[PATCH] net: ethernet: cpsw-phy-sel: prefer phandle for phy sel and update binding

[Tony Lindgren]

The cpsw-phy-sel device is not a child of the cpsw interconnect target
module. It lives in the system control module.

Let's fix this issue by trying to use cpsw-phy-sel phandle first if it
exists and if not fall back to current usage of trying to find the
cpsw-phy-sel child. That way the phy sel driver can be a child of the
system control module where it belongs in the device tree.

Without this fix, we cannot have a proper interconnect target module
hierarchy in device tree for things like genpd.

For documenting it, looks like the cpsw-phy-sel is used for all cpsw device
tree nodes. It's missing the related binding documentation, so let's also
update the binding documentation accordingly.

Cc: devicet...@vger.kernel.org
Cc: Grygorii Strashko <grygorii.stras...@ti.com>
Cc: Ivan Khoronzhuk <ivan.khoronz...@linaro.org>
Cc: Mark Rutland <mark.rutl...@arm.com>
Cc: Murali Karicheri <m-kariche...@ti.com>
Cc: Rob Herring <robh...@kernel.org>
Signed-off-by: Tony Lindgren <t...@atomide.com>
---
 Documentation/devicetree/bindings/net/cpsw.txt | 5 +++++
 drivers/net/ethernet/ti/cpsw-phy-sel.c         | 9 ++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/cpsw.txt 
b/Documentation/devicetree/bindings/net/cpsw.txt
--- a/Documentation/devicetree/bindings/net/cpsw.txt
+++ b/Documentation/devicetree/bindings/net/cpsw.txt
@@ -19,6 +19,9 @@ Required properties:
 - slaves               : Specifies number for slaves
 - active_slave         : Specifies the slave to use for time stamping,
                          ethtool and SIOCGMIIPHY
+- cpsw-phy-sel         : Specifies the phandle to the CPSW phy mode selection
+                         device. Note that in legacy cases cpsw-phy-sel may be
+                         a child device instead of a phandle.
 
 Optional properties:
 - ti,hwmods            : Must be "cpgmac0"
@@ -75,6 +78,7 @@ Examples:
                cpts_clock_mult = <0x80000000>;
                cpts_clock_shift = <29>;
                syscon = <&cm>;
+               cpsw-phy-sel = <&phy_sel>;
                cpsw_emac0: slave@0 {
                        phy_id = <&davinci_mdio>, <0>;
                        phy-mode = "rgmii-txid";
@@ -103,6 +107,7 @@ Examples:
                cpts_clock_mult = <0x80000000>;
                cpts_clock_shift = <29>;
                syscon = <&cm>;
+               cpsw-phy-sel = <&phy_sel>;
                cpsw_emac0: slave@0 {
                        phy_id = <&davinci_mdio>, <0>;
                        phy-mode = "rgmii-txid";
diff --git a/drivers/net/ethernet/ti/cpsw-phy-sel.c 
b/drivers/net/ethernet/ti/cpsw-phy-sel.c
--- a/drivers/net/ethernet/ti/cpsw-phy-sel.c
+++ b/drivers/net/ethernet/ti/cpsw-phy-sel.c
@@ -170,10 +170,13 @@ void cpsw_phy_sel(struct device *dev, phy_interface_t 
phy_mode, int slave)
        struct device_node *node;
        struct cpsw_phy_sel_priv *priv;
 
-       node = of_get_child_by_name(dev->of_node, "cpsw-phy-sel");
+       node = of_parse_phandle(dev->of_node, "cpsw-phy-sel", 0);
        if (!node) {
-               dev_err(dev, "Phy mode driver DT not found\n");
-               return;
+               node = of_get_child_by_name(dev->of_node, "cpsw-phy-sel");
+               if (!node) {
+                       dev_err(dev, "Phy mode driver DT not found\n");
+                       return;
+               }
        }
 
        dev = bus_find_device(&platform_bus_type, NULL, node, match);
-- 
2.17.1