From 2733092baa3e8a1f05fd16088808be17c98990b4 Mon Sep 17 00:00:00 2001 From: David Lechner Date: Fri, 26 Jan 2024 16:00:23 -0600 Subject: [PATCH] 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 Link: https://lore.kernel.org/r/20240126220024.3926403-2-dlechner@baylibre.com Signed-off-by: Mark Brown --- drivers/spi/spi-bcm2835.c | 27 ++++++++++++++------------- 1 file 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;