1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Qualcomm A53 PLL driver
4 *
5 * Copyright (c) 2017, Linaro Limited
6 * Author: Georgi Djakov <georgi.djakov@linaro.org>
7 */
8
9 #include <linux/clk.h>
10 #include <linux/clk-provider.h>
11 #include <linux/kernel.h>
12 #include <linux/platform_device.h>
13 #include <linux/pm_opp.h>
14 #include <linux/regmap.h>
15 #include <linux/module.h>
16
17 #include "clk-pll.h"
18 #include "clk-regmap.h"
19
20 static const struct pll_freq_tbl a53pll_freq[] = {
21 { 998400000, 52, 0x0, 0x1, 0 },
22 { 1094400000, 57, 0x0, 0x1, 0 },
23 { 1152000000, 62, 0x0, 0x1, 0 },
24 { 1209600000, 63, 0x0, 0x1, 0 },
25 { 1248000000, 65, 0x0, 0x1, 0 },
26 { 1363200000, 71, 0x0, 0x1, 0 },
27 { 1401600000, 73, 0x0, 0x1, 0 },
28 { }
29 };
30
31 static const struct regmap_config a53pll_regmap_config = {
32 .reg_bits = 32,
33 .reg_stride = 4,
34 .val_bits = 32,
35 .max_register = 0x40,
36 .fast_io = true,
37 };
38
qcom_a53pll_get_freq_tbl(struct device * dev)39 static struct pll_freq_tbl *qcom_a53pll_get_freq_tbl(struct device *dev)
40 {
41 struct pll_freq_tbl *freq_tbl;
42 unsigned long xo_freq;
43 unsigned long freq;
44 struct clk *xo_clk;
45 int count;
46 int ret;
47 int i;
48
49 xo_clk = devm_clk_get(dev, "xo");
50 if (IS_ERR(xo_clk))
51 return NULL;
52
53 xo_freq = clk_get_rate(xo_clk);
54
55 ret = devm_pm_opp_of_add_table(dev);
56 if (ret)
57 return NULL;
58
59 count = dev_pm_opp_get_opp_count(dev);
60 if (count <= 0)
61 return NULL;
62
63 freq_tbl = devm_kcalloc(dev, count + 1, sizeof(*freq_tbl), GFP_KERNEL);
64 if (!freq_tbl)
65 return NULL;
66
67 for (i = 0, freq = 0; i < count; i++, freq++) {
68 struct dev_pm_opp *opp;
69
70 opp = dev_pm_opp_find_freq_ceil(dev, &freq);
71 if (IS_ERR(opp))
72 return NULL;
73
74 /* Skip the freq that is not divisible */
75 if (freq % xo_freq)
76 continue;
77
78 freq_tbl[i].freq = freq;
79 freq_tbl[i].l = freq / xo_freq;
80 freq_tbl[i].n = 1;
81
82 dev_pm_opp_put(opp);
83 }
84
85 return freq_tbl;
86 }
87
qcom_a53pll_probe(struct platform_device * pdev)88 static int qcom_a53pll_probe(struct platform_device *pdev)
89 {
90 struct device *dev = &pdev->dev;
91 struct device_node *np = dev->of_node;
92 struct regmap *regmap;
93 struct resource *res;
94 struct clk_pll *pll;
95 void __iomem *base;
96 struct clk_init_data init = { };
97 int ret;
98
99 pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
100 if (!pll)
101 return -ENOMEM;
102
103 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
104 base = devm_ioremap_resource(dev, res);
105 if (IS_ERR(base))
106 return PTR_ERR(base);
107
108 regmap = devm_regmap_init_mmio(dev, base, &a53pll_regmap_config);
109 if (IS_ERR(regmap))
110 return PTR_ERR(regmap);
111
112 pll->l_reg = 0x04;
113 pll->m_reg = 0x08;
114 pll->n_reg = 0x0c;
115 pll->config_reg = 0x14;
116 pll->mode_reg = 0x00;
117 pll->status_reg = 0x1c;
118 pll->status_bit = 16;
119
120 pll->freq_tbl = qcom_a53pll_get_freq_tbl(dev);
121 if (!pll->freq_tbl) {
122 /* Fall on a53pll_freq if no freq_tbl is found from OPP */
123 pll->freq_tbl = a53pll_freq;
124 }
125
126 /* Use an unique name by appending @unit-address */
127 init.name = devm_kasprintf(dev, GFP_KERNEL, "a53pll%s",
128 strchrnul(np->full_name, '@'));
129 if (!init.name)
130 return -ENOMEM;
131
132 init.parent_names = (const char *[]){ "xo" };
133 init.num_parents = 1;
134 init.ops = &clk_pll_sr2_ops;
135 pll->clkr.hw.init = &init;
136
137 ret = devm_clk_register_regmap(dev, &pll->clkr);
138 if (ret) {
139 dev_err(dev, "failed to register regmap clock: %d\n", ret);
140 return ret;
141 }
142
143 ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
144 &pll->clkr.hw);
145 if (ret) {
146 dev_err(dev, "failed to add clock provider: %d\n", ret);
147 return ret;
148 }
149
150 return 0;
151 }
152
153 static const struct of_device_id qcom_a53pll_match_table[] = {
154 { .compatible = "qcom,msm8916-a53pll" },
155 { .compatible = "qcom,msm8939-a53pll" },
156 { }
157 };
158 MODULE_DEVICE_TABLE(of, qcom_a53pll_match_table);
159
160 static struct platform_driver qcom_a53pll_driver = {
161 .probe = qcom_a53pll_probe,
162 .driver = {
163 .name = "qcom-a53pll",
164 .of_match_table = qcom_a53pll_match_table,
165 },
166 };
167 module_platform_driver(qcom_a53pll_driver);
168
169 MODULE_DESCRIPTION("Qualcomm A53 PLL Driver");
170 MODULE_LICENSE("GPL v2");
171