1 /*
2  *  Copyright (C) 2010 ST-Ericsson
3  *  Copyright (C) 2009 STMicroelectronics
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  */
9 
10 /**
11  * struct clkops - ux500 clock operations
12  * @enable:	function to enable the clock
13  * @disable:	function to disable the clock
14  * @get_rate:	function to get the current clock rate
15  *
16  * This structure contains function pointers to functions that will be used to
17  * control the clock.  All of these functions are optional.  If get_rate is
18  * NULL, the rate in the struct clk will be used.
19  */
20 struct clkops {
21 	void (*enable) (struct clk *);
22 	void (*disable) (struct clk *);
23 	unsigned long (*get_rate) (struct clk *);
24 };
25 
26 /**
27  * struct clk - ux500 clock structure
28  * @ops:		pointer to clkops struct used to control this clock
29  * @name:		name, for debugging
30  * @enabled:		refcount. positive if enabled, zero if disabled
31  * @get_rate:		custom callback for getting the clock rate
32  * @data:		custom per-clock data for example for the get_rate
33  *			callback
34  * @rate:		fixed rate for clocks which don't implement
35  * 			ops->getrate
36  * @prcmu_cg_off:	address offset of the combined enable/disable register
37  * 			(used on u8500v1)
38  * @prcmu_cg_bit:	bit in the combined enable/disable register (used on
39  * 			u8500v1)
40  * @prcmu_cg_mgt:	address of the enable/disable register (used on
41  * 			u8500ed)
42  * @cluster:		peripheral cluster number
43  * @prcc_bus:		bit for the bus clock in the peripheral's CLKRST
44  * @prcc_kernel:	bit for the kernel clock in the peripheral's CLKRST.
45  * 			-1 if no kernel clock exists.
46  * @parent_cluster:	pointer to parent's cluster clk struct
47  * @parent_periph:	pointer to parent's peripheral clk struct
48  *
49  * Peripherals are organised into clusters, and each cluster has an associated
50  * bus clock.  Some peripherals also have a parent peripheral clock.
51  *
52  * In order to enable a clock for a peripheral, we need to enable:
53  * 	(1) the parent cluster (bus) clock at the PRCMU level
54  * 	(2) the parent peripheral clock (if any) at the PRCMU level
55  * 	(3) the peripheral's bus & kernel clock at the PRCC level
56  *
57  * (1) and (2) are handled by defining clk structs (DEFINE_PRCMU_CLK) for each
58  * of the cluster and peripheral clocks, and hooking these as the parents of
59  * the individual peripheral clocks.
60  *
61  * (3) is handled by specifying the bits in the PRCC control registers required
62  * to enable these clocks and modifying them in the ->enable and
63  * ->disable callbacks of the peripheral clocks (DEFINE_PRCC_CLK).
64  *
65  * This structure describes both the PRCMU-level clocks and PRCC-level clocks.
66  * The prcmu_* fields are only used for the PRCMU clocks, and the cluster,
67  * prcc, and parent pointers are only used for the PRCC-level clocks.
68  */
69 struct clk {
70 	const struct clkops	*ops;
71 	const char 		*name;
72 	unsigned int		enabled;
73 	unsigned long		(*get_rate)(struct clk *);
74 	void			*data;
75 
76 	unsigned long		rate;
77 	struct list_head	list;
78 
79 	/* These three are only for PRCMU clks */
80 
81 	unsigned int		prcmu_cg_off;
82 	unsigned int		prcmu_cg_bit;
83 	unsigned int		prcmu_cg_mgt;
84 
85 	/* The rest are only for PRCC clks */
86 
87 	int			cluster;
88 	unsigned int		prcc_bus;
89 	unsigned int		prcc_kernel;
90 
91 	struct clk		*parent_cluster;
92 	struct clk		*parent_periph;
93 #if defined(CONFIG_DEBUG_FS)
94 	struct dentry		*dent;		/* For visible tree hierarchy */
95 	struct dentry		*dent_bus;	/* For visible tree hierarchy */
96 #endif
97 };
98 
99 #define DEFINE_PRCMU_CLK(_name, _cg_off, _cg_bit, _reg)		\
100 struct clk clk_##_name = {					\
101 		.name		= #_name,			\
102 		.ops    	= &clk_prcmu_ops, 		\
103 		.prcmu_cg_off	= _cg_off, 			\
104 		.prcmu_cg_bit	= _cg_bit,			\
105 		.prcmu_cg_mgt	= PRCM_##_reg##_MGT		\
106 	}
107 
108 #define DEFINE_PRCMU_CLK_RATE(_name, _cg_off, _cg_bit, _reg, _rate)	\
109 struct clk clk_##_name = {						\
110 		.name		= #_name,				\
111 		.ops    	= &clk_prcmu_ops, 			\
112 		.prcmu_cg_off	= _cg_off, 				\
113 		.prcmu_cg_bit	= _cg_bit,				\
114 		.rate		= _rate,				\
115 		.prcmu_cg_mgt	= PRCM_##_reg##_MGT			\
116 	}
117 
118 #define DEFINE_PRCC_CLK(_pclust, _name, _bus_en, _kernel_en, _kernclk)	\
119 struct clk clk_##_name = {						\
120 		.name		= #_name,				\
121 		.ops    	= &clk_prcc_ops, 			\
122 		.cluster 	= _pclust,				\
123 		.prcc_bus 	= _bus_en, 				\
124 		.prcc_kernel 	= _kernel_en, 				\
125 		.parent_cluster = &clk_per##_pclust##clk,		\
126 		.parent_periph 	= _kernclk				\
127 	}
128 
129 #define DEFINE_PRCC_CLK_CUSTOM(_pclust, _name, _bus_en, _kernel_en, _kernclk, _callback, _data) \
130 struct clk clk_##_name = {						\
131 		.name		= #_name,				\
132 		.ops		= &clk_prcc_ops,			\
133 		.cluster	= _pclust,				\
134 		.prcc_bus	= _bus_en,				\
135 		.prcc_kernel	= _kernel_en,				\
136 		.parent_cluster = &clk_per##_pclust##clk,		\
137 		.parent_periph	= _kernclk,				\
138 		.get_rate	= _callback,				\
139 		.data		= (void *) _data			\
140 	}
141 
142 
143 #define CLK(_clk, _devname, _conname)			\
144 	{						\
145 		.clk	= &clk_##_clk,			\
146 		.dev_id	= _devname,			\
147 		.con_id = _conname,			\
148 	}
149 
150 int __init clk_db8500_ed_fixup(void);
151 int __init clk_init(void);
152