linux/drivers/clk/axs10x/i2s_pll_clock.c
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   1/*
   2 * Synopsys AXS10X SDP I2S PLL clock driver
   3 *
   4 * Copyright (C) 2016 Synopsys
   5 *
   6 * This file is licensed under the terms of the GNU General Public
   7 * License version 2. This program is licensed "as is" without any
   8 * warranty of any kind, whether express or implied.
   9 */
  10
  11#include <linux/platform_device.h>
  12#include <linux/module.h>
  13#include <linux/clk-provider.h>
  14#include <linux/err.h>
  15#include <linux/device.h>
  16#include <linux/io.h>
  17#include <linux/of_address.h>
  18#include <linux/slab.h>
  19#include <linux/of.h>
  20
  21/* PLL registers addresses */
  22#define PLL_IDIV_REG    0x0
  23#define PLL_FBDIV_REG   0x4
  24#define PLL_ODIV0_REG   0x8
  25#define PLL_ODIV1_REG   0xC
  26
  27struct i2s_pll_cfg {
  28        unsigned int rate;
  29        unsigned int idiv;
  30        unsigned int fbdiv;
  31        unsigned int odiv0;
  32        unsigned int odiv1;
  33};
  34
  35static const struct i2s_pll_cfg i2s_pll_cfg_27m[] = {
  36        /* 27 Mhz */
  37        { 1024000, 0x104, 0x451, 0x10E38, 0x2000 },
  38        { 1411200, 0x104, 0x596, 0x10D35, 0x2000 },
  39        { 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 },
  40        { 2048000, 0x82, 0x451, 0x10E38, 0x2000 },
  41        { 2822400, 0x82, 0x596, 0x10D35, 0x2000 },
  42        { 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 },
  43        { 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 },
  44        { 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 },
  45        { 0, 0, 0, 0, 0 },
  46};
  47
  48static const struct i2s_pll_cfg i2s_pll_cfg_28m[] = {
  49        /* 28.224 Mhz */
  50        { 1024000, 0x82, 0x105, 0x107DF, 0x2000 },
  51        { 1411200, 0x28A, 0x1, 0x10001, 0x2000 },
  52        { 1536000, 0xA28, 0x187, 0x10042, 0x2000 },
  53        { 2048000, 0x41, 0x105, 0x107DF, 0x2000 },
  54        { 2822400, 0x145, 0x1, 0x10001, 0x2000 },
  55        { 3072000, 0x514, 0x187, 0x10042, 0x2000 },
  56        { 2116800, 0x514, 0x42, 0x10001, 0x2000 },
  57        { 2304000, 0x619, 0x82, 0x10001, 0x2000 },
  58        { 0, 0, 0, 0, 0 },
  59};
  60
  61struct i2s_pll_clk {
  62        void __iomem *base;
  63        struct clk_hw hw;
  64        struct device *dev;
  65};
  66
  67static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg,
  68                unsigned int val)
  69{
  70        writel_relaxed(val, clk->base + reg);
  71}
  72
  73static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk,
  74                unsigned int reg)
  75{
  76        return readl_relaxed(clk->base + reg);
  77}
  78
  79static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
  80{
  81        return container_of(hw, struct i2s_pll_clk, hw);
  82}
  83
  84static inline unsigned int i2s_pll_get_value(unsigned int val)
  85{
  86        return (val & 0x3F) + ((val >> 6) & 0x3F);
  87}
  88
  89static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate)
  90{
  91        switch (prate) {
  92        case 27000000:
  93                return i2s_pll_cfg_27m;
  94        case 28224000:
  95                return i2s_pll_cfg_28m;
  96        default:
  97                return NULL;
  98        }
  99}
 100
 101static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw,
 102                        unsigned long parent_rate)
 103{
 104        struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
 105        unsigned int idiv, fbdiv, odiv;
 106
 107        idiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_IDIV_REG));
 108        fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG));
 109        odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG));
 110
 111        return ((parent_rate / idiv) * fbdiv) / odiv;
 112}
 113
 114static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 115                        unsigned long *prate)
 116{
 117        struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
 118        const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate);
 119        int i;
 120
 121        if (!pll_cfg) {
 122                dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
 123                return -EINVAL;
 124        }
 125
 126        for (i = 0; pll_cfg[i].rate != 0; i++)
 127                if (pll_cfg[i].rate == rate)
 128                        return rate;
 129
 130        return -EINVAL;
 131}
 132
 133static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 134                        unsigned long parent_rate)
 135{
 136        struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
 137        const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate);
 138        int i;
 139
 140        if (!pll_cfg) {
 141                dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
 142                return -EINVAL;
 143        }
 144
 145        for (i = 0; pll_cfg[i].rate != 0; i++) {
 146                if (pll_cfg[i].rate == rate) {
 147                        i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv);
 148                        i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv);
 149                        i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0);
 150                        i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1);
 151                        return 0;
 152                }
 153        }
 154
 155        dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
 156                        parent_rate);
 157        return -EINVAL;
 158}
 159
 160static const struct clk_ops i2s_pll_ops = {
 161        .recalc_rate = i2s_pll_recalc_rate,
 162        .round_rate = i2s_pll_round_rate,
 163        .set_rate = i2s_pll_set_rate,
 164};
 165
 166static int i2s_pll_clk_probe(struct platform_device *pdev)
 167{
 168        struct device *dev = &pdev->dev;
 169        struct device_node *node = dev->of_node;
 170        const char *clk_name;
 171        const char *parent_name;
 172        struct clk *clk;
 173        struct i2s_pll_clk *pll_clk;
 174        struct clk_init_data init;
 175        struct resource *mem;
 176
 177        pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
 178        if (!pll_clk)
 179                return -ENOMEM;
 180
 181        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 182        pll_clk->base = devm_ioremap_resource(dev, mem);
 183        if (IS_ERR(pll_clk->base))
 184                return PTR_ERR(pll_clk->base);
 185
 186        memset(&init, 0, sizeof(init));
 187        clk_name = node->name;
 188        init.name = clk_name;
 189        init.ops = &i2s_pll_ops;
 190        parent_name = of_clk_get_parent_name(node, 0);
 191        init.parent_names = &parent_name;
 192        init.num_parents = 1;
 193        pll_clk->hw.init = &init;
 194        pll_clk->dev = dev;
 195
 196        clk = devm_clk_register(dev, &pll_clk->hw);
 197        if (IS_ERR(clk)) {
 198                dev_err(dev, "failed to register %s clock (%ld)\n",
 199                                clk_name, PTR_ERR(clk));
 200                return PTR_ERR(clk);
 201        }
 202
 203        return of_clk_add_provider(node, of_clk_src_simple_get, clk);
 204}
 205
 206static int i2s_pll_clk_remove(struct platform_device *pdev)
 207{
 208        of_clk_del_provider(pdev->dev.of_node);
 209        return 0;
 210}
 211
 212static const struct of_device_id i2s_pll_clk_id[] = {
 213        { .compatible = "snps,axs10x-i2s-pll-clock", },
 214        { },
 215};
 216MODULE_DEVICE_TABLE(of, i2s_pll_clk_id);
 217
 218static struct platform_driver i2s_pll_clk_driver = {
 219        .driver = {
 220                .name = "axs10x-i2s-pll-clock",
 221                .of_match_table = i2s_pll_clk_id,
 222        },
 223        .probe = i2s_pll_clk_probe,
 224        .remove = i2s_pll_clk_remove,
 225};
 226module_platform_driver(i2s_pll_clk_driver);
 227
 228MODULE_AUTHOR("Jose Abreu <joabreu@synopsys.com>");
 229MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver");
 230MODULE_LICENSE("GPL v2");
 231