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
msc313_mpll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)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
msc313_mpll_probe(struct platform_device * pdev)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);
156