reply_len);
+	now = (u32)((req.reply[3] << 24) + (req.reply[4] << 16) +
+		    (req.reply[5] << 8) + req.reply[6]);
+	/* it's either after year 2040, or the RTC has gone backwards */
+	WARN_ON(now < RTC_OFFSET);
+
+	return now - RTC_OFFSET;
+}
+
+#define cuda_get_rtc_time(tm)	rtc_time64_to_tm(cuda_get_time(), (tm))
+
+static int cuda_set_rtc_time(struct rtc_time *tm)
+{
+	u32 nowtime;
+	struct adb_request req;
+
+	nowtime = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET);
+	if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
+			 nowtime >> 24, nowtime >> 16, nowtime >> 8,
+			 nowtime) < 0)
+		return -ENXIO;
+	while (!req.complete)
+		cuda_poll();
+	if ((req.reply_len != 3) && (req.reply_len != 7))
+		printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n",
+		       req.reply_len);
+	return 0;
+}
+
+#else
+#define cuda_get_time()		0
+#define cuda_get_rtc_time(tm)
+#define cuda_set_rtc_time(tm)	0
+#endif
+
+#ifdef CONFIG_ADB_PMU
+static time64_t pmu_get_time(void)
+{
+	struct adb_request req;
+	time64_t now;
+
+	if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
+		return 0;
+	pmu_wait_complete(&req);
+	if (req.reply_len != 4)
+		printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
+		       req.reply_len);
+	now = (u32)((req.reply[0] << 24) + (req.reply[1] << 16)	+
+		    (req.reply[2] << 8) + req.reply[3]);
+
+	/* it's either after year 2040, or the RTC has gone backwards */
+	WARN_ON(now < RTC_OFFSET);
+
+	return now - RTC_OFFSET;
+}
+
+#define pmu_get_rtc_time(tm)	rtc_time64_to_tm(pmu_get_time(), (tm))
+
+static int pmu_set_rtc_time(struct rtc_time *tm)
+{
+	u32 nowtime;
+	struct adb_request req;
+
+	nowtime = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET);
+	if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
+			nowtime >> 16, nowtime >> 8, nowtime) < 0)
+		return -ENXIO;
+	pmu_wait_complete(&req);
+	if (req.reply_len != 0)
+		printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n",
+		       req.reply_len);
+	return 0;
+}
+
+#else
+#define pmu_get_time()		0
+#define pmu_get_rtc_time(tm)
+#define pmu_set_rtc_time(tm)	0
+#endif
+
+#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);
+}
+
+#else
+#define smu_get_time()			0
+#define smu_get_rtc_time(tm, spin)
+#define smu_set_rtc_time(tm, spin)	0
+#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) {
+	case SYS_CTRLER_CUDA:
+		return cuda_get_time();
+	case SYS_CTRLER_PMU:
+		return pmu_get_time();
+	case SYS_CTRLER_SMU:
+		return smu_get_time();
+	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) {
+	case SYS_CTRLER_CUDA:
+		cuda_get_rtc_time(tm);
+		break;
+	case SYS_CTRLER_PMU:
+		pmu_get_rtc_time(tm);
+		break;
+	case SYS_CTRLER_SMU:
+		smu_get_rtc_time(tm, 1);
+		break;
+	default:
+		;
+	}
+}
+
+int pmac_set_rtc_time(struct rtc_time *tm)
+{
+	switch (sys_ctrler) {
+	case SYS_CTRLER_CUDA:
+		return cuda_set_rtc_time(tm);
+	case SYS_CTRLER_PMU:
+		return pmu_set_rtc_time(tm);
+	case SYS_CTRLER_SMU:
+		return smu_set_rtc_time(tm, 1);
+	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
+}