1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * linux/drivers/mfd/mcp-core.c 4 * 5 * Copyright (C) 2001 Russell King 6 * 7 * Generic MCP (Multimedia Communications Port) layer. All MCP locking 8 * 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, 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 int 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 return 0; 43} 44 45static struct bus_type mcp_bus_type = { 46 .name = "mcp", 47 .match = mcp_bus_match, 48 .probe = mcp_bus_probe, 49 .remove = mcp_bus_remove, 50}; 51 52/** 53 * mcp_set_telecom_divisor - set the telecom divisor 54 * @mcp: MCP interface structure 55 * @div: SIB clock divisor 56 * 57 * Set the telecom divisor on the MCP interface. The resulting 58 * sample rate is SIBCLOCK/div. 59 */ 60void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div) 61{ 62 unsigned long flags; 63 64 spin_lock_irqsave(&mcp->lock, flags); 65 mcp->ops->set_telecom_divisor(mcp, div); 66 spin_unlock_irqrestore(&mcp->lock, flags); 67} 68EXPORT_SYMBOL(mcp_set_telecom_divisor); 69 70/** 71 * mcp_set_audio_divisor - set the audio divisor 72 * @mcp: MCP interface structure 73 * @div: SIB clock divisor 74 * 75 * Set the audio divisor on the MCP interface. 76 */ 77void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div) 78{ 79 unsigned long flags; 80 81 spin_lock_irqsave(&mcp->lock, flags); 82 mcp->ops->set_audio_divisor(mcp, div); 83 spin_unlock_irqrestore(&mcp->lock, flags); 84} 85EXPORT_SYMBOL(mcp_set_audio_divisor); 86 87/** 88 * mcp_reg_write - write a device register 89 * @mcp: MCP interface structure 90 * @reg: 4-bit register index 91 * @val: 16-bit data value 92 * 93 * Write a device register. The MCP interface must be enabled 94 * to prevent this function hanging. 95 */ 96void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val) 97{ 98 unsigned long flags; 99 100 spin_lock_irqsave(&mcp->lock, flags); 101 mcp->ops->reg_write(mcp, reg, val); 102 spin_unlock_irqrestore(&mcp->lock, flags); 103} 104EXPORT_SYMBOL(mcp_reg_write); 105 106/** 107 * mcp_reg_read - read a device register 108 * @mcp: MCP interface structure 109 * @reg: 4-bit register index 110 * 111 * Read a device register and return its value. The MCP interface 112 * must be enabled to prevent this function hanging. 113 */ 114unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg) 115{ 116 unsigned long flags; 117 unsigned int val; 118 119 spin_lock_irqsave(&mcp->lock, flags); 120 val = mcp->ops->reg_read(mcp, reg); 121 spin_unlock_irqrestore(&mcp->lock, flags); 122 123 return val; 124} 125EXPORT_SYMBOL(mcp_reg_read); 126 127/** 128 * mcp_enable - enable the MCP interface 129 * @mcp: MCP interface to enable 130 * 131 * Enable the MCP interface. Each call to mcp_enable will need 132 * a corresponding call to mcp_disable to disable the interface. 133 */ 134void mcp_enable(struct mcp *mcp) 135{ 136 unsigned long flags; 137 138 spin_lock_irqsave(&mcp->lock, flags); 139 if (mcp->use_count++ == 0) 140 mcp->ops->enable(mcp); 141 spin_unlock_irqrestore(&mcp->lock, flags); 142} 143EXPORT_SYMBOL(mcp_enable); 144 145/** 146 * mcp_disable - disable the MCP interface 147 * @mcp: MCP interface to disable 148 * 149 * Disable the MCP interface. The MCP interface will only be 150 * disabled once the number of calls to mcp_enable matches the 151 * number of calls to mcp_disable. 152 */ 153void mcp_disable(struct mcp *mcp) 154{ 155 unsigned long flags; 156 157 spin_lock_irqsave(&mcp->lock, flags); 158 if (--mcp->use_count == 0) 159 mcp->ops->disable(mcp); 160 spin_unlock_irqrestore(&mcp->lock, flags); 161} 162EXPORT_SYMBOL(mcp_disable); 163 164static void mcp_release(struct device *dev) 165{ 166 struct mcp *mcp = container_of(dev, struct mcp, attached_device); 167 168 kfree(mcp); 169} 170 171struct mcp *mcp_host_alloc(struct device *parent, size_t size) 172{ 173 struct mcp *mcp; 174 175 mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL); 176 if (mcp) { 177 spin_lock_init(&mcp->lock); 178 device_initialize(&mcp->attached_device); 179 mcp->attached_device.parent = parent; 180 mcp->attached_device.bus = &mcp_bus_type; 181 mcp->attached_device.dma_mask = parent->dma_mask; 182 mcp->attached_device.release = mcp_release; 183 } 184 return mcp; 185} 186EXPORT_SYMBOL(mcp_host_alloc); 187 188int mcp_host_add(struct mcp *mcp, void *pdata) 189{ 190 mcp->attached_device.platform_data = pdata; 191 dev_set_name(&mcp->attached_device, "mcp0"); 192 return device_add(&mcp->attached_device); 193} 194EXPORT_SYMBOL(mcp_host_add); 195 196void mcp_host_del(struct mcp *mcp) 197{ 198 device_del(&mcp->attached_device); 199} 200EXPORT_SYMBOL(mcp_host_del); 201 202void mcp_host_free(struct mcp *mcp) 203{ 204 put_device(&mcp->attached_device); 205} 206EXPORT_SYMBOL(mcp_host_free); 207 208int mcp_driver_register(struct mcp_driver *mcpdrv) 209{ 210 mcpdrv->drv.bus = &mcp_bus_type; 211 return driver_register(&mcpdrv->drv); 212} 213EXPORT_SYMBOL(mcp_driver_register); 214 215void mcp_driver_unregister(struct mcp_driver *mcpdrv) 216{ 217 driver_unregister(&mcpdrv->drv); 218} 219EXPORT_SYMBOL(mcp_driver_unregister); 220 221static int __init mcp_init(void) 222{ 223 return bus_register(&mcp_bus_type); 224} 225 226static void __exit mcp_exit(void) 227{ 228 bus_unregister(&mcp_bus_type); 229} 230 231module_init(mcp_init); 232module_exit(mcp_exit); 233 234MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 235MODULE_DESCRIPTION("Core multimedia communications port driver"); 236MODULE_LICENSE("GPL"); 237