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