Commit graph

12 commits

Author SHA1 Message Date
Simon Glass
0efc02499f spi_flash: Add spi_flash_probe_fdt() to locate SPI by FDT node
This allows us to put the SPI flash chip inside the SPI interface node,
with U-Boot finding the correct bus and chip select automatically.

Signed-off-by: Simon Glass <sjg@chromium.org>
2013-12-09 12:22:12 -07:00
Rajeshwari Shinde
c4a796329d spi: exynos: Support word transfers
Since SPI register access is so expensive, it is worth transferring data
a word at a time if we can. This complicates the driver unfortunately.

Use the byte-swapping feature to avoid having to convert to/from big
endian in software.

This change increases speed from about 2MB/s to about 4.5MB/s.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari S Shinde <rajeshwari.s@samsung.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
2013-10-08 18:18:12 +05:30
Rajeshwari Shinde
120af1572a spi: exynos: Minimise access to SPI FIFO level
Accessing SPI registers is slow, but access to the FIFO level register
in particular seems to be extraordinarily expensive (I measure up to
600ns). Perhaps it is required to synchronise with the SPI byte output
logic which might run at 1/8th of the 40MHz SPI speed (just a guess).

Reduce access to this register by filling up and emptying FIFOs
more completely, rather than just one word each time around the inner
loop.

Since the rxfifo value will now likely be much greater that what we read
before we fill the txfifo, we only fill the txfifo halfway. This is
because if the txfifo is empty, but the rxfifo has data in it, then writing
too much data to the txfifo may overflow the rxfifo as data arrives.

This speeds up SPI flash reading from about 1MB/s to about 2MB/s on snow.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari S Shinde <rajeshwari.s@samsung.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
2013-10-08 18:18:11 +05:30
Rajeshwari Shinde
8d203afdd3 spi: exynos: Support a delay after deactivate
For devices that need some time to react after a spi transaction
finishes, add the ability to set a delay.

Implement this as a delay on the first/next transaction to avoid
any delay in the fairly common case where a SPI transaction is
followed by other processing.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari S Shinde <rajeshwari.s@samsung.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
2013-10-08 18:18:11 +05:30
Wolfgang Denk
1a4596601f Add GPL-2.0+ SPDX-License-Identifier to source files
Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
2013-07-24 09:44:38 -04:00
Hung-ying Tyan
f3424c554c cros: exynos: add SPI support for cros_ec
This patch adds SPI support for carrying out the cros_ec protocol.

Signed-off-by: Hung-ying Tyan <tyanh@chromium.org>
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
2013-06-26 10:13:24 -04:00
Rajeshwari Shinde
e4eaef8910 spi: exynos: Support SPI_PREAMBLE mode
Support interfaces with a preamble before each received message.

We handle this when the client has requested a SPI_XFER_END, meaning
that we must close of the transaction. In this case we read until we
see the preamble (or a timeout occurs), skipping all data before and
including the preamble. The client will receive only data bytes after
the preamble.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
2013-06-03 00:04:40 +05:30
Albert ARIBAUD
fed029f3c3 Merge branch 'u-boot-samsung/master' into 'u-boot-arm/master' 2013-04-04 15:44:57 +02:00
Vivek Gautam
7d17958408 spi: exynos: Fix compiler warnings for non-dt systems
Enclosing process_nodes() and spi_get_config() inside
CONFIG_OF_CONTROL, since they are compiled only for DT systems.

This fixes following warning:
exynos_spi.c:391:12: warning: 'process_nodes' defined but not used [-Wunused-function]

Signed-off-by: Vivek Gautam <gautam.vivek@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2013-03-29 11:16:25 +09:00
Simon Glass
d3504fee73 spi: Use spi_alloc_slave() in each SPI driver
Rather than each driver having its own way to allocate a SPI slave,
use the new allocation function everywhere. This will make it easier
to extend the interface without breaking drivers.

Signed-off-by: Simon Glass <sjg@chromium.org>
2013-03-19 08:45:36 -07:00
Rajeshwari Shinde
4d3acb9df3 SPI: EXYNOS: Add FDT support to driver.
This patch adds FDT support to the SPI driver.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2013-01-08 10:54:34 +09:00
Rajeshwari Shinde
1bf43b829e SPI: Add SPI Driver for EXYNOS.
This patch adds SPI driver for EXYNOS.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Padmavathi Venna <padma.v@samsung.com>
Signed-off-by: Gabe Black <gabeblack@google.com>
Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
Signed-off-by: Hatim Ali <hatim.rv@samsung.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: jy0922.shim@samsung.com
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
2012-11-15 21:08:21 +09:00