2 * Driver for the MDIO interface of Marvell network interfaces.
4 * Since the MDIO interface of Marvell network interfaces is shared
5 * between all network interfaces, having a single driver allows to
6 * handle concurrent accesses properly (you may have four Ethernet
7 * ports, but they in fact share the same SMI interface to access the
8 * MDIO bus). Moreover, this MDIO interface code is similar between
9 * the mv643xx_eth driver and the mvneta driver. For now, it is only
10 * used by the mvneta driver, but it could later be used by the
11 * mv643xx_eth driver as well.
13 * Copyright (C) 2012 Marvell
15 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
17 * This file is licensed under the terms of the GNU General Public
18 * License version 2. This program is licensed "as is" without any
19 * warranty of any kind, whether express or implied.
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26 #include <linux/phy.h>
27 #include <linux/of_address.h>
28 #include <linux/of_mdio.h>
29 #include <linux/platform_device.h>
30 #include <linux/delay.h>
32 #define MVMDIO_SMI_DATA_SHIFT 0
33 #define MVMDIO_SMI_PHY_ADDR_SHIFT 16
34 #define MVMDIO_SMI_PHY_REG_SHIFT 21
35 #define MVMDIO_SMI_READ_OPERATION BIT(26)
36 #define MVMDIO_SMI_WRITE_OPERATION 0
37 #define MVMDIO_SMI_READ_VALID BIT(27)
38 #define MVMDIO_SMI_BUSY BIT(28)
40 struct orion_mdio_dev
{
45 /* Wait for the SMI unit to be ready for another operation
47 static int orion_mdio_wait_ready(struct mii_bus
*bus
)
49 struct orion_mdio_dev
*dev
= bus
->priv
;
55 val
= readl(dev
->smireg
);
56 if (!(val
& MVMDIO_SMI_BUSY
))
60 dev_err(bus
->parent
, "Timeout: SMI busy for too long\n");
71 static int orion_mdio_read(struct mii_bus
*bus
, int mii_id
,
74 struct orion_mdio_dev
*dev
= bus
->priv
;
79 mutex_lock(&dev
->lock
);
81 ret
= orion_mdio_wait_ready(bus
);
83 mutex_unlock(&dev
->lock
);
87 writel(((mii_id
<< MVMDIO_SMI_PHY_ADDR_SHIFT
) |
88 (regnum
<< MVMDIO_SMI_PHY_REG_SHIFT
) |
89 MVMDIO_SMI_READ_OPERATION
),
92 /* Wait for the value to become available */
95 val
= readl(dev
->smireg
);
96 if (val
& MVMDIO_SMI_READ_VALID
)
100 dev_err(bus
->parent
, "Timeout when reading PHY\n");
101 mutex_unlock(&dev
->lock
);
109 mutex_unlock(&dev
->lock
);
114 static int orion_mdio_write(struct mii_bus
*bus
, int mii_id
,
115 int regnum
, u16 value
)
117 struct orion_mdio_dev
*dev
= bus
->priv
;
120 mutex_lock(&dev
->lock
);
122 ret
= orion_mdio_wait_ready(bus
);
124 mutex_unlock(&dev
->lock
);
128 writel(((mii_id
<< MVMDIO_SMI_PHY_ADDR_SHIFT
) |
129 (regnum
<< MVMDIO_SMI_PHY_REG_SHIFT
) |
130 MVMDIO_SMI_WRITE_OPERATION
|
131 (value
<< MVMDIO_SMI_DATA_SHIFT
)),
134 mutex_unlock(&dev
->lock
);
139 static int orion_mdio_reset(struct mii_bus
*bus
)
144 static int orion_mdio_probe(struct platform_device
*pdev
)
146 struct device_node
*np
= pdev
->dev
.of_node
;
148 struct orion_mdio_dev
*dev
;
151 bus
= mdiobus_alloc_size(sizeof(struct orion_mdio_dev
));
153 dev_err(&pdev
->dev
, "Cannot allocate MDIO bus\n");
157 bus
->name
= "orion_mdio_bus";
158 bus
->read
= orion_mdio_read
;
159 bus
->write
= orion_mdio_write
;
160 bus
->reset
= orion_mdio_reset
;
161 snprintf(bus
->id
, MII_BUS_ID_SIZE
, "%s-mii",
162 dev_name(&pdev
->dev
));
163 bus
->parent
= &pdev
->dev
;
165 bus
->irq
= kmalloc(sizeof(int) * PHY_MAX_ADDR
, GFP_KERNEL
);
171 for (i
= 0; i
< PHY_MAX_ADDR
; i
++)
172 bus
->irq
[i
] = PHY_POLL
;
175 dev
->smireg
= of_iomap(pdev
->dev
.of_node
, 0);
177 dev_err(&pdev
->dev
, "No SMI register address given in DT\n");
183 mutex_init(&dev
->lock
);
185 ret
= of_mdiobus_register(bus
, np
);
187 dev_err(&pdev
->dev
, "Cannot register MDIO bus (%d)\n", ret
);
188 iounmap(dev
->smireg
);
194 platform_set_drvdata(pdev
, bus
);
199 static int orion_mdio_remove(struct platform_device
*pdev
)
201 struct mii_bus
*bus
= platform_get_drvdata(pdev
);
202 mdiobus_unregister(bus
);
208 static const struct of_device_id orion_mdio_match
[] = {
209 { .compatible
= "marvell,orion-mdio" },
212 MODULE_DEVICE_TABLE(of
, orion_mdio_match
);
214 static struct platform_driver orion_mdio_driver
= {
215 .probe
= orion_mdio_probe
,
216 .remove
= orion_mdio_remove
,
218 .name
= "orion-mdio",
219 .of_match_table
= orion_mdio_match
,
223 module_platform_driver(orion_mdio_driver
);
225 MODULE_DESCRIPTION("Marvell MDIO interface driver");
226 MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
227 MODULE_LICENSE("GPL");