From mboxrd@z Thu Jan 1 00:00:00 1970 From: Quan Nguyen Date: Fri, 22 Apr 2022 11:17:08 +0700 Subject: [PATCH v7 3/3] i2c: aspeed: Assert NAK when slave is busy In-Reply-To: <20220422040803.2524940-4-quan@os.amperecomputing.com> References: <20220422040803.2524940-1-quan@os.amperecomputing.com> <20220422040803.2524940-4-quan@os.amperecomputing.com> Message-ID: <6fcbe1e0-b011-7537-b61b-50bfe15f0ce5@os.amperecomputing.com> List-Id: To: linux-aspeed@lists.ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Added Krzysztof Kozlowski as I'm not aware of the email change - Quan On 22/04/2022 11:08, Quan Nguyen wrote: > When processing I2C_SLAVE_WRITE_REQUESTED event, if slave returns > -EBUSY, i2c controller should issue RxCmdLast command to assert NAK > on the bus. > > Signed-off-by: Quan Nguyen > --- > v7: > + None > > v6: > + New introduced in v6 [Quan] > > drivers/i2c/busses/i2c-aspeed.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c > index 771e53d3d197..ebc2b92656c8 100644 > --- a/drivers/i2c/busses/i2c-aspeed.c > +++ b/drivers/i2c/busses/i2c-aspeed.c > @@ -244,6 +244,7 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > u32 command, irq_handled = 0; > struct i2c_client *slave = bus->slave; > u8 value; > + int ret; > > if (!slave) > return 0; > @@ -311,7 +312,9 @@ static u32 aspeed_i2c_slave_irq(struct aspeed_i2c_bus *bus, u32 irq_status) > break; > case ASPEED_I2C_SLAVE_WRITE_REQUESTED: > bus->slave_state = ASPEED_I2C_SLAVE_WRITE_RECEIVED; > - i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); > + ret = i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); > + if (ret == -EBUSY) > + writel(ASPEED_I2CD_M_S_RX_CMD_LAST, bus->base + ASPEED_I2C_CMD_REG); > break; > case ASPEED_I2C_SLAVE_WRITE_RECEIVED: > i2c_slave_event(slave, I2C_SLAVE_WRITE_RECEIVED, &value);