By specification the FIFO size would be in a range 2-256 bytes. From TX Level
prospective it means we can set threshold in the range 0-(FIFO size - 1) bytes.
Hence there are currently two issues:
a) FIFO size 2 bytes is actually skipped since TX Level is 1 bit and could be
either 0 or 1 byte;
b) FIFO size is incorrectly decreased by 1 which already done by meaning of
TX Level register.
Fixes: 501943696e (spi: designware_spi: Fix detecting FIFO depth)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
This is common to all SPI drivers and specifies a structure used by the
uclass. It makes more sense to define it in the uclass.
Reviewed-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
Linux now also contains SPI driver, yet the name is 'snps,dw-apb-ssi'.
Fix the naming before we have to support both names.
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Chin Liang See <clsee@opensource.altera.com>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Pavel Machek <pavel@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Vince Bridgers <vbridger@opensource.altera.com>
Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Current code tries to find the highest valid fifo depth by checking the value
it wrote to DW_SPI_TXFLTR. There are a few problems in current code:
1) There is an off-by-one in dws->fifo_len setting because it assumes the latest
register write fails so the latest valid value should be fifo - 1.
2) We know the depth could be from 2 to 256 from HW spec, so it is not necessary
to test fifo == 257. In the case fifo is 257, it means the latest valid
setting is fifo = 256. So after the for loop iteration, we should check
fifo == 2 case instead of fifo == 257 if detecting the FIFO depth fails.
This patch fixes above issues.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Stefan Roese <sr@denx.de>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
As suggested by Pavel, here some fixes to the designware SPI driver:
- Spelling fixes
- Comment for timeout added
- Removed n_bytes completely (bits_per_word is enough for this)
- Unput clock now not defined via macro. The function to
get the clock value is now called directly from within the driver
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Pavel Machek <pavel@denx.de>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
This patch adds the driver for the Designware master SPI controller. This
IP core is integrated on the Altera SoCFPGA. This implementation is a
driver model (DM) implementation. So multiple SPI drivers can be used.
Thats necessary, since SoCFPGA also integrates the Cadence QSPI controller
used to connect the SPI NOR flashes. Without DM, using multiple SPI
drivers is not possible.
This driver is very loosely based on the Linux driver. Most of the Linux
driver is removed. Only the polling loop for the transfer is really used
from this driver, as we don't support interrupts and DMA right now.
This is tested on the SoCrates SoCFPGA board using the SPI pins on the
P14 header.
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Pavel Machek <pavel@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Axel Lin
Simon Glass
Marek Vasut
Stefan Roese