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
|
/*
* Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
*
* MDIO implementation for ARC EMAC
*/
#include <linux/delay.h>
#include <linux/of_mdio.h>
#include <linux/platform_device.h>
#include <linux/gpio/consumer.h>
#include "emac.h"
/* Number of seconds we wait for "MDIO complete" flag to appear */
#define ARC_MDIO_COMPLETE_POLL_COUNT 1
/**
* arc_mdio_complete_wait - Waits until MDIO transaction is completed.
* @priv: Pointer to ARC EMAC private data structure.
*
* returns: 0 on success, -ETIMEDOUT on a timeout.
*/
static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
{
unsigned int i;
for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
unsigned int status = arc_reg_get(priv, R_STATUS);
status &= MDIO_MASK;
if (status) {
/* Reset "MDIO complete" flag */
arc_reg_set(priv, R_STATUS, status);
return 0;
}
msleep(25);
}
return -ETIMEDOUT;
}
/**
* arc_mdio_read - MDIO interface read function.
* @bus: Pointer to MII bus structure.
* @phy_addr: Address of the PHY device.
* @reg_num: PHY register to read.
*
* returns: The register contents on success, -ETIMEDOUT on a timeout.
*
* Reads the contents of the requested register from the requested PHY
* address.
*/
static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
{
struct arc_emac_priv *priv = bus->priv;
unsigned int value;
int error;
arc_reg_set(priv, R_MDIO,
0x60020000 | (phy_addr << 23) | (reg_num << 18));
error = arc_mdio_complete_wait(priv);
if (error < 0)
return error;
value = arc_reg_get(priv, R_MDIO) & 0xffff;
dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
phy_addr, reg_num, value);
return value;
}
/**
* arc_mdio_write - MDIO interface write function.
* @bus: Pointer to MII bus structure.
* @phy_addr: Address of the PHY device.
* @reg_num: PHY register to write to.
* @value: Value to be written into the register.
*
* returns: 0 on success, -ETIMEDOUT on a timeout.
*
* Writes the value to the requested register.
*/
static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
int reg_num, u16 value)
{
struct arc_emac_priv *priv = bus->priv;
dev_dbg(priv->dev,
"arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
phy_addr, reg_num, value);
arc_reg_set(priv, R_MDIO,
0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
return arc_mdio_complete_wait(priv);
}
/**
* arc_mdio_reset
* @bus: points to the mii_bus structure
* Description: reset the MII bus
*/
int arc_mdio_reset(struct mii_bus *bus)
{
struct arc_emac_priv *priv = bus->priv;
struct arc_emac_mdio_bus_data *data = &priv->bus_data;
if (data->reset_gpio) {
gpiod_set_value_cansleep(data->reset_gpio, 1);
msleep(data->msec);
gpiod_set_value_cansleep(data->reset_gpio, 0);
}
return 0;
}
/**
* arc_mdio_probe - MDIO probe function.
* @priv: Pointer to ARC EMAC private data structure.
*
* returns: 0 on success, -ENOMEM when mdiobus_alloc
* (to allocate memory for MII bus structure) fails.
*
* Sets up and registers the MDIO interface.
*/
int arc_mdio_probe(struct arc_emac_priv *priv)
{
struct arc_emac_mdio_bus_data *data = &priv->bus_data;
struct device_node *np = priv->dev->of_node;
struct mii_bus *bus;
int error;
bus = mdiobus_alloc();
if (!bus)
return -ENOMEM;
priv->bus = bus;
bus->priv = priv;
bus->parent = priv->dev;
bus->name = "Synopsys MII Bus";
bus->read = &arc_mdio_read;
bus->write = &arc_mdio_write;
bus->reset = &arc_mdio_reset;
/* optional reset-related properties */
data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",
GPIOD_OUT_LOW);
if (IS_ERR(data->reset_gpio)) {
error = PTR_ERR(data->reset_gpio);
dev_err(priv->dev, "Failed to request gpio: %d\n", error);
return error;
}
of_property_read_u32(np, "phy-reset-duration", &data->msec);
/* A sane reset duration should not be longer than 1s */
if (data->msec > 1000)
data->msec = 1;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);
error = of_mdiobus_register(bus, priv->dev->of_node);
if (error) {
dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name);
mdiobus_free(bus);
return error;
}
return 0;
}
/**
* arc_mdio_remove - MDIO remove function.
* @priv: Pointer to ARC EMAC private data structure.
*
* Unregisters the MDIO and frees any associate memory for MII bus.
*/
int arc_mdio_remove(struct arc_emac_priv *priv)
{
mdiobus_unregister(priv->bus);
mdiobus_free(priv->bus);
priv->bus = NULL;
return 0;
}
|
