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 <tali.perry1@gmail.com>
Signed-off-by: Mohammed Elbadry <mohammed.0.elbadry@gmail.com>
Reviewed-by: Mukesh Kumar Savaliya <quic_msavaliy@quicinc.com>
Link: https://lore.kernel.org/r/20250328193252.1570811-1-mohammed.0.elbadry@gmail.com
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index 0947e3d155c566ad7c4d3c308f892979f21a5174..828234d1ee47721778604280e93d6574decf7013 100644 (file)
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -1973,10 +1973,14 @@ 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);