The Zynq QSPI controller features 2 CS. When the num-cs DT property
is set to 2, the hardware will be initialized to support having two
devices connected over each CS.
In this case, both CS lines are driven by the state of the U_PAGE
(upper page) bit. When unset, the lower page (CS0) is selected,
otherwise it is the upper page (CS1).
Change tested on a custom design featuring two SPI-NORs with different
CS on the Zynq-7000 QSPI bus.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-8-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Supporting more than one CS will need some tweaking of the linear
configuration register which is (rightfully) initialized in the
hardware initialization helper. The extra initialization needs the
knowledge of the actual number of CS, which is retrieved by reading
the value of the num-cs DT property.
As the initialization helper is called pretty early and might be
called much later in the probe without side effect, let's delay it a
bit so that the number of CS will be available when running this
helper. This way, adding support for multiple CS lines in a next patch
will be eased.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-7-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
The code used to assert and de-assert a chip select line is very
complicated for no reason. Simplify the logic by either setting or
resetting the concerned bit, which actually only changes an electrical
state.
Update the comment to reflect that there is no possibility to actually
choose a CS as the default (CS0) will be driven in any case.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-6-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.
// <smpl>
@@
expression ret;
struct platform_device *E;
@@
ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);
if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>
While we're here, remove braces on if statements that only have one
statement (manually).
Cc: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-42-swboyd@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Alpha and some of the architectures are missing readsl/writesl functions.
so the zynq-qspi driver won't be able to build on these arches. hence use
ioread32_rep()/iowrite32_rep() instead of readsl()/writesl().
Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
