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i2c: npcm: Add clock toggle recovery

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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>
This commit is contained in:
Tali Perry
2025-05-19 22:23:54 +02:00
committed by Andi Shyti
parent 504cb3ce52
commit 38010591a0
1 changed files with 8 additions and 4 deletions
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drivers/i2c/busses/i2c-npcm7xx.c
+8 -4
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@@ -2174,10 +2174,14 @@ 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);