The gpiolib code does not allow people to do gpio_request() on a GPIO
once it has already been requested. So make sure we only request the
pin on the first setup of a SPI device. Otherwise, if you attempts to
reconfigure a SPI device on the fly (like change bit sizes), the setup
function incorrectly fails.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The error interrupt on the BF537 SIC cannot be enabled on a
per-peripheral basis. Once the error interrupt is enabled
for one peripheral, it is automatically enabled for all.
So in the Blackfin on-chip SPI driver, we need to clear out
these known errors in the data interrupt once we've successfully
finished processing all of the pending data.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Some systems using this bus sometimes have very basic devices on them
such as regulators. So we need to be loaded even earlier in case the
devices are used by things such as early board init code. Therefore
register in subsys_initcall().
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Currently, if the bits_per_word when doing a transfer is not 8bits, we
always treat it as 16bits when we should actually be returning an error.
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
When the hardware is controlling the CS, there are some SPI options
we are unable to support. So issue a warning in the hopes that the
user will change to a SPI mode where we can support things sanely.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Using disable_irq() on the IRQ whose handler we are currently executing in
can easily lead to a hang. So use the nosync variant here.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
While combining things, also switch to the proper SPI bit define names.
This lets us punt the rarely used SPI defines.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
During runtime, the spi setup function may be called multiple times on the
same device in order to reconfigure some settings on the fly. When this
happens, we need to reset the ctl_reg bits so that changing the mode works
as expected.
Reported-by: Andy Getzendanner <james.getzendanner@students.olin.edu>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
This reduces duplication between the setup/transfer functions and keeps
values cached during setup from overriding values changed on a transfer
basis (like bits_per_word).
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Using disable_irq() on the IRQ whose handler we are currently executing in
can easily lead to a hang. So use the nosync variant here.
Signed-off-by: Yi Li <yi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Sometimes under load, the Blackfin core is able to send SPI register
updates out before the controller is actually disabled. So when we
go to reprogram the entire state (to switch to a different slave),
make sure we sync after disabling the controller.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
We can't rely on the SPI_CTL/SPI_FLG registers retaining their state when
suspending, so save/restore their entire values.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The common SPI layers take care of detecting CS conflicts and preventing
two devices from claiming the same CS. This causes problems for the GPIO
CS support we currently have as we are using CS0 to mean "GPIO CS". But
if we have multiple devices using a GPIO CS, the common SPI layers see
multiple devices using the virtual "CS0" and reject any such attempts.
To make both work, we introduce an offset define. This represents the
max number of hardware CS values that the SPI peripheral supports. If
the CS is below this limit, we know we can use the hardware CS. If it's
above, we treat it as a GPIO CS. This keeps the CS unique as seen by
the common code and prevents conflicts.
Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The driver that we based ours on uses a little extra memory behind the
normal driver state, but we don't. So drop this useless bit of memory.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The current structure names are a bit confusing as to what they represent,
so use better names.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Rather than having to look up the same 3 sets of functions at the same
time, just use an ops structure so we only need to set one pointer.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
No point in creating our own version of true/false defines when there is
already a standard stdbool available to us.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The chip ops should always be initialized, so having null fallback
functions are useless.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
As David points out, the cs_change_per_word option isn't standard, nor is
anyone actually using it. So punt all of the dead code considering it
makes up ~10% of the code size.
Reported-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Michael Hennerich
Mike Frysinger
Bob Liu
Barry Song
Rob Maris
Yi Li