From: Martin Sperl <[email protected]> Start to use spi_translate_message method when running in DMA mode and (for now) split spi_transfers with len > 60kB transparently into multiple transfers using the core method spi_split_transfers_maxsize.
Eventually the bcm2835_translate_message may get moved into SPI-core as shared code (when we find the common denominators for different HW) Signed-off-by: Martin Sperl <[email protected]> --- drivers/spi/spi-bcm2835.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index cf04960..03c889d 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -353,6 +353,14 @@ static int bcm2835_spi_transfer_one_dma(struct spi_master *master, return 1; } +static int bcm2835_translate_message(struct spi_master *master, + struct spi_message *message) +{ + /* translate the message */ + return spi_split_transfers_maxsize(master, message, + master->max_dma_len); +} + static bool bcm2835_spi_can_dma(struct spi_master *master, struct spi_device *spi, struct spi_transfer *tfr) @@ -365,19 +373,6 @@ static bool bcm2835_spi_can_dma(struct spi_master *master, if (tfr->len < BCM2835_SPI_DMA_MIN_LENGTH) return false; - /* BCM2835_SPI_DLEN has defined a max transfer size as - * 16 bit, so max is 65535 - * we can revisit this by using an alternative transfer - * method - ideally this would get done without any more - * interaction... - */ - if (tfr->len > 65535) { - dev_warn_once(&spi->dev, - "transfer size of %d too big for dma-transfer\n", - tfr->len); - return false; - } - /* if we run rx/tx_buf with word aligned addresses then we are OK */ if ((((size_t)tfr->rx_buf & 3) == 0) && (((size_t)tfr->tx_buf & 3) == 0)) @@ -461,7 +456,15 @@ static void bcm2835_dma_init(struct spi_master *master, struct device *dev) /* all went well, so set can_dma */ master->can_dma = bcm2835_spi_can_dma; - master->max_dma_len = 65535; /* limitation by BCM2835_SPI_DLEN */ + + /* also set up transform message */ + master->translate_message = bcm2835_translate_message; + + /* the max_dma_size limited by BCM2835_SPI_DLEN is actually 65535, + * but for al practical purposes we use 15 pages (60k) + */ + master->max_dma_len = 15 * PAGE_SIZE; + master->dma_alignment = 4; /* word alignment is recommended */ /* need to do TX AND RX DMA, so we need dummy buffers */ master->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX; -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
