diff options
Diffstat (limited to 'include')
-rw-r--r-- | include/config.h | 3 | ||||
-rw-r--r-- | include/usb_i2c.h | 92 |
2 files changed, 69 insertions, 26 deletions
diff --git a/include/config.h b/include/config.h index dba87924db..45e144484d 100644 --- a/include/config.h +++ b/include/config.h @@ -2873,8 +2873,9 @@ /* USB I2C config */ #undef CONFIG_USB_I2C -/* Allowed write count for USB over I2C */ +/* Allowed read/write count for USB over I2C */ #define CONFIG_USB_I2C_MAX_WRITE_COUNT 60 +#define CONFIG_USB_I2C_MAX_READ_COUNT 60 /*****************************************************************************/ /* USB Power monitoring interface config */ diff --git a/include/usb_i2c.h b/include/usb_i2c.h index 3e8eb3e7e5..c135066e26 100644 --- a/include/usb_i2c.h +++ b/include/usb_i2c.h @@ -14,27 +14,63 @@ #define __CROS_USB_I2C_H /* - * Command: - * +----------+-----------+---------------+---------------+---------------+ - * | port: 1B | addr: 1B | wr count : 1B | rd count : 1B | data : <= 60B | - * +----------+-----------+---------------+---------------+---------------+ + * 2 forms of command are supported: + * - When write payload + header is larger than 64 bytes, which exceed the + * common USB packet (64 bytes), remaining payload should send without + * header. * - * port address: 1 byte, i2c interface index + * - CONFIG_USB_I2C_MAX_WRITE_COUNT / CONFIG_USB_I2C_MAX_READ_COUNT have to + * be defined properly based on the use cases. * - * slave address: 1 byte, i2c 7-bit bus address + * - Read less than 128 (0x80) bytes. + * +------+------+----+----+---------------+ + * | port | addr | wc | rc | write payload | + * +------+------+----+----+---------------+ + * | 1B | 1B | 1B | 1B | < 256 bytes | + * +------+------+----+----+---------------+ * - * write count: 1 byte, zero based count of bytes to write. If write - * count exceed 60 bytes, following packets are expected - * to continue the payload without header. + * - Read less than 32768 (0x8000) bytes. + * +------+------+----+----+-----+----------+---------------+ + * | port | addr | wc | rc | rc1 | reserved | write payload | + * +------+------+----+----+----------------+---------------+ + * | 1B | 1B | 1B | 1B | 1B | 1B | < 256 bytes | + * +------+------+----+----+----------------+---------------+ * - * read count: 1 byte, zero based count of bytes to read + * - Special notes for rc and rc1: + * If the most significant bit in rc is set (rc >= 0x80), this indicates + * that we want to read back more than 127 bytes, so the first byte of + * data contains rc1 (read count continuation), and the final read count + * will be (rc1 << 7) | (rc & 0x7F). * - * data: payload of data to write. + * Fields: + * - port: port address, 1 byte, i2c interface index. + * + * - addr: slave address, 1 byte, i2c 7-bit bus address. + * + * - wc: write count, 1 byte, zero based count of bytes to write. If the + * indicated write count cause the payload + header exceeds 64 bytes, + * Following packets are expected to continue the payload without + * header. + * + * - rc: read count, 1 byte, zero based count of bytes to read. To read more + * than 127 (0x7F) bytes please see the special notes above. + * + * - data: payload of data to write. See wc above for more information. + * + * - rc1: extended read count, 1 byte. An extended version indicates we want + * to read more data. While the most significant bits is set in read + * count (rc >= 0x80), rc1 will concatenate with rc together. See the + * special notes above for concatenating details. + * + * - reserved: reserved byte, 1 byte. * * Response: - * +-------------+---+---+-----------------------+ - * | status : 2B | 0 | 0 | read payload : <= 60B | - * +-------------+---+---+-----------------------+ + * +-------------+---+---+--------------+ + * | status : 2B | 0 | 0 | read payload | + * +-------------+---+---+--------------+ + * + * - read payload might not fit into a single USB packets. Remaining will be + * transimitted witout header. Receiving side should concatenate them. * * status: 2 byte status * 0x0000: Success @@ -43,15 +79,15 @@ * This can happen if someone else has acquired the shared memory * buffer that the I2C driver uses as /dev/null * 0x0003: Write count invalid (mismatch with merged payload) - * 0x0004: Read count invalid (> 60 bytes) + * 0x0004: Read count invalid (e.g. larger than available buffer) * 0x0005: The port specified is invalid. * 0x0006: The I2C interface is disabled. * 0x8000: Unknown error mask * The bottom 15 bits will contain the bottom 15 bits from the EC * error code. * - * read payload: up to 60 bytes of data read from I2C, length will match - * requested read count + * read payload: Depends on the buffer size and implementation. Length will + * match requested read count */ enum usb_i2c_error { @@ -66,12 +102,18 @@ enum usb_i2c_error { }; -#define USB_I2C_MAX_READ_COUNT 60 -#define USB_I2C_CONFIG_BUFFER_SIZE \ - ((CONFIG_USB_I2C_MAX_WRITE_COUNT+4) > USB_MAX_PACKET_SIZE ? \ - (CONFIG_USB_I2C_MAX_WRITE_COUNT+4) : USB_MAX_PACKET_SIZE) +#define USB_I2C_WRITE_BUFFER (CONFIG_USB_I2C_MAX_WRITE_COUNT + 4) +/* If read payload is larger or equal to 128 bytes, header contains rc1 */ +#define USB_I2C_READ_BUFFER ((CONFIG_USB_I2C_MAX_READ_COUNT < 128) ? \ + (CONFIG_USB_I2C_MAX_READ_COUNT + 4) : \ + (CONFIG_USB_I2C_MAX_READ_COUNT + 6)) + +#define USB_I2C_BUFFER_SIZE \ + (USB_I2C_READ_BUFFER > USB_I2C_WRITE_BUFFER ? \ + USB_I2C_READ_BUFFER : USB_I2C_WRITE_BUFFER) -BUILD_ASSERT(USB_MAX_PACKET_SIZE == (2 + 1 + 1 + USB_I2C_MAX_READ_COUNT)); +BUILD_ASSERT(POWER_OF_TWO(USB_I2C_READ_BUFFER)); +BUILD_ASSERT(POWER_OF_TWO(USB_I2C_WRITE_BUFFER)); /* * Compile time Per-USB gpio configuration stored in flash. Instances of this @@ -110,7 +152,7 @@ extern struct consumer_ops const usb_i2c_consumer_ops; ENDPOINT) \ static uint16_t \ CONCAT2(NAME, _buffer_) \ - [USB_I2C_CONFIG_BUFFER_SIZE / 2]; \ + [USB_I2C_BUFFER_SIZE / 2]; \ static void CONCAT2(NAME, _deferred_)(void); \ DECLARE_DEFERRED(CONCAT2(NAME, _deferred_)); \ static struct queue const CONCAT2(NAME, _to_usb_); \ @@ -136,10 +178,10 @@ extern struct consumer_ops const usb_i2c_consumer_ops; .tx_queue = &CONCAT2(NAME, _to_usb_), \ }; \ static struct queue const CONCAT2(NAME, _to_usb_) = \ - QUEUE_DIRECT(USB_MAX_PACKET_SIZE, uint8_t, \ + QUEUE_DIRECT(USB_I2C_READ_BUFFER, uint8_t, \ null_producer, CONCAT2(NAME, _usb_).consumer); \ static struct queue const CONCAT3(usb_to_, NAME, _) = \ - QUEUE_DIRECT(CONFIG_USB_I2C_MAX_WRITE_COUNT+4, uint8_t, \ + QUEUE_DIRECT(USB_I2C_WRITE_BUFFER, uint8_t, \ CONCAT2(NAME, _usb_).producer, NAME.consumer); \ static void CONCAT2(NAME, _deferred_)(void) \ { usb_i2c_deferred(&NAME); } |