1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright 2024 NXP
  4 */
  5
  6#include <linux/auxiliary_bus.h>
  7#include <linux/device.h>
  8#include <linux/io.h>
  9#include <linux/module.h>
 10#include <linux/of.h>
 11#include <linux/of_address.h>
 12#include <linux/reset-controller.h>
 13
 14#define EARC			0x200
 15#define EARC_RESET_MASK		0x3
 16
 17struct imx8mp_audiomix_reset {
 18	struct reset_controller_dev rcdev;
 19	spinlock_t lock; /* protect register read-modify-write cycle */
 20	void __iomem *base;
 21};
 22
 23static struct imx8mp_audiomix_reset *to_imx8mp_audiomix_reset(struct reset_controller_dev *rcdev)
 24{
 25	return container_of(rcdev, struct imx8mp_audiomix_reset, rcdev);
 26}
 27
 28static int imx8mp_audiomix_reset_assert(struct reset_controller_dev *rcdev,
 29					unsigned long id)
 30{
 31	struct imx8mp_audiomix_reset *priv = to_imx8mp_audiomix_reset(rcdev);
 32	void __iomem *reg_addr = priv->base;
 33	unsigned int mask, reg;
 34	unsigned long flags;
 35
 36	mask = BIT(id);
 37	spin_lock_irqsave(&priv->lock, flags);
 38	reg = readl(reg_addr + EARC);
 39	writel(reg & ~mask, reg_addr + EARC);
 40	spin_unlock_irqrestore(&priv->lock, flags);
 41
 42	return 0;
 43}
 44
 45static int imx8mp_audiomix_reset_deassert(struct reset_controller_dev *rcdev,
 46					  unsigned long id)
 47{
 48	struct imx8mp_audiomix_reset *priv = to_imx8mp_audiomix_reset(rcdev);
 49	void __iomem *reg_addr = priv->base;
 50	unsigned int mask, reg;
 51	unsigned long flags;
 52
 53	mask = BIT(id);
 54	spin_lock_irqsave(&priv->lock, flags);
 55	reg = readl(reg_addr + EARC);
 56	writel(reg | mask, reg_addr + EARC);
 57	spin_unlock_irqrestore(&priv->lock, flags);
 58
 59	return 0;
 60}
 61
 62static const struct reset_control_ops imx8mp_audiomix_reset_ops = {
 63	.assert   = imx8mp_audiomix_reset_assert,
 64	.deassert = imx8mp_audiomix_reset_deassert,
 65};
 66
 67static int imx8mp_audiomix_reset_probe(struct auxiliary_device *adev,
 68				       const struct auxiliary_device_id *id)
 69{
 70	struct imx8mp_audiomix_reset *priv;
 71	struct device *dev = &adev->dev;
 72	int ret;
 73
 74	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 75	if (!priv)
 76		return -ENOMEM;
 77
 78	spin_lock_init(&priv->lock);
 79
 80	priv->rcdev.owner     = THIS_MODULE;
 81	priv->rcdev.nr_resets = fls(EARC_RESET_MASK);
 82	priv->rcdev.ops       = &imx8mp_audiomix_reset_ops;
 83	priv->rcdev.of_node   = dev->parent->of_node;
 84	priv->rcdev.dev	      = dev;
 85	priv->rcdev.of_reset_n_cells = 1;
 86	priv->base            = of_iomap(dev->parent->of_node, 0);
 87	if (!priv->base)
 88		return -ENOMEM;
 89
 90	dev_set_drvdata(dev, priv);
 91
 92	ret = devm_reset_controller_register(dev, &priv->rcdev);
 93	if (ret)
 94		goto out_unmap;
 95
 96	return 0;
 97
 98out_unmap:
 99	iounmap(priv->base);
100	return ret;
101}
102
103static void imx8mp_audiomix_reset_remove(struct auxiliary_device *adev)
104{
105	struct imx8mp_audiomix_reset *priv = dev_get_drvdata(&adev->dev);
106
107	iounmap(priv->base);
108}
109
110static const struct auxiliary_device_id imx8mp_audiomix_reset_ids[] = {
111	{
112		.name = "clk_imx8mp_audiomix.reset",
113	},
114	{ }
115};
116MODULE_DEVICE_TABLE(auxiliary, imx8mp_audiomix_reset_ids);
117
118static struct auxiliary_driver imx8mp_audiomix_reset_driver = {
119	.probe		= imx8mp_audiomix_reset_probe,
120	.remove		= imx8mp_audiomix_reset_remove,
121	.id_table	= imx8mp_audiomix_reset_ids,
122};
123
124module_auxiliary_driver(imx8mp_audiomix_reset_driver);
125
126MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
127MODULE_DESCRIPTION("Freescale i.MX8MP Audio Block Controller reset driver");
128MODULE_LICENSE("GPL");