Hi Sergey,

On Wed, Mar 31, 2021 at 11:10 AM Serge Semin [off-list ref] wrote:

On Sun, Mar 28, 2021 at 06:59:26PM -0700, Brad Larson wrote:

quoted

This GPIO driver is for the Pensando Elba SoC which
provides control of four chip selects on two SPI busses.

[...]

quoted

+static int elba_spics_probe(struct platform_device *pdev)
+{
+     struct elba_spics_priv *p;
+     struct resource *res;
+     int ret = 0;
+
+     p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
+     if (!p)
+             return -ENOMEM;
+

quoted

+     res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+     p->base = devm_ioremap_resource(&pdev->dev, res);

In accordance with the DTS-node this is just a single register
0x307c2468-0x307c24C picked from some bigger block, which most likely
belongs to something like a system controller. PCIe node has got
another register from there "0x307c2480-0x307c2484/* MS CFG_WDT */",
and some BSM device too "0x307c2080-0x307c2084". Please consider using
syscon instead of directly requesting the resource here.

-Sergey

I've looked into a few syscon based implementations which resulted in
a regressions to include Elba spi probe failure and host machine check
trying to perform PCIe access to Elba SoC.  I like the idea of
refactoring to use syscon but I don't have a functional solution to do
so.

Regards,
Brad