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
 16struct sun6i_drc {
 17	struct clk		*bus_clk;
 18	struct clk		*mod_clk;
 19	struct reset_control	*reset;
 20};
 21
 22static 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
 70err_disable_bus_clk:
 71	clk_disable_unprepare(drc->bus_clk);
 72err_assert_reset:
 73	reset_control_assert(drc->reset);
 74	return ret;
 75}
 76
 77static 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
 88static const struct component_ops sun6i_drc_ops = {
 89	.bind	= sun6i_drc_bind,
 90	.unbind	= sun6i_drc_unbind,
 91};
 92
 93static int sun6i_drc_probe(struct platform_device *pdev)
 94{
 95	return component_add(&pdev->dev, &sun6i_drc_ops);
 96}
 97
 98static int sun6i_drc_remove(struct platform_device *pdev)
 99{
100	component_del(&pdev->dev, &sun6i_drc_ops);
101
102	return 0;
103}
104
105static const struct of_device_id sun6i_drc_of_table[] = {
106	{ .compatible = "allwinner,sun6i-a31-drc" },
107	{ .compatible = "allwinner,sun6i-a31s-drc" },
108	{ .compatible = "allwinner,sun8i-a23-drc" },
109	{ .compatible = "allwinner,sun8i-a33-drc" },
110	{ .compatible = "allwinner,sun9i-a80-drc" },
111	{ }
112};
113MODULE_DEVICE_TABLE(of, sun6i_drc_of_table);
114
115static struct platform_driver sun6i_drc_platform_driver = {
116	.probe		= sun6i_drc_probe,
117	.remove		= sun6i_drc_remove,
118	.driver		= {
119		.name		= "sun6i-drc",
120		.of_match_table	= sun6i_drc_of_table,
121	},
122};
123module_platform_driver(sun6i_drc_platform_driver);
124
125MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
126MODULE_DESCRIPTION("Allwinner A31 Dynamic Range Control (DRC) Driver");
127MODULE_LICENSE("GPL");