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[v5] i2c: npcm: Add clock toggle recovery

Message ID 20250527030506.79191-1-mohammed.0.elbadry@gmail.com
State New
Headers show
Series [v5] i2c: npcm: Add clock toggle recovery | expand

Commit Message

Mohammed Elbadry May 27, 2025, 3:05 a.m. UTC 
From: Tali Perry <tali.perry1@gmail.com>

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>
---
 drivers/i2c/busses/i2c-npcm7xx.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)
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Patch

diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
index de713b5747fe..4738fc450a6b 100644
--- a/drivers/i2c/busses/i2c-npcm7xx.c
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -2178,10 +2178,15 @@  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),
-			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));
+		ret = npcm_i2c_recovery_tgclk(&bus->adap);
+		if (ret) {
+			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 ret;
+		}
 	}
 
 	npcm_i2c_int_enable(bus, true);