From: Tali Perry Date: Fri, 28 Mar 2025 19:32:50 +0000 (+0000) Subject: i2c: npcm: Add clock toggle recovery X-Git-Tag: v5.15.186~101 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ef1b88325c749021538e1c0ce0b66a9409521de7;p=thirdparty%2Fkernel%2Fstable.git i2c: npcm: Add clock toggle recovery [ Upstream commit 38010591a0fc3203f1cee45b01ab358b72dd9ab2 ] 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: Tali Perry Signed-off-by: Mohammed Elbadry Reviewed-by: Mukesh Kumar Savaliya Link: https://lore.kernel.org/r/20250328193252.1570811-1-mohammed.0.elbadry@gmail.com Signed-off-by: Andi Shyti Signed-off-by: Sasha Levin --- diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c index d97694ac29ca9..3f30c3cff7201 100644 --- a/drivers/i2c/busses/i2c-npcm7xx.c +++ b/drivers/i2c/busses/i2c-npcm7xx.c @@ -1950,10 +1950,14 @@ 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), - npcm_i2c_get_SCL(&bus->adap)); - return -ENXIO; + 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);