[RFC PATCH v4 net-next 02/23] net: mdio: mscc-miim: convert to a regmap implementation

Colin Foster
2021-11-16T06:26:45Z

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>
---
drivers/net/mdio/mdio-mscc-miim.c | 148 +++++++++++++++++++++---------
1 file changed, 105 insertions(+), 43 deletions(-)

diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c
index 17f98f609ec8..ea599b980bbf 100644
--- a/drivers/net/mdio/mdio-mscc-miim.c
+++ b/drivers/net/mdio/mdio-mscc-miim.c
@@ -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)
@@ -35,37 +36,47 @@
#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, err;
+
+ err = regmap_read(miim->regs, MSCC_MIIM_REG_STATUS, &val);
+ if (err < 0)
+ WARN_ONCE(1, "mscc miim status read error %d\n", err);
+
+ 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);
}
@@ -73,22 +84,30 @@ static int mscc_miim_wait_pending(struct mii_bus *bus)
static int mscc_miim_read(struct mii_bus *bus, int mii_id, int regnum)
{
struct mscc_miim_dev *miim = bus->priv;
+ int ret, err;
u32 val;
- int ret;

ret = mscc_miim_wait_pending(bus);
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);
+ err = 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 (err < 0)
+ WARN_ONCE(1, "mscc miim write cmd reg error %d\n", err);

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

- val = readl(miim->regs + MSCC_MIIM_REG_DATA);
+ err = regmap_read(miim->regs, MSCC_MIIM_REG_DATA, &val);
+
+ if (err < 0)
+ WARN_ONCE(1, "mscc miim read data reg error %d\n", err);
+
if (val & MSCC_MIIM_DATA_ERROR) {
ret = -EIO;
goto out;
@@ -103,18 +122,20 @@ static int mscc_miim_write(struct mii_bus *bus, int mii_id,
int regnum, u16 value)
{
struct mscc_miim_dev *miim = bus->priv;
- int ret;
+ int err, ret;

ret = mscc_miim_wait_pending(bus);
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);
+ err = 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 (err < 0)
+ WARN_ONCE(1, "mscc miim write error %d\n", err);
out:
return ret;
}
@@ -122,24 +143,37 @@ static int mscc_miim_write(struct mii_bus *bus, int mii_id,
static int mscc_miim_reset(struct mii_bus *bus)
{
struct mscc_miim_dev *miim = bus->priv;
+ int err;

if (miim->phy_regs) {
- writel(0, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
- writel(0x1ff, miim->phy_regs + MSCC_PHY_REG_PHY_CFG);
+ err = regmap_write(miim->phy_regs, MSCC_PHY_REG_PHY_CFG, 0);
+ if (err < 0)
+ WARN_ONCE(1, "mscc reset set error %d\n", err);
+
+ err = regmap_write(miim->phy_regs, MSCC_PHY_REG_PHY_CFG, 0x1ff);
+ if (err < 0)
+ WARN_ONCE(1, "mscc reset clear error %d\n", err);
+
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 *bus,
+ struct regmap *mii_regmap, struct regmap *phy_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;

@@ -147,26 +181,54 @@ static int mscc_miim_probe(struct platform_device *pdev)
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;
+
+ miim->regs = mii_regmap;
+ miim->phy_regs = phy_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 *dev;
+ 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(dev->phy_regs)) {
+ dev_err(&pdev->dev, "Unable to map internal phy registers\n");
+ return PTR_ERR(dev->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(dev->phy_regs);
+ }
+
+ mscc_miim_setup(&pdev->dev, bus, mii_regmap, 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);
--
2.25.1