1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2018 The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/module.h>
7 #include <linux/of_device.h>
8 #include <linux/platform_device.h>
9 #include <linux/regmap.h>
10 #include <linux/reset-controller.h>
11 
12 #include <dt-bindings/reset/qcom,sdm845-pdc.h>
13 
14 #define RPMH_PDC_SYNC_RESET	0x100
15 
16 struct qcom_pdc_reset_map {
17 	u8 bit;
18 };
19 
20 struct qcom_pdc_reset_data {
21 	struct reset_controller_dev rcdev;
22 	struct regmap *regmap;
23 };
24 
25 static const struct regmap_config sdm845_pdc_regmap_config = {
26 	.name		= "pdc-reset",
27 	.reg_bits	= 32,
28 	.reg_stride	= 4,
29 	.val_bits	= 32,
30 	.max_register	= 0x20000,
31 	.fast_io	= true,
32 };
33 
34 static const struct qcom_pdc_reset_map sdm845_pdc_resets[] = {
35 	[PDC_APPS_SYNC_RESET] = {0},
36 	[PDC_SP_SYNC_RESET] = {1},
37 	[PDC_AUDIO_SYNC_RESET] = {2},
38 	[PDC_SENSORS_SYNC_RESET] = {3},
39 	[PDC_AOP_SYNC_RESET] = {4},
40 	[PDC_DEBUG_SYNC_RESET] = {5},
41 	[PDC_GPU_SYNC_RESET] = {6},
42 	[PDC_DISPLAY_SYNC_RESET] = {7},
43 	[PDC_COMPUTE_SYNC_RESET] = {8},
44 	[PDC_MODEM_SYNC_RESET] = {9},
45 };
46 
47 static inline struct qcom_pdc_reset_data *to_qcom_pdc_reset_data(
48 				struct reset_controller_dev *rcdev)
49 {
50 	return container_of(rcdev, struct qcom_pdc_reset_data, rcdev);
51 }
52 
53 static int qcom_pdc_control_assert(struct reset_controller_dev *rcdev,
54 					unsigned long idx)
55 {
56 	struct qcom_pdc_reset_data *data = to_qcom_pdc_reset_data(rcdev);
57 
58 	return regmap_update_bits(data->regmap, RPMH_PDC_SYNC_RESET,
59 				  BIT(sdm845_pdc_resets[idx].bit),
60 				  BIT(sdm845_pdc_resets[idx].bit));
61 }
62 
63 static int qcom_pdc_control_deassert(struct reset_controller_dev *rcdev,
64 					unsigned long idx)
65 {
66 	struct qcom_pdc_reset_data *data = to_qcom_pdc_reset_data(rcdev);
67 
68 	return regmap_update_bits(data->regmap, RPMH_PDC_SYNC_RESET,
69 				  BIT(sdm845_pdc_resets[idx].bit), 0);
70 }
71 
72 static const struct reset_control_ops qcom_pdc_reset_ops = {
73 	.assert = qcom_pdc_control_assert,
74 	.deassert = qcom_pdc_control_deassert,
75 };
76 
77 static int qcom_pdc_reset_probe(struct platform_device *pdev)
78 {
79 	struct qcom_pdc_reset_data *data;
80 	struct device *dev = &pdev->dev;
81 	void __iomem *base;
82 	struct resource *res;
83 
84 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
85 	if (!data)
86 		return -ENOMEM;
87 
88 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
89 	base = devm_ioremap_resource(dev, res);
90 	if (IS_ERR(base))
91 		return PTR_ERR(base);
92 
93 	data->regmap = devm_regmap_init_mmio(dev, base,
94 					     &sdm845_pdc_regmap_config);
95 	if (IS_ERR(data->regmap)) {
96 		dev_err(dev, "Unable to initialize regmap\n");
97 		return PTR_ERR(data->regmap);
98 	}
99 
100 	data->rcdev.owner = THIS_MODULE;
101 	data->rcdev.ops = &qcom_pdc_reset_ops;
102 	data->rcdev.nr_resets = ARRAY_SIZE(sdm845_pdc_resets);
103 	data->rcdev.of_node = dev->of_node;
104 
105 	return devm_reset_controller_register(dev, &data->rcdev);
106 }
107 
108 static const struct of_device_id qcom_pdc_reset_of_match[] = {
109 	{ .compatible = "qcom,sdm845-pdc-global" },
110 	{}
111 };
112 MODULE_DEVICE_TABLE(of, qcom_pdc_reset_of_match);
113 
114 static struct platform_driver qcom_pdc_reset_driver = {
115 	.probe = qcom_pdc_reset_probe,
116 	.driver = {
117 		.name = "qcom_pdc_reset",
118 		.of_match_table = qcom_pdc_reset_of_match,
119 	},
120 };
121 module_platform_driver(qcom_pdc_reset_driver);
122 
123 MODULE_DESCRIPTION("Qualcomm PDC Reset Driver");
124 MODULE_LICENSE("GPL v2");
125