aboutsummaryrefslogtreecommitdiff
path: root/hw/i2c/aspeed_i2c.c
AgeCommit message (Collapse)Author
2017-06-02aspeed/i2c: introduce a state machineCédric Le Goater
The Aspeed I2C controller maintains a state machine in the command register, which is mostly used for debug. Let's start adding a few states to handle abnormal STOP commands. Today, the model uses the busy status of the bus as a condition to do so but it is not precise enough. Also remove the ABNORMAL bit for failing TX commands. This is incorrect with respect to the specs. Signed-off-by: Cédric Le Goater <clg@kaod.org> Message-id: 1494827476-1487-4-git-send-email-clg@kaod.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-02aspeed/i2c: handle LAST command under the RX commandCédric Le Goater
Today, the LAST command is handled with the STOP command but this is incorrect. Also nack the I2C bus when a LAST is issued. Signed-off-by: Cédric Le Goater <clg@kaod.org> Message-id: 1494827476-1487-3-git-send-email-clg@kaod.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-06-02aspeed/i2c: improve command handlingCédric Le Goater
Multiple I2C commands can be fired simultaneously and the controller execute the commands following these priorities: (1) Master Start Command (2) Master Transmit Command (3) Slave Transmit Command or Master Receive Command (4) Master Stop Command The current code is incorrect with respect to the above sequence and needs to be reworked to handle each individual command. Signed-off-by: Cédric Le Goater <clg@kaod.org> Message-id: 1494827476-1487-2-git-send-email-clg@kaod.org Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-06-06i2c: add aspeed i2c controllerCédric Le Goater
The Aspeed AST2400 integrates a set of 14 I2C/SMBus bus controllers directly connected to the APB bus. They can be programmed as master or slave but the propopsed model only supports the master mode. On the TODO list, we also have : - improve and harden the state machine. - bus recovery support (used by the Linux driver). - transfer mode state machine bits. this is not strictly necessary as it is mostly used for debug. The bus busy bit is deducted from the I2C core engine of qemu. - support of the pool buffer: 2048 bytes of internal SRAM (not used by the Linux driver). Signed-off-by: Cédric Le Goater <clg@kaod.org> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Message-id: 1464704307-25178-1-git-send-email-clg@kaod.org [PMM: removed unused functions aspeed_i2c_bus_get_state() and aspeed_i2c_bus_set_state()] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>