Loading...
1/*
2 * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
3 *
4 * MDIO implementation for ARC EMAC
5 */
6
7#include <linux/delay.h>
8#include <linux/of_mdio.h>
9#include <linux/platform_device.h>
10
11#include "emac.h"
12
13/* Number of seconds we wait for "MDIO complete" flag to appear */
14#define ARC_MDIO_COMPLETE_POLL_COUNT 1
15
16/**
17 * arc_mdio_complete_wait - Waits until MDIO transaction is completed.
18 * @priv: Pointer to ARC EMAC private data structure.
19 *
20 * returns: 0 on success, -ETIMEDOUT on a timeout.
21 */
22static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
23{
24 unsigned int i;
25
26 for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
27 unsigned int status = arc_reg_get(priv, R_STATUS);
28
29 status &= MDIO_MASK;
30
31 if (status) {
32 /* Reset "MDIO complete" flag */
33 arc_reg_set(priv, R_STATUS, status);
34 return 0;
35 }
36
37 msleep(25);
38 }
39
40 return -ETIMEDOUT;
41}
42
43/**
44 * arc_mdio_read - MDIO interface read function.
45 * @bus: Pointer to MII bus structure.
46 * @phy_addr: Address of the PHY device.
47 * @reg_num: PHY register to read.
48 *
49 * returns: The register contents on success, -ETIMEDOUT on a timeout.
50 *
51 * Reads the contents of the requested register from the requested PHY
52 * address.
53 */
54static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
55{
56 struct arc_emac_priv *priv = bus->priv;
57 unsigned int value;
58 int error;
59
60 arc_reg_set(priv, R_MDIO,
61 0x60020000 | (phy_addr << 23) | (reg_num << 18));
62
63 error = arc_mdio_complete_wait(priv);
64 if (error < 0)
65 return error;
66
67 value = arc_reg_get(priv, R_MDIO) & 0xffff;
68
69 dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
70 phy_addr, reg_num, value);
71
72 return value;
73}
74
75/**
76 * arc_mdio_write - MDIO interface write function.
77 * @bus: Pointer to MII bus structure.
78 * @phy_addr: Address of the PHY device.
79 * @reg_num: PHY register to write to.
80 * @value: Value to be written into the register.
81 *
82 * returns: 0 on success, -ETIMEDOUT on a timeout.
83 *
84 * Writes the value to the requested register.
85 */
86static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
87 int reg_num, u16 value)
88{
89 struct arc_emac_priv *priv = bus->priv;
90
91 dev_dbg(priv->dev,
92 "arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
93 phy_addr, reg_num, value);
94
95 arc_reg_set(priv, R_MDIO,
96 0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
97
98 return arc_mdio_complete_wait(priv);
99}
100
101/**
102 * arc_mdio_probe - MDIO probe function.
103 * @pdev: Pointer to platform device.
104 * @priv: Pointer to ARC EMAC private data structure.
105 *
106 * returns: 0 on success, -ENOMEM when mdiobus_alloc
107 * (to allocate memory for MII bus structure) fails.
108 *
109 * Sets up and registers the MDIO interface.
110 */
111int arc_mdio_probe(struct platform_device *pdev, struct arc_emac_priv *priv)
112{
113 struct mii_bus *bus;
114 int error;
115
116 bus = mdiobus_alloc();
117 if (!bus)
118 return -ENOMEM;
119
120 priv->bus = bus;
121 bus->priv = priv;
122 bus->parent = priv->dev;
123 bus->name = "Synopsys MII Bus",
124 bus->read = &arc_mdio_read;
125 bus->write = &arc_mdio_write;
126
127 snprintf(bus->id, MII_BUS_ID_SIZE, "%s", pdev->name);
128
129 error = of_mdiobus_register(bus, pdev->dev.of_node);
130 if (error) {
131 dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name);
132 mdiobus_free(bus);
133 return error;
134 }
135
136 return 0;
137}
138
139/**
140 * arc_mdio_remove - MDIO remove function.
141 * @priv: Pointer to ARC EMAC private data structure.
142 *
143 * Unregisters the MDIO and frees any associate memory for MII bus.
144 */
145int arc_mdio_remove(struct arc_emac_priv *priv)
146{
147 mdiobus_unregister(priv->bus);
148 mdiobus_free(priv->bus);
149 priv->bus = NULL;
150
151 return 0;
152}
1/*
2 * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
3 *
4 * MDIO implementation for ARC EMAC
5 */
6
7#include <linux/delay.h>
8#include <linux/of_mdio.h>
9#include <linux/platform_device.h>
10#include <linux/gpio/consumer.h>
11
12#include "emac.h"
13
14/* Number of seconds we wait for "MDIO complete" flag to appear */
15#define ARC_MDIO_COMPLETE_POLL_COUNT 1
16
17/**
18 * arc_mdio_complete_wait - Waits until MDIO transaction is completed.
19 * @priv: Pointer to ARC EMAC private data structure.
20 *
21 * returns: 0 on success, -ETIMEDOUT on a timeout.
22 */
23static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
24{
25 unsigned int i;
26
27 for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
28 unsigned int status = arc_reg_get(priv, R_STATUS);
29
30 status &= MDIO_MASK;
31
32 if (status) {
33 /* Reset "MDIO complete" flag */
34 arc_reg_set(priv, R_STATUS, status);
35 return 0;
36 }
37
38 msleep(25);
39 }
40
41 return -ETIMEDOUT;
42}
43
44/**
45 * arc_mdio_read - MDIO interface read function.
46 * @bus: Pointer to MII bus structure.
47 * @phy_addr: Address of the PHY device.
48 * @reg_num: PHY register to read.
49 *
50 * returns: The register contents on success, -ETIMEDOUT on a timeout.
51 *
52 * Reads the contents of the requested register from the requested PHY
53 * address.
54 */
55static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
56{
57 struct arc_emac_priv *priv = bus->priv;
58 unsigned int value;
59 int error;
60
61 arc_reg_set(priv, R_MDIO,
62 0x60020000 | (phy_addr << 23) | (reg_num << 18));
63
64 error = arc_mdio_complete_wait(priv);
65 if (error < 0)
66 return error;
67
68 value = arc_reg_get(priv, R_MDIO) & 0xffff;
69
70 dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
71 phy_addr, reg_num, value);
72
73 return value;
74}
75
76/**
77 * arc_mdio_write - MDIO interface write function.
78 * @bus: Pointer to MII bus structure.
79 * @phy_addr: Address of the PHY device.
80 * @reg_num: PHY register to write to.
81 * @value: Value to be written into the register.
82 *
83 * returns: 0 on success, -ETIMEDOUT on a timeout.
84 *
85 * Writes the value to the requested register.
86 */
87static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
88 int reg_num, u16 value)
89{
90 struct arc_emac_priv *priv = bus->priv;
91
92 dev_dbg(priv->dev,
93 "arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
94 phy_addr, reg_num, value);
95
96 arc_reg_set(priv, R_MDIO,
97 0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
98
99 return arc_mdio_complete_wait(priv);
100}
101
102/**
103 * arc_mdio_reset
104 * @bus: points to the mii_bus structure
105 * Description: reset the MII bus
106 */
107static int arc_mdio_reset(struct mii_bus *bus)
108{
109 struct arc_emac_priv *priv = bus->priv;
110 struct arc_emac_mdio_bus_data *data = &priv->bus_data;
111
112 if (data->reset_gpio) {
113 gpiod_set_value_cansleep(data->reset_gpio, 1);
114 msleep(data->msec);
115 gpiod_set_value_cansleep(data->reset_gpio, 0);
116 }
117
118 return 0;
119}
120
121/**
122 * arc_mdio_probe - MDIO probe function.
123 * @priv: Pointer to ARC EMAC private data structure.
124 *
125 * returns: 0 on success, -ENOMEM when mdiobus_alloc
126 * (to allocate memory for MII bus structure) fails.
127 *
128 * Sets up and registers the MDIO interface.
129 */
130int arc_mdio_probe(struct arc_emac_priv *priv)
131{
132 struct arc_emac_mdio_bus_data *data = &priv->bus_data;
133 struct device_node *np = priv->dev->of_node;
134 struct mii_bus *bus;
135 int error;
136
137 bus = mdiobus_alloc();
138 if (!bus)
139 return -ENOMEM;
140
141 priv->bus = bus;
142 bus->priv = priv;
143 bus->parent = priv->dev;
144 bus->name = "Synopsys MII Bus";
145 bus->read = &arc_mdio_read;
146 bus->write = &arc_mdio_write;
147 bus->reset = &arc_mdio_reset;
148
149 /* optional reset-related properties */
150 data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",
151 GPIOD_OUT_LOW);
152 if (IS_ERR(data->reset_gpio)) {
153 error = PTR_ERR(data->reset_gpio);
154 dev_err(priv->dev, "Failed to request gpio: %d\n", error);
155 return error;
156 }
157
158 of_property_read_u32(np, "phy-reset-duration", &data->msec);
159 /* A sane reset duration should not be longer than 1s */
160 if (data->msec > 1000)
161 data->msec = 1;
162
163 snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);
164
165 error = of_mdiobus_register(bus, priv->dev->of_node);
166 if (error) {
167 dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name);
168 mdiobus_free(bus);
169 return error;
170 }
171
172 return 0;
173}
174
175/**
176 * arc_mdio_remove - MDIO remove function.
177 * @priv: Pointer to ARC EMAC private data structure.
178 *
179 * Unregisters the MDIO and frees any associate memory for MII bus.
180 */
181int arc_mdio_remove(struct arc_emac_priv *priv)
182{
183 mdiobus_unregister(priv->bus);
184 mdiobus_free(priv->bus);
185 priv->bus = NULL;
186
187 return 0;
188}