From f4502dd1da9b060a49d539eb754ff86cb97b89f0 Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Wed, 8 Jun 2016 12:18:31 +0530 Subject: spi: Add DMA support for spi_flash_read() Few SPI devices provide accelerated read interfaces to read from SPI-NOR flash devices. These hardwares also support DMA to transfer data from flash to memory either via mem-to-mem DMA or dedicated slave DMA channels. Hence, add support for DMA in order to improve throughput and reduce CPU load. Use spi_map_buf() to get sg table for the buffer and pass it to SPI driver. Signed-off-by: Vignesh R Signed-off-by: Mark Brown --- include/linux/spi/spi.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux') diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 1f03483f61e5..7b53af4ba5f8 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -1143,6 +1143,8 @@ static inline ssize_t spi_w8r16be(struct spi_device *spi, u8 cmd) * @opcode_nbits: number of lines to send opcode * @addr_nbits: number of lines to send address * @data_nbits: number of lines for data + * @rx_sg: Scatterlist for receive data read from flash + * @cur_msg_mapped: message has been mapped for DMA */ struct spi_flash_read_message { void *buf; @@ -1155,6 +1157,8 @@ struct spi_flash_read_message { u8 opcode_nbits; u8 addr_nbits; u8 data_nbits; + struct sg_table rx_sg; + bool cur_msg_mapped; }; /* SPI core interface for flash read support */ -- cgit v1.2.3-71-gd317