net: dsa: rework switch parsing

When parsing a switch, we have to identify to which tree it belongs and
parse its ports. Provide two functions to separate the OF and platform
data specific paths.

Also use the of_property_read_variable_u32_array function to parse the
OF member array instead of calling of_property_read_u32_index twice.

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 58 insertions, 59 deletions

diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index 5918fbddb0ab..dfcb6247f2f2 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -617,7 +617,8 @@ static int dsa_port_parse_of(struct dsa_port *dp, struct device_node *dn)
         return 0;
 }
 
-static int dsa_parse_ports_of(struct device_node *dn, struct dsa_switch *ds)
+static int dsa_switch_parse_ports_of(struct dsa_switch *ds,
+                                     struct device_node *dn)
 {
         struct device_node *ports, *port;
         struct dsa_port *dp;
@@ -648,6 +649,39 @@ static int dsa_parse_ports_of(struct device_node *dn, struct dsa_switch *ds)
         return 0;
 }
 
+static int dsa_switch_parse_member_of(struct dsa_switch *ds,
+                                      struct device_node *dn)
+{
+        u32 m[2] = { 0, 0 };
+        int sz;
+
+        /* Don't error out if this optional property isn't found */
+        sz = of_property_read_variable_u32_array(dn, "dsa,member", m, 2, 2);
+        if (sz < 0 && sz != -EINVAL)
+                return sz;
+
+        ds->index = m[1];
+        if (ds->index >= DSA_MAX_SWITCHES)
+                return -EINVAL;
+
+        ds->dst = dsa_tree_touch(m[0]);
+        if (!ds->dst)
+                return -ENOMEM;
+
+        return 0;
+}
+
+static int dsa_switch_parse_of(struct dsa_switch *ds, struct device_node *dn)
+{
+        int err;
+
+        err = dsa_switch_parse_member_of(ds, dn);
+        if (err)
+                return err;
+
+        return dsa_switch_parse_ports_of(ds, dn);
+}
+
 static int dsa_port_parse(struct dsa_port *dp, const char *name,
                           struct device *dev)
 {
@@ -673,7 +707,8 @@ static int dsa_port_parse(struct dsa_port *dp, const char *name,
         return 0;
 }
 
-static int dsa_parse_ports(struct dsa_chip_data *cd, struct dsa_switch *ds)
+static int dsa_switch_parse_ports(struct dsa_switch *ds,
+                                  struct dsa_chip_data *cd)
 {
         bool valid_name_found = false;
         struct dsa_port *dp;
@@ -703,40 +738,19 @@ static int dsa_parse_ports(struct dsa_chip_data *cd, struct dsa_switch *ds)
         return 0;
 }
 
-static int dsa_parse_member_dn(struct device_node *np, u32 *tree, u32 *index)
-{
-        int err;
-
-        *tree = *index = 0;
-
-        err = of_property_read_u32_index(np, "dsa,member", 0, tree);
-        if (err) {
-                /* Does not exist, but it is optional */
-                if (err == -EINVAL)
-                        return 0;
-                return err;
-        }
-
-        err = of_property_read_u32_index(np, "dsa,member", 1, index);
-        if (err)
-                return err;
-
-        if (*index >= DSA_MAX_SWITCHES)
-                return -EINVAL;
-
-        return 0;
-}
-
-static int dsa_parse_member(struct dsa_chip_data *pd, u32 *tree, u32 *index)
+static int dsa_switch_parse(struct dsa_switch *ds, struct dsa_chip_data *cd)
 {
-        if (!pd)
-                return -ENODEV;
+        ds->cd = cd;
 
-        /* We do not support complex trees with dsa_chip_data */
-        *tree = 0;
-        *index = 0;
+        /* We don't support interconnected switches nor multiple trees via
+         * platform data, so this is the unique switch of the tree.
+         */
+        ds->index = 0;
+        ds->dst = dsa_tree_touch(0);
+        if (!ds->dst)
+                return -ENOMEM;
 
-        return 0;
+        return dsa_switch_parse_ports(ds, cd);
 }
 
 static int _dsa_register_switch(struct dsa_switch *ds)
@@ -744,36 +758,21 @@ static int _dsa_register_switch(struct dsa_switch *ds)
         struct dsa_chip_data *pdata = ds->dev->platform_data;
         struct device_node *np = ds->dev->of_node;
         struct dsa_switch_tree *dst;
-        u32 tree, index;
+        unsigned int index;
         int i, err;
 
-        if (np) {
-                err = dsa_parse_member_dn(np, &tree, &index);
-                if (err)
-                        return err;
-        } else {
-                err = dsa_parse_member(pdata, &tree, &index);
-                if (err)
-                        return err;
-        }
+        if (np)
+                err = dsa_switch_parse_of(ds, np);
+        else if (pdata)
+                err = dsa_switch_parse(ds, pdata);
+        else
+                err = -ENODEV;
 
-        dst = dsa_tree_touch(tree);
-        if (!dst)
-                return -ENOMEM;
-
-        ds->dst = dst;
-        ds->index = index;
-        ds->cd = pdata;
+        if (err)
+                return err;
 
-        if (np) {
-                err = dsa_parse_ports_of(np, ds);
-                if (err)
-                        return err;
-        } else {
-                err = dsa_parse_ports(pdata, ds);
-                if (err)
-                        return err;
-        }
+        index = ds->index;
+        dst = ds->dst;
 
         /* Initialize the routing table */
         for (i = 0; i < DSA_MAX_SWITCHES; ++i)