USB: otg: adding nop usb transceiver

NOP transceiver is used by all the usb transceiver which are mostly
autonomous and doesn't require any programming or which are built
into the usb ip itself.NOP transceiver only allocates the memory
for struct xceiv and calls otg_set_transceiver() so function call
to otg_get_transceiver() will return a valid transceiver.

NOP transceiver device should be registered by calling
usb_nop_xceiv_register() from platform files.

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/otg/Kconfig

@@ -51,4 +51,12 @@ config TWL4030_USB
 	  This transceiver supports high and full speed devices plus,
 	  in host mode, low speed.
 
+config NOP_USB_XCEIV
+	tristate "NOP USB Transceiver Driver"
+	select USB_OTG_UTILS
+	help
+	 this driver is to be used by all the usb transceiver which are either
+	 built-in with usb ip or which are autonomous and doesn't require any
+	 phy programming such as ISP1x04 etc.
+
 endif # USB || OTG

drivers/usb/otg/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_USB_OTG_UTILS)	+= otg.o
 obj-$(CONFIG_USB_GPIO_VBUS)	+= gpio_vbus.o
 obj-$(CONFIG_ISP1301_OMAP)	+= isp1301_omap.o
 obj-$(CONFIG_TWL4030_USB)	+= twl4030-usb.o
+obj-$(CONFIG_NOP_USB_XCEIV)	+= nop-usb-xceiv.o
 
 ccflags-$(CONFIG_USB_DEBUG)	+= -DDEBUG
 ccflags-$(CONFIG_USB_GADGET_DEBUG) += -DDEBUG

drivers/usb/otg/nop-usb-xceiv.c

@@ -0,0 +1,180 @@
+/*
+ * drivers/usb/otg/nop-usb-xceiv.c
+ *
+ * NOP USB transceiver for all USB transceiver which are either built-in
+ * into USB IP or which are mostly autonomous.
+ *
+ * Copyright (C) 2009 Texas Instruments Inc
+ * Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * Current status:
+ * 	this is to add "nop" transceiver for all those phy which is
+ * 	autonomous such as isp1504 etc.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/usb/otg.h>
+
+struct nop_usb_xceiv {
+	struct otg_transceiver	otg;
+	struct device		*dev;
+};
+
+static u64 nop_xceiv_dmamask = DMA_32BIT_MASK;
+
+static struct platform_device nop_xceiv_device = {
+	.name           = "nop_usb_xceiv",
+	.id             = -1,
+	.dev = {
+		.dma_mask               = &nop_xceiv_dmamask,
+		.coherent_dma_mask      = DMA_32BIT_MASK,
+		.platform_data          = NULL,
+	},
+};
+
+void usb_nop_xceiv_register(void)
+{
+	if (platform_device_register(&nop_xceiv_device) < 0) {
+		printk(KERN_ERR "Unable to register usb nop transceiver\n");
+		return;
+	}
+}
+
+void usb_nop_xceiv_unregister(void)
+{
+	platform_device_unregister(&nop_xceiv_device);
+}
+
+static inline struct nop_usb_xceiv *xceiv_to_nop(struct otg_transceiver *x)
+{
+	return container_of(x, struct nop_usb_xceiv, otg);
+}
+
+static int nop_set_suspend(struct otg_transceiver *x, int suspend)
+{
+	return 0;
+}
+
+static int nop_set_peripheral(struct otg_transceiver *x,
+		struct usb_gadget *gadget)
+{
+	struct nop_usb_xceiv *nop;
+
+	if (!x)
+		return -ENODEV;
+
+	nop = xceiv_to_nop(x);
+
+	if (!gadget) {
+		nop->otg.gadget = NULL;
+		return -ENODEV;
+	}
+
+	nop->otg.gadget = gadget;
+	nop->otg.state = OTG_STATE_B_IDLE;
+	return 0;
+}
+
+static int nop_set_host(struct otg_transceiver *x, struct usb_bus *host)
+{
+	struct nop_usb_xceiv *nop;
+
+	if (!x)
+		return -ENODEV;
+
+	nop = xceiv_to_nop(x);
+
+	if (!host) {
+		nop->otg.host = NULL;
+		return -ENODEV;
+	}
+
+	nop->otg.host = host;
+	return 0;
+}
+
+static int __devinit nop_usb_xceiv_probe(struct platform_device *pdev)
+{
+	struct nop_usb_xceiv	*nop;
+	int err;
+
+	nop = kzalloc(sizeof *nop, GFP_KERNEL);
+	if (!nop)
+		return -ENOMEM;
+
+	nop->dev		= &pdev->dev;
+	nop->otg.dev		= nop->dev;
+	nop->otg.label		= "nop-xceiv";
+	nop->otg.state		= OTG_STATE_UNDEFINED;
+	nop->otg.set_host	= nop_set_host;
+	nop->otg.set_peripheral	= nop_set_peripheral;
+	nop->otg.set_suspend	= nop_set_suspend;
+
+	err = otg_set_transceiver(&nop->otg);
+	if (err) {
+		dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
+			err);
+		goto exit;
+	}
+
+	platform_set_drvdata(pdev, nop);
+
+	return 0;
+exit:
+	kfree(nop);
+	return err;
+}
+
+static int __devexit nop_usb_xceiv_remove(struct platform_device *pdev)
+{
+	struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
+
+	otg_set_transceiver(NULL);
+
+	platform_set_drvdata(pdev, NULL);
+	kfree(nop);
+
+	return 0;
+}
+
+static struct platform_driver nop_usb_xceiv_driver = {
+	.probe		= nop_usb_xceiv_probe,
+	.remove		= __devexit_p(nop_usb_xceiv_remove),
+	.driver		= {
+		.name	= "nop_usb_xceiv",
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init nop_usb_xceiv_init(void)
+{
+	return platform_driver_register(&nop_usb_xceiv_driver);
+}
+subsys_initcall(nop_usb_xceiv_init);
+
+static void __exit nop_usb_xceiv_exit(void)
+{
+	platform_driver_unregister(&nop_usb_xceiv_driver);
+}
+module_exit(nop_usb_xceiv_exit);
+
+MODULE_ALIAS("platform:nop_usb_xceiv");
+MODULE_AUTHOR("Texas Instruments Inc");
+MODULE_DESCRIPTION("NOP USB Transceiver driver");
+MODULE_LICENSE("GPL");

include/linux/usb/otg.h

@@ -80,6 +80,10 @@ struct otg_transceiver {
 
 /* for board-specific init logic */
 extern int otg_set_transceiver(struct otg_transceiver *);
+#ifdef CONFIG_NOP_USB_XCEIV
+extern void usb_nop_xceiv_register(void);
+extern void usb_nop_xceiv_unregister(void);
+#endif
 
 
 /* for usb host and peripheral controller drivers */