The controller can only support up to 31 dummy cycles. If the command
requires more it falls back to using 31. This command is likely to fail
because the correct number of cycles are not waited upon. Rather than
silently issuing an incorrect command, fail loudly so the caller can get
a chance to find out the command can't be supported by the controller.
Fixes: 1406234105 ("mtd: spi-nor: Add driver for Cadence Quad SPI Flash Controller")
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-3-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
As of commit 9326e4f1e5 ("spi: Limit the spi device max speed to
controller's max speed"), the SPI device max speed is set to the
controller's max speed if it is larger. The Cadence QSPI controller does
not set the controller's max speed so it is left at its initial value of
0. This means the SPI device max speed is always set to 0.
The SPI device max speed is used to calculate the baud rate divider when
performing an operation. If this speed is 0, the default divider of 32
is used. No matter what speed is specified by the device tree property
'spi-max-frequency', the device will always operate at ref_clk / 32.
Fix this by setting master->max_speed_hz to the ref clock speed so the
correct divider can be calculated.
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/r/20201222184425.7028-2-p.yadav@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Buffers need to mapped to DMA channel's device pointer instead of SPI
controller's device pointer as its system DMA that actually does data
transfer.
Data inconsistencies have been reported when reading from flash
without this fix.
Fixes: ffa639e069 ("mtd: spi-nor: cadence-quadspi: Add DMA support for direct mode reads")
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Tested-by: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lore.kernel.org/r/20200831130720.4524-1-vigneshr@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
