/*
* 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");
