usb: chipidea: add xilinx zynq platform data

Due to having hardware tx buffers less than 512 bytes in size, streaming
must be enabled on the Zynq for the udc to work at all. Add platform data
specific to the Zynq udc, which does not set the CI_HDRC_DISABLE_STREAMING
flag.

Based on a patch by the same name from the Xilinx vendor tree.

Signed-off-by: Nathan Sullivan <[e-mail]>
Signed-off-by: Peter Chen <[e-mail]>

drivers/usb/chipidea/ci_hdrc_usb2.c

···
 #include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_platform.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/usb/chipidea.h>
···
 	.flags		= CI_HDRC_DISABLE_STREAMING,
 };
 
+static struct ci_hdrc_platform_data ci_zynq_pdata = {
+	.capoffset	= DEF_CAPOFFSET,
+};
+
+static const struct of_device_id ci_hdrc_usb2_of_match[] = {
+	{ .compatible = "chipidea,usb2"},
+	{ .compatible = "xlnx,zynq-usb-2.20a", .data = &ci_zynq_pdata},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ci_hdrc_usb2_of_match);
+
 static int ci_hdrc_usb2_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct ci_hdrc_usb2_priv *priv;
 	struct ci_hdrc_platform_data *ci_pdata = dev_get_platdata(dev);
 	int ret;
+	const struct of_device_id *match;
 
 	if (!ci_pdata) {
 		ci_pdata = devm_kmalloc(dev, sizeof(*ci_pdata), GFP_KERNEL);
 		*ci_pdata = ci_default_pdata;	/* struct copy */
+	}
+
+	match = of_match_device(ci_hdrc_usb2_of_match, &pdev->dev);
+	if (match && match->data) {
+		/* struct copy */
+		*ci_pdata = *(struct ci_hdrc_platform_data *)match->data;
 	}
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
···
 
 	return 0;
 }
-
-static const struct of_device_id ci_hdrc_usb2_of_match[] = {
-	{ .compatible = "chipidea,usb2" },
-	{ }
-};
-MODULE_DEVICE_TABLE(of, ci_hdrc_usb2_of_match);
 
 static struct platform_driver ci_hdrc_usb2_driver = {
 	.probe	= ci_hdrc_usb2_probe,