On 10/31/2013 05:17 PM, Steffen Trumtrar wrote:
On Thu, Oct 31, 2013 at 04:07:23PM +0000, Jamie Iles wrote:
On Thu, Oct 31, 2013 at 04:58:03PM +0100, Steffen Trumtrar wrote:
I wonder if we want to really keep the binding as it is proposed by
Jamie. Do we really win anything by having to specify the banks in the
DT? In my version I get the number of ports, width etc. from the config registers
of the device. I think everything that the device knows itself and can be read
out at runtime shouldn't be specified in the DT.
And it seems that the binding was never merged, so I guess we can change it.
The reason for having it split into banks is that for hardware that has
a mixture of bank sizes (odd hardware admittedly, but that includes
hardware that I was writing the driver for), we had a setup like 16 pins
on bank A, 16 on B, 1 on C and 16 on D where each bank could have a
maximum of 32, so converting from a data sheet to GPIO number is not
obvious. Grant Likely suggested representing the banks as different
devices, so that's how I created the binding.
I have no problem with the binding, if it is worth it. Do you mean you had
hardware where the gpio lines where not connected? Or maybe you had an older
version of the IP core?
In the Socfpga case there is gpio_config_reg2, which specifies the width
for every of the 4 ports. So I thought I use those values to describe my
hardware. The Socfpga however only uses the first bank of its three GPIO cores,
so I wouldn't be able to test if the code works for more than just that.
Having talked with Heiko at ELCE, both upcoming mach-berlin and
mach-rockchip will be using dw-apb-gpio as GPIO driver. Unfortunately,
while berlin has the CONFIG[12] registers, rockchip has not. So there
must be bindings to at least overwrite the obvious settings derived
from that registers.
Also, IIRC Heiko prefers to use platform_data driven registration as it
is tightly coupled with rk's pinmux. So there should really be support
for that and DT parsing on top that fills platform_data.
Can you please resend the whole set on list so we can review it again
with more machs involved?
Sebastian
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