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![Uwe Kleine-König](/assets/img/avatar_default.png)
The driver core ignores the return value of this callback because there is only little it can do when a device disappears. This is the final bit of a long lasting cleanup quest where several buses were converted to also return void from their remove callback. Additionally some resource leaks were fixed that were caused by drivers returning an error code in the expectation that the driver won't go away. With struct bus_type::remove returning void it's prevented that newly implemented buses return an ignored error code and so don't anticipate wrong expectations for driver authors. Reviewed-by: Tom Rix <trix@redhat.com> (For fpga) Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio) Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts) Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb) Acked-by: Pali Rohár <pali@kernel.org> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media) Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform) Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-By: Vinod Koul <vkoul@kernel.org> Acked-by: Juergen Gross <jgross@suse.com> (For xen) Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd) Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb) Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus) Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio) Acked-by: Maximilian Luz <luzmaximilian@gmail.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec) Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack) Acked-by: Geoff Levand <geoff@infradead.org> (For ps3) Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt) Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th) Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia) Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI) Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr) Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid) Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM) Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa) Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire) Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid) Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox) Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss) Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC) Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
235 lines
5.4 KiB
C
235 lines
5.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* linux/drivers/mfd/mcp-core.c
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*
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* Copyright (C) 2001 Russell King
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*
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* Generic MCP (Multimedia Communications Port) layer. All MCP locking
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* is solely held within this file.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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#include <linux/smp.h>
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/mfd/mcp.h>
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#define to_mcp(d) container_of(d, struct mcp, attached_device)
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#define to_mcp_driver(d) container_of(d, struct mcp_driver, drv)
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static int mcp_bus_match(struct device *dev, struct device_driver *drv)
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{
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return 1;
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}
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static int mcp_bus_probe(struct device *dev)
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{
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struct mcp *mcp = to_mcp(dev);
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struct mcp_driver *drv = to_mcp_driver(dev->driver);
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return drv->probe(mcp);
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}
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static void mcp_bus_remove(struct device *dev)
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{
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struct mcp *mcp = to_mcp(dev);
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struct mcp_driver *drv = to_mcp_driver(dev->driver);
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drv->remove(mcp);
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}
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static struct bus_type mcp_bus_type = {
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.name = "mcp",
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.match = mcp_bus_match,
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.probe = mcp_bus_probe,
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.remove = mcp_bus_remove,
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};
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/**
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* mcp_set_telecom_divisor - set the telecom divisor
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* @mcp: MCP interface structure
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* @div: SIB clock divisor
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*
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* Set the telecom divisor on the MCP interface. The resulting
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* sample rate is SIBCLOCK/div.
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*/
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void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div)
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{
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unsigned long flags;
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spin_lock_irqsave(&mcp->lock, flags);
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mcp->ops->set_telecom_divisor(mcp, div);
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spin_unlock_irqrestore(&mcp->lock, flags);
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}
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EXPORT_SYMBOL(mcp_set_telecom_divisor);
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/**
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* mcp_set_audio_divisor - set the audio divisor
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* @mcp: MCP interface structure
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* @div: SIB clock divisor
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*
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* Set the audio divisor on the MCP interface.
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*/
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void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div)
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{
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unsigned long flags;
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spin_lock_irqsave(&mcp->lock, flags);
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mcp->ops->set_audio_divisor(mcp, div);
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spin_unlock_irqrestore(&mcp->lock, flags);
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}
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EXPORT_SYMBOL(mcp_set_audio_divisor);
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/**
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* mcp_reg_write - write a device register
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* @mcp: MCP interface structure
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* @reg: 4-bit register index
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* @val: 16-bit data value
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*
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* Write a device register. The MCP interface must be enabled
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* to prevent this function hanging.
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*/
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void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val)
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{
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unsigned long flags;
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spin_lock_irqsave(&mcp->lock, flags);
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mcp->ops->reg_write(mcp, reg, val);
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spin_unlock_irqrestore(&mcp->lock, flags);
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}
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EXPORT_SYMBOL(mcp_reg_write);
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/**
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* mcp_reg_read - read a device register
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* @mcp: MCP interface structure
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* @reg: 4-bit register index
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*
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* Read a device register and return its value. The MCP interface
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* must be enabled to prevent this function hanging.
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*/
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unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg)
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{
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unsigned long flags;
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unsigned int val;
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spin_lock_irqsave(&mcp->lock, flags);
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val = mcp->ops->reg_read(mcp, reg);
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spin_unlock_irqrestore(&mcp->lock, flags);
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return val;
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}
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EXPORT_SYMBOL(mcp_reg_read);
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/**
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* mcp_enable - enable the MCP interface
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* @mcp: MCP interface to enable
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*
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* Enable the MCP interface. Each call to mcp_enable will need
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* a corresponding call to mcp_disable to disable the interface.
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*/
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void mcp_enable(struct mcp *mcp)
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{
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unsigned long flags;
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spin_lock_irqsave(&mcp->lock, flags);
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if (mcp->use_count++ == 0)
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mcp->ops->enable(mcp);
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spin_unlock_irqrestore(&mcp->lock, flags);
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}
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EXPORT_SYMBOL(mcp_enable);
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/**
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* mcp_disable - disable the MCP interface
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* @mcp: MCP interface to disable
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*
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* Disable the MCP interface. The MCP interface will only be
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* disabled once the number of calls to mcp_enable matches the
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* number of calls to mcp_disable.
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*/
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void mcp_disable(struct mcp *mcp)
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{
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unsigned long flags;
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spin_lock_irqsave(&mcp->lock, flags);
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if (--mcp->use_count == 0)
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mcp->ops->disable(mcp);
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spin_unlock_irqrestore(&mcp->lock, flags);
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}
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EXPORT_SYMBOL(mcp_disable);
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static void mcp_release(struct device *dev)
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{
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struct mcp *mcp = container_of(dev, struct mcp, attached_device);
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kfree(mcp);
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}
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struct mcp *mcp_host_alloc(struct device *parent, size_t size)
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{
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struct mcp *mcp;
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mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL);
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if (mcp) {
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spin_lock_init(&mcp->lock);
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device_initialize(&mcp->attached_device);
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mcp->attached_device.parent = parent;
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mcp->attached_device.bus = &mcp_bus_type;
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mcp->attached_device.dma_mask = parent->dma_mask;
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mcp->attached_device.release = mcp_release;
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}
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return mcp;
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}
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EXPORT_SYMBOL(mcp_host_alloc);
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int mcp_host_add(struct mcp *mcp, void *pdata)
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{
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mcp->attached_device.platform_data = pdata;
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dev_set_name(&mcp->attached_device, "mcp0");
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return device_add(&mcp->attached_device);
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}
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EXPORT_SYMBOL(mcp_host_add);
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void mcp_host_del(struct mcp *mcp)
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{
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device_del(&mcp->attached_device);
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}
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EXPORT_SYMBOL(mcp_host_del);
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void mcp_host_free(struct mcp *mcp)
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{
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put_device(&mcp->attached_device);
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}
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EXPORT_SYMBOL(mcp_host_free);
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int mcp_driver_register(struct mcp_driver *mcpdrv)
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{
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mcpdrv->drv.bus = &mcp_bus_type;
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return driver_register(&mcpdrv->drv);
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}
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EXPORT_SYMBOL(mcp_driver_register);
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void mcp_driver_unregister(struct mcp_driver *mcpdrv)
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{
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driver_unregister(&mcpdrv->drv);
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}
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EXPORT_SYMBOL(mcp_driver_unregister);
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static int __init mcp_init(void)
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{
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return bus_register(&mcp_bus_type);
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}
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static void __exit mcp_exit(void)
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{
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bus_unregister(&mcp_bus_type);
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}
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module_init(mcp_init);
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module_exit(mcp_exit);
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MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
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MODULE_DESCRIPTION("Core multimedia communications port driver");
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MODULE_LICENSE("GPL");
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