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path: root/drivers/spi/exynos_spi.c
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* dm: exynos: Convert SPI to driver modelSimon Glass2014-10-22-333/+180
| | | | | | | | | | Move the exynos SPI driver over to driver model. This removes quite a bit of boilerplate from the driver, although it adds some for driver model. A few device tree additions are needed to make the SPI flash available. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
* exynos: spi: Fix calculation of SPI transaction start timeSimon Glass2014-08-06-4/+5
| | | | | | | | | | The SPI transaction delay is supposed to be measured from the end of one transaction to the start of the next. The code does not work that way, so fix it. Signed-off-by: Simon Glass <sjg@chromium.org> Tested-by: Ajay Kumar <ajaykumar.rs@samsung.com> Reviewed-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
* Exynos: SPI: Fix reading data from SPI flashAkshay Saraswat2014-06-23-1/+4
| | | | | | | | | | | | | | | SPI recieve and transfer code in exynos_spi driver has a logical bug. We read data in a variable which can hold an integer. Then we assign this integer 32 bit value to another variable which has data type uchar. Latter represents a unit of our recieve buffer. Everytime when we write a value to our recieve buffer we step ahead by 4 units when actually we wrote to one unit. This results in the loss of 3 bytes out of every 4 bytes recieved. This patch intends to fix this bug. Signed-off-by: Akshay Saraswat <akshay.s@samsung.com> Acked-by: Simon Glass <sjg@chromium.org> Tested-by: Simon Glass <sjg@chromium.org> Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
* spi_flash: Add spi_flash_probe_fdt() to locate SPI by FDT nodeSimon Glass2013-12-09-5/+5
| | | | | | | 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>
* spi: exynos: Support word transfersRajeshwari Shinde2013-10-08-15/+61
| | | | | | | | | | | | | | 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>
* spi: exynos: Minimise access to SPI FIFO levelRajeshwari Shinde2013-10-08-12/+15
| | | | | | | | | | | | | | | | | | | | | | 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>
* spi: exynos: Support a delay after deactivateRajeshwari Shinde2013-10-08-0/+20
| | | | | | | | | | | | | 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>
* Add GPL-2.0+ SPDX-License-Identifier to source filesWolfgang Denk2013-07-24-13/+1
| | | | | | Signed-off-by: Wolfgang Denk <wd@denx.de> [trini: Fixup common/cmd_io.c] Signed-off-by: Tom Rini <trini@ti.com>
* cros: exynos: add SPI support for cros_ecHung-ying Tyan2013-06-26-0/+22
| | | | | | | | | 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>
* spi: exynos: Support SPI_PREAMBLE modeRajeshwari Shinde2013-06-03-10/+59
| | | | | | | | | | | | | | 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>
* Merge branch 'u-boot-samsung/master' into 'u-boot-arm/master'Albert ARIBAUD2013-04-04-0/+2
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| * spi: exynos: Fix compiler warnings for non-dt systemsVivek Gautam2013-03-29-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | spi: Use spi_alloc_slave() in each SPI driverSimon Glass2013-03-19-3/+1
|/ | | | | | | | 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>
* SPI: EXYNOS: Add FDT support to driver.Rajeshwari Shinde2013-01-08-6/+90
| | | | | | | | | 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>
* SPI: Add SPI Driver for EXYNOS.Rajeshwari Shinde2012-11-15-0/+367
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>
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