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drivers/i2c: it8xxx2: Avoid entering power policy during PIO transfers

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Avoid entering low-power state during I2C host transfers in PIO mode.
Entering a low-power state during an active PIO transfer may prevent
the peripheral from generating the clock signal correctly,
resulting in transmission errors.

Signed-off-by: Tim Lin <tim2.lin@ite.corp-partner.google.com>
This commit is contained in:
Tim Lin 2025-07-17 15:00:35 +08:00 committed by Fabio Baltieri
parent 7cf9a58b7b
commit f0af5be2b4
1 changed files with 11 additions and 8 deletions
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19
drivers/i2c/i2c_ite_enhance.c
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@ -836,12 +836,11 @@ static int enhanced_i2c_cmd_queue_trans(const struct device *dev)
IT8XXX2_I2C_MODE_SEL(base) = 0;
IT8XXX2_I2C_CTR2(base) = 1;
/*
* The EC processor(CPU) cannot be in the k_cpu_idle() and power
* policy during the transactions with the CQ mode(DMA mode).
* The EC processor(CPU) cannot be in the k_cpu_idle() during the
* transactions with the CQ mode(DMA mode).
* Otherwise, the EC processor would be clock gated.
*/
chip_block_idle();
pm_policy_state_lock_get(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
/* Start */
IT8XXX2_I2C_CTR(base) = E_START_CQ;
@ -876,8 +875,7 @@ static int i2c_enhance_cq_transfer(const struct device *dev,
config->port, data->addr_16bit, I2C_RC_TIMEOUT);
}
/* Permit to enter power policy and idle mode. */
pm_policy_state_lock_put(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
/* Permit to enter idle mode. */
chip_permit_idle();
return data->err;
@ -966,6 +964,8 @@ static int i2c_enhance_transfer(const struct device *dev,
#endif
/* Lock mutex of i2c controller */
k_mutex_lock(&data->mutex, K_FOREVER);
/* Block to enter power policy. */
pm_policy_state_lock_get(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
data->num_msgs = num_msgs;
data->addr_16bit = addr;
@ -984,9 +984,8 @@ static int i2c_enhance_transfer(const struct device *dev,
* (No external pull-up), drop the transaction.
*/
if (i2c_bus_not_available(dev)) {
/* Unlock mutex of i2c controller */
k_mutex_unlock(&data->mutex);
return -EIO;
ret = -EIO;
goto done;
}
}
}
@ -1001,6 +1000,10 @@ static int i2c_enhance_transfer(const struct device *dev,
}
/* Save return value. */
ret = i2c_parsing_return_value(dev);
done:
/* Permit to enter power policy */
pm_policy_state_lock_put(PM_STATE_STANDBY, PM_ALL_SUBSTATES);
/* Unlock mutex of i2c controller */
k_mutex_unlock(&data->mutex);