The 'poll_transfer' function employs a conditional to test whether the
transmit buffer is valid; in doing so, on a receive operation no data is
clocked out, thus no data is clocked in and ultimately errors appear.
This removes the conditional as the transmit function will be set to a null
writer when the transmit buffer is invalid, allowing the driver to clock
0x00 out to the device to receive data from the device.
Signed-off-by: George Shore <george@georgeshore.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
FIFO depth is configurable for each implementation of DW core,
so add a depth detection for those interface drivers who don't set
the fifo_len explicitly
Signed-off-by: Feng Tang <feng.tang@intel.com>
Acked-by: Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Now dw_spi core fully supports 3 transfer modes: pure polling,
DMA and IRQ mode. IRQ mode will use the FIFO half empty as
the IRQ trigger, so each interface driver need set the fifo_len,
so that core driver can handle it properly
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Make the driver wait at least for 1 jiffie before issuing the
warning, no matter what HZ is set to
Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Driver for the Designware SPI core, it supports multipul interfaces like
PCI/APB etc. User can use "dw_apb_ssi_db.pdf" from Synopsys as HW
datasheet.
[randy.dunlap@oracle.com: fix build]
[akpm@linux-foundation.org: build fix]
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
