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
|
/*
* Simple memory-mapped device MDIO MUX driver
*
* Author: Timur Tabi <timur@freescale.com>
*
* Copyright 2012 Freescale Semiconductor, Inc.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/of_address.h>
#include <linux/of_mdio.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/phy.h>
#include <linux/mdio-mux.h>
struct mdio_mux_mmioreg_state {
void *mux_handle;
phys_addr_t phys;
uint8_t mask;
};
/*
* MDIO multiplexing switch function
*
* This function is called by the mdio-mux layer when it thinks the mdio bus
* multiplexer needs to switch.
*
* 'current_child' is the current value of the mux register (masked via
* s->mask).
*
* 'desired_child' is the value of the 'reg' property of the target child MDIO
* node.
*
* The first time this function is called, current_child == -1.
*
* If current_child == desired_child, then the mux is already set to the
* correct bus.
*/
static int mdio_mux_mmioreg_switch_fn(int current_child, int desired_child,
void *data)
{
struct mdio_mux_mmioreg_state *s = data;
if (current_child ^ desired_child) {
void *p = ioremap(s->phys, 1);
uint8_t x, y;
if (!p)
return -ENOMEM;
x = ioread8(p);
y = (x & ~s->mask) | desired_child;
if (x != y) {
iowrite8((x & ~s->mask) | desired_child, p);
pr_debug("%s: %02x -> %02x\n", __func__, x, y);
}
iounmap(p);
}
return 0;
}
static int mdio_mux_mmioreg_probe(struct platform_device *pdev)
{
struct device_node *np2, *np = pdev->dev.of_node;
struct mdio_mux_mmioreg_state *s;
struct resource res;
const __be32 *iprop;
int len, ret;
dev_dbg(&pdev->dev, "probing node %s\n", np->full_name);
s = devm_kzalloc(&pdev->dev, sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
ret = of_address_to_resource(np, 0, &res);
if (ret) {
dev_err(&pdev->dev, "could not obtain memory map for node %s\n",
np->full_name);
return ret;
}
s->phys = res.start;
if (resource_size(&res) != sizeof(uint8_t)) {
dev_err(&pdev->dev, "only 8-bit registers are supported\n");
return -EINVAL;
}
iprop = of_get_property(np, "mux-mask", &len);
if (!iprop || len != sizeof(uint32_t)) {
dev_err(&pdev->dev, "missing or invalid mux-mask property\n");
return -ENODEV;
}
if (be32_to_cpup(iprop) > 255) {
dev_err(&pdev->dev, "only 8-bit registers are supported\n");
return -EINVAL;
}
s->mask = be32_to_cpup(iprop);
/*
* Verify that the 'reg' property of each child MDIO bus does not
* set any bits outside of the 'mask'.
*/
for_each_available_child_of_node(np, np2) {
iprop = of_get_property(np2, "reg", &len);
if (!iprop || len != sizeof(uint32_t)) {
dev_err(&pdev->dev, "mdio-mux child node %s is "
"missing a 'reg' property\n", np2->full_name);
return -ENODEV;
}
if (be32_to_cpup(iprop) & ~s->mask) {
dev_err(&pdev->dev, "mdio-mux child node %s has "
"a 'reg' value with unmasked bits\n",
np2->full_name);
return -ENODEV;
}
}
ret = mdio_mux_init(&pdev->dev, mdio_mux_mmioreg_switch_fn,
&s->mux_handle, s);
if (ret) {
dev_err(&pdev->dev, "failed to register mdio-mux bus %s\n",
np->full_name);
return ret;
}
pdev->dev.platform_data = s;
return 0;
}
static int mdio_mux_mmioreg_remove(struct platform_device *pdev)
{
struct mdio_mux_mmioreg_state *s = dev_get_platdata(&pdev->dev);
mdio_mux_uninit(s->mux_handle);
return 0;
}
static struct of_device_id mdio_mux_mmioreg_match[] = {
{
.compatible = "mdio-mux-mmioreg",
},
{},
};
MODULE_DEVICE_TABLE(of, mdio_mux_mmioreg_match);
static struct platform_driver mdio_mux_mmioreg_driver = {
.driver = {
.name = "mdio-mux-mmioreg",
.owner = THIS_MODULE,
.of_match_table = mdio_mux_mmioreg_match,
},
.probe = mdio_mux_mmioreg_probe,
.remove = mdio_mux_mmioreg_remove,
};
module_platform_driver(mdio_mux_mmioreg_driver);
MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
MODULE_DESCRIPTION("Memory-mapped device MDIO MUX driver");
MODULE_LICENSE("GPL v2");
|
