net: sun8i_emac: Simplify mdio_read/mdio_write functions

When preparing the register value for the MDIO command register, we
start with a zeroed register, so there is no need to mask off certain
bits before setting them.
Simplify the sequence, and rename the variable to a more matching
mii_cmd on the way.

Also the open-coded time-out routine can be replaced with a much safer
and easier-to-read call to wait_for_bit_le32().

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Tested-by: Amit Singh Tomar <amittomer25@gmail.com> # Pine64+
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>

diff --git a/drivers/net/sun8i_emac.c b/drivers/net/sun8i_emac.c
index 9f31e6d..f11033c 100644 (file)
--- a/drivers/net/sun8i_emac.c
+++ b/drivers/net/sun8i_emac.c
@@ -29,6 +29,7 @@
 #include <net.h>
 #include <reset.h>
 #include <dt-bindings/pinctrl/sun4i-a10.h>
+#include <wait_bit.h>
 #if CONFIG_IS_ENABLED(DM_GPIO)
 #include <asm-generic/gpio.h>
 #endif
@@ -166,32 +167,25 @@ static int sun8i_mdio_read(struct mii_dev *bus, int addr, int devad, int reg)
 {
        struct udevice *dev = bus->priv;
        struct emac_eth_dev *priv = dev_get_priv(dev);
-       ulong start;
-       u32 miiaddr = 0;
-       int timeout = CONFIG_MDIO_TIMEOUT;
+       u32 mii_cmd;
+       int ret;
 
-       miiaddr &= ~MDIO_CMD_MII_WRITE;
-       miiaddr &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK;
-       miiaddr |= (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
+       mii_cmd = (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_REG_ADDR_MASK;
-
-       miiaddr &= ~MDIO_CMD_MII_PHY_ADDR_MASK;
-
-       miiaddr |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
+       mii_cmd |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_ADDR_MASK;
 
-       miiaddr |= MDIO_CMD_MII_BUSY;
+       mii_cmd |= MDIO_CMD_MII_BUSY;
 
-       writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);
+       writel(mii_cmd, priv->mac_reg + EMAC_MII_CMD);
 
-       start = get_timer(0);
-       while (get_timer(start) < timeout) {
-               if (!(readl(priv->mac_reg + EMAC_MII_CMD) & MDIO_CMD_MII_BUSY))
-                       return readl(priv->mac_reg + EMAC_MII_DATA);
-               udelay(10);
-       };
+       ret = wait_for_bit_le32(priv->mac_reg + EMAC_MII_CMD,
+                               MDIO_CMD_MII_BUSY, false,
+                               CONFIG_MDIO_TIMEOUT, true);
+       if (ret < 0)
+               return ret;
 
-       return -1;
+       return readl(priv->mac_reg + EMAC_MII_DATA);
 }
 
 static int sun8i_mdio_write(struct mii_dev *bus, int addr, int devad, int reg,
@@ -199,35 +193,22 @@ static int sun8i_mdio_write(struct mii_dev *bus, int addr, int devad, int reg,
 {
        struct udevice *dev = bus->priv;
        struct emac_eth_dev *priv = dev_get_priv(dev);
-       ulong start;
-       u32 miiaddr = 0;
-       int ret = -1, timeout = CONFIG_MDIO_TIMEOUT;
+       u32 mii_cmd;
 
-       miiaddr &= ~MDIO_CMD_MII_PHY_REG_ADDR_MASK;
-       miiaddr |= (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
+       mii_cmd = (reg << MDIO_CMD_MII_PHY_REG_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_REG_ADDR_MASK;
-
-       miiaddr &= ~MDIO_CMD_MII_PHY_ADDR_MASK;
-       miiaddr |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
+       mii_cmd |= (addr << MDIO_CMD_MII_PHY_ADDR_SHIFT) &
                MDIO_CMD_MII_PHY_ADDR_MASK;
 
-       miiaddr |= MDIO_CMD_MII_WRITE;
-       miiaddr |= MDIO_CMD_MII_BUSY;
+       mii_cmd |= MDIO_CMD_MII_WRITE;
+       mii_cmd |= MDIO_CMD_MII_BUSY;
 
        writel(val, priv->mac_reg + EMAC_MII_DATA);
-       writel(miiaddr, priv->mac_reg + EMAC_MII_CMD);
+       writel(mii_cmd, priv->mac_reg + EMAC_MII_CMD);
 
-       start = get_timer(0);
-       while (get_timer(start) < timeout) {
-               if (!(readl(priv->mac_reg + EMAC_MII_CMD) &
-                                       MDIO_CMD_MII_BUSY)) {
-                       ret = 0;
-                       break;
-               }
-               udelay(10);
-       };
-
-       return ret;
+       return wait_for_bit_le32(priv->mac_reg + EMAC_MII_CMD,
+                                MDIO_CMD_MII_BUSY, false,
+                                CONFIG_MDIO_TIMEOUT, true);
 }
 
 static int _sun8i_write_hwaddr(struct emac_eth_dev *priv, u8 *mac_id)