[JUST RFC] ARM: DIGIC: add csrc-dummy

[Antony Pavlov]

The clocksource csrc-timer driver that uses DIGIC
hardware TIMER2 perfectrly works on Canon A1100,
but does not works on Canon EOS 600D.
IMHO we need additional timer initialisation.

This patch introduces a quick-and-dirty termporary
solution for this situation: a clocksource driver that
does not use any hardware at all.

Also this driver is very handy for running barebox
on Magic Lantern EOS qemu-based emulator as
the emulator does not realize timer counter register at all!

Signed-off-by: Antony Pavlov <antonynpavlov at gmail.com>
---
 arch/arm/mach-digic/Kconfig      |  3 +++
 arch/arm/mach-digic/Makefile     |  1 +
 arch/arm/mach-digic/csrc-dummy.c | 49 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 53 insertions(+)
 create mode 100644 arch/arm/mach-digic/csrc-dummy.c

diff --git a/arch/arm/mach-digic/Kconfig b/arch/arm/mach-digic/Kconfig
index 557cad4..d0524bc 100644
--- a/arch/arm/mach-digic/Kconfig
+++ b/arch/arm/mach-digic/Kconfig
@@ -16,4 +16,7 @@ config ARCH_TEXT_BASE
 config DIGIC_CSRC_TIMER
 	bool
 
+config DIGIC_CSRC_DUMMY
+	bool
+
 endif
diff --git a/arch/arm/mach-digic/Makefile b/arch/arm/mach-digic/Makefile
index 1d7cb72..31e5ac1 100644
--- a/arch/arm/mach-digic/Makefile
+++ b/arch/arm/mach-digic/Makefile
@@ -1,2 +1,3 @@
 obj-y += core.o
 obj-$(CONFIG_DIGIC_CSRC_TIMER) += csrc-timer.o
+obj-$(CONFIG_DIGIC_CSRC_DUMMY) += csrc-dummy.o
diff --git a/arch/arm/mach-digic/csrc-dummy.c b/arch/arm/mach-digic/csrc-dummy.c
new file mode 100644
index 0000000..68c68a3
--- /dev/null
+++ b/arch/arm/mach-digic/csrc-dummy.c
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2013 Antony Pavlov <antonynpavlov at gmail.com>
+ *
+ * This file is part of barebox.
+ * See file CREDITS for list of people who contributed to this project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <init.h>
+#include <clock.h>
+
+#include <stdio.h>
+
+static uint64_t dummy_counter;
+
+static uint64_t dummy_cs_read(void)
+{
+	dummy_counter += 2000;
+	return dummy_counter;
+}
+
+static struct clocksource dummy_cs = {
+	.read	= dummy_cs_read,
+	.mask   = CLOCKSOURCE_MASK(32),
+};
+
+static int clocksource_init(void)
+{
+	dummy_counter = 0;
+
+	clocks_calc_mult_shift(&dummy_cs.mult, &dummy_cs.shift,
+		100000000, NSEC_PER_SEC, 10);
+
+	printf("clocksource_init: mult=%08x, shift=%08x\n",
+			dummy_cs.mult, dummy_cs.shift);
+	init_clock(&dummy_cs);
+
+	return 0;
+}
+core_initcall(clocksource_init);
-- 
1.8.5