drivers/clk/ingenic/cgu.h

   1 /*
   2  * Ingenic SoC CGU driver
   3  *
   4  * Copyright (c) 2013-2015 Imagination Technologies
   5  * Author: Paul Burton <paul.burton@imgtec.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #ifndef __DRIVERS_CLK_INGENIC_CGU_H__
  19 #define __DRIVERS_CLK_INGENIC_CGU_H__
  20
  21 #include <linux/bitops.h>
  22 #include <linux/of.h>
  23 #include <linux/spinlock.h>
  24
  25 /**
  26  * struct ingenic_cgu_pll_info - information about a PLL
  27  * @reg: the offset of the PLL's control register within the CGU
  28  * @m_shift: the number of bits to shift the multiplier value by (ie. the
  29  *           index of the lowest bit of the multiplier value in the PLL's
  30  *           control register)
  31  * @m_bits: the size of the multiplier field in bits
  32  * @m_offset: the multiplier value which encodes to 0 in the PLL's control
  33  *            register
  34  * @n_shift: the number of bits to shift the divider value by (ie. the
  35  *           index of the lowest bit of the divider value in the PLL's
  36  *           control register)
  37  * @n_bits: the size of the divider field in bits
  38  * @n_offset: the divider value which encodes to 0 in the PLL's control
  39  *            register
  40  * @od_shift: the number of bits to shift the post-VCO divider value by (ie.
  41  *            the index of the lowest bit of the post-VCO divider value in
  42  *            the PLL's control register)
  43  * @od_bits: the size of the post-VCO divider field in bits
  44  * @od_max: the maximum post-VCO divider value
  45  * @od_encoding: a pointer to an array mapping post-VCO divider values to
  46  *               their encoded values in the PLL control register, or -1 for
  47  *               unsupported values
  48  * @bypass_bit: the index of the bypass bit in the PLL control register
  49  * @enable_bit: the index of the enable bit in the PLL control register
  50  * @stable_bit: the index of the stable bit in the PLL control register
  51  */
  52 struct ingenic_cgu_pll_info {
  53         unsigned reg;
  54         const s8 *od_encoding;
  55         u8 m_shift, m_bits, m_offset;
  56         u8 n_shift, n_bits, n_offset;
  57         u8 od_shift, od_bits, od_max;
  58         u8 bypass_bit;
  59         u8 enable_bit;
  60         u8 stable_bit;
  61 };
  62
  63 /**
  64  * struct ingenic_cgu_mux_info - information about a clock mux
  65  * @reg: offset of the mux control register within the CGU
  66  * @shift: number of bits to shift the mux value by (ie. the index of
  67  *         the lowest bit of the mux value within its control register)
  68  * @bits: the size of the mux value in bits
  69  */
  70 struct ingenic_cgu_mux_info {
  71         unsigned reg;
  72         u8 shift;
  73         u8 bits;
  74 };
  75
  76 /**
  77  * struct ingenic_cgu_div_info - information about a divider
  78  * @reg: offset of the divider control register within the CGU
  79  * @shift: number of bits to shift the divide value by (ie. the index of
  80  *         the lowest bit of the divide value within its control register)
  81  * @bits: the size of the divide value in bits
  82  * @ce_bit: the index of the change enable bit within reg, or -1 if there
  83  *          isn't one
  84  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
  85  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
  86  */
  87 struct ingenic_cgu_div_info {
  88         unsigned reg;
  89         u8 shift;
  90         u8 bits;
  91         s8 ce_bit;
  92         s8 busy_bit;
  93         s8 stop_bit;
  94 };
  95
  96 /**
  97  * struct ingenic_cgu_fixdiv_info - information about a fixed divider
  98  * @div: the divider applied to the parent clock
  99  */
 100 struct ingenic_cgu_fixdiv_info {
 101         unsigned div;
 102 };
 103
 104 /**
 105  * struct ingenic_cgu_gate_info - information about a clock gate
 106  * @reg: offset of the gate control register within the CGU
 107  * @bit: offset of the bit in the register that controls the gate
 108  */
 109 struct ingenic_cgu_gate_info {
 110         unsigned reg;
 111         u8 bit;
 112 };
 113
 114 /**
 115  * struct ingenic_cgu_custom_info - information about a custom (SoC) clock
 116  * @clk_ops: custom clock operation callbacks
 117  */
 118 struct ingenic_cgu_custom_info {
 119         struct clk_ops *clk_ops;
 120 };
 121
 122 /**
 123  * struct ingenic_cgu_clk_info - information about a clock
 124  * @name: name of the clock
 125  * @type: a bitmask formed from CGU_CLK_* values
 126  * @parents: an array of the indices of potential parents of this clock
 127  *           within the clock_info array of the CGU, or -1 in entries
 128  *           which correspond to no valid parent
 129  * @pll: information valid if type includes CGU_CLK_PLL
 130  * @gate: information valid if type includes CGU_CLK_GATE
 131  * @mux: information valid if type includes CGU_CLK_MUX
 132  * @div: information valid if type includes CGU_CLK_DIV
 133  * @fixdiv: information valid if type includes CGU_CLK_FIXDIV
 134  * @custom: information valid if type includes CGU_CLK_CUSTOM
 135  */
 136 struct ingenic_cgu_clk_info {
 137         const char *name;
 138
 139         enum {
 140                 CGU_CLK_NONE            = 0,
 141                 CGU_CLK_EXT             = BIT(0),
 142                 CGU_CLK_PLL             = BIT(1),
 143                 CGU_CLK_GATE            = BIT(2),
 144                 CGU_CLK_MUX             = BIT(3),
 145                 CGU_CLK_MUX_GLITCHFREE  = BIT(4),
 146                 CGU_CLK_DIV             = BIT(5),
 147                 CGU_CLK_FIXDIV          = BIT(6),
 148                 CGU_CLK_CUSTOM          = BIT(7),
 149         } type;
 150
 151         int parents[4];
 152
 153         union {
 154                 struct ingenic_cgu_pll_info pll;
 155
 156                 struct {
 157                         struct ingenic_cgu_gate_info gate;
 158                         struct ingenic_cgu_mux_info mux;
 159                         struct ingenic_cgu_div_info div;
 160                         struct ingenic_cgu_fixdiv_info fixdiv;
 161                 };
 162
 163                 struct ingenic_cgu_custom_info custom;
 164         };
 165 };
 166
 167 /**
 168  * struct ingenic_cgu - data about the CGU
 169  * @np: the device tree node that caused the CGU to be probed
 170  * @base: the ioremap'ed base address of the CGU registers
 171  * @clock_info: an array containing information about implemented clocks
 172  * @clocks: used to provide clocks to DT, allows lookup of struct clk*
 173  * @lock: lock to be held whilst manipulating CGU registers
 174  */
 175 struct ingenic_cgu {
 176         struct device_node *np;
 177         void __iomem *base;
 178
 179         const struct ingenic_cgu_clk_info *clock_info;
 180         struct clk_onecell_data clocks;
 181
 182         spinlock_t lock;
 183 };
 184
 185 /**
 186  * struct ingenic_clk - private data for a clock
 187  * @hw: see Documentation/clk.txt
 188  * @cgu: a pointer to the CGU data
 189  * @idx: the index of this clock in cgu->clock_info
 190  */
 191 struct ingenic_clk {
 192         struct clk_hw hw;
 193         struct ingenic_cgu *cgu;
 194         unsigned idx;
 195 };
 196
 197 #define to_ingenic_clk(_hw) container_of(_hw, struct ingenic_clk, hw)
 198
 199 /**
 200  * ingenic_cgu_new() - create a new CGU instance
 201  * @clock_info: an array of clock information structures describing the clocks
 202  *              which are implemented by the CGU
 203  * @num_clocks: the number of entries in clock_info
 204  * @np: the device tree node which causes this CGU to be probed
 205  *
 206  * Return: a pointer to the CGU instance if initialisation is successful,
 207  *         otherwise NULL.
 208  */
 209 struct ingenic_cgu *
 210 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
 211                 unsigned num_clocks, struct device_node *np);
 212
 213 /**
 214  * ingenic_cgu_register_clocks() - Registers the clocks
 215  * @cgu: pointer to cgu data
 216  *
 217  * Register the clocks described by the CGU with the common clock framework.
 218  *
 219  * Return: 0 on success or -errno if unsuccesful.
 220  */
 221 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu);
 222
 223 #endif /* __DRIVERS_CLK_INGENIC_CGU_H__ */