diff options
| -rw-r--r-- | drivers/spi/spi.c | 110 |
1 files changed, 68 insertions, 42 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index f68d92b57543..ba4d3fde2054 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1747,38 +1747,6 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr, trace_spi_message_start(msg); - /* - * If an SPI controller does not support toggling the CS line on each - * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO - * for the CS line, we can emulate the CS-per-word hardware function by - * splitting transfers into one-word transfers and ensuring that - * cs_change is set for each transfer. - */ - if ((msg->spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || - spi_is_csgpiod(msg->spi))) { - ret = spi_split_transfers_maxwords(ctlr, msg, 1); - if (ret) { - msg->status = ret; - spi_finalize_current_message(ctlr); - return ret; - } - - list_for_each_entry(xfer, &msg->transfers, transfer_list) { - /* Don't change cs_change on the last entry in the list */ - if (list_is_last(&xfer->transfer_list, &msg->transfers)) - break; - xfer->cs_change = 1; - } - } else { - ret = spi_split_transfers_maxsize(ctlr, msg, - spi_max_transfer_size(msg->spi)); - if (ret) { - msg->status = ret; - spi_finalize_current_message(ctlr); - return ret; - } - } - if (ctlr->prepare_message) { ret = ctlr->prepare_message(ctlr, msg); if (ret) { @@ -2124,6 +2092,8 @@ static void __spi_unoptimize_message(struct spi_message *msg) if (ctlr->unoptimize_message) ctlr->unoptimize_message(msg); + spi_res_release(ctlr, msg); + msg->optimized = false; msg->opt_state = NULL; } @@ -2169,15 +2139,6 @@ void spi_finalize_current_message(struct spi_controller *ctlr) spi_unmap_msg(ctlr, mesg); - /* - * In the prepare_messages callback the SPI bus has the opportunity - * to split a transfer to smaller chunks. - * - * Release the split transfers here since spi_map_msg() is done on - * the split transfers. - */ - spi_res_release(ctlr, mesg); - if (mesg->prepared && ctlr->unprepare_message) { ret = ctlr->unprepare_message(ctlr, mesg); if (ret) { @@ -3819,6 +3780,10 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, * @msg: the @spi_message to transform * @maxsize: the maximum when to apply this * + * This function allocates resources that are automatically freed during the + * spi message unoptimize phase so this function should only be called from + * optimize_message callbacks. + * * Return: status of transformation */ int spi_split_transfers_maxsize(struct spi_controller *ctlr, @@ -3857,6 +3822,10 @@ EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); * @msg: the @spi_message to transform * @maxwords: the number of words to limit each transfer to * + * This function allocates resources that are automatically freed during the + * spi message unoptimize phase so this function should only be called from + * optimize_message callbacks. + * * Return: status of transformation */ int spi_split_transfers_maxwords(struct spi_controller *ctlr, @@ -4232,6 +4201,57 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) } /* + * spi_split_transfers - generic handling of transfer splitting + * @msg: the message to split + * + * Under certain conditions, a SPI controller may not support arbitrary + * transfer sizes or other features required by a peripheral. This function + * will split the transfers in the message into smaller transfers that are + * supported by the controller. + * + * Controllers with special requirements not covered here can also split + * transfers in the optimize_message() callback. + * + * Context: can sleep + * Return: zero on success, else a negative error code + */ +static int spi_split_transfers(struct spi_message *msg) +{ + struct spi_controller *ctlr = msg->spi->controller; + struct spi_transfer *xfer; + int ret; + + /* + * If an SPI controller does not support toggling the CS line on each + * transfer (indicated by the SPI_CS_WORD flag) or we are using a GPIO + * for the CS line, we can emulate the CS-per-word hardware function by + * splitting transfers into one-word transfers and ensuring that + * cs_change is set for each transfer. + */ + if ((msg->spi->mode & SPI_CS_WORD) && + (!(ctlr->mode_bits & SPI_CS_WORD) || spi_is_csgpiod(msg->spi))) { + ret = spi_split_transfers_maxwords(ctlr, msg, 1); + if (ret) + return ret; + + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + /* Don't change cs_change on the last entry in the list */ + if (list_is_last(&xfer->transfer_list, &msg->transfers)) + break; + + xfer->cs_change = 1; + } + } else { + ret = spi_split_transfers_maxsize(ctlr, msg, + spi_max_transfer_size(msg->spi)); + if (ret) + return ret; + } + + return 0; +} + +/* * __spi_optimize_message - shared implementation for spi_optimize_message() * and spi_maybe_optimize_message() * @spi: the device that will be used for the message @@ -4254,10 +4274,16 @@ static int __spi_optimize_message(struct spi_device *spi, if (ret) return ret; + ret = spi_split_transfers(msg); + if (ret) + return ret; + if (ctlr->optimize_message) { ret = ctlr->optimize_message(msg); - if (ret) + if (ret) { + spi_res_release(ctlr, msg); return ret; + } } msg->optimized = true; |