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@mips.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  * @no_bypass_bit: if set, the PLL has no bypass functionality
  52  */
  53 struct ingenic_cgu_pll_info {
  54         unsigned reg;
  55         const s8 *od_encoding;
  56         u8 m_shift, m_bits, m_offset;
  57         u8 n_shift, n_bits, n_offset;
  58         u8 od_shift, od_bits, od_max;
  59         u8 bypass_bit;
  60         u8 enable_bit;
  61         u8 stable_bit;
  62         bool no_bypass_bit;
  63 };
  64
  65 /**
  66  * struct ingenic_cgu_mux_info - information about a clock mux
  67  * @reg: offset of the mux control register within the CGU
  68  * @shift: number of bits to shift the mux value by (ie. the index of
  69  *         the lowest bit of the mux value within its control register)
  70  * @bits: the size of the mux value in bits
  71  */
  72 struct ingenic_cgu_mux_info {
  73         unsigned reg;
  74         u8 shift;
  75         u8 bits;
  76 };
  77
  78 /**
  79  * struct ingenic_cgu_div_info - information about a divider
  80  * @reg: offset of the divider control register within the CGU
  81  * @shift: number of bits to left shift the divide value by (ie. the index of
  82  *         the lowest bit of the divide value within its control register)
  83  * @div: number of bits to divide the divider value by (i.e. if the
  84  *       effective divider value is the value written to the register
  85  *       multiplied by some constant)
  86  * @bits: the size of the divide value in bits
  87  * @ce_bit: the index of the change enable bit within reg, or -1 if there
  88  *          isn't one
  89  * @busy_bit: the index of the busy bit within reg, or -1 if there isn't one
  90  * @stop_bit: the index of the stop bit within reg, or -1 if there isn't one
  91  */
  92 struct ingenic_cgu_div_info {
  93         unsigned reg;
  94         u8 shift;
  95         u8 div;
  96         u8 bits;
  97         s8 ce_bit;
  98         s8 busy_bit;
  99         s8 stop_bit;
 100 };
 101
 102 /**
 103  * struct ingenic_cgu_fixdiv_info - information about a fixed divider
 104  * @div: the divider applied to the parent clock
 105  */
 106 struct ingenic_cgu_fixdiv_info {
 107         unsigned div;
 108 };
 109
 110 /**
 111  * struct ingenic_cgu_gate_info - information about a clock gate
 112  * @reg: offset of the gate control register within the CGU
 113  * @bit: offset of the bit in the register that controls the gate
 114  * @clear_to_gate: if set, the clock is gated when the bit is cleared
 115  * @delay_us: delay in microseconds after which the clock is considered stable
 116  */
 117 struct ingenic_cgu_gate_info {
 118         unsigned reg;
 119         u8 bit;
 120         bool clear_to_gate;
 121         u16 delay_us;
 122 };
 123
 124 /**
 125  * struct ingenic_cgu_custom_info - information about a custom (SoC) clock
 126  * @clk_ops: custom clock operation callbacks
 127  */
 128 struct ingenic_cgu_custom_info {
 129         const struct clk_ops *clk_ops;
 130 };
 131
 132 /**
 133  * struct ingenic_cgu_clk_info - information about a clock
 134  * @name: name of the clock
 135  * @type: a bitmask formed from CGU_CLK_* values
 136  * @parents: an array of the indices of potential parents of this clock
 137  *           within the clock_info array of the CGU, or -1 in entries
 138  *           which correspond to no valid parent
 139  * @pll: information valid if type includes CGU_CLK_PLL
 140  * @gate: information valid if type includes CGU_CLK_GATE
 141  * @mux: information valid if type includes CGU_CLK_MUX
 142  * @div: information valid if type includes CGU_CLK_DIV
 143  * @fixdiv: information valid if type includes CGU_CLK_FIXDIV
 144  * @custom: information valid if type includes CGU_CLK_CUSTOM
 145  */
 146 struct ingenic_cgu_clk_info {
 147         const char *name;
 148
 149         enum {
 150                 CGU_CLK_NONE            = 0,
 151                 CGU_CLK_EXT             = BIT(0),
 152                 CGU_CLK_PLL             = BIT(1),
 153                 CGU_CLK_GATE            = BIT(2),
 154                 CGU_CLK_MUX             = BIT(3),
 155                 CGU_CLK_MUX_GLITCHFREE  = BIT(4),
 156                 CGU_CLK_DIV             = BIT(5),
 157                 CGU_CLK_FIXDIV          = BIT(6),
 158                 CGU_CLK_CUSTOM          = BIT(7),
 159         } type;
 160
 161         int parents[4];
 162
 163         union {
 164                 struct ingenic_cgu_pll_info pll;
 165
 166                 struct {
 167                         struct ingenic_cgu_gate_info gate;
 168                         struct ingenic_cgu_mux_info mux;
 169                         struct ingenic_cgu_div_info div;
 170                         struct ingenic_cgu_fixdiv_info fixdiv;
 171                 };
 172
 173                 struct ingenic_cgu_custom_info custom;
 174         };
 175 };
 176
 177 /**
 178  * struct ingenic_cgu - data about the CGU
 179  * @np: the device tree node that caused the CGU to be probed
 180  * @base: the ioremap'ed base address of the CGU registers
 181  * @clock_info: an array containing information about implemented clocks
 182  * @clocks: used to provide clocks to DT, allows lookup of struct clk*
 183  * @lock: lock to be held whilst manipulating CGU registers
 184  */
 185 struct ingenic_cgu {
 186         struct device_node *np;
 187         void __iomem *base;
 188
 189         const struct ingenic_cgu_clk_info *clock_info;
 190         struct clk_onecell_data clocks;
 191
 192         spinlock_t lock;
 193 };
 194
 195 /**
 196  * struct ingenic_clk - private data for a clock
 197  * @hw: see Documentation/driver-api/clk.rst
 198  * @cgu: a pointer to the CGU data
 199  * @idx: the index of this clock in cgu->clock_info
 200  */
 201 struct ingenic_clk {
 202         struct clk_hw hw;
 203         struct ingenic_cgu *cgu;
 204         unsigned idx;
 205 };
 206
 207 #define to_ingenic_clk(_hw) container_of(_hw, struct ingenic_clk, hw)
 208
 209 /**
 210  * ingenic_cgu_new() - create a new CGU instance
 211  * @clock_info: an array of clock information structures describing the clocks
 212  *              which are implemented by the CGU
 213  * @num_clocks: the number of entries in clock_info
 214  * @np: the device tree node which causes this CGU to be probed
 215  *
 216  * Return: a pointer to the CGU instance if initialisation is successful,
 217  *         otherwise NULL.
 218  */
 219 struct ingenic_cgu *
 220 ingenic_cgu_new(const struct ingenic_cgu_clk_info *clock_info,
 221                 unsigned num_clocks, struct device_node *np);
 222
 223 /**
 224  * ingenic_cgu_register_clocks() - Registers the clocks
 225  * @cgu: pointer to cgu data
 226  *
 227  * Register the clocks described by the CGU with the common clock framework.
 228  *
 229  * Return: 0 on success or -errno if unsuccesful.
 230  */
 231 int ingenic_cgu_register_clocks(struct ingenic_cgu *cgu);
 232
 233 #endif /* __DRIVERS_CLK_INGENIC_CGU_H__ */