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(lock: &arb->lock);
68 val = readl(addr: 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, addr: arb->regs);
76 spin_unlock(lock: &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(addr: 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, assert: 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, assert: 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(lock: &arb->lock);
129 writel(val: 0, addr: arb->regs);
130 spin_unlock(lock: &arb->lock);
131
132 clk_disable_unprepare(clk: 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 struct resource *res;
143 int ret;
144
145 data = of_device_get_match_data(dev);
146 if (!data)
147 return -EINVAL;
148
149 arb = devm_kzalloc(dev, size: sizeof(*arb), GFP_KERNEL);
150 if (!arb)
151 return -ENOMEM;
152 platform_set_drvdata(pdev, data: arb);
153
154 arb->clk = devm_clk_get(dev, NULL);
155 if (IS_ERR(ptr: arb->clk))
156 return dev_err_probe(dev, err: PTR_ERR(ptr: arb->clk), fmt: "failed to get clock\n");
157
158 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
159 arb->regs = devm_ioremap_resource(dev, res);
160 if (IS_ERR(ptr: arb->regs))
161 return PTR_ERR(ptr: arb->regs);
162
163 spin_lock_init(&arb->lock);
164 arb->reset_bits = data->reset_bits;
165 arb->rstc.nr_resets = data->reset_num;
166 arb->rstc.ops = &meson_audio_arb_rstc_ops;
167 arb->rstc.of_node = dev->of_node;
168 arb->rstc.owner = THIS_MODULE;
169
170 /*
171 * Enable general :
172 * In the initial state, all memory interfaces are disabled
173 * and the general bit is on
174 */
175 ret = clk_prepare_enable(clk: arb->clk);
176 if (ret) {
177 dev_err(dev, "failed to enable arb clock\n");
178 return ret;
179 }
180 writel(BIT(ARB_GENERAL_BIT), addr: arb->regs);
181
182 /* Register reset controller */
183 ret = devm_reset_controller_register(dev, rcdev: &arb->rstc);
184 if (ret) {
185 dev_err(dev, "failed to register arb reset controller\n");
186 meson_audio_arb_remove(pdev);
187 }
188
189 return ret;
190}
191
192static struct platform_driver meson_audio_arb_pdrv = {
193 .probe = meson_audio_arb_probe,
194 .remove = meson_audio_arb_remove,
195 .driver = {
196 .name = "meson-audio-arb-reset",
197 .of_match_table = meson_audio_arb_of_match,
198 },
199};
200module_platform_driver(meson_audio_arb_pdrv);
201
202MODULE_DESCRIPTION("Amlogic A113 Audio Memory Arbiter");
203MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
204MODULE_LICENSE("GPL v2");
205

source code of linux/drivers/reset/reset-meson-audio-arb.c