spi: correct the transfer_one_message documentation wording

[linux-2.6-block.git] / include / linux / spi / spi.h

diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 8c62ba74dd91d9800439038d86298f2e2477f1fe..4203c66d88033269692fa38ce50aebe17fee9419 100644 (file)
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -75,6 +75,7 @@ struct spi_device {
        struct spi_master       *master;
        u32                     max_speed_hz;
        u8                      chip_select;
+       u8                      bits_per_word;
        u16                     mode;
 #define        SPI_CPHA        0x01                    /* clock phase */
 #define        SPI_CPOL        0x02                    /* clock polarity */
@@ -92,7 +93,6 @@ struct spi_device {
 #define        SPI_TX_QUAD     0x200                   /* transmit with 4 wires */
 #define        SPI_RX_DUAL     0x400                   /* receive with 2 wires */
 #define        SPI_RX_QUAD     0x800                   /* receive with 4 wires */
-       u8                      bits_per_word;
        int                     irq;
        void                    *controller_state;
        void                    *controller_data;
@@ -273,19 +273,24 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
  *     message while queuing transfers that arrive in the meantime. When the
  *     driver is finished with this message, it must call
  *     spi_finalize_current_message() so the subsystem can issue the next
- *     transfer
+ *     message
  * @unprepare_transfer_hardware: there are currently no more messages on the
  *     queue so the subsystem notifies the driver that it may relax the
  *     hardware by issuing this call
- * @set_cs: assert or deassert chip select, true to assert.  May be called
+ * @set_cs: set the logic level of the chip select line.  May be called
  *          from interrupt context.
  * @prepare_message: set up the controller to transfer a single message,
  *                   for example doing DMA mapping.  Called from threaded
  *                   context.
- * @transfer_one: transfer a single spi_transfer. When the
- *               driver is finished with this transfer it must call
- *               spi_finalize_current_transfer() so the subsystem can issue
- *                the next transfer
+ * @transfer_one: transfer a single spi_transfer.
+ *                  - return 0 if the transfer is finished,
+ *                  - return 1 if the transfer is still in progress. When
+ *                    the driver is finished with this transfer it must
+ *                    call spi_finalize_current_transfer() so the subsystem
+ *                    can issue the next transfer. Note: transfer_one and
+ *                    transfer_one_message are mutually exclusive; when both
+ *                    are set, the generic subsystem does not call your
+ *                    transfer_one callback.
  * @unprepare_message: undo any work done by prepare_message().
  * @cs_gpios: Array of GPIOs to use as chip select lines; one per CS
  *     number. Any individual value may be -ENOENT for CS lines that
@@ -576,8 +581,8 @@ struct spi_transfer {
        dma_addr_t      rx_dma;
 
        unsigned        cs_change:1;
-       u8              tx_nbits;
-       u8              rx_nbits;
+       unsigned        tx_nbits:3;
+       unsigned        rx_nbits:3;
 #define        SPI_NBITS_SINGLE        0x01 /* 1bit transfer */
 #define        SPI_NBITS_DUAL          0x02 /* 2bits transfer */
 #define        SPI_NBITS_QUAD          0x04 /* 4bits transfer */
@@ -847,7 +852,7 @@ static inline ssize_t spi_w8r16(struct spi_device *spi, u8 cmd)
        ssize_t                 status;
        u16                     result;
 
-       status = spi_write_then_read(spi, &cmd, 1, (u8 *) &result, 2);
+       status = spi_write_then_read(spi, &cmd, 1, &result, 2);
 
        /* return negative errno or unsigned value */
        return (status < 0) ? status : result;