i2c: at91_i2c: remove the .probe_chip function

The .probe_chip function is supposed to probe an i2c device on the bus to
determine whether a device is answering to a particular address.
at91_i2c_probe_chip() did not do anything resembling this and always
returned 0.

It looks as though at91_i2c_probe_chip() was intended to be a .probe
function for the controller, as it was copied-and-pasted to become
at91_i2c_probe() in 0bc8f640a4.

Removing the at91_i2c_probe_chip() function makes the higher layer
(i2c_probe_chip()) try a zero-length read transfer to test for the
presence of a device instead, which does work.

Signed-off-by: Alan Ott <alan@softiron.com>
Acked-by: Wenyou Yang <wenyou.yang@microchip.com>
Reviewed-by: Heiko Schocher <hs@denx.de>

drivers/i2c/at91_i2c.c

@@ -201,27 +201,6 @@ static int at91_i2c_enable_clk(struct udevice *dev)
 	return 0;
 }
 
-static int at91_i2c_probe_chip(struct udevice *dev, uint chip, uint chip_flags)
-{
-	struct at91_i2c_bus *bus = dev_get_priv(dev);
-	struct at91_i2c_regs *reg = bus->regs;
-	int ret;
-
-	ret = at91_i2c_enable_clk(dev);
-	if (ret)
-		return ret;
-
-	writel(TWI_CR_SWRST, &reg->cr);
-
-	at91_calc_i2c_clock(dev, bus->clock_frequency);
-
-	writel(bus->cwgr_val, &reg->cwgr);
-	writel(TWI_CR_MSEN, &reg->cr);
-	writel(TWI_CR_SVDIS, &reg->cr);
-
-	return 0;
-}
-
 static int at91_i2c_set_bus_speed(struct udevice *dev, unsigned int speed)
 {
 	struct at91_i2c_bus *bus = dev_get_priv(dev);
@@ -256,7 +235,6 @@ static int at91_i2c_ofdata_to_platdata(struct udevice *dev)
 
 static const struct dm_i2c_ops at91_i2c_ops = {
 	.xfer		= at91_i2c_xfer,
-	.probe_chip	= at91_i2c_probe_chip,
 	.set_bus_speed	= at91_i2c_set_bus_speed,
 	.get_bus_speed	= at91_i2c_get_bus_speed,
 };