diff options
| author | David Lechner <dlechner@baylibre.com> | 2024-01-26 23:00:23 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2024-02-05 15:35:44 +0100 |
| commit | 2733092baa3e8a1f05fd16088808be17c98990b4 (patch) | |
| tree | b17ec3ea00c6fd04015aad2f9fcefc7f7283e734 | |
| parent | spi: move split xfers for CS_WORD emulation (diff) | |
| download | linux-2733092baa3e8a1f05fd16088808be17c98990b4.tar.xz linux-2733092baa3e8a1f05fd16088808be17c98990b4.zip | |
spi: bcm2835: implement ctlr->max_transfer_size
The core SPI code will handle splitting transfers if needed as long
as ctlr->max_transfer_size is implemented. It does this in
__spi_pump_transfer_message() immediately before calling
ctlr->prepare_message. So effectively, this change does not
alter the behavior of the driver.
Also, several peripheral drivers make use of spi_max_transfer_size(),
so this should improve compatibility with those drivers.
Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20240126220024.3926403-2-dlechner@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | drivers/spi/spi-bcm2835.c | 27 |
1 files changed, 14 insertions, 13 deletions
diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index e709887eb2a9..e1b9b1235787 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1117,19 +1117,6 @@ static int bcm2835_spi_prepare_message(struct spi_controller *ctlr, struct spi_device *spi = msg->spi; struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr); struct bcm2835_spidev *target = spi_get_ctldata(spi); - int ret; - - if (ctlr->can_dma) { - /* - * DMA transfers are limited to 16 bit (0 to 65535 bytes) by - * the SPI HW due to DLEN. Split up transfers (32-bit FIFO - * aligned) if the limit is exceeded. - */ - ret = spi_split_transfers_maxsize(ctlr, msg, 65532, - GFP_KERNEL | GFP_DMA); - if (ret) - return ret; - } /* * Set up clock polarity before spi_transfer_one_message() asserts @@ -1219,6 +1206,19 @@ static int bcm2835_spi_setup_dma(struct spi_controller *ctlr, return 0; } +static size_t bcm2835_spi_max_transfer_size(struct spi_device *spi) +{ + /* + * DMA transfers are limited to 16 bit (0 to 65535 bytes) by + * the SPI HW due to DLEN. Split up transfers (32-bit FIFO + * aligned) if the limit is exceeded. + */ + if (spi->controller->can_dma) + return 65532; + + return SIZE_MAX; +} + static int bcm2835_spi_setup(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; @@ -1348,6 +1348,7 @@ static int bcm2835_spi_probe(struct platform_device *pdev) ctlr->mode_bits = BCM2835_SPI_MODE_BITS; ctlr->bits_per_word_mask = SPI_BPW_MASK(8); ctlr->num_chipselect = 3; + ctlr->max_transfer_size = bcm2835_spi_max_transfer_size; ctlr->setup = bcm2835_spi_setup; ctlr->cleanup = bcm2835_spi_cleanup; ctlr->transfer_one = bcm2835_spi_transfer_one; |