[PATCH v3 net-next 08/14] net: dsa: felix: update init_regmap to be string-based

[Colin Foster <colin.foster@in-advantage.com>]

During development, it was believed that a wrapper for ocelot_regmap_init()
would be sufficient for the felix driver to work in non-mmio scenarios.
This was merged in during commit 242bd0c10bbd ("net: dsa: ocelot: felix:
add interface for custom regmaps")

As the external ocelot DSA driver grew closer to an acceptable state, it
was realized that most of the parameters that were passed in from struct
resource *res were useless and ignored. This is due to the fact that the
external ocelot DSA driver utilizes dev_get_regmap(dev, resource->name).

Instead of simply ignoring those parameters, refactor the API to only
require the name as an argument. MMIO scenarios this will reconstruct the
struct resource before calling ocelot_regmap_init(ocelot, resource). MFD
scenarios need only call dev_get_regmap(dev, name).

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
---

v3
    * Assign match = NULL for the default case
    * Don't export felix_init_regmap symbol - the felix.o object is
      compiled directly into "mscc_felix-objs" and "mscc_seville-objs"

v2
    * New patch

---
 drivers/net/dsa/ocelot/felix.c           | 58 ++++++++++++++++++------
 drivers/net/dsa/ocelot/felix.h           |  4 +-
 drivers/net/dsa/ocelot/felix_vsc9959.c   |  2 +-
 drivers/net/dsa/ocelot/seville_vsc9953.c |  2 +-
 4 files changed, 48 insertions(+), 18 deletions(-)

diff --git a/drivers/net/dsa/ocelot/felix.c b/drivers/net/dsa/ocelot/felix.c
index a8196cdedcc5..b01482b24e7a 100644
--- a/drivers/net/dsa/ocelot/felix.c
+++ b/drivers/net/dsa/ocelot/felix.c
@@ -1318,11 +1318,48 @@ static int felix_parse_dt(struct felix *felix, phy_interface_t *port_phy_modes)
 	return err;
 }
 
+struct regmap *felix_init_regmap(struct ocelot *ocelot, const char *name)
+{
+	struct felix *felix = ocelot_to_felix(ocelot);
+	const struct resource *match = NULL;
+	struct resource res;
+	int i;
+
+	for (i = 0; i < TARGET_MAX; i++) {
+		if (!felix->info->target_io_res[i].name)
+			continue;
+
+		if (!strcmp(name, felix->info->target_io_res[i].name)) {
+			match = &felix->info->target_io_res[i];
+			break;
+		}
+	}
+
+	if (!match) {
+		for (i = 0; i < ocelot->num_phys_ports; i++) {
+			if (!strcmp(name, felix->info->port_io_res[i].name)) {
+				match = &felix->info->port_io_res[i];
+				break;
+			}
+		}
+	}
+
+	if (!match)
+		return ERR_PTR(-EINVAL);
+
+	memcpy(&res, match, sizeof(res));
+	res.flags = IORESOURCE_MEM;
+	res.start += felix->switch_base;
+	res.end += felix->switch_base;
+
+	return ocelot_regmap_init(ocelot, &res);
+}
+
 static int felix_init_structs(struct felix *felix, int num_phys_ports)
 {
 	struct ocelot *ocelot = &felix->ocelot;
 	phy_interface_t *port_phy_modes;
-	struct resource res;
+	const char *name;
 	int port, i, err;
 
 	ocelot->num_phys_ports = num_phys_ports;
@@ -1358,15 +1395,12 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 	for (i = 0; i < TARGET_MAX; i++) {
 		struct regmap *target;
 
-		if (!felix->info->target_io_res[i].name)
-			continue;
+		name = felix->info->target_io_res[i].name;
 
-		memcpy(&res, &felix->info->target_io_res[i], sizeof(res));
-		res.flags = IORESOURCE_MEM;
-		res.start += felix->switch_base;
-		res.end += felix->switch_base;
+		if (!name)
+			continue;
 
-		target = felix->info->init_regmap(ocelot, &res);
+		target = felix->info->init_regmap(ocelot, name);
 		if (IS_ERR(target)) {
 			dev_err(ocelot->dev,
 				"Failed to map device memory space\n");
@@ -1398,12 +1432,8 @@ static int felix_init_structs(struct felix *felix, int num_phys_ports)
 			return -ENOMEM;
 		}
 
-		memcpy(&res, &felix->info->port_io_res[port], sizeof(res));
-		res.flags = IORESOURCE_MEM;
-		res.start += felix->switch_base;
-		res.end += felix->switch_base;
-
-		target = felix->info->init_regmap(ocelot, &res);
+		name = felix->info->port_io_res[port].name;
+		target = felix->info->init_regmap(ocelot, name);
 		if (IS_ERR(target)) {
 			dev_err(ocelot->dev,
 				"Failed to map memory space for port %d\n",
diff --git a/drivers/net/dsa/ocelot/felix.h b/drivers/net/dsa/ocelot/felix.h
index f94a445c2542..e623806eb8ee 100644
--- a/drivers/net/dsa/ocelot/felix.h
+++ b/drivers/net/dsa/ocelot/felix.h
@@ -57,8 +57,7 @@ struct felix_info {
 	void	(*tas_guard_bands_update)(struct ocelot *ocelot, int port);
 	void	(*port_sched_speed_set)(struct ocelot *ocelot, int port,
 					u32 speed);
-	struct regmap *(*init_regmap)(struct ocelot *ocelot,
-				      struct resource *res);
+	struct regmap *(*init_regmap)(struct ocelot *ocelot, const char *name);
 };
 
 /* Methods for initializing the hardware resources specific to a tagging
@@ -97,5 +96,6 @@ struct felix {
 
 struct net_device *felix_port_to_netdev(struct ocelot *ocelot, int port);
 int felix_netdev_to_port(struct net_device *dev);
+struct regmap *felix_init_regmap(struct ocelot *ocelot, const char *name);
 
 #endif
diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c
index 2fd2bb499e9c..e20d5d5d2de9 100644
--- a/drivers/net/dsa/ocelot/felix_vsc9959.c
+++ b/drivers/net/dsa/ocelot/felix_vsc9959.c
@@ -2615,7 +2615,7 @@ static const struct felix_info felix_info_vsc9959 = {
 	.port_setup_tc		= vsc9959_port_setup_tc,
 	.port_sched_speed_set	= vsc9959_sched_speed_set,
 	.tas_guard_bands_update	= vsc9959_tas_guard_bands_update,
-	.init_regmap		= ocelot_regmap_init,
+	.init_regmap		= felix_init_regmap,
 };
 
 static irqreturn_t felix_irq_handler(int irq, void *data)
diff --git a/drivers/net/dsa/ocelot/seville_vsc9953.c b/drivers/net/dsa/ocelot/seville_vsc9953.c
index e589d07f84db..7c698e19d818 100644
--- a/drivers/net/dsa/ocelot/seville_vsc9953.c
+++ b/drivers/net/dsa/ocelot/seville_vsc9953.c
@@ -1079,7 +1079,7 @@ static const struct felix_info seville_info_vsc9953 = {
 	.mdio_bus_free		= vsc9953_mdio_bus_free,
 	.phylink_validate	= vsc9953_phylink_validate,
 	.port_modes		= vsc9953_port_modes,
-	.init_regmap		= ocelot_regmap_init,
+	.init_regmap		= felix_init_regmap,
 };
 
 static int seville_probe(struct platform_device *pdev)
-- 
2.25.1