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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"); |