[linux-2.6-block.git] / drivers / reset / reset-meson-audio-arb.c

// SPDX-License-Identifier: (GPL-2.0 OR MIT)
// Copyright (c) 2018 BayLibre, SAS.
// Author: Jerome Brunet <jbrunet@baylibre.com>

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/reset-controller.h>
#include <linux/spinlock.h>

#include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>

struct meson_audio_arb_data {
	struct reset_controller_dev rstc;
	void __iomem *regs;
	struct clk *clk;
	const unsigned int *reset_bits;
	spinlock_t lock;
};

#define ARB_GENERAL_BIT	31

static const unsigned int axg_audio_arb_reset_bits[] = {
	[AXG_ARB_TODDR_A]	= 0,
	[AXG_ARB_TODDR_B]	= 1,
	[AXG_ARB_TODDR_C]	= 2,
	[AXG_ARB_FRDDR_A]	= 4,
	[AXG_ARB_FRDDR_B]	= 5,
	[AXG_ARB_FRDDR_C]	= 6,
};

static int meson_audio_arb_update(struct reset_controller_dev *rcdev,
				  unsigned long id, bool assert)
{
	u32 val;
	struct meson_audio_arb_data *arb =
		container_of(rcdev, struct meson_audio_arb_data, rstc);

	spin_lock(&arb->lock);
	val = readl(arb->regs);

	if (assert)
		val &= ~BIT(arb->reset_bits[id]);
	else
		val |= BIT(arb->reset_bits[id]);

	writel(val, arb->regs);
	spin_unlock(&arb->lock);

	return 0;
}

static int meson_audio_arb_status(struct reset_controller_dev *rcdev,
				  unsigned long id)
{
	u32 val;
	struct meson_audio_arb_data *arb =
		container_of(rcdev, struct meson_audio_arb_data, rstc);

	val = readl(arb->regs);

	return !(val & BIT(arb->reset_bits[id]));
}

static int meson_audio_arb_assert(struct reset_controller_dev *rcdev,
				  unsigned long id)
{
	return meson_audio_arb_update(rcdev, id, true);
}

static int meson_audio_arb_deassert(struct reset_controller_dev *rcdev,
				    unsigned long id)
{
	return meson_audio_arb_update(rcdev, id, false);
}

static const struct reset_control_ops meson_audio_arb_rstc_ops = {
	.assert = meson_audio_arb_assert,
	.deassert = meson_audio_arb_deassert,
	.status = meson_audio_arb_status,
};

static const struct of_device_id meson_audio_arb_of_match[] = {
	{ .compatible = "amlogic,meson-axg-audio-arb", },
	{}
};
MODULE_DEVICE_TABLE(of, meson_audio_arb_of_match);

static int meson_audio_arb_remove(struct platform_device *pdev)
{
	struct meson_audio_arb_data *arb = platform_get_drvdata(pdev);

	/* Disable all access */
	spin_lock(&arb->lock);
	writel(0, arb->regs);
	spin_unlock(&arb->lock);

	clk_disable_unprepare(arb->clk);

	return 0;
}

static int meson_audio_arb_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct meson_audio_arb_data *arb;
	struct resource *res;
	int ret;

	arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);
	if (!arb)
		return -ENOMEM;
	platform_set_drvdata(pdev, arb);

	arb->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(arb->clk)) {
		if (PTR_ERR(arb->clk) != -EPROBE_DEFER)
			dev_err(dev, "failed to get clock\n");
		return PTR_ERR(arb->clk);
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	arb->regs = devm_ioremap_resource(dev, res);
	if (IS_ERR(arb->regs))
		return PTR_ERR(arb->regs);

	spin_lock_init(&arb->lock);
	arb->reset_bits = axg_audio_arb_reset_bits;
	arb->rstc.nr_resets = ARRAY_SIZE(axg_audio_arb_reset_bits);
	arb->rstc.ops = &meson_audio_arb_rstc_ops;
	arb->rstc.of_node = dev->of_node;
	arb->rstc.owner = THIS_MODULE;

	/*
	 * Enable general :
	 * In the initial state, all memory interfaces are disabled
	 * and the general bit is on
	 */
	ret = clk_prepare_enable(arb->clk);
	if (ret) {
		dev_err(dev, "failed to enable arb clock\n");
		return ret;
	}
	writel(BIT(ARB_GENERAL_BIT), arb->regs);

	/* Register reset controller */
	ret = devm_reset_controller_register(dev, &arb->rstc);
	if (ret) {
		dev_err(dev, "failed to register arb reset controller\n");
		meson_audio_arb_remove(pdev);
	}

	return ret;
}

static struct platform_driver meson_audio_arb_pdrv = {
	.probe = meson_audio_arb_probe,
	.remove = meson_audio_arb_remove,
	.driver = {
		.name = "meson-audio-arb-reset",
		.of_match_table = meson_audio_arb_of_match,
	},
};
module_platform_driver(meson_audio_arb_pdrv);

MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter");
MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
d903779b JB	1	// SPDX-License-Identifier: (GPL-2.0 OR MIT)
	2	// Copyright (c) 2018 BayLibre, SAS.
	3	// Author: Jerome Brunet <jbrunet@baylibre.com>
	4
	5	#include <linux/clk.h>
	6	#include <linux/io.h>
	7	#include <linux/module.h>
	8	#include <linux/of_platform.h>
	9	#include <linux/reset-controller.h>
	10	#include <linux/spinlock.h>
	11
	12	#include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
	13
	14	struct meson_audio_arb_data {
	15	struct reset_controller_dev rstc;
	16	void __iomem *regs;
	17	struct clk *clk;
	18	const unsigned int *reset_bits;
	19	spinlock_t lock;
	20	};
	21
	22	#define ARB_GENERAL_BIT 31
	23
	24	static const unsigned int axg_audio_arb_reset_bits[] = {
	25	[AXG_ARB_TODDR_A] = 0,
	26	[AXG_ARB_TODDR_B] = 1,
	27	[AXG_ARB_TODDR_C] = 2,
	28	[AXG_ARB_FRDDR_A] = 4,
	29	[AXG_ARB_FRDDR_B] = 5,
	30	[AXG_ARB_FRDDR_C] = 6,
	31	};
	32
	33	static int meson_audio_arb_update(struct reset_controller_dev *rcdev,
	34	unsigned long id, bool assert)
	35	{
	36	u32 val;
	37	struct meson_audio_arb_data *arb =
	38	container_of(rcdev, struct meson_audio_arb_data, rstc);
	39
	40	spin_lock(&arb->lock);
	41	val = readl(arb->regs);
	42
	43	if (assert)
	44	val &= ~BIT(arb->reset_bits[id]);
	45	else
	46	val \|= BIT(arb->reset_bits[id]);
	47
	48	writel(val, arb->regs);
	49	spin_unlock(&arb->lock);
	50
	51	return 0;
	52	}
	53
	54	static int meson_audio_arb_status(struct reset_controller_dev *rcdev,
	55	unsigned long id)
	56	{
	57	u32 val;
	58	struct meson_audio_arb_data *arb =
	59	container_of(rcdev, struct meson_audio_arb_data, rstc);
	60
	61	val = readl(arb->regs);
	62
	63	return !(val & BIT(arb->reset_bits[id]));
	64	}
65
66	static int meson_audio_arb_assert(struct reset_controller_dev *rcdev,
67	unsigned long id)
68	{
69	return meson_audio_arb_update(rcdev, id, true);
70	}
71
72	static int meson_audio_arb_deassert(struct reset_controller_dev *rcdev,
73	unsigned long id)
74	{
75	return meson_audio_arb_update(rcdev, id, false);
76	}
77
78	static const struct reset_control_ops meson_audio_arb_rstc_ops = {
79	.assert = meson_audio_arb_assert,
80	.deassert = meson_audio_arb_deassert,
81	.status = meson_audio_arb_status,
82	};
83
84	static const struct of_device_id meson_audio_arb_of_match[] = {
85	{ .compatible = "amlogic,meson-axg-audio-arb", },
86	{}
87	};
88	MODULE_DEVICE_TABLE(of, meson_audio_arb_of_match);
89
90	static int meson_audio_arb_remove(struct platform_device *pdev)
91	{
92	struct meson_audio_arb_data *arb = platform_get_drvdata(pdev);
93
94	/* Disable all access */
95	spin_lock(&arb->lock);
96	writel(0, arb->regs);
97	spin_unlock(&arb->lock);
98
99	clk_disable_unprepare(arb->clk);
100
101	return 0;
102	}
103
104	static int meson_audio_arb_probe(struct platform_device *pdev)
105	{
106	struct device *dev = &pdev->dev;
107	struct meson_audio_arb_data *arb;
108	struct resource *res;
109	int ret;
110
111	arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);
112	if (!arb)
113	return -ENOMEM;
114	platform_set_drvdata(pdev, arb);
115
116	arb->clk = devm_clk_get(dev, NULL);
117	if (IS_ERR(arb->clk)) {
118	if (PTR_ERR(arb->clk) != -EPROBE_DEFER)
119	dev_err(dev, "failed to get clock\n");
120	return PTR_ERR(arb->clk);
121	}
122
123	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
124	arb->regs = devm_ioremap_resource(dev, res);
125	if (IS_ERR(arb->regs))
126	return PTR_ERR(arb->regs);
127
128	spin_lock_init(&arb->lock);
129	arb->reset_bits = axg_audio_arb_reset_bits;
130	arb->rstc.nr_resets = ARRAY_SIZE(axg_audio_arb_reset_bits);
131	arb->rstc.ops = &meson_audio_arb_rstc_ops;
132	arb->rstc.of_node = dev->of_node;
13e8a05b	133	arb->rstc.owner = THIS_MODULE;
d903779b JB	134
	135	/*
	136	* Enable general :
	137	* In the initial state, all memory interfaces are disabled
	138	* and the general bit is on
	139	*/
	140	ret = clk_prepare_enable(arb->clk);
	141	if (ret) {
	142	dev_err(dev, "failed to enable arb clock\n");
	143	return ret;
	144	}
	145	writel(BIT(ARB_GENERAL_BIT), arb->regs);
	146
	147	/* Register reset controller */
	148	ret = devm_reset_controller_register(dev, &arb->rstc);
	149	if (ret) {
	150	dev_err(dev, "failed to register arb reset controller\n");
	151	meson_audio_arb_remove(pdev);
	152	}
	153
	154	return ret;
	155	}
	156
	157	static struct platform_driver meson_audio_arb_pdrv = {
	158	.probe = meson_audio_arb_probe,
	159	.remove = meson_audio_arb_remove,
	160	.driver = {
	161	.name = "meson-audio-arb-reset",
	162	.of_match_table = meson_audio_arb_of_match,
	163	},
	164	};
	165	module_platform_driver(meson_audio_arb_pdrv);
	166
	167	MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter");
	168	MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
	169	MODULE_LICENSE("GPL v2");