net: phy: introduce phy_read_poll_timeout macro

it is sometimes necessary to poll a phy register by phy_read()
function until its value satisfies some condition. introduce
phy_read_poll_timeout() macros that do this.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/phy.h b/include/linux/phy.h
index 3984f375126efd59b7b7155e72c697985b472f5c..2432ca463ddc080db6cbe81b974409806da8fe95 100644 (file)
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -717,6 +717,19 @@ static inline int phy_read(struct phy_device *phydev, u32 regnum)
        return mdiobus_read(phydev->mdio.bus, phydev->mdio.addr, regnum);
 }
 
+#define phy_read_poll_timeout(phydev, regnum, val, cond, sleep_us, \
+                               timeout_us, sleep_before_read) \
+({ \
+       int __ret = read_poll_timeout(phy_read, val, (cond) || val < 0, \
+               sleep_us, timeout_us, sleep_before_read, phydev, regnum); \
+       if (val <  0) \
+               __ret = val; \
+       if (__ret) \
+               phydev_err(phydev, "%s failed: %d\n", __func__, __ret); \
+       __ret; \
+})
+
+
 /**
  * __phy_read - convenience function for reading a given PHY register
  * @phydev: the phy_device struct