Commit 3e5f06be authored Dec 04, 2017 by Wolfram Sang Committed by Wolfram Sang Dec 31, 2017

i2c: algo-bit: init the bus to a known state



Ensure the bus is free when we register the adapter. Before the SCL/SDA
wires were in an unknown state. It used to work because sending a byte
has a retry mechanism which was triggered if the bus was initially in a
non-free state. But the graceful way to do it is to initialize
correctly.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

parent e5353765

drivers/i2c/algos/i2c-algo-bit.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -649,6 +649,11 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap,
		if (bit_adap->getscl == NULL)
		adap->quirks = &i2c_bit_quirk_no_clk_stretch;

		/* Bring bus to a known state. Looks like STOP if bus is not free yet */
		setscl(bit_adap, 1);
		udelay(bit_adap->udelay);
		setsda(bit_adap, 1);

		ret = add_adapter(adap);
		if (ret < 0)
		return ret;