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| author | Michael Wu <michael.wu@vatics.com> | 2020-10-30 09:04:20 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2020-11-06 16:02:00 +0100 |
| commit | 3b5f7f10ff6e6b66f553e12cc50d9bb751ce60ad (patch) | |
| tree | c84ae2f911eab4bd7ac94bad5d1dae4ea2c819f6 /drivers | |
| parent | i2c: designware: call i2c_dw_read_clear_intrbits_slave() once (diff) | |
| download | linux-3b5f7f10ff6e6b66f553e12cc50d9bb751ce60ad.tar.xz linux-3b5f7f10ff6e6b66f553e12cc50d9bb751ce60ad.zip | |
i2c: designware: slave should do WRITE_REQUESTED before WRITE_RECEIVED
Sometimes we would get the following flow when doing an i2cset:
0x1 STATUS SLAVE_ACTIVITY=0x1 : RAW_INTR_STAT=0x514 : INTR_STAT=0x4
I2C_SLAVE_WRITE_RECEIVED
0x1 STATUS SLAVE_ACTIVITY=0x0 : RAW_INTR_STAT=0x714 : INTR_STAT=0x204
I2C_SLAVE_WRITE_REQUESTED
I2C_SLAVE_WRITE_RECEIVED
Documentation/i2c/slave-interface.rst says that I2C_SLAVE_WRITE_REQUESTED,
which is mandatory, should be sent while the data did not arrive yet. It
means in a write-request I2C_SLAVE_WRITE_REQUESTED should be reported
before any I2C_SLAVE_WRITE_RECEIVED.
By the way, I2C_SLAVE_STOP didn't be reported in the above case because
DW_IC_INTR_STAT was not 0x200.
dev->status can be used to record the current state, especially Designware
I2C controller has no interrupts to identify a write-request. This patch
makes not only I2C_SLAVE_WRITE_REQUESTED been reported first when
IC_INTR_RX_FULL is rising and dev->status isn't STATUS_WRITE_IN_PROGRESS
but also I2C_SLAVE_STOP been reported when a STOP condition is received.
Signed-off-by: Michael Wu <michael.wu@vatics.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-slave.c | 45 |
1 files changed, 18 insertions, 27 deletions
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c index 13de01a0f75f..0d15f4c1e9f7 100644 --- a/drivers/i2c/busses/i2c-designware-slave.c +++ b/drivers/i2c/busses/i2c-designware-slave.c @@ -172,26 +172,25 @@ 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) && (stat & DW_IC_INTR_STOP_DET)) - i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_REQUESTED, &val); + if (stat & DW_IC_INTR_RX_FULL) { + if (dev->status != STATUS_WRITE_IN_PROGRESS) { + 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 (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); - } + regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp); + + dev->status = STATUS_READ_IN_PROGRESS; if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_REQUESTED, &val)) @@ -203,18 +202,10 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev) 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_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 { + if (stat & DW_IC_INTR_STOP_DET) { + dev->status = STATUS_IDLE; i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val); } |