Re: [PATCH v2 net-next 1/3] net: mdio: mscc-miim: convert to a regmap implementation
From: Colin Foster
Date: Thu Nov 25 2021 - 17:23:21 EST
On Thu, Nov 25, 2021 at 12:12:59PM -0800, Colin Foster wrote:
> 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@xxxxxxxxxxxxxxxx>
> ---
> drivers/net/mdio/mdio-mscc-miim.c | 161 ++++++++++++++++++++++--------
> 1 file changed, 119 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/net/mdio/mdio-mscc-miim.c b/drivers/net/mdio/mdio-mscc-miim.c
> index 17f98f609ec8..5a9c0b311bdb 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 +36,49 @@
> #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);
> }
> @@ -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;
> @@ -109,12 +134,14 @@ 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;
> }
> @@ -122,24 +149,40 @@ 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 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 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;
>
> @@ -147,24 +190,58 @@ 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;
> +
> + *pbus = bus;
> +
> + 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)) {
Oops. I'll fix this in V3.
> + 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);
> + }
> +
> + ret = mscc_miim_setup(&pdev->dev, &bus, mii_regmap, phy_regmap);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Unable to setup the MDIO bus\n");
> + return ret;
> }
>
> ret = of_mdiobus_register(bus, pdev->dev.of_node);
> --
> 2.25.1
>