Thread (33 messages) 33 messages, 6 authors, 2017-07-05

Re: [PATCH 3/3] mtd: spi-nor: Altera Quadspi Flash Controller v2 Platform driver

From: <hidden>
Date: 2017-06-27 17:38:56
Also in: lkml


On Tue, 27 Jun 2017, Marek Vasut wrote:
On 06/27/2017 05:15 PM, matthew.gerlach-VuQAYsv1563Yd54FQh9/CA@public.gmane.org wrote:
quoted

On Tue, 27 Jun 2017, Marek Vasut wrote:
quoted
On 06/26/2017 06:13 PM, matthew.gerlach-VuQAYsv1563Yd54FQh9/CA@public.gmane.org wrote:
quoted
From: Matthew Gerlach <matthew.gerlach-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Just wrap it into the Altera QSPI driver , no need for separate platform
driver IMO.
Hi Marek,

I answered this question when you asked why the header file was
necessary, but I think further discussion could be helpful, since this
problem is becoming more prevelent.  The Altera Quadspi component is a
soft IP in a
FPGA, and the processor using the component may or may not have device
tree support compiled into the Linux kernel.  Since device tree support
may or may not be available, the device tree specific code must be
separated
from the core driver code.
I see, that's fine, although there is no PCIe or other support in this
submission. Is that planned ?
You probably would not see a PCIe driver for a card with a FPGA that would 
only have the Altera Quadspi component on it.  Usually a FPGA has several 
components, each requiring their own driver which are considered 
sub-drivers of the PCIe driver.  I will be adding Altera Quadspi support 
to the Intel-FPGA PCIe driver that is currently under review.  We have 
also seen people use the Altera Quadspi with a NIOS-II soft processor, and 
I expect someone would want to use the component with ARM SOCFPGAs.

Matthew Gerlach
quoted
One can certainly make the case, that device tree support could/should
be available everywhere, but the current reality is most x86 Linux
kernel configurations do not include device tree support.

For the record, I believe device trees, and more specifically device
tree overlays, are the best way for Linux to use FPGAs, but I have to
deal with the current realities.

Thanks again for all the great feedback.

Matthew Gerlach
[...]

-- 
Best regards,
Marek Vasut
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help