ARM: SAMSUNG: Add core clock implementation for clksrc based clocks

Add a core for the clksrc clock implementation, which is found in many of
the newer Samsung SoCs into plat-samsung.

Signed-off-by: Harald Welte <laforge@gnumonks.org>
[ben-linux@fluff.org: split from original patch to make change smaller]
[ben-linux@fluff.org: split clk and clksrc changes]
[ben-linux@fluff.org: moved to plat-samsung from plat-s3c]
[ben-linux@fluff.org: re-wrote headers after splits]
[ben-linux@fluff.org: added better documentation to headers]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 75 insertions, 0 deletions

diff --git a/arch/arm/plat-samsung/include/plat/clock-clksrc.h b/arch/arm/plat-samsung/include/plat/clock-clksrc.h
new file mode 100644
index 00000000000..283dfa02875
--- /dev/null
+++ b/arch/arm/plat-samsung/include/plat/clock-clksrc.h
@@ -0,0 +1,75 @@
+/* linux/arch/arm/plat-samsung/include/plat/clock-clksrc.h
+ *
+ * Parts taken from arch/arm/plat-s3c64xx/clock.c
+ *	Copyright 2008 Openmoko, Inc.
+ *	Copyright 2008 Simtec Electronics
+ *		Ben Dooks <ben@simtec.co.uk>
+ *		http://armlinux.simtec.co.uk/
+ *
+ * Copyright 2009 Ben Dooks <ben-linux@fluff.org>
+ * Copyright 2009 Harald Welte
+ *
+ * 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.
+*/
+
+/**
+ * struct clksrc_sources - list of sources for a given clock
+ * @sources: array of pointers to clocks
+ * @nr_sources: The size of @sources
+ */
+struct clksrc_sources {
+	unsigned int	nr_sources;
+	struct clk	**sources;
+};
+
+/**
+ * struct clksrc_reg - register definition for clock control bits
+ * @reg: pointer to the register in virtual memory.
+ * @shift: the shift in bits to where the bitfield is.
+ * @size: the size in bits of the bitfield.
+ *
+ * This specifies the size and position of the bits we are interested
+ * in within the register specified by @reg.
+ */
+struct clksrc_reg {
+	void __iomem		*reg;
+	unsigned short		shift;
+	unsigned short		size;
+};
+
+/**
+ * struct clksrc_clk - class of clock for newer style samsung devices.
+ * @clk: the standard clock representation
+ * @sources: the sources for this clock
+ * @reg_src: the register definition for selecting the clock's source
+ * @reg_div: the register definition for the clock's output divisor
+ *
+ * This clock implements the features required by the newer SoCs where
+ * the standard clock block provides an input mux and a post-mux divisor
+ * to provide the periperhal's clock.
+ *
+ * The array of @sources provides the mapping of mux position to the
+ * clock, and @reg_src shows the code where to modify to change the mux
+ * position. The @reg_div defines how to change the divider settings on
+ * the output.
+ */
+struct clksrc_clk {
+	struct clk		clk;
+	struct clksrc_sources	*sources;
+
+	struct clksrc_reg	reg_src;
+	struct clksrc_reg	reg_div;
+};
+
+extern void s3c_set_clksrc(struct clksrc_clk *clk);
+
+/**
+ * s3c_register_clksrc() register clocks from an array of clksrc clocks
+ * @srcs: The array of clocks to register
+ * @size: The size of the @srcs array.
+ *
+ * Initialise and register the array of clocks described by @srcs.
+ */
+extern void s3c_register_clksrc(struct clksrc_clk *srcs, int size);