[PATCH 0/2] spi: dw: Reintroduce optional 16 bit data register I/O
Michael van der Westhuizen
michael at smart-africa.com
Fri Jun 19 01:43:53 PDT 2015
The commit dd11444327ce ("spi: dw-spi: Convert 16bit accesses to 32bit
accesses") globally changed all register access in the dw_apb_ssi driver
to 32 bit access, which breaks data register (FIFO) access on picoXcell
platforms.
This series introduces a boolean to the core spi-dw driver to indicate
to the core that 16 bit data register access is appropriate, implements
the code that respects that flag and updates the dw-spi-mmio driver to
allow setting this boolean from the device tree.
A binding documentation fix is included in this series.
Prior to applying this change the following error presents on
a picoCell pc3x3 platform:
spi_master spi32766: interrupt_transfer: fifo overrun/underrun
m25p80 spi32766.0: error -5 reading 9f
m25p80: probe of spi32766.0 failed with error -5
With this series applied:
m25p80 spi32766.0: m25p40 (512 Kbytes)
Michael van der Westhuizen (2):
dt: snps,dw-apb-ssi: Describe 16 bit data register usage limitations
spi: dw: Allow interface drivers to limit data I/O to word sizes
Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt | 3 +++
drivers/spi/spi-dw-mmio.c | 5 +++++
drivers/spi/spi-dw.c | 13 +++++++++++--
drivers/spi/spi-dw.h | 11 +++++++++++
4 files changed, 30 insertions(+), 2 deletions(-)
--
2.1.4
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