@@ -172,50 +172,55 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
"%#x STATUS SLAVE_ACTIVITY=%#x : RAW_INTR_STAT=%#x : INTR_STAT=%#x\n",
enabled, slave_activity, raw_stat, stat);
+ if (stat & DW_IC_INTR_RX_FULL) {
+ if (dev->status != STATUS_WRITE_IN_PROGRESS) {
+ if (dev->status != STATUS_IDLE)
+ i2c_slave_event(dev->slave, I2C_SLAVE_STOP,
+ &val);
+
+ dev->status = STATUS_WRITE_IN_PROGRESS;
+ i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED,
+ &val);
+ }
+
+ regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
+ val = tmp;
+ if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED,
+ &val))
+ dev_vdbg(dev->dev, "Byte %X acked!", val);
+ }
+
if (stat & DW_IC_INTR_RD_REQ) {
+ if (dev->status != STATUS_IDLE) {
+ dev->status = STATUS_IDLE;
+ i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
+ }
+
if (slave_activity) {
- if (stat & DW_IC_INTR_RX_FULL) {
- regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
- val = tmp;
-
- if (!i2c_slave_event(dev->slave,
- I2C_SLAVE_WRITE_RECEIVED,
- &val)) {
- dev_vdbg(dev->dev, "Byte %X acked!",
- val);
- }
- regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
- } else {
- regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
- regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp);
- }
- if (!i2c_slave_event(dev->slave,
- I2C_SLAVE_READ_REQUESTED,
- &val))
- regmap_write(dev->map, DW_IC_DATA_CMD, val);
+ regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
+ regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp);
+
+ dev->status = STATUS_READ_IN_PROGRESS;
+ i2c_slave_event(dev->slave, I2C_SLAVE_READ_REQUESTED,
+ &val);
+ regmap_write(dev->map, DW_IC_DATA_CMD, val);
}
}
if (stat & DW_IC_INTR_RX_DONE) {
- if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED,
- &val))
- regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp);
+ i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED, &val);
+ regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp);
+ dev->status = STATUS_IDLE;
i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
- return 1;
}
- if (stat & DW_IC_INTR_RX_FULL) {
- regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
- val = tmp;
- if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED,
- &val))
- dev_vdbg(dev->dev, "Byte %X acked!", val);
- } else
- i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
-
- if ((stat & DW_IC_INTR_RX_FULL) && (stat & DW_IC_INTR_STOP_DET))
- i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val);
+ if (stat & DW_IC_INTR_STOP_DET) {
+ if (dev->status != STATUS_IDLE) {
+ dev->status = STATUS_IDLE;
+ i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
+ }
+ }
return 1;
}
Sometime we would get the following flows when doing an i2cset: 1. No any WRITE_REQUESTED 0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 WRITE_RECEIVED 0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 WRITE_RECEIVED 0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x710 : INTR_STAT=0x200 STOP 2. WRITE_REQUESTED after WRITE_RECEIVED 0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4 WRITE_RECEIVED 0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204 WRITE_RECEIVED WRITE_REQUESTED Documentation/i2c/slave-interface.rst said that I2C_SLAVE_WRITE_REQUESTED, which is mandatory, comes without any data arrived. It means I2C_SLAVE_WRITE_REQUESTED should be in front of any I2C_SLAVE_WRITE_RECEIVED in a write-request. Obviously the 1st log shows no I2C_SLAVE_WRITE_REQUESTED, and 2nd log shows I2C_SLAVE_WRITE_REQUESTED occurred after I2C_SLAVE_WRITE_RECEIVED. I2C_SLAVE_STOP is mandatory to notify a request finish to reset the state machine of the backend. In case 2 it never do I2C_SLAVE_STOP when STOP condition is received. This is one of illegal issues to be fixed. dev->status can be used to record the current machine state, especially DesignWare I2C controller has no interrupts to notify a new write-request coming, an IC_INTR_RX_FULL rising while dev->status isn't STATUS_WRITE_IN_PROGRESS is notified to do an I2C_SLAVE_WRITE_REQUESTED by checking dev->status. dev->status also helps to resolve the omitted I2C_SLAVE_STOP in case 2. Signed-off-by: Michael Wu <michael.wu@vatics.com> --- drivers/i2c/busses/i2c-designware-slave.c | 73 ++++++++++++----------- 1 file changed, 39 insertions(+), 34 deletions(-)