From 90603c5b894eae0e4c8a4a6fdde622143142489c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Thu, 17 Jun 2021 13:53:34 +0200 Subject: [PATCH] hw/i2c: Introduce i2c_start_recv() and i2c_start_send() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To ease reviewing code using the I2C bus API, introduce the i2c_start_recv() and i2c_start_send() helpers which don't take the confusing 'is_recv' boolean argument. Use these new helpers in the SMBus / AUX bus models. Suggested-by: Richard Henderson Reviewed-by: Richard Henderson Signed-off-by: Philippe Mathieu-Daudé Signed-off-by: Corey Minyard --- hw/i2c/core.c | 10 ++++++++++ hw/i2c/pm_smbus.c | 4 ++-- hw/i2c/smbus_master.c | 22 +++++++++++----------- hw/misc/auxbus.c | 12 ++++++------ include/hw/i2c/i2c.h | 24 ++++++++++++++++++++++++ 5 files changed, 53 insertions(+), 19 deletions(-) diff --git a/hw/i2c/core.c b/hw/i2c/core.c index 5483bf95a3..416372ad00 100644 --- a/hw/i2c/core.c +++ b/hw/i2c/core.c @@ -180,6 +180,16 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, bool is_recv) : I2C_START_SEND); } +int i2c_start_recv(I2CBus *bus, uint8_t address) +{ + return i2c_do_start_transfer(bus, address, I2C_START_RECV); +} + +int i2c_start_send(I2CBus *bus, uint8_t address) +{ + return i2c_do_start_transfer(bus, address, I2C_START_SEND); +} + void i2c_end_transfer(I2CBus *bus) { I2CSlaveClass *sc; diff --git a/hw/i2c/pm_smbus.c b/hw/i2c/pm_smbus.c index 06e1e5321b..d7eae548cb 100644 --- a/hw/i2c/pm_smbus.c +++ b/hw/i2c/pm_smbus.c @@ -128,14 +128,14 @@ static void smb_transaction(PMSMBus *s) * So at least Linux may or may not set the read bit here. * So just ignore the read bit for this command. */ - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { goto error; } ret = i2c_send(bus, s->smb_data1); if (ret) { goto error; } - if (i2c_start_transfer(bus, addr, 1)) { + if (i2c_start_recv(bus, addr)) { goto error; } s->in_i2c_block_read = true; diff --git a/hw/i2c/smbus_master.c b/hw/i2c/smbus_master.c index dc43b8637d..6a53c34e70 100644 --- a/hw/i2c/smbus_master.c +++ b/hw/i2c/smbus_master.c @@ -29,7 +29,7 @@ int smbus_receive_byte(I2CBus *bus, uint8_t addr) { uint8_t data; - if (i2c_start_transfer(bus, addr, 1)) { + if (i2c_start_recv(bus, addr)) { return -1; } data = i2c_recv(bus); @@ -40,7 +40,7 @@ int smbus_receive_byte(I2CBus *bus, uint8_t addr) int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data) { - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, data); @@ -51,11 +51,11 @@ int smbus_send_byte(I2CBus *bus, uint8_t addr, uint8_t data) int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command) { uint8_t data; - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, command); - if (i2c_start_transfer(bus, addr, 1)) { + if (i2c_start_recv(bus, addr)) { i2c_end_transfer(bus); return -1; } @@ -67,7 +67,7 @@ int smbus_read_byte(I2CBus *bus, uint8_t addr, uint8_t command) int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data) { - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, command); @@ -79,11 +79,11 @@ int smbus_write_byte(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t data) int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command) { uint16_t data; - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, command); - if (i2c_start_transfer(bus, addr, 1)) { + if (i2c_start_recv(bus, addr)) { i2c_end_transfer(bus); return -1; } @@ -96,7 +96,7 @@ int smbus_read_word(I2CBus *bus, uint8_t addr, uint8_t command) int smbus_write_word(I2CBus *bus, uint8_t addr, uint8_t command, uint16_t data) { - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, command); @@ -113,12 +113,12 @@ int smbus_read_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data, int i; if (send_cmd) { - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, command); } - if (i2c_start_transfer(bus, addr, 1)) { + if (i2c_start_recv(bus, addr)) { if (send_cmd) { i2c_end_transfer(bus); } @@ -149,7 +149,7 @@ int smbus_write_block(I2CBus *bus, uint8_t addr, uint8_t command, uint8_t *data, len = 32; } - if (i2c_start_transfer(bus, addr, 0)) { + if (i2c_start_send(bus, addr)) { return -1; } i2c_send(bus, command); diff --git a/hw/misc/auxbus.c b/hw/misc/auxbus.c index 44aa9730bc..434ff8d910 100644 --- a/hw/misc/auxbus.c +++ b/hw/misc/auxbus.c @@ -135,7 +135,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address, i2c_end_transfer(i2c_bus); } - if (i2c_start_transfer(i2c_bus, address, true)) { + if (i2c_start_recv(i2c_bus, address)) { ret = AUX_I2C_NACK; break; } @@ -151,7 +151,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address, i2c_end_transfer(i2c_bus); } - if (i2c_start_transfer(i2c_bus, address, false)) { + if (i2c_start_send(i2c_bus, address)) { ret = AUX_I2C_NACK; break; } @@ -179,7 +179,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address, /* * No transactions started.. */ - if (i2c_start_transfer(i2c_bus, address, false)) { + if (i2c_start_send(i2c_bus, address)) { break; } } else if ((address != bus->last_i2c_address) || @@ -188,7 +188,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address, * Transaction started but we need to restart.. */ i2c_end_transfer(i2c_bus); - if (i2c_start_transfer(i2c_bus, address, false)) { + if (i2c_start_send(i2c_bus, address)) { break; } } @@ -210,7 +210,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address, /* * No transactions started.. */ - if (i2c_start_transfer(i2c_bus, address, true)) { + if (i2c_start_recv(i2c_bus, address)) { break; } } else if ((address != bus->last_i2c_address) || @@ -219,7 +219,7 @@ AUXReply aux_request(AUXBus *bus, AUXCommand cmd, uint32_t address, * Transaction started but we need to restart.. */ i2c_end_transfer(i2c_bus); - if (i2c_start_transfer(i2c_bus, address, true)) { + if (i2c_start_recv(i2c_bus, address)) { break; } } diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 21f2dba1bf..5ca3b708c0 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -88,9 +88,33 @@ int i2c_bus_busy(I2CBus *bus); * @address: address of the slave * @is_recv: indicates the transfer direction * + * When @is_recv is a known boolean constant, use the + * i2c_start_recv() or i2c_start_send() helper instead. + * * Returns: 0 on success, -1 on error */ int i2c_start_transfer(I2CBus *bus, uint8_t address, bool is_recv); + +/** + * i2c_start_recv: start a 'receive' transfer on an I2C bus. + * + * @bus: #I2CBus to be used + * @address: address of the slave + * + * Returns: 0 on success, -1 on error + */ +int i2c_start_recv(I2CBus *bus, uint8_t address); + +/** + * i2c_start_send: start a 'send' transfer on an I2C bus. + * + * @bus: #I2CBus to be used + * @address: address of the slave + * + * Returns: 0 on success, -1 on error + */ +int i2c_start_send(I2CBus *bus, uint8_t address); + void i2c_end_transfer(I2CBus *bus); void i2c_nack(I2CBus *bus); int i2c_send(I2CBus *bus, uint8_t data);