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