net: mdio-mux: Add MDIO mux driver for iProc SoCs

iProc based SoCs supports the integrated mdio multiplexer which
has the bus selection as well as mdio transaction generation logic
inside.

This multiplexer has child buses for PCIe, SATA, USB and ETH. These
buses could be internal or external to SOC where PHYs are attached.
These buses could use C-45 or C-22 mdio transaction.

Signed-off-by: Pramod Kumar <pramod.kumar@broadcom.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Pramod Kumar 2016-06-10 11:03:49 +05:30 committed by David S. Miller
parent 5f1a067bfa
commit 98bc865a1e
3 changed files with 260 additions and 0 deletions

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@ -254,6 +254,17 @@ config MDIO_BUS_MUX_MMIOREG
Currently, only 8-bit registers are supported.
config MDIO_BUS_MUX_BCM_IPROC
tristate "Support for iProc based MDIO bus multiplexers"
depends on OF && OF_MDIO && (ARCH_BCM_IPROC || COMPILE_TEST)
select MDIO_BUS_MUX
default ARCH_BCM_IPROC
help
This module provides a driver for MDIO bus multiplexers found in
iProc based Broadcom SoCs. This multiplexer connects one of several
child MDIO bus to a parent bus. Buses could be internal as well as
external and selection logic lies inside the same multiplexer.
config MDIO_BCM_UNIMAC
tristate "Broadcom UniMAC MDIO bus controller"
depends on HAS_IOMEM

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@ -39,6 +39,7 @@ obj-$(CONFIG_AMD_PHY) += amd.o
obj-$(CONFIG_MDIO_BUS_MUX) += mdio-mux.o
obj-$(CONFIG_MDIO_BUS_MUX_GPIO) += mdio-mux-gpio.o
obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) += mdio-mux-mmioreg.o
obj-$(CONFIG_MDIO_BUS_MUX_BCM_IPROC) += mdio-mux-bcm-iproc.o
obj-$(CONFIG_MDIO_SUN4I) += mdio-sun4i.o
obj-$(CONFIG_MDIO_MOXART) += mdio-moxart.o
obj-$(CONFIG_MDIO_BCM_UNIMAC) += mdio-bcm-unimac.o

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@ -0,0 +1,248 @@
/*
* Copyright 2016 Broadcom
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation (the "GPL").
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 (GPLv2) for more details.
*
* You should have received a copy of the GNU General Public License
* version 2 (GPLv2) along with this source code.
*/
#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/of_mdio.h>
#include <linux/module.h>
#include <linux/phy.h>
#include <linux/mdio-mux.h>
#include <linux/delay.h>
#define MDIO_PARAM_OFFSET 0x00
#define MDIO_PARAM_MIIM_CYCLE 29
#define MDIO_PARAM_INTERNAL_SEL 25
#define MDIO_PARAM_BUS_ID 22
#define MDIO_PARAM_C45_SEL 21
#define MDIO_PARAM_PHY_ID 16
#define MDIO_PARAM_PHY_DATA 0
#define MDIO_READ_OFFSET 0x04
#define MDIO_READ_DATA_MASK 0xffff
#define MDIO_ADDR_OFFSET 0x08
#define MDIO_CTRL_OFFSET 0x0C
#define MDIO_CTRL_WRITE_OP 0x1
#define MDIO_CTRL_READ_OP 0x2
#define MDIO_STAT_OFFSET 0x10
#define MDIO_STAT_DONE 1
#define BUS_MAX_ADDR 32
#define EXT_BUS_START_ADDR 16
struct iproc_mdiomux_desc {
void *mux_handle;
void __iomem *base;
struct device *dev;
struct mii_bus *mii_bus;
};
static int iproc_mdio_wait_for_idle(void __iomem *base, bool result)
{
unsigned int timeout = 1000; /* loop for 1s */
u32 val;
do {
val = readl(base + MDIO_STAT_OFFSET);
if ((val & MDIO_STAT_DONE) == result)
return 0;
usleep_range(1000, 2000);
} while (timeout--);
return -ETIMEDOUT;
}
/* start_miim_ops- Program and start MDIO transaction over mdio bus.
* @base: Base address
* @phyid: phyid of the selected bus.
* @reg: register offset to be read/written.
* @val :0 if read op else value to be written in @reg;
* @op: Operation that need to be carried out.
* MDIO_CTRL_READ_OP: Read transaction.
* MDIO_CTRL_WRITE_OP: Write transaction.
*
* Return value: Successful Read operation returns read reg values and write
* operation returns 0. Failure operation returns negative error code.
*/
static int start_miim_ops(void __iomem *base,
u16 phyid, u32 reg, u16 val, u32 op)
{
u32 param;
int ret;
writel(0, base + MDIO_CTRL_OFFSET);
ret = iproc_mdio_wait_for_idle(base, 0);
if (ret)
goto err;
param = readl(base + MDIO_PARAM_OFFSET);
param |= phyid << MDIO_PARAM_PHY_ID;
param |= val << MDIO_PARAM_PHY_DATA;
if (reg & MII_ADDR_C45)
param |= BIT(MDIO_PARAM_C45_SEL);
writel(param, base + MDIO_PARAM_OFFSET);
writel(reg, base + MDIO_ADDR_OFFSET);
writel(op, base + MDIO_CTRL_OFFSET);
ret = iproc_mdio_wait_for_idle(base, 1);
if (ret)
goto err;
if (op == MDIO_CTRL_READ_OP)
ret = readl(base + MDIO_READ_OFFSET) & MDIO_READ_DATA_MASK;
err:
return ret;
}
static int iproc_mdiomux_read(struct mii_bus *bus, int phyid, int reg)
{
struct iproc_mdiomux_desc *md = bus->priv;
int ret;
ret = start_miim_ops(md->base, phyid, reg, 0, MDIO_CTRL_READ_OP);
if (ret < 0)
dev_err(&bus->dev, "mdiomux read operation failed!!!");
return ret;
}
static int iproc_mdiomux_write(struct mii_bus *bus,
int phyid, int reg, u16 val)
{
struct iproc_mdiomux_desc *md = bus->priv;
int ret;
/* Write val at reg offset */
ret = start_miim_ops(md->base, phyid, reg, val, MDIO_CTRL_WRITE_OP);
if (ret < 0)
dev_err(&bus->dev, "mdiomux write operation failed!!!");
return ret;
}
static int mdio_mux_iproc_switch_fn(int current_child, int desired_child,
void *data)
{
struct iproc_mdiomux_desc *md = data;
u32 param, bus_id;
bool bus_dir;
/* select bus and its properties */
bus_dir = (desired_child < EXT_BUS_START_ADDR);
bus_id = bus_dir ? desired_child : (desired_child - EXT_BUS_START_ADDR);
param = (bus_dir ? 1 : 0) << MDIO_PARAM_INTERNAL_SEL;
param |= (bus_id << MDIO_PARAM_BUS_ID);
writel(param, md->base + MDIO_PARAM_OFFSET);
return 0;
}
static int mdio_mux_iproc_probe(struct platform_device *pdev)
{
struct iproc_mdiomux_desc *md;
struct mii_bus *bus;
struct resource *res;
int rc;
md = devm_kzalloc(&pdev->dev, sizeof(*md), GFP_KERNEL);
if (!md)
return -ENOMEM;
md->dev = &pdev->dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
md->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(md->base)) {
dev_err(&pdev->dev, "failed to ioremap register\n");
return PTR_ERR(md->base);
}
md->mii_bus = mdiobus_alloc();
if (!md->mii_bus) {
dev_err(&pdev->dev, "mdiomux bus alloc failed\n");
return -ENOMEM;
}
bus = md->mii_bus;
bus->priv = md;
bus->name = "iProc MDIO mux bus";
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-%d", pdev->name, pdev->id);
bus->parent = &pdev->dev;
bus->read = iproc_mdiomux_read;
bus->write = iproc_mdiomux_write;
bus->phy_mask = ~0;
bus->dev.of_node = pdev->dev.of_node;
rc = mdiobus_register(bus);
if (rc) {
dev_err(&pdev->dev, "mdiomux registration failed\n");
goto out;
}
platform_set_drvdata(pdev, md);
rc = mdio_mux_init(md->dev, mdio_mux_iproc_switch_fn,
&md->mux_handle, md, md->mii_bus);
if (rc) {
dev_info(md->dev, "mdiomux initialization failed\n");
goto out;
}
dev_info(md->dev, "iProc mdiomux registered\n");
return 0;
out:
mdiobus_free(bus);
return rc;
}
static int mdio_mux_iproc_remove(struct platform_device *pdev)
{
struct iproc_mdiomux_desc *md = dev_get_platdata(&pdev->dev);
mdio_mux_uninit(md->mux_handle);
mdiobus_unregister(md->mii_bus);
mdiobus_free(md->mii_bus);
return 0;
}
static const struct of_device_id mdio_mux_iproc_match[] = {
{
.compatible = "brcm,mdio-mux-iproc",
},
{},
};
MODULE_DEVICE_TABLE(of, mdio_mux_iproc_match);
static struct platform_driver mdiomux_iproc_driver = {
.driver = {
.name = "mdio-mux-iproc",
.of_match_table = mdio_mux_iproc_match,
},
.probe = mdio_mux_iproc_probe,
.remove = mdio_mux_iproc_remove,
};
module_platform_driver(mdiomux_iproc_driver);
MODULE_DESCRIPTION("iProc MDIO Mux Bus Driver");
MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
MODULE_LICENSE("GPL v2");