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mtd: devices: m25p80: add support for mmap read request

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Certain SPI controllers may provide accelerated hardware interface to
read from m25p80 type flash devices in order to provide better read
performance. SPI core supports such devices with spi_flash_read() API.
Call spi_flash_read(), if supported, to make use of such interface.

Signed-off-by: Vignesh R <vigneshr@ti.com>
[Brian: add memset()]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
This commit is contained in:
Vignesh R 2016-03-29 11:16:17 +05:30 committed by Brian Norris
parent 5651d6aaf4
commit 08922f6448
1 changed files with 22 additions and 0 deletions
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22
drivers/mtd/devices/m25p80.c
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@ -131,6 +131,28 @@ 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;
memset(&msg, 0, sizeof(msg));
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));