USB: chipidea: add imx usbmisc support

i.MX usb controllers share non-core registers, which may include
SoC specific controls. We turn it into a usbmisc device and usbmisc
driver set operations needed by ci13xxx_imx driver.

For example, Sabrelite board has bad over-current design, we can
usbmisc to disable over-current detection.

Acked-by: Sascha Hauer <[e-mail]>
Signed-off-by: Richard Zhao <[e-mail]>
Signed-off-by: Alexander Shishkin <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/devicetree/bindings/usb/ci13xxx-imx.txt

···
 
 Optional properties:
 - fsl,usbphy: phandler of usb phy that connects to the only one port
+- fsl,usbmisc: phandler of non-core register device, with one argument
+  that indicate usb controller index
 - vbus-supply: regulator for vbus
+- disable-over-current: disable over current detect
 
 Examples:
 usb@02184000 { /* USB OTG */
···
 	reg = <0x02184000 0x200>;
 	interrupts = <0 43 0x04>;
 	fsl,usbphy = <&usbphy1>;
+	fsl,usbmisc = <&usbmisc 0>;
+	disable-over-current;
 };

Documentation/devicetree/bindings/usb/usbmisc-imx.txt

···
+* Freescale i.MX non-core registers
+
+Required properties:
+- #index-cells: Cells used to descibe usb controller index. Should be <1>
+- compatible: Should be one of below:
+	"fsl,imx6q-usbmisc" for imx6q
+- reg: Should contain registers location and length
+
+Examples:
+usbmisc@02184800 {
+	#index-cells = <1>;
+	compatible = "fsl,imx6q-usbmisc";
+	reg = <0x02184800 0x200>;
+};

drivers/usb/chipidea/Makefile

···
 endif
 
 ifneq ($(CONFIG_OF_DEVICE),)
-	obj-$(CONFIG_USB_CHIPIDEA)	+= ci13xxx_imx.o
+	obj-$(CONFIG_USB_CHIPIDEA)	+= ci13xxx_imx.o usbmisc_imx6q.o
 endif

drivers/usb/chipidea/ci13xxx_imx.c

···
 #include <linux/regulator/consumer.h>
 
 #include "ci.h"
+#include "ci13xxx_imx.h"
 
 #define pdev_to_phy(pdev) \
 	((struct usb_phy *)platform_get_drvdata(pdev))
···
 	struct clk *clk;
 	struct regulator *reg_vbus;
 };
+
+static const struct usbmisc_ops *usbmisc_ops;
+
+/* Common functions shared by usbmisc drivers */
+
+int usbmisc_set_ops(const struct usbmisc_ops *ops)
+{
+	if (usbmisc_ops)
+		return -EBUSY;
+
+	usbmisc_ops = ops;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usbmisc_set_ops);
+
+void usbmisc_unset_ops(const struct usbmisc_ops *ops)
+{
+	usbmisc_ops = NULL;
+}
+EXPORT_SYMBOL_GPL(usbmisc_unset_ops);
+
+int usbmisc_get_init_data(struct device *dev, struct usbmisc_usb_device *usbdev)
+{
+	struct device_node *np = dev->of_node;
+	struct of_phandle_args args;
+	int ret;
+
+	usbdev->dev = dev;
+
+	ret = of_parse_phandle_with_args(np, "fsl,usbmisc", "#index-cells",
+					0, &args);
+	if (ret) {
+		dev_err(dev, "Failed to parse property fsl,usbmisc, errno %d\n",
+			ret);
+		memset(usbdev, 0, sizeof(*usbdev));
+		return ret;
+	}
+	usbdev->index = args.args[0];
+	of_node_put(args.np);
+
+	if (of_find_property(np, "disable-over-current", NULL))
+		usbdev->disable_oc = 1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(usbmisc_get_init_data);
+
+/* End of common functions shared by usbmisc drivers*/
 
 static struct ci13xxx_platform_data ci13xxx_imx_platdata __devinitdata  = {
 	.name			= "ci13xxx_imx",
···
 	struct resource *res;
 	struct regulator *reg_vbus;
 	int ret;
+
+	if (of_find_property(pdev->dev.of_node, "fsl,usbmisc", NULL)
+		&& !usbmisc_ops)
+		return -EPROBE_DEFER;
 
 	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
 	if (!data) {
···
 		*pdev->dev.dma_mask = DMA_BIT_MASK(32);
 		dma_set_coherent_mask(&pdev->dev, *pdev->dev.dma_mask);
 	}
+
+	if (usbmisc_ops && usbmisc_ops->init) {
+		ret = usbmisc_ops->init(&pdev->dev);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"usbmisc init failed, ret=%d\n", ret);
+			goto err;
+		}
+	}
+
 	plat_ci = ci13xxx_add_device(&pdev->dev,
 				pdev->resource, pdev->num_resources,
 				&ci13xxx_imx_platdata);

drivers/usb/chipidea/ci13xxx_imx.h

···
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/* Used to set SoC specific callbacks */
+struct usbmisc_ops {
+	/* It's called once when probe a usb device */
+	int (*init)(struct device *dev);
+};
+
+struct usbmisc_usb_device {
+	struct device *dev; /* usb controller device */
+	int index;
+
+	int disable_oc:1; /* over current detect disabled */
+};
+
+int usbmisc_set_ops(const struct usbmisc_ops *ops);
+void usbmisc_unset_ops(const struct usbmisc_ops *ops);
+int
+usbmisc_get_init_data(struct device *dev, struct usbmisc_usb_device *usbdev);

drivers/usb/chipidea/usbmisc_imx6q.c

···
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include "ci13xxx_imx.h"
+
+#define USB_DEV_MAX 4
+
+#define BM_OVER_CUR_DIS		BIT(7)
+
+struct imx6q_usbmisc {
+	void __iomem *base;
+	spinlock_t lock;
+	struct clk *clk;
+	struct usbmisc_usb_device usbdev[USB_DEV_MAX];
+};
+
+static struct imx6q_usbmisc *usbmisc;
+
+static struct usbmisc_usb_device *get_usbdev(struct device *dev)
+{
+	int i, ret;
+
+	for (i = 0; i < USB_DEV_MAX; i++) {
+		if (usbmisc->usbdev[i].dev == dev)
+			return &usbmisc->usbdev[i];
+		else if (!usbmisc->usbdev[i].dev)
+			break;
+	}
+
+	if (i >= USB_DEV_MAX)
+		return ERR_PTR(-EBUSY);
+
+	ret = usbmisc_get_init_data(dev, &usbmisc->usbdev[i]);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &usbmisc->usbdev[i];
+}
+
+static int usbmisc_imx6q_init(struct device *dev)
+{
+
+	struct usbmisc_usb_device *usbdev;
+	unsigned long flags;
+	u32 reg;
+
+	usbdev = get_usbdev(dev);
+	if (IS_ERR(usbdev))
+		return PTR_ERR(usbdev);
+
+	if (usbdev->disable_oc) {
+		spin_lock_irqsave(&usbmisc->lock, flags);
+		reg = readl(usbmisc->base + usbdev->index * 4);
+		writel(reg | BM_OVER_CUR_DIS,
+			usbmisc->base + usbdev->index * 4);
+		spin_unlock_irqrestore(&usbmisc->lock, flags);
+	}
+
+	return 0;
+}
+
+static const struct usbmisc_ops imx6q_usbmisc_ops = {
+	.init = usbmisc_imx6q_init,
+};
+
+static const struct of_device_id usbmisc_imx6q_dt_ids[] = {
+	{ .compatible = "fsl,imx6q-usbmisc"},
+	{ /* sentinel */ }
+};
+
+static int __devinit usbmisc_imx6q_probe(struct platform_device *pdev)
+{
+	struct resource	*res;
+	struct imx6q_usbmisc *data;
+	int ret;
+
+	if (usbmisc)
+		return -EBUSY;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	spin_lock_init(&data->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!data->base)
+		return -EADDRNOTAVAIL;
+
+	data->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(data->clk)) {
+		dev_err(&pdev->dev,
+			"failed to get clock, err=%ld\n", PTR_ERR(data->clk));
+		return PTR_ERR(data->clk);
+	}
+
+	ret = clk_prepare_enable(data->clk);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"clk_prepare_enable failed, err=%d\n", ret);
+		return ret;
+	}
+
+	ret = usbmisc_set_ops(&imx6q_usbmisc_ops);
+	if (ret) {
+		clk_disable_unprepare(data->clk);
+		return ret;
+	}
+
+	usbmisc = data;
+
+	return 0;
+}
+
+static int __devexit usbmisc_imx6q_remove(struct platform_device *pdev)
+{
+	usbmisc_unset_ops(&imx6q_usbmisc_ops);
+	clk_disable_unprepare(usbmisc->clk);
+	return 0;
+}
+
+static struct platform_driver usbmisc_imx6q_driver = {
+	.probe = usbmisc_imx6q_probe,
+	.remove = __devexit_p(usbmisc_imx6q_remove),
+	.driver = {
+		.name = "usbmisc_imx6q",
+		.owner = THIS_MODULE,
+		.of_match_table = usbmisc_imx6q_dt_ids,
+	 },
+};
+
+int __init usbmisc_imx6q_drv_init(void)
+{
+	return platform_driver_register(&usbmisc_imx6q_driver);
+}
+subsys_initcall(usbmisc_imx6q_drv_init);
+
+void __exit usbmisc_imx6q_drv_exit(void)
+{
+	platform_driver_unregister(&usbmisc_imx6q_driver);
+}
+module_exit(usbmisc_imx6q_drv_exit);
+
+MODULE_ALIAS("platform:usbmisc-imx6q");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("driver for imx6q usb non-core registers");
+MODULE_AUTHOR("Richard Zhao <[e-mail]>");