[PATCH v6 4/4] i2c: aspeed: Assert NAK when slave is busy

Quan Nguyen
2022-03-10T11:42:20Z

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 <quan@os.amperecomputing.com>
---
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);
--
2.35.1