tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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");