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| author | Klaus Jensen <k.jensen@samsung.com> | 2022-06-30 09:21:14 +0200 |
|---|---|---|
| committer | Cédric Le Goater <clg@kaod.org> | 2022-06-30 09:21:14 +0200 |
| commit | a78e9839ae5eb0b95d9db8dd672e2977d2831605 (patch) | |
| tree | 1c0d7b678c12f55dd03ff41dc850578d29409be8 /include/hw | |
| parent | 37fa5ca42623ef08ac99c8d927b6a3af0c76dc7b (diff) | |
| download | qemu-a78e9839ae5eb0b95d9db8dd672e2977d2831605.zip qemu-a78e9839ae5eb0b95d9db8dd672e2977d2831605.tar.gz qemu-a78e9839ae5eb0b95d9db8dd672e2977d2831605.tar.bz2 | |
hw/i2c: add asynchronous send
Add an asynchronous version of i2c_send() that requires the slave to
explicitly acknowledge on the bus with i2c_ack().
The current master must use the new i2c_start_send_async() to indicate
that it wants to do an asynchronous transfer. This allows the i2c core
to check if the target slave supports this or not. This approach relies
on adding a new enum i2c_event member, which is why a bunch of other
devices needs changes in their event handling switches.
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Message-Id: <20220601210831.67259-5-its@irrelevant.dk>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220630045133.32251-6-me@pjd.dev>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Diffstat (limited to 'include/hw')
| -rw-r--r-- | include/hw/i2c/i2c.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index be8bb8b..9b9581d 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -12,6 +12,7 @@ enum i2c_event { I2C_START_RECV, I2C_START_SEND, + I2C_START_SEND_ASYNC, I2C_FINISH, I2C_NACK /* Masker NACKed a receive byte. */ }; @@ -28,6 +29,9 @@ struct I2CSlaveClass { /* Master to slave. Returns non-zero for a NAK, 0 for success. */ int (*send)(I2CSlave *s, uint8_t data); + /* Master to slave (asynchronous). Receiving slave must call i2c_ack(). */ + void (*send_async)(I2CSlave *s, uint8_t data); + /* * Slave to master. This cannot fail, the device should always * return something here. @@ -127,11 +131,23 @@ int i2c_start_recv(I2CBus *bus, uint8_t address); */ int i2c_start_send(I2CBus *bus, uint8_t address); +/** + * i2c_start_send_async: start an asynchronous 'send' transfer on an I2C bus. + * + * @bus: #I2CBus to be used + * @address: address of the slave + * + * Return: 0 on success, -1 on error + */ +int i2c_start_send_async(I2CBus *bus, uint8_t address); + void i2c_end_transfer(I2CBus *bus); void i2c_nack(I2CBus *bus); +void i2c_ack(I2CBus *bus); void i2c_bus_master(I2CBus *bus, QEMUBH *bh); void i2c_bus_release(I2CBus *bus); int i2c_send(I2CBus *bus, uint8_t data); +int i2c_send_async(I2CBus *bus, uint8_t data); uint8_t i2c_recv(I2CBus *bus); bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast, I2CNodeList *current_devs); |