@@ -334,6 +334,7 @@ struct npcm_i2c {
u64 nack_cnt;
u64 timeout_cnt;
u64 tx_complete_cnt;
+ bool ber_state; /* Indicate the bus error state */
};
static inline void npcm_i2c_select_bank(struct npcm_i2c *bus,
@@ -1521,6 +1522,7 @@ static void npcm_i2c_irq_handle_ber(struct npcm_i2c *bus)
if (npcm_i2c_is_master(bus)) {
npcm_i2c_master_abort(bus);
} else {
+ bus->ber_state = true;
npcm_i2c_clear_master_status(bus);
/* Clear BB (BUS BUSY) bit */
@@ -1699,6 +1701,7 @@ static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
dev_dbg(bus->dev, "bus%d-0x%x recovery skipped, bus not stuck",
bus->num, bus->dest_addr);
npcm_i2c_reset(bus);
+ bus->ber_state = false;
return 0;
}
@@ -1763,6 +1766,7 @@ static int npcm_i2c_recovery_tgclk(struct i2c_adapter *_adap)
if (bus->rec_succ_cnt < ULLONG_MAX)
bus->rec_succ_cnt++;
}
+ bus->ber_state = false;
return status;
}
@@ -2158,7 +2162,16 @@ static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
} while (time_is_after_jiffies(time_left) && bus_busy);
- if (bus_busy) {
+ /*
+ * Check the BER (bus error) state, when ber_state is true, it means that the module
+ * detects the bus error which is caused by some factor like that the electricity
+ * noise occurs on the bus. Under this condition, the module is reset and the bus
+ * gets recovered.
+ *
+ * While ber_state is false, the module reset and bus recovery also get done as the
+ * bus is busy.
+ */
+ if (bus_busy || bus->ber_state) {
iowrite8(NPCM_I2CCST_BB, bus->reg + NPCM_I2CCST);
npcm_i2c_reset(bus);
i2c_recover_bus(adap);