usb: phy: nop: Add device tree support and binding information

The PHY clock, clock rate, VCC regulator and RESET regulator
can now be provided via device tree.

Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 61 insertions, 8 deletions

diff --git a/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt b/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt
new file mode 100644
index 000000000000..d7e272671c7e
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt
@@ -0,0 +1,34 @@
+USB NOP PHY
+
+Required properties:
+- compatible: should be usb-nop-xceiv
+
+Optional properties:
+- clocks: phandle to the PHY clock. Use as per Documentation/devicetree
+  /bindings/clock/clock-bindings.txt
+  This property is required if clock-frequency is specified.
+
+- clock-names: Should be "main_clk"
+
+- clock-frequency: the clock frequency (in Hz) that the PHY clock must
+  be configured to.
+
+- vcc-supply: phandle to the regulator that provides RESET to the PHY.
+
+- reset-supply: phandle to the regulator that provides power to the PHY.
+
+Example:
+
+        hsusb1_phy {
+                compatible = "usb-nop-xceiv";
+                clock-frequency = <19200000>;
+                clocks = <&osc 0>;
+                clock-names = "main_clk";
+                vcc-supply = <&hsusb1_vcc_regulator>;
+                reset-supply = <&hsusb1_reset_regulator>;
+        };
+
+hsusb1_phy is a NOP USB PHY device that gets its clock from an oscillator
+and expects that clock to be configured to 19.2MHz by the NOP PHY driver.
+hsusb1_vcc_regulator provides power to the PHY and hsusb1_reset_regulator
+controls RESET.
diff --git a/drivers/usb/otg/nop-usb-xceiv.c b/drivers/usb/otg/nop-usb-xceiv.c
index fe7a46001854..b26b1c29194e 100644
--- a/drivers/usb/otg/nop-usb-xceiv.c
+++ b/drivers/usb/otg/nop-usb-xceiv.c
@@ -34,13 +34,14 @@
 #include <linux/slab.h>
 #include <linux/clk.h>
 #include <linux/regulator/consumer.h>
+#include <linux/of.h>
 
 struct nop_usb_xceiv {
-        struct usb_phy          phy;
-        struct device           *dev;
-        struct clk              *clk;
-        struct regulator        *vcc;
-        struct regulator        *reset;
+        struct usb_phy phy;
+        struct device *dev;
+        struct clk *clk;
+        struct regulator *vcc;
+        struct regulator *reset;
 };
 
 static struct platform_device *pd;
@@ -140,10 +141,12 @@ static int nop_set_host(struct usb_otg *otg, struct usb_bus *host)
 
 static int nop_usb_xceiv_probe(struct platform_device *pdev)
 {
+        struct device *dev = &pdev->dev;
         struct nop_usb_xceiv_platform_data *pdata = pdev->dev.platform_data;
         struct nop_usb_xceiv    *nop;
         enum usb_phy_type       type = USB_PHY_TYPE_USB2;
         int err;
+        u32 clk_rate = 0;
 
         nop = devm_kzalloc(&pdev->dev, sizeof(*nop), GFP_KERNEL);
         if (!nop)
@@ -154,8 +157,16 @@ static int nop_usb_xceiv_probe(struct platform_device *pdev)
         if (!nop->phy.otg)
                 return -ENOMEM;
 
-        if (pdata)
+        if (dev->of_node) {
+                struct device_node *node = dev->of_node;
+
+                if (of_property_read_u32(node, "clock-frequency", &clk_rate))
+                        clk_rate = 0;
+
+        } else if (pdata) {
                 type = pdata->type;
+                clk_rate = pdata->clk_rate;
+        }
 
         nop->clk = devm_clk_get(&pdev->dev, "main_clk");
         if (IS_ERR(nop->clk)) {
@@ -163,8 +174,8 @@ static int nop_usb_xceiv_probe(struct platform_device *pdev)
                                         PTR_ERR(nop->clk));
         }
 
-        if (!IS_ERR(nop->clk) && pdata && pdata->clk_rate) {
-                err = clk_set_rate(nop->clk, pdata->clk_rate);
+        if (!IS_ERR(nop->clk) && clk_rate) {
+                err = clk_set_rate(nop->clk, clk_rate);
                 if (err) {
                         dev_err(&pdev->dev, "Error setting clock rate\n");
                         return err;
@@ -237,12 +248,20 @@ static int nop_usb_xceiv_remove(struct platform_device *pdev)
         return 0;
 }
 
+static const struct of_device_id nop_xceiv_dt_ids[] = {
+        { .compatible = "usb-nop-xceiv" },
+        { }
+};
+
+MODULE_DEVICE_TABLE(of, nop_xceiv_dt_ids);
+
 static struct platform_driver nop_usb_xceiv_driver = {
         .probe          = nop_usb_xceiv_probe,
         .remove         = nop_usb_xceiv_remove,
         .driver         = {
                 .name   = "nop_usb_xceiv",
                 .owner  = THIS_MODULE,
+                .of_match_table = of_match_ptr(nop_xceiv_dt_ids),
         },
 };