arch/arm/mach-ux500/clock.h

   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);