xref: /openbmc/linux/drivers/reset/reset-zynqmp.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2018 Xilinx, Inc.
4  *
5  */
6 
7 #include <linux/err.h>
8 #include <linux/of.h>
9 #include <linux/platform_device.h>
10 #include <linux/reset-controller.h>
11 #include <linux/firmware/xlnx-zynqmp.h>
12 
13 #define ZYNQMP_NR_RESETS (ZYNQMP_PM_RESET_END - ZYNQMP_PM_RESET_START)
14 #define ZYNQMP_RESET_ID ZYNQMP_PM_RESET_START
15 
16 struct zynqmp_reset_data {
17 	struct reset_controller_dev rcdev;
18 };
19 
20 static inline struct zynqmp_reset_data *
21 to_zynqmp_reset_data(struct reset_controller_dev *rcdev)
22 {
23 	return container_of(rcdev, struct zynqmp_reset_data, rcdev);
24 }
25 
26 static int zynqmp_reset_assert(struct reset_controller_dev *rcdev,
27 			       unsigned long id)
28 {
29 	return zynqmp_pm_reset_assert(ZYNQMP_RESET_ID + id,
30 				      PM_RESET_ACTION_ASSERT);
31 }
32 
33 static int zynqmp_reset_deassert(struct reset_controller_dev *rcdev,
34 				 unsigned long id)
35 {
36 	return zynqmp_pm_reset_assert(ZYNQMP_RESET_ID + id,
37 				      PM_RESET_ACTION_RELEASE);
38 }
39 
40 static int zynqmp_reset_status(struct reset_controller_dev *rcdev,
41 			       unsigned long id)
42 {
43 	int val, err;
44 
45 	err = zynqmp_pm_reset_get_status(ZYNQMP_RESET_ID + id, &val);
46 	if (err)
47 		return err;
48 
49 	return val;
50 }
51 
52 static int zynqmp_reset_reset(struct reset_controller_dev *rcdev,
53 			      unsigned long id)
54 {
55 	return zynqmp_pm_reset_assert(ZYNQMP_RESET_ID + id,
56 				      PM_RESET_ACTION_PULSE);
57 }
58 
59 static const struct reset_control_ops zynqmp_reset_ops = {
60 	.reset = zynqmp_reset_reset,
61 	.assert = zynqmp_reset_assert,
62 	.deassert = zynqmp_reset_deassert,
63 	.status = zynqmp_reset_status,
64 };
65 
66 static int zynqmp_reset_probe(struct platform_device *pdev)
67 {
68 	struct zynqmp_reset_data *priv;
69 
70 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
71 	if (!priv)
72 		return -ENOMEM;
73 
74 	platform_set_drvdata(pdev, priv);
75 
76 	priv->rcdev.ops = &zynqmp_reset_ops;
77 	priv->rcdev.owner = THIS_MODULE;
78 	priv->rcdev.of_node = pdev->dev.of_node;
79 	priv->rcdev.nr_resets = ZYNQMP_NR_RESETS;
80 
81 	return devm_reset_controller_register(&pdev->dev, &priv->rcdev);
82 }
83 
84 static const struct of_device_id zynqmp_reset_dt_ids[] = {
85 	{ .compatible = "xlnx,zynqmp-reset", },
86 	{ /* sentinel */ },
87 };
88 
89 static struct platform_driver zynqmp_reset_driver = {
90 	.probe	= zynqmp_reset_probe,
91 	.driver = {
92 		.name		= KBUILD_MODNAME,
93 		.of_match_table	= zynqmp_reset_dt_ids,
94 	},
95 };
96 
97 static int __init zynqmp_reset_init(void)
98 {
99 	return platform_driver_register(&zynqmp_reset_driver);
100 }
101 
102 arch_initcall(zynqmp_reset_init);
103