[PATCH v4 3/5] mtd: devices: m25p80: add support for mmap read request
From: vigneshr@ti.com (Vignesh R)
Date: 2015-11-30 05:17:28
Also in:
linux-devicetree, linux-omap, linux-spi, lkml
Subsystem:
memory technology devices (mtd), the rest · Maintainers:
Miquel Raynal, Richard Weinberger, Vignesh Raghavendra, Linus Torvalds
Certain spi controllers may provide accelerated interface to read from m25p80 type flash devices. This interface provides better read performance than regular SPI interface. Call spi_flash_read(), if supported, to make use of such interface. Signed-off-by: Vignesh R <vigneshr@ti.com> --- v4: * Use spi_flash_read_message struct to pass args. * support passing of opcode/addr/data nbits. drivers/mtd/devices/m25p80.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+)
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index fe9ceb7b5405..00094a668c62 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c@@ -131,6 +131,26 @@ static int m25p80_read(struct spi_nor *nor, loff_t from, size_t len, /* convert the dummy cycles to the number of bytes */ dummy /= 8; + if (spi_flash_read_supported(spi)) { + struct spi_flash_read_message msg; + int ret; + + msg.buf = buf; + msg.from = from; + msg.len = len; + msg.read_opcode = nor->read_opcode; + msg.addr_width = nor->addr_width; + msg.dummy_bytes = dummy; + /* TODO: Support other combinations */ + msg.opcode_nbits = SPI_NBITS_SINGLE; + msg.addr_nbits = SPI_NBITS_SINGLE; + msg.data_nbits = m25p80_rx_nbits(nor); + + ret = spi_flash_read(spi, &msg); + *retlen = msg.retlen; + return ret; + } + spi_message_init(&m); memset(t, 0, (sizeof t));
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2.6.3