net: dsa: felix: add support for MFD configurations

The architecture around the VSC7512 differs from existing felix drivers. In
order to add support for all the chip's features (pinctrl, MDIO, gpio) the
device had to be laid out as a multi-function device (MFD).

One difference between an MFD and a standard platform device is that the
regmaps are allocated to the parent device before the child devices are
probed. As such, there is no need for felix to initialize new regmaps in
these configurations, they can simply be requested from the parent device.

Add support for MFD configurations by performing this request from the
parent device.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com> # regression
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index 462a1a683996f4da186dead33de512ce1f93bd8d..d3ff6e8a82e930d06ebb1fa8c9cc0a44d7b9468a 100644 (file)
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1315,6 +1315,13 @@ static struct regmap *felix_request_regmap_by_name(struct felix *felix,
        struct resource res;
        int i;
 
+       /* In an MFD configuration, regmaps are registered directly to the
+        * parent device before the child devices are probed, so there is no
+        * need to initialize a new one.
+        */
+       if (!felix->info->resources)
+               return dev_get_regmap(ocelot->dev->parent, resource_name);
+
        for (i = 0; i < felix->info->num_resources; i++) {
                if (strcmp(resource_name, felix->info->resources[i].name))
                        continue;