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This patch adds BLOCKING_INIT_NOTIFIER_HEAD in nop_usb_xceiv_probe, so that we can avoid oops caused by uninitialized nop->otg.notifier.rwsem which will be touched in otg_register_notifier path. Reported-by: Gupta, Ajay Kumar <ajay.gupta@ti.com> Tested-by: Gupta, Ajay Kumar <ajay.gupta@ti.com> Cc: Balbi, Felipe <balbi@ti.com> Cc: David Brownell <david-b@pacbell.net> Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
180 lines
4.0 KiB
C
180 lines
4.0 KiB
C
/*
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* drivers/usb/otg/nop-usb-xceiv.c
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*
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* NOP USB transceiver for all USB transceiver which are either built-in
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* into USB IP or which are mostly autonomous.
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*
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* Copyright (C) 2009 Texas Instruments Inc
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* Author: Ajay Kumar Gupta <ajay.gupta@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*
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* Current status:
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* This provides a "nop" transceiver for PHYs which are
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* autonomous such as isp1504, isp1707, etc.
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*/
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/dma-mapping.h>
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#include <linux/usb/otg.h>
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#include <linux/slab.h>
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struct nop_usb_xceiv {
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struct otg_transceiver otg;
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struct device *dev;
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};
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static struct platform_device *pd;
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void usb_nop_xceiv_register(void)
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{
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if (pd)
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return;
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pd = platform_device_register_simple("nop_usb_xceiv", -1, NULL, 0);
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if (!pd) {
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printk(KERN_ERR "Unable to register usb nop transceiver\n");
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return;
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}
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}
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EXPORT_SYMBOL(usb_nop_xceiv_register);
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void usb_nop_xceiv_unregister(void)
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{
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platform_device_unregister(pd);
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pd = NULL;
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}
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EXPORT_SYMBOL(usb_nop_xceiv_unregister);
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static inline struct nop_usb_xceiv *xceiv_to_nop(struct otg_transceiver *x)
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{
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return container_of(x, struct nop_usb_xceiv, otg);
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}
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static int nop_set_suspend(struct otg_transceiver *x, int suspend)
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{
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return 0;
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}
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static int nop_set_peripheral(struct otg_transceiver *x,
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struct usb_gadget *gadget)
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{
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struct nop_usb_xceiv *nop;
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if (!x)
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return -ENODEV;
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nop = xceiv_to_nop(x);
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if (!gadget) {
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nop->otg.gadget = NULL;
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return -ENODEV;
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}
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nop->otg.gadget = gadget;
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nop->otg.state = OTG_STATE_B_IDLE;
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return 0;
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}
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static int nop_set_host(struct otg_transceiver *x, struct usb_bus *host)
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{
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struct nop_usb_xceiv *nop;
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if (!x)
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return -ENODEV;
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nop = xceiv_to_nop(x);
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if (!host) {
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nop->otg.host = NULL;
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return -ENODEV;
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}
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nop->otg.host = host;
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return 0;
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}
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static int __devinit nop_usb_xceiv_probe(struct platform_device *pdev)
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{
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struct nop_usb_xceiv *nop;
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int err;
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nop = kzalloc(sizeof *nop, GFP_KERNEL);
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if (!nop)
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return -ENOMEM;
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nop->dev = &pdev->dev;
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nop->otg.dev = nop->dev;
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nop->otg.label = "nop-xceiv";
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nop->otg.state = OTG_STATE_UNDEFINED;
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nop->otg.set_host = nop_set_host;
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nop->otg.set_peripheral = nop_set_peripheral;
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nop->otg.set_suspend = nop_set_suspend;
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err = otg_set_transceiver(&nop->otg);
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if (err) {
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dev_err(&pdev->dev, "can't register transceiver, err: %d\n",
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err);
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goto exit;
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}
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platform_set_drvdata(pdev, nop);
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BLOCKING_INIT_NOTIFIER_HEAD(&nop->otg.notifier);
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return 0;
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exit:
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kfree(nop);
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return err;
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}
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static int __devexit nop_usb_xceiv_remove(struct platform_device *pdev)
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{
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struct nop_usb_xceiv *nop = platform_get_drvdata(pdev);
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otg_set_transceiver(NULL);
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platform_set_drvdata(pdev, NULL);
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kfree(nop);
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return 0;
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}
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static struct platform_driver nop_usb_xceiv_driver = {
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.probe = nop_usb_xceiv_probe,
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.remove = __devexit_p(nop_usb_xceiv_remove),
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.driver = {
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.name = "nop_usb_xceiv",
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.owner = THIS_MODULE,
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},
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};
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static int __init nop_usb_xceiv_init(void)
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{
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return platform_driver_register(&nop_usb_xceiv_driver);
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}
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subsys_initcall(nop_usb_xceiv_init);
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static void __exit nop_usb_xceiv_exit(void)
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{
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platform_driver_unregister(&nop_usb_xceiv_driver);
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}
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module_exit(nop_usb_xceiv_exit);
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MODULE_ALIAS("platform:nop_usb_xceiv");
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MODULE_AUTHOR("Texas Instruments Inc");
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MODULE_DESCRIPTION("NOP USB Transceiver driver");
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MODULE_LICENSE("GPL");
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