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-rw-r--r--arch/arm/mach-omap2/timer.c167
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diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
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+++ b/arch/arm/mach-omap2/timer.c
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+/*
+ * linux/arch/arm/mach-omap2/timer.c
+ *
+ * OMAP2 GP timer support.
+ *
+ * Copyright (C) 2009 Nokia Corporation
+ *
+ * Update to use new clocksource/clockevent layers
+ * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
+ * Copyright (C) 2007 MontaVista Software, Inc.
+ *
+ * Original driver:
+ * Copyright (C) 2005 Nokia Corporation
+ * Author: Paul Mundt <paul.mundt@nokia.com>
+ * Juha Yrjölä <juha.yrjola@nokia.com>
+ * OMAP Dual-mode timer framework support by Timo Teras
+ *
+ * Some parts based off of TI's 24xx code:
+ *
+ * Copyright (C) 2004-2009 Texas Instruments, Inc.
+ *
+ * Roughly modelled after the OMAP1 MPU timer code.
+ * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+
+#include "soc.h"
+#include "common.h"
+#include "control.h"
+#include "omap-secure.h"
+
+#define REALTIME_COUNTER_BASE 0x48243200
+#define INCREMENTER_NUMERATOR_OFFSET 0x10
+#define INCREMENTER_DENUMERATOR_RELOAD_OFFSET 0x14
+#define NUMERATOR_DENUMERATOR_MASK 0xfffff000
+
+static unsigned long arch_timer_freq;
+
+void set_cntfreq(void)
+{
+ omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
+}
+
+/*
+ * The realtime counter also called master counter, is a free-running
+ * counter, which is related to real time. It produces the count used
+ * by the CPU local timer peripherals in the MPU cluster. The timer counts
+ * at a rate of 6.144 MHz. Because the device operates on different clocks
+ * in different power modes, the master counter shifts operation between
+ * clocks, adjusting the increment per clock in hardware accordingly to
+ * maintain a constant count rate.
+ */
+static void __init realtime_counter_init(void)
+{
+ void __iomem *base;
+ static struct clk *sys_clk;
+ unsigned long rate;
+ unsigned int reg;
+ unsigned long long num, den;
+
+ base = ioremap(REALTIME_COUNTER_BASE, SZ_32);
+ if (!base) {
+ pr_err("%s: ioremap failed\n", __func__);
+ return;
+ }
+ sys_clk = clk_get(NULL, "sys_clkin");
+ if (IS_ERR(sys_clk)) {
+ pr_err("%s: failed to get system clock handle\n", __func__);
+ iounmap(base);
+ return;
+ }
+
+ rate = clk_get_rate(sys_clk);
+ clk_put(sys_clk);
+
+ if (soc_is_dra7xx()) {
+ /*
+ * Errata i856 says the 32.768KHz crystal does not start at
+ * power on, so the CPU falls back to an emulated 32KHz clock
+ * based on sysclk / 610 instead. This causes the master counter
+ * frequency to not be 6.144MHz but at sysclk / 610 * 375 / 2
+ * (OR sysclk * 75 / 244)
+ *
+ * This affects at least the DRA7/AM572x 1.0, 1.1 revisions.
+ * Of course any board built without a populated 32.768KHz
+ * crystal would also need this fix even if the CPU is fixed
+ * later.
+ *
+ * Either case can be detected by using the two speedselect bits
+ * If they are not 0, then the 32.768KHz clock driving the
+ * coarse counter that corrects the fine counter every time it
+ * ticks is actually rate/610 rather than 32.768KHz and we
+ * should compensate to avoid the 570ppm (at 20MHz, much worse
+ * at other rates) too fast system time.
+ */
+ reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP);
+ if (reg & DRA7_SPEEDSELECT_MASK) {
+ num = 75;
+ den = 244;
+ goto sysclk1_based;
+ }
+ }
+
+ /* Numerator/denumerator values refer TRM Realtime Counter section */
+ switch (rate) {
+ case 12000000:
+ num = 64;
+ den = 125;
+ break;
+ case 13000000:
+ num = 768;
+ den = 1625;
+ break;
+ case 19200000:
+ num = 8;
+ den = 25;
+ break;
+ case 20000000:
+ num = 192;
+ den = 625;
+ break;
+ case 26000000:
+ num = 384;
+ den = 1625;
+ break;
+ case 27000000:
+ num = 256;
+ den = 1125;
+ break;
+ case 38400000:
+ default:
+ /* Program it for 38.4 MHz */
+ num = 4;
+ den = 25;
+ break;
+ }
+
+sysclk1_based:
+ /* Program numerator and denumerator registers */
+ reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) &
+ NUMERATOR_DENUMERATOR_MASK;
+ reg |= num;
+ writel_relaxed(reg, base + INCREMENTER_NUMERATOR_OFFSET);
+
+ reg = readl_relaxed(base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET) &
+ NUMERATOR_DENUMERATOR_MASK;
+ reg |= den;
+ writel_relaxed(reg, base + INCREMENTER_DENUMERATOR_RELOAD_OFFSET);
+
+ arch_timer_freq = DIV_ROUND_UP_ULL(rate * num, den);
+ set_cntfreq();
+
+ iounmap(base);
+}
+
+void __init omap5_realtime_timer_init(void)
+{
+ omap_clk_init();
+ realtime_counter_init();
+
+ timer_probe();
+}