OMAP: split plat-omap/common.c

Split plat-omap/common.c into three pieces:

1. the 32KiHz sync timer and clocksource code, which now lives in
   plat-omap/counter_32k.c;

2. the OMAP2+ common code, which has been moved to mach-omap2/common.c;

3. and the remainder of the OMAP-wide common code, which includes the
   deprecated ATAGs code and a deprecated video RAM reservation function.

The primary motivation for doing this is to move the OMAP2+-specific parts
into an OMAP2+-specific file, so that build breakage related to the
System Control Module code can be resolved.

Benoît Cousson <b-cousson@ti.com> suggested a new filename and found
some bugs in the counter_32k.c comments - thanks Benoît.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>

1 files changed, 183 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/counter_32k.c b/arch/arm/plat-omap/counter_32k.c
new file mode 100644
index 0000000..155fe43
--- /dev/null
+++ b/arch/arm/plat-omap/counter_32k.c
@@ -0,0 +1,183 @@
+/*
+ * OMAP 32ksynctimer/counter_32k-related code
+ *
+ * Copyright (C) 2009 Texas Instruments
+ * Copyright (C) 2010 Nokia Corporation
+ * Tony Lindgren <tony@atomide.com>
+ * Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * NOTE: This timer is not the same timer as the old OMAP1 MPU timer.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <plat/common.h>
+#include <plat/board.h>
+
+#include <plat/clock.h>
+
+
+/*
+ * 32KHz clocksource ... always available, on pretty most chips except
+ * OMAP 730 and 1510.  Other timers could be used as clocksources, with
+ * higher resolution in free-running counter modes (e.g. 12 MHz xtal),
+ * but systems won't necessarily want to spend resources that way.
+ */
+
+#define OMAP16XX_TIMER_32K_SYNCHRONIZED		0xfffbc410
+
+#if !(defined(CONFIG_ARCH_OMAP730) || defined(CONFIG_ARCH_OMAP15XX))
+
+#include <linux/clocksource.h>
+
+/*
+ * offset_32k holds the init time counter value. It is then subtracted
+ * from every counter read to achieve a counter that counts time from the
+ * kernel boot (needed for sched_clock()).
+ */
+static u32 offset_32k __read_mostly;
+
+#ifdef CONFIG_ARCH_OMAP16XX
+static cycle_t omap16xx_32k_read(struct clocksource *cs)
+{
+	return omap_readl(OMAP16XX_TIMER_32K_SYNCHRONIZED) - offset_32k;
+}
+#else
+#define omap16xx_32k_read	NULL
+#endif
+
+#ifdef CONFIG_ARCH_OMAP2420
+static cycle_t omap2420_32k_read(struct clocksource *cs)
+{
+	return omap_readl(OMAP2420_32KSYNCT_BASE + 0x10) - offset_32k;
+}
+#else
+#define omap2420_32k_read	NULL
+#endif
+
+#ifdef CONFIG_ARCH_OMAP2430
+static cycle_t omap2430_32k_read(struct clocksource *cs)
+{
+	return omap_readl(OMAP2430_32KSYNCT_BASE + 0x10) - offset_32k;
+}
+#else
+#define omap2430_32k_read	NULL
+#endif
+
+#ifdef CONFIG_ARCH_OMAP3
+static cycle_t omap34xx_32k_read(struct clocksource *cs)
+{
+	return omap_readl(OMAP3430_32KSYNCT_BASE + 0x10) - offset_32k;
+}
+#else
+#define omap34xx_32k_read	NULL
+#endif
+
+#ifdef CONFIG_ARCH_OMAP4
+static cycle_t omap44xx_32k_read(struct clocksource *cs)
+{
+	return omap_readl(OMAP4430_32KSYNCT_BASE + 0x10) - offset_32k;
+}
+#else
+#define omap44xx_32k_read	NULL
+#endif
+
+/*
+ * Kernel assumes that sched_clock can be called early but may not have
+ * things ready yet.
+ */
+static cycle_t omap_32k_read_dummy(struct clocksource *cs)
+{
+	return 0;
+}
+
+static struct clocksource clocksource_32k = {
+	.name		= "32k_counter",
+	.rating		= 250,
+	.read		= omap_32k_read_dummy,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.shift		= 10,
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * Returns current time from boot in nsecs. It's OK for this to wrap
+ * around for now, as it's just a relative time stamp.
+ */
+unsigned long long sched_clock(void)
+{
+	return clocksource_cyc2ns(clocksource_32k.read(&clocksource_32k),
+				  clocksource_32k.mult, clocksource_32k.shift);
+}
+
+/**
+ * read_persistent_clock -  Return time from a persistent clock.
+ *
+ * Reads the time from a source which isn't disabled during PM, the
+ * 32k sync timer.  Convert the cycles elapsed since last read into
+ * nsecs and adds to a monotonically increasing timespec.
+ */
+static struct timespec persistent_ts;
+static cycles_t cycles, last_cycles;
+void read_persistent_clock(struct timespec *ts)
+{
+	unsigned long long nsecs;
+	cycles_t delta;
+	struct timespec *tsp = &persistent_ts;
+
+	last_cycles = cycles;
+	cycles = clocksource_32k.read(&clocksource_32k);
+	delta = cycles - last_cycles;
+
+	nsecs = clocksource_cyc2ns(delta,
+				   clocksource_32k.mult, clocksource_32k.shift);
+
+	timespec_add_ns(tsp, nsecs);
+	*ts = *tsp;
+}
+
+static int __init omap_init_clocksource_32k(void)
+{
+	static char err[] __initdata = KERN_ERR
+			"%s: can't register clocksource!\n";
+
+	if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
+		struct clk *sync_32k_ick;
+
+		if (cpu_is_omap16xx())
+			clocksource_32k.read = omap16xx_32k_read;
+		else if (cpu_is_omap2420())
+			clocksource_32k.read = omap2420_32k_read;
+		else if (cpu_is_omap2430())
+			clocksource_32k.read = omap2430_32k_read;
+		else if (cpu_is_omap34xx())
+			clocksource_32k.read = omap34xx_32k_read;
+		else if (cpu_is_omap44xx())
+			clocksource_32k.read = omap44xx_32k_read;
+		else
+			return -ENODEV;
+
+		sync_32k_ick = clk_get(NULL, "omap_32ksync_ick");
+		if (sync_32k_ick)
+			clk_enable(sync_32k_ick);
+
+		clocksource_32k.mult = clocksource_hz2mult(32768,
+					    clocksource_32k.shift);
+
+		offset_32k = clocksource_32k.read(&clocksource_32k);
+
+		if (clocksource_register(&clocksource_32k))
+			printk(err, clocksource_32k.name);
+	}
+	return 0;
+}
+arch_initcall(omap_init_clocksource_32k);
+
+#endif	/* !(defined(CONFIG_ARCH_OMAP730) || defined(CONFIG_ARCH_OMAP15XX)) */
+