usb: dwc3: make maximum-speed a per-instance attribute

in order to allow different instances of the
core work in different maximum speeds, we will
move the maximum_speed module_parameter to
both DeviceTree (making use the new maximum-speed
DT property) and platform_data.
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/core.c

@@ -36,6 +36,7 @@
 #include <linux/usb/otg.h>
 #include <linux/usb/ch9.h>
 #include <linux/usb/gadget.h>
+#include <linux/usb/of.h>
 
 #include "platform_data.h"
 #include "core.h"
@@ -44,10 +45,6 @@
 
 #include "debug.h"
 
-static char *maximum_speed = "super";
-module_param(maximum_speed, charp, 0);
-MODULE_PARM_DESC(maximum_speed, "Maximum supported speed.");
-
 /* -------------------------------------------------------------------------- */
 
 void dwc3_set_mode(struct dwc3 *dwc, u32 mode)
@@ -412,17 +409,25 @@ static int dwc3_probe(struct platform_device *pdev)
 	}
 
 	if (node) {
+		dwc->maximum_speed = of_usb_get_maximum_speed(node);
+
 		dwc->usb2_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
 		dwc->usb3_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 1);
 
 		dwc->needs_fifo_resize = of_property_read_bool(node, "tx-fifo-resize");
 	} else {
+		dwc->maximum_speed = pdata->maximum_speed;
+
 		dwc->usb2_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
 		dwc->usb3_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB3);
 
 		dwc->needs_fifo_resize = pdata->tx_fifo_resize;
 	}
 
+	/* default to superspeed if no maximum_speed passed */
+	if (dwc->maximum_speed == USB_SPEED_UNKNOWN)
+		dwc->maximum_speed = USB_SPEED_SUPER;
+
 	if (IS_ERR(dwc->usb2_phy)) {
 		ret = PTR_ERR(dwc->usb2_phy);
 
@@ -467,17 +472,6 @@ static int dwc3_probe(struct platform_device *pdev)
 	dev->dma_parms	= dev->parent->dma_parms;
 	dma_set_coherent_mask(dev, dev->parent->coherent_dma_mask);
 
-	if (!strncmp("super", maximum_speed, 5))
-		dwc->maximum_speed = DWC3_DCFG_SUPERSPEED;
-	else if (!strncmp("high", maximum_speed, 4))
-		dwc->maximum_speed = DWC3_DCFG_HIGHSPEED;
-	else if (!strncmp("full", maximum_speed, 4))
-		dwc->maximum_speed = DWC3_DCFG_FULLSPEED1;
-	else if (!strncmp("low", maximum_speed, 3))
-		dwc->maximum_speed = DWC3_DCFG_LOWSPEED;
-	else
-		dwc->maximum_speed = DWC3_DCFG_SUPERSPEED;
-
 	pm_runtime_enable(dev);
 	pm_runtime_get_sync(dev);
 	pm_runtime_forbid(dev);

drivers/usb/dwc3/gadget.c

@@ -1525,10 +1525,25 @@ static int dwc3_gadget_start(struct usb_gadget *g,
 	 * STAR#9000525659: Clock Domain Crossing on DCTL in
 	 * USB 2.0 Mode
 	 */
-	if (dwc->revision < DWC3_REVISION_220A)
+	if (dwc->revision < DWC3_REVISION_220A) {
 		reg |= DWC3_DCFG_SUPERSPEED;
-	else
-		reg |= dwc->maximum_speed;
+	} else {
+		switch (dwc->maximum_speed) {
+		case USB_SPEED_LOW:
+			reg |= DWC3_DSTS_LOWSPEED;
+			break;
+		case USB_SPEED_FULL:
+			reg |= DWC3_DSTS_FULLSPEED1;
+			break;
+		case USB_SPEED_HIGH:
+			reg |= DWC3_DSTS_HIGHSPEED;
+			break;
+		case USB_SPEED_SUPER:	/* FALLTHROUGH */
+		case USB_SPEED_UNKNOWN:	/* FALTHROUGH */
+		default:
+			reg |= DWC3_DSTS_SUPERSPEED;
+		}
+	}
 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
 
 	dwc->start_config_issued = false;

drivers/usb/dwc3/platform_data.h

@@ -17,6 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/usb/ch9.h>
+
 struct dwc3_platform_data {
+	enum usb_device_speed maximum_speed;
 	bool tx_fifo_resize;
 };