1 /* linux/arch/arm/plat-samsung/include/plat/clock-clksrc.h
2  *
3  * Parts taken from arch/arm/plat-s3c64xx/clock.c
4  *	Copyright 2008 Openmoko, Inc.
5  *	Copyright 2008 Simtec Electronics
6  *		Ben Dooks <ben@simtec.co.uk>
7  *		http://armlinux.simtec.co.uk/
8  *
9  * Copyright 2009 Ben Dooks <ben-linux@fluff.org>
10  * Copyright 2009 Harald Welte
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License version 2 as
14  * published by the Free Software Foundation.
15 */
16 
17 /**
18  * struct clksrc_sources - list of sources for a given clock
19  * @sources: array of pointers to clocks
20  * @nr_sources: The size of @sources
21  */
22 struct clksrc_sources {
23 	unsigned int	nr_sources;
24 	struct clk	**sources;
25 };
26 
27 /**
28  * struct clksrc_reg - register definition for clock control bits
29  * @reg: pointer to the register in virtual memory.
30  * @shift: the shift in bits to where the bitfield is.
31  * @size: the size in bits of the bitfield.
32  *
33  * This specifies the size and position of the bits we are interested
34  * in within the register specified by @reg.
35  */
36 struct clksrc_reg {
37 	void __iomem		*reg;
38 	unsigned short		shift;
39 	unsigned short		size;
40 };
41 
42 /**
43  * struct clksrc_clk - class of clock for newer style samsung devices.
44  * @clk: the standard clock representation
45  * @sources: the sources for this clock
46  * @reg_src: the register definition for selecting the clock's source
47  * @reg_div: the register definition for the clock's output divisor
48  *
49  * This clock implements the features required by the newer SoCs where
50  * the standard clock block provides an input mux and a post-mux divisor
51  * to provide the periperhal's clock.
52  *
53  * The array of @sources provides the mapping of mux position to the
54  * clock, and @reg_src shows the code where to modify to change the mux
55  * position. The @reg_div defines how to change the divider settings on
56  * the output.
57  */
58 struct clksrc_clk {
59 	struct clk		clk;
60 	struct clksrc_sources	*sources;
61 
62 	struct clksrc_reg	reg_src;
63 	struct clksrc_reg	reg_div;
64 };
65 
66 /**
67  * s3c_set_clksrc() - setup the clock from the register settings
68  * @clk: The clock to setup.
69  * @announce: true to announce the setting to printk().
70  *
71  * Setup the clock from the current register settings, for when the
72  * kernel boots or if it is resuming from a possibly unknown state.
73  */
74 extern void s3c_set_clksrc(struct clksrc_clk *clk, bool announce);
75 
76 /**
77  * s3c_register_clksrc() register clocks from an array of clksrc clocks
78  * @srcs: The array of clocks to register
79  * @size: The size of the @srcs array.
80  *
81  * Initialise and register the array of clocks described by @srcs.
82  */
83 extern void s3c_register_clksrc(struct clksrc_clk *srcs, int size);
84