Commit 8de3e97f authored by Liu Peibao's avatar Liu Peibao Committed by Andi Shyti
Browse files

i2c: designware: do not hold SCL low when I2C_DYNAMIC_TAR_UPDATE is not set 



When the Tx FIFO is empty and the last command has no STOP bit
set, the master holds SCL low. If I2C_DYNAMIC_TAR_UPDATE is not
set, BIT(13) MST_ON_HOLD of IC_RAW_INTR_STAT is not enabled,
causing the __i2c_dw_disable() timeout. This is quite similar to
commit 2409205a ("i2c: designware: fix __i2c_dw_disable() in
case master is holding SCL low"). Also check BIT(7)
MST_HOLD_TX_FIFO_EMPTY in IC_STATUS, which is available when
IC_STAT_FOR_CLK_STRETCH is set.

Fixes: 2409205a ("i2c: designware: fix __i2c_dw_disable() in case master is holding SCL low")
Co-developed-by: default avatarXiaowu Ding <xiaowu.ding@jaguarmicro.com>
Signed-off-by: default avatarXiaowu Ding <xiaowu.ding@jaguarmicro.com>
Co-developed-by: default avatarAngus Chen <angus.chen@jaguarmicro.com>
Signed-off-by: default avatarAngus Chen <angus.chen@jaguarmicro.com>
Signed-off-by: default avatarLiu Peibao <loven.liu@jaguarmicro.com>
Acked-by: default avatarJarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: default avatarAndi Shyti <andi.shyti@kernel.org>
parent ab2e5c8f

drivers/i2c/busses/i2c-designware-common.c

+4 −2
Original line number Diff line number Diff line
@@ -524,7 +524,7 @@ int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev) 
void __i2c_dw_disable(struct dw_i2c_dev *dev)

{

	struct i2c_timings *t = &dev->timings;

	unsigned int raw_intr_stats;

	unsigned int raw_intr_stats, ic_stats;

	unsigned int enable;

	int timeout = 100;

	bool abort_needed;
@@ -532,9 +532,11 @@ void __i2c_dw_disable(struct dw_i2c_dev *dev) 
	int ret;



	regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_intr_stats);

	regmap_read(dev->map, DW_IC_STATUS, &ic_stats);

	regmap_read(dev->map, DW_IC_ENABLE, &enable);



	abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD;

	abort_needed = (raw_intr_stats & DW_IC_INTR_MST_ON_HOLD) ||

			(ic_stats & DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY);

	if (abort_needed) {

		if (!(enable & DW_IC_ENABLE_ENABLE)) {

			regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE);

drivers/i2c/busses/i2c-designware-core.h

+1 −0
Original line number Diff line number Diff line
@@ -116,6 +116,7 @@ 
#define DW_IC_STATUS_RFNE			BIT(3)

#define DW_IC_STATUS_MASTER_ACTIVITY		BIT(5)

#define DW_IC_STATUS_SLAVE_ACTIVITY		BIT(6)

#define DW_IC_STATUS_MASTER_HOLD_TX_FIFO_EMPTY	BIT(7)



#define DW_IC_SDA_HOLD_RX_SHIFT			16

#define DW_IC_SDA_HOLD_RX_MASK			GENMASK(23, 16)