1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2016 Free Electrons
4 *
5 * Maxime Ripard <maxime.ripard@free-electrons.com>
6 */
7
8 #include <linux/clk.h>
9 #include <linux/component.h>
10 #include <linux/module.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/platform_device.h>
13 #include <linux/regmap.h>
14 #include <linux/reset.h>
15
16 struct sun6i_drc {
17 struct clk *bus_clk;
18 struct clk *mod_clk;
19 struct reset_control *reset;
20 };
21
sun6i_drc_bind(struct device * dev,struct device * master,void * data)22 static int sun6i_drc_bind(struct device *dev, struct device *master,
23 void *data)
24 {
25 struct sun6i_drc *drc;
26 int ret;
27
28 drc = devm_kzalloc(dev, sizeof(*drc), GFP_KERNEL);
29 if (!drc)
30 return -ENOMEM;
31 dev_set_drvdata(dev, drc);
32
33 drc->reset = devm_reset_control_get(dev, NULL);
34 if (IS_ERR(drc->reset)) {
35 dev_err(dev, "Couldn't get our reset line\n");
36 return PTR_ERR(drc->reset);
37 }
38
39 ret = reset_control_deassert(drc->reset);
40 if (ret) {
41 dev_err(dev, "Couldn't deassert our reset line\n");
42 return ret;
43 }
44
45 drc->bus_clk = devm_clk_get(dev, "ahb");
46 if (IS_ERR(drc->bus_clk)) {
47 dev_err(dev, "Couldn't get our bus clock\n");
48 ret = PTR_ERR(drc->bus_clk);
49 goto err_assert_reset;
50 }
51 clk_prepare_enable(drc->bus_clk);
52
53 drc->mod_clk = devm_clk_get(dev, "mod");
54 if (IS_ERR(drc->mod_clk)) {
55 dev_err(dev, "Couldn't get our mod clock\n");
56 ret = PTR_ERR(drc->mod_clk);
57 goto err_disable_bus_clk;
58 }
59
60 ret = clk_set_rate_exclusive(drc->mod_clk, 300000000);
61 if (ret) {
62 dev_err(dev, "Couldn't set the module clock frequency\n");
63 goto err_disable_bus_clk;
64 }
65
66 clk_prepare_enable(drc->mod_clk);
67
68 return 0;
69
70 err_disable_bus_clk:
71 clk_disable_unprepare(drc->bus_clk);
72 err_assert_reset:
73 reset_control_assert(drc->reset);
74 return ret;
75 }
76
sun6i_drc_unbind(struct device * dev,struct device * master,void * data)77 static void sun6i_drc_unbind(struct device *dev, struct device *master,
78 void *data)
79 {
80 struct sun6i_drc *drc = dev_get_drvdata(dev);
81
82 clk_rate_exclusive_put(drc->mod_clk);
83 clk_disable_unprepare(drc->mod_clk);
84 clk_disable_unprepare(drc->bus_clk);
85 reset_control_assert(drc->reset);
86 }
87
88 static const struct component_ops sun6i_drc_ops = {
89 .bind = sun6i_drc_bind,
90 .unbind = sun6i_drc_unbind,
91 };
92
sun6i_drc_probe(struct platform_device * pdev)93 static int sun6i_drc_probe(struct platform_device *pdev)
94 {
95 return component_add(&pdev->dev, &sun6i_drc_ops);
96 }
97
sun6i_drc_remove(struct platform_device * pdev)98 static void sun6i_drc_remove(struct platform_device *pdev)
99 {
100 component_del(&pdev->dev, &sun6i_drc_ops);
101 }
102
103 static const struct of_device_id sun6i_drc_of_table[] = {
104 { .compatible = "allwinner,sun6i-a31-drc" },
105 { .compatible = "allwinner,sun6i-a31s-drc" },
106 { .compatible = "allwinner,sun8i-a23-drc" },
107 { .compatible = "allwinner,sun8i-a33-drc" },
108 { .compatible = "allwinner,sun9i-a80-drc" },
109 { }
110 };
111 MODULE_DEVICE_TABLE(of, sun6i_drc_of_table);
112
113 static struct platform_driver sun6i_drc_platform_driver = {
114 .probe = sun6i_drc_probe,
115 .remove_new = sun6i_drc_remove,
116 .driver = {
117 .name = "sun6i-drc",
118 .of_match_table = sun6i_drc_of_table,
119 },
120 };
121 module_platform_driver(sun6i_drc_platform_driver);
122
123 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
124 MODULE_DESCRIPTION("Allwinner A31 Dynamic Range Control (DRC) Driver");
125 MODULE_LICENSE("GPL");
126