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| author | Klaus Jensen | 2022-06-30 09:21:14 +0200 |
|---|---|---|
| committer | Cédric Le Goater | 2022-06-30 09:21:14 +0200 |
| commit | a78e9839ae5eb0b95d9db8dd672e2977d2831605 (patch) | |
| tree | 1c0d7b678c12f55dd03ff41dc850578d29409be8 /hw/i2c | |
| parent | hw/i2c: support multiple masters (diff) | |
| download | qemu-a78e9839ae5eb0b95d9db8dd672e2977d2831605.tar.gz qemu-a78e9839ae5eb0b95d9db8dd672e2977d2831605.tar.xz qemu-a78e9839ae5eb0b95d9db8dd672e2977d2831605.zip | |
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 'hw/i2c')
| -rw-r--r-- | hw/i2c/core.c | 36 | ||||
| -rw-r--r-- | hw/i2c/smbus_slave.c | 4 | ||||
| -rw-r--r-- | hw/i2c/trace-events | 2 |
3 files changed, 41 insertions, 1 deletions
diff --git a/hw/i2c/core.c b/hw/i2c/core.c index 145dce6078..d4ba8146bf 100644 --- a/hw/i2c/core.c +++ b/hw/i2c/core.c @@ -161,7 +161,8 @@ static int i2c_do_start_transfer(I2CBus *bus, uint8_t address, start condition. */ if (sc->event) { - trace_i2c_event("start", s->address); + trace_i2c_event(event == I2C_START_SEND ? "start" : "start_async", + s->address); rv = sc->event(s, event); if (rv && !bus->broadcast) { if (bus_scanned) { @@ -212,6 +213,11 @@ int i2c_start_send(I2CBus *bus, uint8_t address) return i2c_do_start_transfer(bus, address, I2C_START_SEND); } +int i2c_start_send_async(I2CBus *bus, uint8_t address) +{ + return i2c_do_start_transfer(bus, address, I2C_START_SEND_ASYNC); +} + void i2c_end_transfer(I2CBus *bus) { I2CSlaveClass *sc; @@ -261,6 +267,23 @@ int i2c_send(I2CBus *bus, uint8_t data) return ret ? -1 : 0; } +int i2c_send_async(I2CBus *bus, uint8_t data) +{ + I2CNode *node = QLIST_FIRST(&bus->current_devs); + I2CSlave *slave = node->elt; + I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(slave); + + if (!sc->send_async) { + return -1; + } + + trace_i2c_send_async(slave->address, data); + + sc->send_async(slave, data); + + return 0; +} + uint8_t i2c_recv(I2CBus *bus) { uint8_t data = 0xff; @@ -297,6 +320,17 @@ void i2c_nack(I2CBus *bus) } } +void i2c_ack(I2CBus *bus) +{ + if (!bus->bh) { + return; + } + + trace_i2c_ack(); + + qemu_bh_schedule(bus->bh); +} + static int i2c_slave_post_load(void *opaque, int version_id) { I2CSlave *dev = opaque; diff --git a/hw/i2c/smbus_slave.c b/hw/i2c/smbus_slave.c index 5d10e27664..feb3ec6333 100644 --- a/hw/i2c/smbus_slave.c +++ b/hw/i2c/smbus_slave.c @@ -143,6 +143,10 @@ static int smbus_i2c_event(I2CSlave *s, enum i2c_event event) dev->mode = SMBUS_CONFUSED; break; } + break; + + default: + return -1; } return 0; diff --git a/hw/i2c/trace-events b/hw/i2c/trace-events index 209275ed2d..af181d43ee 100644 --- a/hw/i2c/trace-events +++ b/hw/i2c/trace-events @@ -4,7 +4,9 @@ i2c_event(const char *event, uint8_t address) "%s(addr:0x%02x)" i2c_send(uint8_t address, uint8_t data) "send(addr:0x%02x) data:0x%02x" +i2c_send_async(uint8_t address, uint8_t data) "send_async(addr:0x%02x) data:0x%02x" i2c_recv(uint8_t address, uint8_t data) "recv(addr:0x%02x) data:0x%02x" +i2c_ack(void) "" # aspeed_i2c.c |