Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ARM System Control and Management Interface (ARM SCMI) reset driver
4 *
5 * Copyright (C) 2019 ARM Ltd.
6 */
7
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/device.h>
11#include <linux/reset-controller.h>
12#include <linux/scmi_protocol.h>
13
14/**
15 * struct scmi_reset_data - reset controller information structure
16 * @rcdev: reset controller entity
17 * @handle: ARM SCMI handle used for communication with system controller
18 */
19struct scmi_reset_data {
20 struct reset_controller_dev rcdev;
21 const struct scmi_handle *handle;
22};
23
24#define to_scmi_reset_data(p) container_of((p), struct scmi_reset_data, rcdev)
25#define to_scmi_handle(p) (to_scmi_reset_data(p)->handle)
26
27/**
28 * scmi_reset_assert() - assert device reset
29 * @rcdev: reset controller entity
30 * @id: ID of the reset to be asserted
31 *
32 * This function implements the reset driver op to assert a device's reset
33 * using the ARM SCMI protocol.
34 *
35 * Return: 0 for successful request, else a corresponding error value
36 */
37static int
38scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
39{
40 const struct scmi_handle *handle = to_scmi_handle(rcdev);
41
42 return handle->reset_ops->assert(handle, id);
43}
44
45/**
46 * scmi_reset_deassert() - deassert device reset
47 * @rcdev: reset controller entity
48 * @id: ID of the reset to be deasserted
49 *
50 * This function implements the reset driver op to deassert a device's reset
51 * using the ARM SCMI protocol.
52 *
53 * Return: 0 for successful request, else a corresponding error value
54 */
55static int
56scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
57{
58 const struct scmi_handle *handle = to_scmi_handle(rcdev);
59
60 return handle->reset_ops->deassert(handle, id);
61}
62
63/**
64 * scmi_reset_reset() - reset the device
65 * @rcdev: reset controller entity
66 * @id: ID of the reset signal to be reset(assert + deassert)
67 *
68 * This function implements the reset driver op to trigger a device's
69 * reset signal using the ARM SCMI protocol.
70 *
71 * Return: 0 for successful request, else a corresponding error value
72 */
73static int
74scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
75{
76 const struct scmi_handle *handle = to_scmi_handle(rcdev);
77
78 return handle->reset_ops->reset(handle, id);
79}
80
81static const struct reset_control_ops scmi_reset_ops = {
82 .assert = scmi_reset_assert,
83 .deassert = scmi_reset_deassert,
84 .reset = scmi_reset_reset,
85};
86
87static int scmi_reset_probe(struct scmi_device *sdev)
88{
89 struct scmi_reset_data *data;
90 struct device *dev = &sdev->dev;
91 struct device_node *np = dev->of_node;
92 const struct scmi_handle *handle = sdev->handle;
93
94 if (!handle || !handle->reset_ops)
95 return -ENODEV;
96
97 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
98 if (!data)
99 return -ENOMEM;
100
101 data->rcdev.ops = &scmi_reset_ops;
102 data->rcdev.owner = THIS_MODULE;
103 data->rcdev.of_node = np;
104 data->rcdev.nr_resets = handle->reset_ops->num_domains_get(handle);
105 data->handle = handle;
106
107 return devm_reset_controller_register(dev, &data->rcdev);
108}
109
110static const struct scmi_device_id scmi_id_table[] = {
111 { SCMI_PROTOCOL_RESET, "reset" },
112 { },
113};
114MODULE_DEVICE_TABLE(scmi, scmi_id_table);
115
116static struct scmi_driver scmi_reset_driver = {
117 .name = "scmi-reset",
118 .probe = scmi_reset_probe,
119 .id_table = scmi_id_table,
120};
121module_scmi_driver(scmi_reset_driver);
122
123MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
124MODULE_DESCRIPTION("ARM SCMI reset controller driver");
125MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * ARM System Control and Management Interface (ARM SCMI) reset driver
4 *
5 * Copyright (C) 2019-2021 ARM Ltd.
6 */
7
8#include <linux/module.h>
9#include <linux/of.h>
10#include <linux/device.h>
11#include <linux/reset-controller.h>
12#include <linux/scmi_protocol.h>
13
14static const struct scmi_reset_proto_ops *reset_ops;
15
16/**
17 * struct scmi_reset_data - reset controller information structure
18 * @rcdev: reset controller entity
19 * @ph: ARM SCMI protocol handle used for communication with system controller
20 */
21struct scmi_reset_data {
22 struct reset_controller_dev rcdev;
23 const struct scmi_protocol_handle *ph;
24};
25
26#define to_scmi_reset_data(p) container_of((p), struct scmi_reset_data, rcdev)
27#define to_scmi_handle(p) (to_scmi_reset_data(p)->ph)
28
29/**
30 * scmi_reset_assert() - assert device reset
31 * @rcdev: reset controller entity
32 * @id: ID of the reset to be asserted
33 *
34 * This function implements the reset driver op to assert a device's reset
35 * using the ARM SCMI protocol.
36 *
37 * Return: 0 for successful request, else a corresponding error value
38 */
39static int
40scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
41{
42 const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev);
43
44 return reset_ops->assert(ph, id);
45}
46
47/**
48 * scmi_reset_deassert() - deassert device reset
49 * @rcdev: reset controller entity
50 * @id: ID of the reset to be deasserted
51 *
52 * This function implements the reset driver op to deassert a device's reset
53 * using the ARM SCMI protocol.
54 *
55 * Return: 0 for successful request, else a corresponding error value
56 */
57static int
58scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
59{
60 const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev);
61
62 return reset_ops->deassert(ph, id);
63}
64
65/**
66 * scmi_reset_reset() - reset the device
67 * @rcdev: reset controller entity
68 * @id: ID of the reset signal to be reset(assert + deassert)
69 *
70 * This function implements the reset driver op to trigger a device's
71 * reset signal using the ARM SCMI protocol.
72 *
73 * Return: 0 for successful request, else a corresponding error value
74 */
75static int
76scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
77{
78 const struct scmi_protocol_handle *ph = to_scmi_handle(rcdev);
79
80 return reset_ops->reset(ph, id);
81}
82
83static const struct reset_control_ops scmi_reset_ops = {
84 .assert = scmi_reset_assert,
85 .deassert = scmi_reset_deassert,
86 .reset = scmi_reset_reset,
87};
88
89static int scmi_reset_probe(struct scmi_device *sdev)
90{
91 struct scmi_reset_data *data;
92 struct device *dev = &sdev->dev;
93 struct device_node *np = dev->of_node;
94 const struct scmi_handle *handle = sdev->handle;
95 struct scmi_protocol_handle *ph;
96
97 if (!handle)
98 return -ENODEV;
99
100 reset_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_RESET, &ph);
101 if (IS_ERR(reset_ops))
102 return PTR_ERR(reset_ops);
103
104 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
105 if (!data)
106 return -ENOMEM;
107
108 data->rcdev.ops = &scmi_reset_ops;
109 data->rcdev.owner = THIS_MODULE;
110 data->rcdev.of_node = np;
111 data->rcdev.nr_resets = reset_ops->num_domains_get(ph);
112 data->ph = ph;
113
114 return devm_reset_controller_register(dev, &data->rcdev);
115}
116
117static const struct scmi_device_id scmi_id_table[] = {
118 { SCMI_PROTOCOL_RESET, "reset" },
119 { },
120};
121MODULE_DEVICE_TABLE(scmi, scmi_id_table);
122
123static struct scmi_driver scmi_reset_driver = {
124 .name = "scmi-reset",
125 .probe = scmi_reset_probe,
126 .id_table = scmi_id_table,
127};
128module_scmi_driver(scmi_reset_driver);
129
130MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
131MODULE_DESCRIPTION("ARM SCMI reset controller driver");
132MODULE_LICENSE("GPL v2");