drivers/clk/mstar/clk-msc313-mpll.c

   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
  16 static const struct regmap_config msc313_mpll_regmap_config = {
  17         .reg_bits = 16,
  18         .val_bits = 16,
  19         .reg_stride = 4,
  20 };
  21
  22 static const struct reg_field config1_loop_div_first = REG_FIELD(REG_CONFIG1, 8, 9);
  23 static const struct reg_field config1_input_div_first = REG_FIELD(REG_CONFIG1, 4, 5);
  24 static const struct reg_field config2_output_div_first = REG_FIELD(REG_CONFIG2, 12, 13);
  25 static const struct reg_field config2_loop_div_second = REG_FIELD(REG_CONFIG2, 0, 7);
  26
  27 static const unsigned int output_dividers[] = {
  28         2, 3, 4, 5, 6, 7, 10
  29 };
  30
  31 #define NUMOUTPUTS (ARRAY_SIZE(output_dividers) + 1)
  32
  33 struct 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
  44 static 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
  63 static const struct clk_ops msc313_mpll_ops = {
  64         .recalc_rate = msc313_mpll_recalc_rate,
  65 };
  66
  67 static const struct clk_parent_data mpll_parent = {
  68         .index  = 0,
  69 };
  70
  71 static 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
 143 static const struct of_device_id msc313_mpll_of_match[] = {
 144         { .compatible = "mstar,msc313-mpll", },
 145         {}
 146 };
 147
 148 static 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 };
 155 builtin_platform_driver(msc313_mpll_driver);