Commit 38010591 authored by Tali Perry's avatar Tali Perry Committed by Andi Shyti
Browse files

i2c: npcm: Add clock toggle recovery 



During init of the bus, the module checks that the bus is idle.
If one of the lines are stuck try to recover them first before failing.
Sometimes SDA and SCL are low if improper reset occurs (e.g., reboot).

Signed-off-by: default avatarTali Perry <tali.perry1@gmail.com>
Signed-off-by: default avatarMohammed Elbadry <mohammed.0.elbadry@gmail.com>
Reviewed-by: default avatarMukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Link: https://lore.kernel.org/r/20250328193252.1570811-1-mohammed.0.elbadry@gmail.com


Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent 504cb3ce

drivers/i2c/busses/i2c-npcm7xx.c

+8 −4
Original line number Diff line number Diff line
@@ -2174,11 +2174,15 @@ static int npcm_i2c_init_module(struct npcm_i2c *bus, enum i2c_mode mode, 


	/* Check HW is OK: SDA and SCL should be high at this point. */

	if ((npcm_i2c_get_SDA(&bus->adap) == 0) || (npcm_i2c_get_SCL(&bus->adap) == 0)) {

		dev_err(bus->dev, "I2C%d init fail: lines are low\n", bus->num);

		dev_err(bus->dev, "SDA=%d SCL=%d\n", npcm_i2c_get_SDA(&bus->adap),

		dev_warn(bus->dev, " I2C%d SDA=%d SCL=%d, attempting to recover\n", bus->num,

				 npcm_i2c_get_SDA(&bus->adap), npcm_i2c_get_SCL(&bus->adap));

		if (npcm_i2c_recovery_tgclk(&bus->adap)) {

			dev_err(bus->dev, "I2C%d init fail: SDA=%d SCL=%d\n",

				bus->num, npcm_i2c_get_SDA(&bus->adap),

				npcm_i2c_get_SCL(&bus->adap));

			return -ENXIO;

		}

	}



	npcm_i2c_int_enable(bus, true);

	return 0;