linux/drivers/clk/mstar/clk-msc313-mpll.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * MStar MSC313 MPLL driver
   4 *
   5 * Copyright (C) 2020 Daniel Palmer <daniel@thingy.jp>
   6 */
   7
   8#include <linux/platform_device.h>
   9#include <linux/of_address.h>
  10#include <linux/clk-provider.h>
  11#include <linux/regmap.h>
  12
  13#define REG_CONFIG1     0x8
  14#define REG_CONFIG2     0xc
  15
  16static const struct regmap_config msc313_mpll_regmap_config = {
  17        .reg_bits = 16,
  18        .val_bits = 16,
  19        .reg_stride = 4,
  20};
  21
  22static const struct reg_field config1_loop_div_first = REG_FIELD(REG_CONFIG1, 8, 9);
  23static const struct reg_field config1_input_div_first = REG_FIELD(REG_CONFIG1, 4, 5);
  24static const struct reg_field config2_output_div_first = REG_FIELD(REG_CONFIG2, 12, 13);
  25static const struct reg_field config2_loop_div_second = REG_FIELD(REG_CONFIG2, 0, 7);
  26
  27static const unsigned int output_dividers[] = {
  28        2, 3, 4, 5, 6, 7, 10
  29};
  30
  31#define NUMOUTPUTS (ARRAY_SIZE(output_dividers) + 1)
  32
  33struct msc313_mpll {
  34        struct clk_hw clk_hw;
  35        struct regmap_field *input_div;
  36        struct regmap_field *loop_div_first;
  37        struct regmap_field *loop_div_second;
  38        struct regmap_field *output_div;
  39        struct clk_hw_onecell_data *clk_data;
  40};
  41
  42#define to_mpll(_hw) container_of(_hw, struct msc313_mpll, clk_hw)
  43
  44static unsigned long msc313_mpll_recalc_rate(struct clk_hw *hw,
  45                unsigned long parent_rate)
  46{
  47        struct msc313_mpll *mpll = to_mpll(hw);
  48        unsigned int input_div, output_div, loop_first, loop_second;
  49        unsigned long output_rate;
  50
  51        regmap_field_read(mpll->input_div, &input_div);
  52        regmap_field_read(mpll->output_div, &output_div);
  53        regmap_field_read(mpll->loop_div_first, &loop_first);
  54        regmap_field_read(mpll->loop_div_second, &loop_second);
  55
  56        output_rate = parent_rate / (1 << input_div);
  57        output_rate *= (1 << loop_first) * max(loop_second, 1U);
  58        output_rate /= max(output_div, 1U);
  59
  60        return output_rate;
  61}
  62
  63static const struct clk_ops msc313_mpll_ops = {
  64        .recalc_rate = msc313_mpll_recalc_rate,
  65};
  66
  67static const struct clk_parent_data mpll_parent = {
  68        .index  = 0,
  69};
  70
  71static int msc313_mpll_probe(struct platform_device *pdev)
  72{
  73        void __iomem *base;
  74        struct msc313_mpll *mpll;
  75        struct clk_init_data clk_init = { };
  76        struct device *dev = &pdev->dev;
  77        struct regmap *regmap;
  78        char *outputname;
  79        struct clk_hw *divhw;
  80        int ret, i;
  81
  82        mpll = devm_kzalloc(dev, sizeof(*mpll), GFP_KERNEL);
  83        if (!mpll)
  84                return -ENOMEM;
  85
  86        base = devm_platform_ioremap_resource(pdev, 0);
  87        if (IS_ERR(base))
  88                return PTR_ERR(base);
  89
  90        regmap = devm_regmap_init_mmio(dev, base, &msc313_mpll_regmap_config);
  91        if (IS_ERR(regmap))
  92                return PTR_ERR(regmap);
  93
  94        mpll->input_div = devm_regmap_field_alloc(dev, regmap, config1_input_div_first);
  95        if (IS_ERR(mpll->input_div))
  96                return PTR_ERR(mpll->input_div);
  97        mpll->output_div = devm_regmap_field_alloc(dev, regmap, config2_output_div_first);
  98        if (IS_ERR(mpll->output_div))
  99                return PTR_ERR(mpll->output_div);
 100        mpll->loop_div_first = devm_regmap_field_alloc(dev, regmap, config1_loop_div_first);
 101        if (IS_ERR(mpll->loop_div_first))
 102                return PTR_ERR(mpll->loop_div_first);
 103        mpll->loop_div_second = devm_regmap_field_alloc(dev, regmap, config2_loop_div_second);
 104        if (IS_ERR(mpll->loop_div_second))
 105                return PTR_ERR(mpll->loop_div_second);
 106
 107        mpll->clk_data = devm_kzalloc(dev, struct_size(mpll->clk_data, hws,
 108                        ARRAY_SIZE(output_dividers)), GFP_KERNEL);
 109        if (!mpll->clk_data)
 110                return -ENOMEM;
 111
 112        clk_init.name = dev_name(dev);
 113        clk_init.ops = &msc313_mpll_ops;
 114        clk_init.parent_data = &mpll_parent;
 115        clk_init.num_parents = 1;
 116        mpll->clk_hw.init = &clk_init;
 117
 118        ret = devm_clk_hw_register(dev, &mpll->clk_hw);
 119        if (ret)
 120                return ret;
 121
 122        mpll->clk_data->num = NUMOUTPUTS;
 123        mpll->clk_data->hws[0] = &mpll->clk_hw;
 124
 125        for (i = 0; i < ARRAY_SIZE(output_dividers); i++) {
 126                outputname = devm_kasprintf(dev, GFP_KERNEL, "%s_div_%u",
 127                                clk_init.name, output_dividers[i]);
 128                if (!outputname)
 129                        return -ENOMEM;
 130                divhw = devm_clk_hw_register_fixed_factor(dev, outputname,
 131                                clk_init.name, 0, 1, output_dividers[i]);
 132                if (IS_ERR(divhw))
 133                        return PTR_ERR(divhw);
 134                mpll->clk_data->hws[i + 1] = divhw;
 135        }
 136
 137        platform_set_drvdata(pdev, mpll);
 138
 139        return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_onecell_get,
 140                        mpll->clk_data);
 141}
 142
 143static const struct of_device_id msc313_mpll_of_match[] = {
 144        { .compatible = "mstar,msc313-mpll", },
 145        {}
 146};
 147
 148static struct platform_driver msc313_mpll_driver = {
 149        .driver = {
 150                .name = "mstar-msc313-mpll",
 151                .of_match_table = msc313_mpll_of_match,
 152        },
 153        .probe = msc313_mpll_probe,
 154};
 155builtin_platform_driver(msc313_mpll_driver);
 156