diff options
Diffstat (limited to 'include/ec_commands.h')
| -rw-r--r-- | include/ec_commands.h | 102 |
1 files changed, 83 insertions, 19 deletions
diff --git a/include/ec_commands.h b/include/ec_commands.h index b9d3a8a2f7..054478743b 100644 --- a/include/ec_commands.h +++ b/include/ec_commands.h @@ -8,25 +8,6 @@ #ifndef __CROS_EC_COMMANDS_H #define __CROS_EC_COMMANDS_H -/* - * Protocol overview - * - * request: CMD [ P0 P1 P2 ... Pn S ] - * response: ERR [ P0 P1 P2 ... Pn S ] - * - * where the bytes are defined as follow : - * - CMD is the command code. (defined by EC_CMD_ constants) - * - ERR is the error code. (defined by EC_RES_ constants) - * - Px is the optional payload. - * it is not sent if the error code is not success. - * (defined by ec_params_ and ec_response_ structures) - * - S is the checksum which is the sum of all payload bytes. - * - * On LPC, CMD and ERR are sent/received at EC_LPC_ADDR_KERNEL|USER_CMD - * and the payloads are sent/received at EC_LPC_ADDR_KERNEL|USER_PARAM. - * On I2C, all bytes are sent serially in the same message. - */ - /* Current version of this protocol */ /* TODO: This is effectively useless; protocol is determined in other ways */ #define EC_PROTO_VERSION 0x00000002 @@ -293,6 +274,89 @@ struct ec_lpc_host_args { #define EC_HOST_ARGS_FLAG_TO_HOST 0x02 /*****************************************************************************/ +/* + * Byte codes returned by EC over SPI interface. + * + * These can be used by the AP to debug the EC interface, and to determine + * when the EC is not in a state where it will ever get around to responding + * to the AP. + * + * Example of sequence of bytes read from EC for a current good transfer: + * 1. - - AP asserts chip select (CS#) + * 2. EC_SPI_OLD_READY - AP sends first byte(s) of request + * 3. - - EC starts handling CS# interrupt + * 4. EC_SPI_RECEIVING - AP sends remaining byte(s) of request + * 5. EC_SPI_PROCESSING - EC starts processing request; AP is clocking in + * bytes looking for EC_SPI_FRAME_START + * 6. - - EC finishes processing and sets up response + * 7. EC_SPI_FRAME_START - AP reads frame byte + * 8. (response packet) - AP reads response packet + * 9. EC_SPI_PAST_END - Any additional bytes read by AP + * 10 - - AP deasserts chip select + * 11 - - EC processes CS# interrupt and sets up DMA for + * next request + * + * If the AP is waiting for EC_SPI_FRAME_START and sees any value other than + * the following byte values: + * EC_SPI_OLD_READY + * EC_SPI_RX_READY + * EC_SPI_RECEIVING + * EC_SPI_PROCESSING + * + * Then the EC found an error in the request, or was not ready for the request + * and lost data. The AP should give up waiting for EC_SPI_FRAME_START, + * because the EC is unable to tell when the AP is done sending its request. + */ + +/* + * Framing byte which precedes a response packet from the EC. After sending a + * request, the AP will clock in bytes until it sees the framing byte, then + * clock in the response packet. + */ +#define EC_SPI_FRAME_START 0xec + +/* + * Padding bytes which are clocked out after the end of a response packet. + */ +#define EC_SPI_PAST_END 0xed + +/* + * EC is ready to receive, and has ignored the byte sent by the AP. EC expects + * that the AP will send a valid packet header (starting with + * EC_COMMAND_PROTOCOL_3) in the next 32 bytes. + */ +#define EC_SPI_RX_READY 0xf8 + +/* + * EC has started receiving the request from the AP, but hasn't started + * processing it yet. + */ +#define EC_SPI_RECEIVING 0xf9 + +/* EC has received the entire request from the AP and is processing it. */ +#define EC_SPI_PROCESSING 0xfa + +/* + * EC received bad data from the AP, such as a packet header with an invalid + * length. EC will ignore all data until chip select deasserts. + */ +#define EC_SPI_RX_BAD_DATA 0xfb + +/* + * EC received data from the AP before it was ready. That is, the AP asserted + * chip select and started clocking data before the EC was ready to receive it. + * EC will ignore all data until chip select deasserts. + */ +#define EC_SPI_NOT_READY 0xfc + +/* + * EC was ready to receive a request from the AP. EC has treated the byte sent + * by the AP as part of a request packet, or (for old-style ECs) is processing + * a fully received packet but is not ready to respond yet. + */ +#define EC_SPI_OLD_READY 0xfd + +/*****************************************************************************/ /* * Protocol version 2 for I2C and SPI send a request this way: |