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net: mdio: mscc-miim: convert to a regmap implementation
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Utilize regmap instead of __iomem to perform indirect mdio access. This
will allow for custom regmaps to be used by way of the mscc_miim_setup
function.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Colin Foster authored and David S. Miller committed Nov 29, 2021
1 parent 77a3124 commit a27a762
Showing 1 changed file with 121 additions and 42 deletions.
163 changes: 121 additions & 42 deletions drivers/net/mdio/mdio-mscc-miim.c
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Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@
#include <linux/of_mdio.h>
#include <linux/phy.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define MSCC_MIIM_REG_STATUS 0x0
#define MSCC_MIIM_STATUS_STAT_PENDING BIT(2)
Expand All @@ -35,37 +36,49 @@
#define MSCC_PHY_REG_PHY_STATUS 0x4

struct mscc_miim_dev {
void __iomem *regs;
void __iomem *phy_regs;
struct regmap *regs;
struct regmap *phy_regs;
};

/* When high resolution timers aren't built-in: we can't use usleep_range() as
* we would sleep way too long. Use udelay() instead.
*/
#define mscc_readl_poll_timeout(addr, val, cond, delay_us, timeout_us) \
({ \
if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \
readl_poll_timeout_atomic(addr, val, cond, delay_us, \
timeout_us); \
readl_poll_timeout(addr, val, cond, delay_us, timeout_us); \
#define mscc_readx_poll_timeout(op, addr, val, cond, delay_us, timeout_us)\
({ \
if (!IS_ENABLED(CONFIG_HIGH_RES_TIMERS)) \
readx_poll_timeout_atomic(op, addr, val, cond, delay_us, \
timeout_us); \
readx_poll_timeout(op, addr, val, cond, delay_us, timeout_us); \
})

static int mscc_miim_wait_ready(struct mii_bus *bus)
static int mscc_miim_status(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
int val, ret;

ret = regmap_read(miim->regs, MSCC_MIIM_REG_STATUS, &val);
if (ret < 0) {
WARN_ONCE(1, "mscc miim status read error %d\n", ret);
return ret;
}

return val;
}

static int mscc_miim_wait_ready(struct mii_bus *bus)
{
u32 val;

return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
return mscc_readx_poll_timeout(mscc_miim_status, bus, val,
!(val & MSCC_MIIM_STATUS_STAT_BUSY), 50,
10000);
}

static int mscc_miim_wait_pending(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
u32 val;

return mscc_readl_poll_timeout(miim->regs + MSCC_MIIM_REG_STATUS, val,
return mscc_readx_poll_timeout(mscc_miim_status, bus, val,
!(val & MSCC_MIIM_STATUS_STAT_PENDING),
50, 10000);
}
Expand All @@ -80,15 +93,27 @@ static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
if (ret)
goto out;

writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) | MSCC_MIIM_CMD_OPR_READ,
miim->regs + MSCC_MIIM_REG_CMD);
ret = regmap_write(miim->regs, MSCC_MIIM_REG_CMD, MSCC_MIIM_CMD_VLD |
(mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
MSCC_MIIM_CMD_OPR_READ);

if (ret < 0) {
WARN_ONCE(1, "mscc miim write cmd reg error %d\n", ret);
goto out;
}

ret = mscc_miim_wait_ready(bus);
if (ret)
goto out;

val = readl(miim->regs + MSCC_MIIM_REG_DATA);
ret = regmap_read(miim->regs, MSCC_MIIM_REG_DATA, &val);

if (ret < 0) {
WARN_ONCE(1, "mscc miim read data reg error %d\n", ret);
goto out;
}

if (val & MSCC_MIIM_DATA_ERROR) {
ret = -EIO;
goto out;
Expand All @@ -109,64 +134,118 @@ static int mscc_miim_write(struct mii_bus *bus, int mii_id,
if (ret < 0)
goto out;

writel(MSCC_MIIM_CMD_VLD | (mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
(value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
MSCC_MIIM_CMD_OPR_WRITE,
miim->regs + MSCC_MIIM_REG_CMD);
ret = regmap_write(miim->regs, MSCC_MIIM_REG_CMD, MSCC_MIIM_CMD_VLD |
(mii_id << MSCC_MIIM_CMD_PHYAD_SHIFT) |
(regnum << MSCC_MIIM_CMD_REGAD_SHIFT) |
(value << MSCC_MIIM_CMD_WRDATA_SHIFT) |
MSCC_MIIM_CMD_OPR_WRITE);

if (ret < 0)
WARN_ONCE(1, "mscc miim write error %d\n", ret);
out:
return ret;
}

static int mscc_miim_reset(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
int ret;

if (miim->phy_regs) {
writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
ret = regmap_write(miim->phy_regs, MSCC_PHY_REG_PHY_CFG, 0);
if (ret < 0) {
WARN_ONCE(1, "mscc reset set error %d\n", ret);
return ret;
}

ret = regmap_write(miim->phy_regs, MSCC_PHY_REG_PHY_CFG, 0x1ff);
if (ret < 0) {
WARN_ONCE(1, "mscc reset clear error %d\n", ret);
return ret;
}

mdelay(500);
}

return 0;
}

static int mscc_miim_probe(struct platform_device *pdev)
static const struct regmap_config mscc_miim_regmap_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};

static int mscc_miim_setup(struct device *dev, struct mii_bus **pbus,
struct regmap *mii_regmap)
{
struct mscc_miim_dev *dev;
struct resource *res;
struct mscc_miim_dev *miim;
struct mii_bus *bus;
int ret;

bus = devm_mdiobus_alloc_size(&pdev->dev, sizeof(*dev));
bus = devm_mdiobus_alloc_size(dev, sizeof(*miim));
if (!bus)
return -ENOMEM;

bus->name = "mscc_miim";
bus->read = mscc_miim_read;
bus->write = mscc_miim_write;
bus->reset = mscc_miim_reset;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev));
bus->parent = &pdev->dev;
snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(dev));
bus->parent = dev;

miim = bus->priv;

*pbus = bus;

miim->regs = mii_regmap;

return 0;
}

static int mscc_miim_probe(struct platform_device *pdev)
{
struct regmap *mii_regmap, *phy_regmap;
void __iomem *regs, *phy_regs;
struct mscc_miim_dev *miim;
struct mii_bus *bus;
int ret;

dev = bus->priv;
dev->regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
if (IS_ERR(dev->regs)) {
regs = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
if (IS_ERR(regs)) {
dev_err(&pdev->dev, "Unable to map MIIM registers\n");
return PTR_ERR(dev->regs);
return PTR_ERR(regs);
}

/* This resource is optional */
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res) {
dev->phy_regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dev->phy_regs)) {
dev_err(&pdev->dev, "Unable to map internal phy registers\n");
return PTR_ERR(dev->phy_regs);
}
mii_regmap = devm_regmap_init_mmio(&pdev->dev, regs,
&mscc_miim_regmap_config);

if (IS_ERR(mii_regmap)) {
dev_err(&pdev->dev, "Unable to create MIIM regmap\n");
return PTR_ERR(mii_regmap);
}

phy_regs = devm_platform_ioremap_resource(pdev, 1);
if (IS_ERR(phy_regs)) {
dev_err(&pdev->dev, "Unable to map internal phy registers\n");
return PTR_ERR(phy_regs);
}

phy_regmap = devm_regmap_init_mmio(&pdev->dev, phy_regs,
&mscc_miim_regmap_config);
if (IS_ERR(phy_regmap)) {
dev_err(&pdev->dev, "Unable to create phy register regmap\n");
return PTR_ERR(phy_regmap);
}

ret = mscc_miim_setup(&pdev->dev, &bus, mii_regmap);
if (ret < 0) {
dev_err(&pdev->dev, "Unable to setup the MDIO bus\n");
return ret;
}

miim = bus->priv;
miim->phy_regs = phy_regmap;

ret = of_mdiobus_register(bus, pdev->dev.of_node);
if (ret < 0) {
dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
Expand Down

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