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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * linux/drivers/mfd/mcp-core.c4 *5 * Copyright (C) 2001 Russell King6 *7 * Generic MCP (Multimedia Communications Port) layer. All MCP locking8 * is solely held within this file.9 */10#include <linux/module.h>11#include <linux/init.h>12#include <linux/errno.h>13#include <linux/smp.h>14#include <linux/device.h>15#include <linux/slab.h>16#include <linux/string.h>17#include <linux/mfd/mcp.h>18 19 20#define to_mcp(d) container_of(d, struct mcp, attached_device)21#define to_mcp_driver(d) container_of(d, struct mcp_driver, drv)22 23static int mcp_bus_match(struct device *dev, const struct device_driver *drv)24{25 return 1;26}27 28static int mcp_bus_probe(struct device *dev)29{30 struct mcp *mcp = to_mcp(dev);31 struct mcp_driver *drv = to_mcp_driver(dev->driver);32 33 return drv->probe(mcp);34}35 36static void mcp_bus_remove(struct device *dev)37{38 struct mcp *mcp = to_mcp(dev);39 struct mcp_driver *drv = to_mcp_driver(dev->driver);40 41 drv->remove(mcp);42}43 44static const struct bus_type mcp_bus_type = {45 .name = "mcp",46 .match = mcp_bus_match,47 .probe = mcp_bus_probe,48 .remove = mcp_bus_remove,49};50 51/**52 * mcp_set_telecom_divisor - set the telecom divisor53 * @mcp: MCP interface structure54 * @div: SIB clock divisor55 *56 * Set the telecom divisor on the MCP interface. The resulting57 * sample rate is SIBCLOCK/div.58 */59void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div)60{61 unsigned long flags;62 63 spin_lock_irqsave(&mcp->lock, flags);64 mcp->ops->set_telecom_divisor(mcp, div);65 spin_unlock_irqrestore(&mcp->lock, flags);66}67EXPORT_SYMBOL(mcp_set_telecom_divisor);68 69/**70 * mcp_set_audio_divisor - set the audio divisor71 * @mcp: MCP interface structure72 * @div: SIB clock divisor73 *74 * Set the audio divisor on the MCP interface.75 */76void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div)77{78 unsigned long flags;79 80 spin_lock_irqsave(&mcp->lock, flags);81 mcp->ops->set_audio_divisor(mcp, div);82 spin_unlock_irqrestore(&mcp->lock, flags);83}84EXPORT_SYMBOL(mcp_set_audio_divisor);85 86/**87 * mcp_reg_write - write a device register88 * @mcp: MCP interface structure89 * @reg: 4-bit register index90 * @val: 16-bit data value91 *92 * Write a device register. The MCP interface must be enabled93 * to prevent this function hanging.94 */95void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val)96{97 unsigned long flags;98 99 spin_lock_irqsave(&mcp->lock, flags);100 mcp->ops->reg_write(mcp, reg, val);101 spin_unlock_irqrestore(&mcp->lock, flags);102}103EXPORT_SYMBOL(mcp_reg_write);104 105/**106 * mcp_reg_read - read a device register107 * @mcp: MCP interface structure108 * @reg: 4-bit register index109 *110 * Read a device register and return its value. The MCP interface111 * must be enabled to prevent this function hanging.112 */113unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg)114{115 unsigned long flags;116 unsigned int val;117 118 spin_lock_irqsave(&mcp->lock, flags);119 val = mcp->ops->reg_read(mcp, reg);120 spin_unlock_irqrestore(&mcp->lock, flags);121 122 return val;123}124EXPORT_SYMBOL(mcp_reg_read);125 126/**127 * mcp_enable - enable the MCP interface128 * @mcp: MCP interface to enable129 *130 * Enable the MCP interface. Each call to mcp_enable will need131 * a corresponding call to mcp_disable to disable the interface.132 */133void mcp_enable(struct mcp *mcp)134{135 unsigned long flags;136 137 spin_lock_irqsave(&mcp->lock, flags);138 if (mcp->use_count++ == 0)139 mcp->ops->enable(mcp);140 spin_unlock_irqrestore(&mcp->lock, flags);141}142EXPORT_SYMBOL(mcp_enable);143 144/**145 * mcp_disable - disable the MCP interface146 * @mcp: MCP interface to disable147 *148 * Disable the MCP interface. The MCP interface will only be149 * disabled once the number of calls to mcp_enable matches the150 * number of calls to mcp_disable.151 */152void mcp_disable(struct mcp *mcp)153{154 unsigned long flags;155 156 spin_lock_irqsave(&mcp->lock, flags);157 if (--mcp->use_count == 0)158 mcp->ops->disable(mcp);159 spin_unlock_irqrestore(&mcp->lock, flags);160}161EXPORT_SYMBOL(mcp_disable);162 163static void mcp_release(struct device *dev)164{165 struct mcp *mcp = container_of(dev, struct mcp, attached_device);166 167 kfree(mcp);168}169 170struct mcp *mcp_host_alloc(struct device *parent, size_t size)171{172 struct mcp *mcp;173 174 mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL);175 if (mcp) {176 spin_lock_init(&mcp->lock);177 device_initialize(&mcp->attached_device);178 mcp->attached_device.parent = parent;179 mcp->attached_device.bus = &mcp_bus_type;180 mcp->attached_device.dma_mask = parent->dma_mask;181 mcp->attached_device.release = mcp_release;182 }183 return mcp;184}185EXPORT_SYMBOL(mcp_host_alloc);186 187int mcp_host_add(struct mcp *mcp, void *pdata)188{189 mcp->attached_device.platform_data = pdata;190 dev_set_name(&mcp->attached_device, "mcp0");191 return device_add(&mcp->attached_device);192}193EXPORT_SYMBOL(mcp_host_add);194 195void mcp_host_del(struct mcp *mcp)196{197 device_del(&mcp->attached_device);198}199EXPORT_SYMBOL(mcp_host_del);200 201void mcp_host_free(struct mcp *mcp)202{203 put_device(&mcp->attached_device);204}205EXPORT_SYMBOL(mcp_host_free);206 207int mcp_driver_register(struct mcp_driver *mcpdrv)208{209 mcpdrv->drv.bus = &mcp_bus_type;210 return driver_register(&mcpdrv->drv);211}212EXPORT_SYMBOL(mcp_driver_register);213 214void mcp_driver_unregister(struct mcp_driver *mcpdrv)215{216 driver_unregister(&mcpdrv->drv);217}218EXPORT_SYMBOL(mcp_driver_unregister);219 220static int __init mcp_init(void)221{222 return bus_register(&mcp_bus_type);223}224 225static void __exit mcp_exit(void)226{227 bus_unregister(&mcp_bus_type);228}229 230module_init(mcp_init);231module_exit(mcp_exit);232 233MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");234MODULE_DESCRIPTION("Core multimedia communications port driver");235MODULE_LICENSE("GPL");236