tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * MDIO bus driver for the Xilinx TEMAC device
3 *
4 * Copyright (c) 2009 Secret Lab Technologies, Ltd.
5 */
6
7#include <linux/io.h>
8#include <linux/netdevice.h>
9#include <linux/mutex.h>
10#include <linux/phy.h>
11#include <linux/of.h>
12#include <linux/of_device.h>
13#include <linux/slab.h>
14#include <linux/of_mdio.h>
15
16#include "ll_temac.h"
17
18/* ---------------------------------------------------------------------
19 * MDIO Bus functions
20 */
21static int temac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
22{
23 struct temac_local *lp = bus->priv;
24 u32 rc;
25
26 /* Write the PHY address to the MIIM Access Initiator register.
27 * When the transfer completes, the PHY register value will appear
28 * in the LSW0 register */
29 mutex_lock(&lp->indirect_mutex);
30 temac_iow(lp, XTE_LSW0_OFFSET, (phy_id << 5) | reg);
31 rc = temac_indirect_in32(lp, XTE_MIIMAI_OFFSET);
32 mutex_unlock(&lp->indirect_mutex);
33
34 dev_dbg(lp->dev, "temac_mdio_read(phy_id=%i, reg=%x) == %x\n",
35 phy_id, reg, rc);
36
37 return rc;
38}
39
40static int temac_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
41{
42 struct temac_local *lp = bus->priv;
43
44 dev_dbg(lp->dev, "temac_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
45 phy_id, reg, val);
46
47 /* First write the desired value into the write data register
48 * and then write the address into the access initiator register
49 */
50 mutex_lock(&lp->indirect_mutex);
51 temac_indirect_out32(lp, XTE_MGTDR_OFFSET, val);
52 temac_indirect_out32(lp, XTE_MIIMAI_OFFSET, (phy_id << 5) | reg);
53 mutex_unlock(&lp->indirect_mutex);
54
55 return 0;
56}
57
58int temac_mdio_setup(struct temac_local *lp, struct device_node *np)
59{
60 struct mii_bus *bus;
61 const u32 *bus_hz;
62 int clk_div;
63 int rc, size;
64 struct resource res;
65
66 /* Calculate a reasonable divisor for the clock rate */
67 clk_div = 0x3f; /* worst-case default setting */
68 bus_hz = of_get_property(np, "clock-frequency", &size);
69 if (bus_hz && size >= sizeof(*bus_hz)) {
70 clk_div = (*bus_hz) / (2500 * 1000 * 2) - 1;
71 if (clk_div < 1)
72 clk_div = 1;
73 if (clk_div > 0x3f)
74 clk_div = 0x3f;
75 }
76
77 /* Enable the MDIO bus by asserting the enable bit and writing
78 * in the clock config */
79 mutex_lock(&lp->indirect_mutex);
80 temac_indirect_out32(lp, XTE_MC_OFFSET, 1 << 6 | clk_div);
81 mutex_unlock(&lp->indirect_mutex);
82
83 bus = mdiobus_alloc();
84 if (!bus)
85 return -ENOMEM;
86
87 of_address_to_resource(np, 0, &res);
88 snprintf(bus->id, MII_BUS_ID_SIZE, "%.8llx",
89 (unsigned long long)res.start);
90 bus->priv = lp;
91 bus->name = "Xilinx TEMAC MDIO";
92 bus->read = temac_mdio_read;
93 bus->write = temac_mdio_write;
94 bus->parent = lp->dev;
95 bus->irq = lp->mdio_irqs; /* preallocated IRQ table */
96
97 lp->mii_bus = bus;
98
99 rc = of_mdiobus_register(bus, np);
100 if (rc)
101 goto err_register;
102
103 mutex_lock(&lp->indirect_mutex);
104 dev_dbg(lp->dev, "MDIO bus registered; MC:%x\n",
105 temac_indirect_in32(lp, XTE_MC_OFFSET));
106 mutex_unlock(&lp->indirect_mutex);
107 return 0;
108
109 err_register:
110 mdiobus_free(bus);
111 return rc;
112}
113
114void temac_mdio_teardown(struct temac_local *lp)
115{
116 mdiobus_unregister(lp->mii_bus);
117 kfree(lp->mii_bus->irq);
118 mdiobus_free(lp->mii_bus);
119 lp->mii_bus = NULL;
120}
121