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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// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2004-2013 Synopsys, Inc. (www.synopsys.com)
4 *
5 * MDIO implementation for ARC EMAC
6 */
7
8#include <linux/delay.h>
9#include <linux/of_mdio.h>
10#include <linux/platform_device.h>
11#include <linux/gpio/consumer.h>
12
13#include "emac.h"
14
15/* Number of seconds we wait for "MDIO complete" flag to appear */
16#define ARC_MDIO_COMPLETE_POLL_COUNT 1
17
18/**
19 * arc_mdio_complete_wait - Waits until MDIO transaction is completed.
20 * @priv: Pointer to ARC EMAC private data structure.
21 *
22 * returns: 0 on success, -ETIMEDOUT on a timeout.
23 */
24static int arc_mdio_complete_wait(struct arc_emac_priv *priv)
25{
26 unsigned int i;
27
28 for (i = 0; i < ARC_MDIO_COMPLETE_POLL_COUNT * 40; i++) {
29 unsigned int status = arc_reg_get(priv, R_STATUS);
30
31 status &= MDIO_MASK;
32
33 if (status) {
34 /* Reset "MDIO complete" flag */
35 arc_reg_set(priv, R_STATUS, status);
36 return 0;
37 }
38
39 msleep(25);
40 }
41
42 return -ETIMEDOUT;
43}
44
45/**
46 * arc_mdio_read - MDIO interface read function.
47 * @bus: Pointer to MII bus structure.
48 * @phy_addr: Address of the PHY device.
49 * @reg_num: PHY register to read.
50 *
51 * returns: The register contents on success, -ETIMEDOUT on a timeout.
52 *
53 * Reads the contents of the requested register from the requested PHY
54 * address.
55 */
56static int arc_mdio_read(struct mii_bus *bus, int phy_addr, int reg_num)
57{
58 struct arc_emac_priv *priv = bus->priv;
59 unsigned int value;
60 int error;
61
62 arc_reg_set(priv, R_MDIO,
63 0x60020000 | (phy_addr << 23) | (reg_num << 18));
64
65 error = arc_mdio_complete_wait(priv);
66 if (error < 0)
67 return error;
68
69 value = arc_reg_get(priv, R_MDIO) & 0xffff;
70
71 dev_dbg(priv->dev, "arc_mdio_read(phy_addr=%i, reg_num=%x) = %x\n",
72 phy_addr, reg_num, value);
73
74 return value;
75}
76
77/**
78 * arc_mdio_write - MDIO interface write function.
79 * @bus: Pointer to MII bus structure.
80 * @phy_addr: Address of the PHY device.
81 * @reg_num: PHY register to write to.
82 * @value: Value to be written into the register.
83 *
84 * returns: 0 on success, -ETIMEDOUT on a timeout.
85 *
86 * Writes the value to the requested register.
87 */
88static int arc_mdio_write(struct mii_bus *bus, int phy_addr,
89 int reg_num, u16 value)
90{
91 struct arc_emac_priv *priv = bus->priv;
92
93 dev_dbg(priv->dev,
94 "arc_mdio_write(phy_addr=%i, reg_num=%x, value=%x)\n",
95 phy_addr, reg_num, value);
96
97 arc_reg_set(priv, R_MDIO,
98 0x50020000 | (phy_addr << 23) | (reg_num << 18) | value);
99
100 return arc_mdio_complete_wait(priv);
101}
102
103/**
104 * arc_mdio_reset
105 * @bus: points to the mii_bus structure
106 * Description: reset the MII bus
107 */
108static int arc_mdio_reset(struct mii_bus *bus)
109{
110 struct arc_emac_priv *priv = bus->priv;
111 struct arc_emac_mdio_bus_data *data = &priv->bus_data;
112
113 if (data->reset_gpio) {
114 gpiod_set_value_cansleep(data->reset_gpio, 1);
115 msleep(data->msec);
116 gpiod_set_value_cansleep(data->reset_gpio, 0);
117 }
118
119 return 0;
120}
121
122/**
123 * arc_mdio_probe - MDIO probe function.
124 * @priv: Pointer to ARC EMAC private data structure.
125 *
126 * returns: 0 on success, -ENOMEM when mdiobus_alloc
127 * (to allocate memory for MII bus structure) fails.
128 *
129 * Sets up and registers the MDIO interface.
130 */
131int arc_mdio_probe(struct arc_emac_priv *priv)
132{
133 struct arc_emac_mdio_bus_data *data = &priv->bus_data;
134 struct device_node *np = priv->dev->of_node;
135 struct mii_bus *bus;
136 int error;
137
138 bus = mdiobus_alloc();
139 if (!bus)
140 return -ENOMEM;
141
142 priv->bus = bus;
143 bus->priv = priv;
144 bus->parent = priv->dev;
145 bus->name = "Synopsys MII Bus";
146 bus->read = &arc_mdio_read;
147 bus->write = &arc_mdio_write;
148 bus->reset = &arc_mdio_reset;
149
150 /* optional reset-related properties */
151 data->reset_gpio = devm_gpiod_get_optional(priv->dev, "phy-reset",
152 GPIOD_OUT_LOW);
153 if (IS_ERR(data->reset_gpio)) {
154 error = PTR_ERR(data->reset_gpio);
155 dev_err(priv->dev, "Failed to request gpio: %d\n", error);
156 return error;
157 }
158
159 of_property_read_u32(np, "phy-reset-duration", &data->msec);
160 /* A sane reset duration should not be longer than 1s */
161 if (data->msec > 1000)
162 data->msec = 1;
163
164 snprintf(bus->id, MII_BUS_ID_SIZE, "%s", bus->name);
165
166 error = of_mdiobus_register(bus, priv->dev->of_node);
167 if (error) {
168 dev_err(priv->dev, "cannot register MDIO bus %s\n", bus->name);
169 mdiobus_free(bus);
170 return error;
171 }
172
173 return 0;
174}
175
176/**
177 * arc_mdio_remove - MDIO remove function.
178 * @priv: Pointer to ARC EMAC private data structure.
179 *
180 * Unregisters the MDIO and frees any associate memory for MII bus.
181 */
182int arc_mdio_remove(struct arc_emac_priv *priv)
183{
184 mdiobus_unregister(priv->bus);
185 mdiobus_free(priv->bus);
186 priv->bus = NULL;
187
188 return 0;
189}