return spi->connection->private;
}
+static int tx_header_fit_operation(u32 tx_size, u32 count, size_t data_max)
+{
+ size_t headers_size;
+
+ data_max -= sizeof(struct gb_spi_transfer_request);
+ headers_size = (count + 1) * sizeof(struct gb_spi_transfer);
+
+ return tx_size + headers_size > data_max ? 0 : 1;
+}
+
+static size_t calc_rx_xfer_size(u32 rx_size, u32 *tx_xfer_size, u32 len,
+ size_t data_max)
+{
+ size_t rx_xfer_size;
+
+ data_max -= sizeof(struct gb_spi_transfer_response);
+
+ if (rx_size + len > data_max)
+ rx_xfer_size = data_max - rx_size;
+ else
+ rx_xfer_size = len;
+
+ /* if this is a write_read, for symmetry read the same as write */
+ if (*tx_xfer_size && rx_xfer_size > *tx_xfer_size)
+ rx_xfer_size = *tx_xfer_size;
+ if (*tx_xfer_size && rx_xfer_size < *tx_xfer_size)
+ *tx_xfer_size = rx_xfer_size;
+
+ return rx_xfer_size;
+}
+
+static size_t calc_tx_xfer_size(u32 tx_size, u32 count, size_t len,
+ size_t data_max)
+{
+ size_t headers_size;
+
+ data_max -= sizeof(struct gb_spi_transfer_request);
+ headers_size = (count + 1) * sizeof(struct gb_spi_transfer);
+
+ if (tx_size + headers_size + len > data_max)
+ return data_max - (tx_size + sizeof(struct gb_spi_transfer));
+
+ return len;
+}
+
/* Routines to transfer data */
static struct gb_operation *
gb_spi_operation_create(struct gb_connection *connection,
struct spi_transfer *xfer;
struct gb_spi_transfer *gb_xfer;
struct gb_operation *operation;
- u32 tx_size = 0, rx_size = 0, count = 0, request_size;
+ 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;
+ size_t data_max;
void *tx_data;
+ data_max = gb_operation_get_payload_size_max(connection);
+
/* Find number of transfers queued and tx/rx length in the message */
list_for_each_entry(xfer, &msg->transfers, transfer_list) {
if (!xfer->tx_buf && !xfer->rx_buf) {
"bufferless transfer, length %u\n", xfer->len);
return NULL;
}
+ last_xfer = xfer;
- if (xfer->tx_buf)
- tx_size += xfer->len;
- if (xfer->rx_buf)
- rx_size += xfer->len;
+ tx_xfer_size = 0;
+ rx_xfer_size = 0;
+
+ if (xfer->tx_buf) {
+ 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;
+ }
+
+ if (xfer->rx_buf) {
+ rx_xfer_size = calc_rx_xfer_size(rx_size, &tx_xfer_size,
+ xfer->len, data_max);
+ last_xfer_size = rx_xfer_size;
+ }
+
+ tx_size += tx_xfer_size;
+ rx_size += rx_xfer_size;
- *total_len += xfer->len;
+ *total_len += last_xfer_size;
count++;
- }
- /* Too many transfers ? */
- if (count > (u32)U16_MAX) {
- dev_err(&connection->bundle->dev,
- "transfer count (%u) too big\n", count);
- return NULL;
+ if (xfer->len != last_xfer_size)
+ break;
}
/*
/* 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;
+ else
+ xfer_len = xfer->len;
+
gb_xfer->speed_hz = cpu_to_le32(xfer->speed_hz);
- gb_xfer->len = cpu_to_le32(xfer->len);
+ gb_xfer->len = cpu_to_le32(xfer_len);
gb_xfer->delay_usecs = cpu_to_le16(xfer->delay_usecs);
gb_xfer->cs_change = xfer->cs_change;
gb_xfer->bits_per_word = xfer->bits_per_word;
/* Copy tx data */
if (xfer->tx_buf) {
- memcpy(tx_data, xfer->tx_buf, xfer->len);
- tx_data += xfer->len;
gb_xfer->rdwr |= GB_SPI_XFER_WRITE;
+ memcpy(tx_data, xfer->tx_buf, xfer_len);
+ tx_data += xfer_len;
}
+
if (xfer->rx_buf)
gb_xfer->rdwr |= GB_SPI_XFER_READ;
+
+ if (last_xfer && xfer == last_xfer)
+ break;
+
gb_xfer++;
}