diff options
| -rw-r--r-- | drivers/staging/greybus/spi.c | 193 |
1 files changed, 153 insertions, 40 deletions
diff --git a/drivers/staging/greybus/spi.c b/drivers/staging/greybus/spi.c index 12e8cd8b1655..0bae7f12ccf1 100644 --- a/drivers/staging/greybus/spi.c +++ b/drivers/staging/greybus/spi.c @@ -18,6 +18,11 @@ struct gb_spi { struct gb_connection *connection; + struct spi_transfer *first_xfer; + struct spi_transfer *last_xfer; + u32 rx_xfer_offset; + u32 tx_xfer_offset; + u32 last_xfer_size; u16 mode; u16 flags; u32 bits_per_word_mask; @@ -26,6 +31,13 @@ struct gb_spi { u32 max_speed_hz; }; +#define GB_SPI_STATE_MSG_DONE ((void *)0) +#define GB_SPI_STATE_MSG_IDLE ((void *)1) +#define GB_SPI_STATE_MSG_RUNNING ((void *)2) +#define GB_SPI_STATE_OP_READY ((void *)3) +#define GB_SPI_STATE_OP_DONE ((void *)4) +#define GB_SPI_STATE_MSG_ERROR ((void *)-1) + static struct spi_master *get_master_from_spi(struct gb_spi *spi) { return gb_connection_get_data(spi->connection); @@ -76,58 +88,120 @@ static size_t calc_tx_xfer_size(u32 tx_size, u32 count, size_t len, return len; } +static void clean_xfer_state(struct gb_spi *spi) +{ + spi->first_xfer = NULL; + spi->last_xfer = NULL; + spi->rx_xfer_offset = 0; + spi->tx_xfer_offset = 0; + spi->last_xfer_size = 0; +} + +static int setup_next_xfer(struct gb_spi *spi, struct spi_message *msg) +{ + struct spi_transfer *last_xfer = spi->last_xfer; + + if (msg->state != GB_SPI_STATE_OP_DONE) + return 0; + + /* + * if we transferred all content of the last transfer, reset values and + * check if this was the last transfer in the message + */ + if ((spi->tx_xfer_offset + spi->last_xfer_size == last_xfer->len) || + (spi->rx_xfer_offset + spi->last_xfer_size == last_xfer->len)) { + spi->tx_xfer_offset = 0; + spi->rx_xfer_offset = 0; + if (last_xfer == list_last_entry(&msg->transfers, + struct spi_transfer, + transfer_list)) + msg->state = GB_SPI_STATE_MSG_DONE; + else + spi->first_xfer = list_next_entry(last_xfer, + transfer_list); + return 0; + } + + spi->first_xfer = last_xfer; + if (last_xfer->tx_buf) + spi->tx_xfer_offset += spi->last_xfer_size; + + if (last_xfer->rx_buf) + spi->rx_xfer_offset += spi->last_xfer_size; + + return 0; +} + +static struct spi_transfer *get_next_xfer(struct spi_transfer *xfer, + struct spi_message *msg) +{ + if (xfer == list_last_entry(&msg->transfers, struct spi_transfer, + transfer_list)) + return NULL; + + return list_next_entry(xfer, transfer_list); +} + /* Routines to transfer data */ static struct gb_operation * -gb_spi_operation_create(struct gb_connection *connection, - struct spi_message *msg, u32 *total_len) +gb_spi_operation_create(struct gb_spi *spi, struct gb_connection *connection, + struct spi_message *msg) { struct gb_spi_transfer_request *request; struct spi_device *dev = msg->spi; struct spi_transfer *xfer; struct gb_spi_transfer *gb_xfer; struct gb_operation *operation; - struct spi_transfer *last_xfer = NULL; u32 tx_size = 0, rx_size = 0, count = 0, xfer_len = 0, request_size; - u32 tx_xfer_size = 0, rx_xfer_size = 0, last_xfer_size = 0; + u32 tx_xfer_size = 0, rx_xfer_size = 0, len; + u32 total_len = 0; size_t data_max; void *tx_data; data_max = gb_operation_get_payload_size_max(connection); + xfer = spi->first_xfer; /* Find number of transfers queued and tx/rx length in the message */ - list_for_each_entry(xfer, &msg->transfers, transfer_list) { + + while (msg->state != GB_SPI_STATE_OP_READY) { + msg->state = GB_SPI_STATE_MSG_RUNNING; + spi->last_xfer = xfer; + if (!xfer->tx_buf && !xfer->rx_buf) { dev_err(&connection->bundle->dev, "bufferless transfer, length %u\n", xfer->len); + msg->state = GB_SPI_STATE_MSG_ERROR; return NULL; } - last_xfer = xfer; tx_xfer_size = 0; rx_xfer_size = 0; if (xfer->tx_buf) { + len = xfer->len - spi->tx_xfer_offset; if (!tx_header_fit_operation(tx_size, count, data_max)) break; tx_xfer_size = calc_tx_xfer_size(tx_size, count, - xfer->len, data_max); - last_xfer_size = tx_xfer_size; + len, data_max); + spi->last_xfer_size = tx_xfer_size; } if (xfer->rx_buf) { + len = xfer->len - spi->rx_xfer_offset; rx_xfer_size = calc_rx_xfer_size(rx_size, &tx_xfer_size, - xfer->len, data_max); - last_xfer_size = rx_xfer_size; + len, data_max); + spi->last_xfer_size = rx_xfer_size; } tx_size += tx_xfer_size; rx_size += rx_xfer_size; - *total_len += last_xfer_size; + total_len += spi->last_xfer_size; count++; - if (xfer->len != last_xfer_size) - break; + xfer = get_next_xfer(xfer, msg); + if (!xfer || total_len >= data_max) + msg->state = GB_SPI_STATE_OP_READY; } /* @@ -153,9 +227,10 @@ gb_spi_operation_create(struct gb_connection *connection, tx_data = gb_xfer + count; /* place tx data after last gb_xfer */ /* Fill in the transfers array */ - list_for_each_entry(xfer, &msg->transfers, transfer_list) { - if (last_xfer && xfer == last_xfer) - xfer_len = last_xfer_size; + xfer = spi->first_xfer; + while (msg->state != GB_SPI_STATE_OP_DONE) { + if (xfer == spi->last_xfer) + xfer_len = spi->last_xfer_size; else xfer_len = xfer->len; @@ -168,34 +243,54 @@ gb_spi_operation_create(struct gb_connection *connection, /* Copy tx data */ if (xfer->tx_buf) { gb_xfer->rdwr |= GB_SPI_XFER_WRITE; - memcpy(tx_data, xfer->tx_buf, xfer_len); + memcpy(tx_data, xfer->tx_buf + spi->tx_xfer_offset, + xfer_len); tx_data += xfer_len; } if (xfer->rx_buf) gb_xfer->rdwr |= GB_SPI_XFER_READ; - if (last_xfer && xfer == last_xfer) - break; + if (xfer == spi->last_xfer) { + msg->state = GB_SPI_STATE_OP_DONE; + continue; + } gb_xfer++; + xfer = get_next_xfer(xfer, msg); } + msg->actual_length += total_len; + return operation; } -static void gb_spi_decode_response(struct spi_message *msg, +static void gb_spi_decode_response(struct gb_spi *spi, struct spi_message *msg, struct gb_spi_transfer_response *response) { - struct spi_transfer *xfer; + struct spi_transfer *xfer = spi->first_xfer; void *rx_data = response->data; + u32 xfer_len; - list_for_each_entry(xfer, &msg->transfers, transfer_list) { + while (xfer) { /* Copy rx data */ if (xfer->rx_buf) { - memcpy(xfer->rx_buf, rx_data, xfer->len); - rx_data += xfer->len; + if (xfer == spi->first_xfer) + xfer_len = xfer->len - spi->rx_xfer_offset; + else if (xfer == spi->last_xfer) + xfer_len = spi->last_xfer_size; + else + xfer_len = xfer->len; + + memcpy(xfer->rx_buf + spi->rx_xfer_offset, rx_data, + xfer_len); + rx_data += xfer_len; } + + if (xfer == spi->last_xfer) + break; + + xfer = list_next_entry(xfer, transfer_list); } } @@ -206,27 +301,45 @@ static int gb_spi_transfer_one_message(struct spi_master *master, struct gb_connection *connection = spi->connection; struct gb_spi_transfer_response *response; struct gb_operation *operation; - u32 len = 0; - int ret; + int ret = 0; + + spi->first_xfer = list_first_entry_or_null(&msg->transfers, + struct spi_transfer, + transfer_list); + if (!spi->first_xfer) { + ret = -ENOMEM; + goto out; + } - operation = gb_spi_operation_create(connection, msg, &len); - if (!operation) - return -ENOMEM; + msg->state = GB_SPI_STATE_MSG_IDLE; + + while (msg->state != GB_SPI_STATE_MSG_DONE && + msg->state != GB_SPI_STATE_MSG_ERROR) { + operation = gb_spi_operation_create(spi, connection, msg); + if (!operation) { + msg->state = GB_SPI_STATE_MSG_ERROR; + ret = -EINVAL; + continue; + } - ret = gb_operation_request_send_sync(operation); - if (!ret) { - response = operation->response->payload; - if (response) - gb_spi_decode_response(msg, response); - } else { - dev_err(&connection->bundle->dev, + ret = gb_operation_request_send_sync(operation); + if (!ret) { + response = operation->response->payload; + if (response) + gb_spi_decode_response(spi, msg, response); + } else { + dev_err(&connection->bundle->dev, "transfer operation failed: %d\n", ret); - } + msg->state = GB_SPI_STATE_MSG_ERROR; + } - gb_operation_put(operation); + gb_operation_put(operation); + setup_next_xfer(spi, msg); + } - msg->actual_length = len; - msg->status = 0; +out: + msg->status = ret; + clean_xfer_state(spi); spi_finalize_current_message(master); return ret; |