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
|
// SPDX-License-Identifier: GPL-2.0+
/*
* rcar-fcp.c -- R-Car Frame Compression Processor Driver
*
* Copyright (C) 2016 Renesas Electronics Corporation
*
* Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*/
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include <media/rcar-fcp.h>
struct rcar_fcp_device {
struct list_head list;
struct device *dev;
};
static LIST_HEAD(fcp_devices);
static DEFINE_MUTEX(fcp_lock);
/* -----------------------------------------------------------------------------
* Public API
*/
/**
* rcar_fcp_get - Find and acquire a reference to an FCP instance
* @np: Device node of the FCP instance
*
* Search the list of registered FCP instances for the instance corresponding to
* the given device node.
*
* Return a pointer to the FCP instance, or an ERR_PTR if the instance can't be
* found.
*/
struct rcar_fcp_device *rcar_fcp_get(const struct device_node *np)
{
struct rcar_fcp_device *fcp;
mutex_lock(&fcp_lock);
list_for_each_entry(fcp, &fcp_devices, list) {
if (fcp->dev->of_node != np)
continue;
get_device(fcp->dev);
goto done;
}
fcp = ERR_PTR(-EPROBE_DEFER);
done:
mutex_unlock(&fcp_lock);
return fcp;
}
EXPORT_SYMBOL_GPL(rcar_fcp_get);
/**
* rcar_fcp_put - Release a reference to an FCP instance
* @fcp: The FCP instance
*
* Release the FCP instance acquired by a call to rcar_fcp_get().
*/
void rcar_fcp_put(struct rcar_fcp_device *fcp)
{
if (fcp)
put_device(fcp->dev);
}
EXPORT_SYMBOL_GPL(rcar_fcp_put);
struct device *rcar_fcp_get_device(struct rcar_fcp_device *fcp)
{
return fcp->dev;
}
EXPORT_SYMBOL_GPL(rcar_fcp_get_device);
/**
* rcar_fcp_enable - Enable an FCP
* @fcp: The FCP instance
*
* Before any memory access through an FCP is performed by a module, the FCP
* must be enabled by a call to this function. The enable calls are reference
* counted, each successful call must be followed by one rcar_fcp_disable()
* call when no more memory transfer can occur through the FCP.
*
* Return 0 on success or a negative error code if an error occurs. The enable
* reference count isn't increased when this function returns an error.
*/
int rcar_fcp_enable(struct rcar_fcp_device *fcp)
{
if (!fcp)
return 0;
return pm_runtime_resume_and_get(fcp->dev);
}
EXPORT_SYMBOL_GPL(rcar_fcp_enable);
/**
* rcar_fcp_disable - Disable an FCP
* @fcp: The FCP instance
*
* This function is the counterpart of rcar_fcp_enable(). As enable calls are
* reference counted a disable call may not disable the FCP synchronously.
*/
void rcar_fcp_disable(struct rcar_fcp_device *fcp)
{
if (fcp)
pm_runtime_put(fcp->dev);
}
EXPORT_SYMBOL_GPL(rcar_fcp_disable);
/* -----------------------------------------------------------------------------
* Platform Driver
*/
static int rcar_fcp_probe(struct platform_device *pdev)
{
struct rcar_fcp_device *fcp;
fcp = devm_kzalloc(&pdev->dev, sizeof(*fcp), GFP_KERNEL);
if (fcp == NULL)
return -ENOMEM;
fcp->dev = &pdev->dev;
dma_set_max_seg_size(fcp->dev, UINT_MAX);
pm_runtime_enable(&pdev->dev);
mutex_lock(&fcp_lock);
list_add_tail(&fcp->list, &fcp_devices);
mutex_unlock(&fcp_lock);
platform_set_drvdata(pdev, fcp);
return 0;
}
static void rcar_fcp_remove(struct platform_device *pdev)
{
struct rcar_fcp_device *fcp = platform_get_drvdata(pdev);
mutex_lock(&fcp_lock);
list_del(&fcp->list);
mutex_unlock(&fcp_lock);
pm_runtime_disable(&pdev->dev);
}
static const struct of_device_id rcar_fcp_of_match[] = {
{ .compatible = "renesas,fcpf" },
{ .compatible = "renesas,fcpv" },
{ },
};
MODULE_DEVICE_TABLE(of, rcar_fcp_of_match);
static struct platform_driver rcar_fcp_platform_driver = {
.probe = rcar_fcp_probe,
.remove_new = rcar_fcp_remove,
.driver = {
.name = "rcar-fcp",
.of_match_table = rcar_fcp_of_match,
.suppress_bind_attrs = true,
},
};
module_platform_driver(rcar_fcp_platform_driver);
MODULE_ALIAS("rcar-fcp");
MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
MODULE_DESCRIPTION("Renesas FCP Driver");
MODULE_LICENSE("GPL");
|
