1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
// SPDX-License-Identifier: GPL-2.0
/*
* Microchip PolarFire SoC (MPFS) system controller driver
*
* Copyright (c) 2020-2021 Microchip Corporation. All rights reserved.
*
* Author: Conor Dooley <conor.dooley@microchip.com>
*
*/
#include <linux/slab.h>
#include <linux/kref.h>
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/of_platform.h>
#include <linux/mailbox_client.h>
#include <linux/platform_device.h>
#include <soc/microchip/mpfs.h>
/*
* This timeout must be long, as some services (example: image authentication)
* take significant time to complete
*/
#define MPFS_SYS_CTRL_TIMEOUT_MS 30000
static DEFINE_MUTEX(transaction_lock);
struct mpfs_sys_controller {
struct mbox_client client;
struct mbox_chan *chan;
struct completion c;
struct kref consumers;
};
int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg)
{
unsigned long timeout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
int ret;
ret = mutex_lock_interruptible(&transaction_lock);
if (ret)
return ret;
reinit_completion(&sys_controller->c);
ret = mbox_send_message(sys_controller->chan, msg);
if (ret < 0) {
dev_warn(sys_controller->client.dev, "MPFS sys controller service timeout\n");
goto out;
}
/*
* Unfortunately, the system controller will only deliver an interrupt
* if a service succeeds. mbox_send_message() will block until the busy
* flag is gone. If the busy flag is gone but no interrupt has arrived
* to trigger the rx callback then the service can be deemed to have
* failed.
* The caller can then interrogate msg::response::resp_status to
* determine the cause of the failure.
* mbox_send_message() returns positive integers in the success path, so
* ret needs to be cleared if we do get an interrupt.
*/
if (!wait_for_completion_timeout(&sys_controller->c, timeout)) {
ret = -EBADMSG;
dev_warn(sys_controller->client.dev, "MPFS sys controller service failed\n");
} else {
ret = 0;
}
out:
mutex_unlock(&transaction_lock);
return ret;
}
EXPORT_SYMBOL(mpfs_blocking_transaction);
static void mpfs_sys_controller_rx_callback(struct mbox_client *client, void *msg)
{
struct mpfs_sys_controller *sys_controller =
container_of(client, struct mpfs_sys_controller, client);
complete(&sys_controller->c);
}
static void mpfs_sys_controller_delete(struct kref *kref)
{
struct mpfs_sys_controller *sys_controller =
container_of(kref, struct mpfs_sys_controller, consumers);
mbox_free_channel(sys_controller->chan);
kfree(sys_controller);
}
static void mpfs_sys_controller_put(void *data)
{
struct mpfs_sys_controller *sys_controller = data;
kref_put(&sys_controller->consumers, mpfs_sys_controller_delete);
}
static struct platform_device subdevs[] = {
{
.name = "mpfs-rng",
.id = -1,
},
{
.name = "mpfs-generic-service",
.id = -1,
}
};
static int mpfs_sys_controller_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mpfs_sys_controller *sys_controller;
int i, ret;
sys_controller = kzalloc(sizeof(*sys_controller), GFP_KERNEL);
if (!sys_controller)
return -ENOMEM;
sys_controller->client.dev = dev;
sys_controller->client.rx_callback = mpfs_sys_controller_rx_callback;
sys_controller->client.tx_block = 1U;
sys_controller->client.tx_tout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
sys_controller->chan = mbox_request_channel(&sys_controller->client, 0);
if (IS_ERR(sys_controller->chan)) {
ret = dev_err_probe(dev, PTR_ERR(sys_controller->chan),
"Failed to get mbox channel\n");
kfree(sys_controller);
return ret;
}
init_completion(&sys_controller->c);
kref_init(&sys_controller->consumers);
platform_set_drvdata(pdev, sys_controller);
dev_info(&pdev->dev, "Registered MPFS system controller\n");
for (i = 0; i < ARRAY_SIZE(subdevs); i++) {
subdevs[i].dev.parent = dev;
if (platform_device_register(&subdevs[i]))
dev_warn(dev, "Error registering sub device %s\n", subdevs[i].name);
}
return 0;
}
static int mpfs_sys_controller_remove(struct platform_device *pdev)
{
struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev);
mpfs_sys_controller_put(sys_controller);
return 0;
}
static const struct of_device_id mpfs_sys_controller_of_match[] = {
{.compatible = "microchip,mpfs-sys-controller", },
{},
};
MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match);
struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev)
{
const struct of_device_id *match;
struct mpfs_sys_controller *sys_controller;
int ret;
if (!dev->parent)
goto err_no_device;
match = of_match_node(mpfs_sys_controller_of_match, dev->parent->of_node);
of_node_put(dev->parent->of_node);
if (!match)
goto err_no_device;
sys_controller = dev_get_drvdata(dev->parent);
if (!sys_controller)
goto err_bad_device;
if (!kref_get_unless_zero(&sys_controller->consumers))
goto err_bad_device;
ret = devm_add_action_or_reset(dev, mpfs_sys_controller_put, sys_controller);
if (ret)
return ERR_PTR(ret);
return sys_controller;
err_no_device:
dev_dbg(dev, "Parent device was not an MPFS system controller\n");
return ERR_PTR(-ENODEV);
err_bad_device:
dev_dbg(dev, "MPFS system controller found but could not register as a sub device\n");
return ERR_PTR(-EPROBE_DEFER);
}
EXPORT_SYMBOL(mpfs_sys_controller_get);
static struct platform_driver mpfs_sys_controller_driver = {
.driver = {
.name = "mpfs-sys-controller",
.of_match_table = mpfs_sys_controller_of_match,
},
.probe = mpfs_sys_controller_probe,
.remove = mpfs_sys_controller_remove,
};
module_platform_driver(mpfs_sys_controller_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
MODULE_DESCRIPTION("MPFS system controller driver");
|
