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greybus: spi: add inprogress bit to xfer_flags 

When a SPI transfer needs to be split by more than one greybus spi
transfer operation, we need to indicate it so the controller can handle
the chip select lines correctly.

Add a new bit to indicate it, GB_SPI_XFER_INPROGRESS, and create an
helper function to calculate when the transfer is done. As we need this
information also in other places.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Rui Miguel Silva 2016-05-16 10:33:21 +01:00 committed by Greg Kroah-Hartman
parent 22e26a3a13
commit 3a238fc784
2 changed files with 15 additions and 2 deletions
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1
drivers/staging/greybus/greybus_protocols.h
View File

@ -879,6 +879,7 @@ struct gb_spi_transfer {
__u8 xfer_flags; __u8 xfer_flags;
#define GB_SPI_XFER_READ 0x01 #define GB_SPI_XFER_READ 0x01
#define GB_SPI_XFER_WRITE 0x02 #define GB_SPI_XFER_WRITE 0x02
#define GB_SPI_XFER_INPROGRESS 0x04
} __packed; } __packed;
struct gb_spi_transfer_request { struct gb_spi_transfer_request {

16
drivers/staging/greybus/spilib.c
View File

@ -102,6 +102,17 @@ static void clean_xfer_state(struct gb_spilib *spi)
spi->op_timeout = 0; spi->op_timeout = 0;
} }
static bool is_last_xfer_done(struct gb_spilib *spi)
{
struct spi_transfer *last_xfer = spi->last_xfer;
if ((spi->tx_xfer_offset + spi->last_xfer_size == last_xfer->len) ||
(spi->rx_xfer_offset + spi->last_xfer_size == last_xfer->len))
return true;
return false;
}
static int setup_next_xfer(struct gb_spilib *spi, struct spi_message *msg) static int setup_next_xfer(struct gb_spilib *spi, struct spi_message *msg)
{ {
struct spi_transfer *last_xfer = spi->last_xfer; struct spi_transfer *last_xfer = spi->last_xfer;
@ -113,8 +124,7 @@ static int setup_next_xfer(struct gb_spilib *spi, struct spi_message *msg)
* if we transferred all content of the last transfer, reset values and * if we transferred all content of the last transfer, reset values and
* check if this was the last transfer in the message * check if this was the last transfer in the message
*/ */
if ((spi->tx_xfer_offset + spi->last_xfer_size == last_xfer->len) || if (is_last_xfer_done(spi)) {
(spi->rx_xfer_offset + spi->last_xfer_size == last_xfer->len)) {
spi->tx_xfer_offset = 0; spi->tx_xfer_offset = 0;
spi->rx_xfer_offset = 0; spi->rx_xfer_offset = 0;
spi->op_timeout = 0; spi->op_timeout = 0;
@ -265,6 +275,8 @@ static struct gb_operation *gb_spi_operation_create(struct gb_spilib *spi,
gb_xfer->xfer_flags |= GB_SPI_XFER_READ; gb_xfer->xfer_flags |= GB_SPI_XFER_READ;
if (xfer == spi->last_xfer) { if (xfer == spi->last_xfer) {
if (!is_last_xfer_done(spi))
gb_xfer->xfer_flags |= GB_SPI_XFER_INPROGRESS;
msg->state = GB_SPI_STATE_OP_DONE; msg->state = GB_SPI_STATE_OP_DONE;
continue; continue;
} }