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.h>
  9#include <linux/platform_device.h>
 10#include <linux/reset-controller.h>
 11#include <linux/spinlock.h>
 12
 13#include <dt-bindings/reset/amlogic,meson-axg-audio-arb.h>
 14
 15struct meson_audio_arb_data {
 16	struct reset_controller_dev rstc;
 17	void __iomem *regs;
 18	struct clk *clk;
 19	const unsigned int *reset_bits;
 20	spinlock_t lock;
 21};
 22
 23struct meson_audio_arb_match_data {
 24	const unsigned int *reset_bits;
 25	unsigned int reset_num;
 26};
 27
 28#define ARB_GENERAL_BIT	31
 29
 30static const unsigned int axg_audio_arb_reset_bits[] = {
 31	[AXG_ARB_TODDR_A]	= 0,
 32	[AXG_ARB_TODDR_B]	= 1,
 33	[AXG_ARB_TODDR_C]	= 2,
 34	[AXG_ARB_FRDDR_A]	= 4,
 35	[AXG_ARB_FRDDR_B]	= 5,
 36	[AXG_ARB_FRDDR_C]	= 6,
 37};
 38
 39static const struct meson_audio_arb_match_data axg_audio_arb_match = {
 40	.reset_bits = axg_audio_arb_reset_bits,
 41	.reset_num = ARRAY_SIZE(axg_audio_arb_reset_bits),
 42};
 43
 44static const unsigned int sm1_audio_arb_reset_bits[] = {
 45	[AXG_ARB_TODDR_A]	= 0,
 46	[AXG_ARB_TODDR_B]	= 1,
 47	[AXG_ARB_TODDR_C]	= 2,
 48	[AXG_ARB_FRDDR_A]	= 4,
 49	[AXG_ARB_FRDDR_B]	= 5,
 50	[AXG_ARB_FRDDR_C]	= 6,
 51	[AXG_ARB_TODDR_D]	= 3,
 52	[AXG_ARB_FRDDR_D]	= 7,
 53};
 54
 55static const struct meson_audio_arb_match_data sm1_audio_arb_match = {
 56	.reset_bits = sm1_audio_arb_reset_bits,
 57	.reset_num = ARRAY_SIZE(sm1_audio_arb_reset_bits),
 58};
 59
 60static int meson_audio_arb_update(struct reset_controller_dev *rcdev,
 61				  unsigned long id, bool assert)
 62{
 63	u32 val;
 64	struct meson_audio_arb_data *arb =
 65		container_of(rcdev, struct meson_audio_arb_data, rstc);
 66
 67	spin_lock(&arb->lock);
 68	val = readl(arb->regs);
 69
 70	if (assert)
 71		val &= ~BIT(arb->reset_bits[id]);
 72	else
 73		val |= BIT(arb->reset_bits[id]);
 74
 75	writel(val, arb->regs);
 76	spin_unlock(&arb->lock);
 77
 78	return 0;
 79}
 80
 81static int meson_audio_arb_status(struct reset_controller_dev *rcdev,
 82				  unsigned long id)
 83{
 84	u32 val;
 85	struct meson_audio_arb_data *arb =
 86		container_of(rcdev, struct meson_audio_arb_data, rstc);
 87
 88	val = readl(arb->regs);
 89
 90	return !(val & BIT(arb->reset_bits[id]));
 91}
 92
 93static int meson_audio_arb_assert(struct reset_controller_dev *rcdev,
 94				  unsigned long id)
 95{
 96	return meson_audio_arb_update(rcdev, id, true);
 97}
 98
 99static int meson_audio_arb_deassert(struct reset_controller_dev *rcdev,
100				    unsigned long id)
101{
102	return meson_audio_arb_update(rcdev, id, false);
103}
104
105static const struct reset_control_ops meson_audio_arb_rstc_ops = {
106	.assert = meson_audio_arb_assert,
107	.deassert = meson_audio_arb_deassert,
108	.status = meson_audio_arb_status,
109};
110
111static const struct of_device_id meson_audio_arb_of_match[] = {
112	{
113		.compatible = "amlogic,meson-axg-audio-arb",
114		.data = &axg_audio_arb_match,
115	}, {
116		.compatible = "amlogic,meson-sm1-audio-arb",
117		.data = &sm1_audio_arb_match,
118	},
119	{}
120};
121MODULE_DEVICE_TABLE(of, meson_audio_arb_of_match);
122
123static int meson_audio_arb_remove(struct platform_device *pdev)
124{
125	struct meson_audio_arb_data *arb = platform_get_drvdata(pdev);
126
127	/* Disable all access */
128	spin_lock(&arb->lock);
129	writel(0, arb->regs);
130	spin_unlock(&arb->lock);
131
132	clk_disable_unprepare(arb->clk);
133
134	return 0;
135}
136
137static int meson_audio_arb_probe(struct platform_device *pdev)
138{
139	struct device *dev = &pdev->dev;
140	const struct meson_audio_arb_match_data *data;
141	struct meson_audio_arb_data *arb;
142	int ret;
143
144	data = of_device_get_match_data(dev);
145	if (!data)
146		return -EINVAL;
147
148	arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);
149	if (!arb)
150		return -ENOMEM;
151	platform_set_drvdata(pdev, arb);
152
153	arb->clk = devm_clk_get(dev, NULL);
154	if (IS_ERR(arb->clk))
155		return dev_err_probe(dev, PTR_ERR(arb->clk), "failed to get clock\n");
156
157	arb->regs = devm_platform_ioremap_resource(pdev, 0);
158	if (IS_ERR(arb->regs))
159		return PTR_ERR(arb->regs);
160
161	spin_lock_init(&arb->lock);
162	arb->reset_bits = data->reset_bits;
163	arb->rstc.nr_resets = data->reset_num;
164	arb->rstc.ops = &meson_audio_arb_rstc_ops;
165	arb->rstc.of_node = dev->of_node;
166	arb->rstc.owner = THIS_MODULE;
167
168	/*
169	 * Enable general :
170	 * In the initial state, all memory interfaces are disabled
171	 * and the general bit is on
172	 */
173	ret = clk_prepare_enable(arb->clk);
174	if (ret) {
175		dev_err(dev, "failed to enable arb clock\n");
176		return ret;
177	}
178	writel(BIT(ARB_GENERAL_BIT), arb->regs);
179
180	/* Register reset controller */
181	ret = devm_reset_controller_register(dev, &arb->rstc);
182	if (ret) {
183		dev_err(dev, "failed to register arb reset controller\n");
184		meson_audio_arb_remove(pdev);
185	}
186
187	return ret;
188}
189
190static struct platform_driver meson_audio_arb_pdrv = {
191	.probe = meson_audio_arb_probe,
192	.remove = meson_audio_arb_remove,
193	.driver = {
194		.name = "meson-audio-arb-reset",
195		.of_match_table = meson_audio_arb_of_match,
196	},
197};
198module_platform_driver(meson_audio_arb_pdrv);
199
200MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter");
201MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
202MODULE_LICENSE("GPL v2");