The driver uses a read polling mechanism to check the status of the MDIO
bus, to know if it is ready to accept next commands. This polling
mechanism uses usleep_delay() under the hood between reads which is fine
as long as high resolution timers are enabled. Otherwise the delays will
end up to be much longer than expected.
This patch fixes this by using udelay() under the hood when
CONFIG_HIGH_RES_TIMERS isn't enabled. This increases CPU usage.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC MIIM MDIO driver uses a waiting logic to wait for the MDIO bus
to be ready to accept next commands. It does so by polling the BUSY
status bit which indicates the MDIO bus has completed all pending
operations. This can take time, and the controller supports writing the
next command as soon as there are no pending commands (which happens
while the MDIO bus is busy completing its current command).
This patch implements this improved logic by adding an helper to poll
the PENDING status bit, and by adjusting where we should wait for the
bus to not be busy or to not be pending.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
readl_poll_timeout already returns -ETIMEDOUT if the condition isn't
satisfied, there's no need to check again the condition after calling
it. Remove the redundant timeout check.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC MIIM MDIO driver uses delays to read poll a status register. I
made multiple tests on a Ocelot PCS120 platform which led me to reduce
those delays. The delay in between which the polling function is allowed
to sleep is reduced from 100us to 50us which in almost all cases is a
good value to succeed at the first retry. The overall delay is also
lowered as the prior value was really way to high, 10000us is large
enough.
Signed-off-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A number of drivers have the following pattern:
if (np)
of_mdiobus_register()
else
mdiobus_register()
which the implementation of of_mdiobus_register() now takes care of.
Remove that pattern in drivers that strictly adhere to it.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Reviewed-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a driver for the Microsemi MII Management controller (MIIM) found on
Microsemi SoCs.
On Ocelot, there are two controllers, one is connected to the internal
PHYs, the other one can communicate with external PHYs.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Antoine Tenart