drivers/mfd/mcp-core.c

   1 /*
   2  *  linux/drivers/mfd/mcp-core.c
   3  *
   4  *  Copyright (C) 2001 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License.
   9  *
  10  *  Generic MCP (Multimedia Communications Port) layer.  All MCP locking
  11  *  is solely held within this file.
  12  */
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/errno.h>
  16 #include <linux/smp.h>
  17 #include <linux/device.h>
  18 #include <linux/slab.h>
  19 #include <linux/string.h>
  20
  21 #include <asm/dma.h>
  22 #include <asm/system.h>
  23
  24 #include "mcp.h"
  25
  26 #define to_mcp(d)               container_of(d, struct mcp, attached_device)
  27 #define to_mcp_driver(d)        container_of(d, struct mcp_driver, drv)
  28
  29 static int mcp_bus_match(struct device *dev, struct device_driver *drv)
  30 {
  31         return 1;
  32 }
  33
  34 static int mcp_bus_probe(struct device *dev)
  35 {
  36         struct mcp *mcp = to_mcp(dev);
  37         struct mcp_driver *drv = to_mcp_driver(dev->driver);
  38
  39         return drv->probe(mcp);
  40 }
  41
  42 static int mcp_bus_remove(struct device *dev)
  43 {
  44         struct mcp *mcp = to_mcp(dev);
  45         struct mcp_driver *drv = to_mcp_driver(dev->driver);
  46
  47         drv->remove(mcp);
  48         return 0;
  49 }
  50
  51 static int mcp_bus_suspend(struct device *dev, pm_message_t state)
  52 {
  53         struct mcp *mcp = to_mcp(dev);
  54         int ret = 0;
  55
  56         if (dev->driver) {
  57                 struct mcp_driver *drv = to_mcp_driver(dev->driver);
  58
  59                 ret = drv->suspend(mcp, state);
  60         }
  61         return ret;
  62 }
  63
  64 static int mcp_bus_resume(struct device *dev)
  65 {
  66         struct mcp *mcp = to_mcp(dev);
  67         int ret = 0;
  68
  69         if (dev->driver) {
  70                 struct mcp_driver *drv = to_mcp_driver(dev->driver);
  71
  72                 ret = drv->resume(mcp);
  73         }
  74         return ret;
  75 }
  76
  77 static struct bus_type mcp_bus_type = {
  78         .name           = "mcp",
  79         .match          = mcp_bus_match,
  80         .probe          = mcp_bus_probe,
  81         .remove         = mcp_bus_remove,
  82         .suspend        = mcp_bus_suspend,
  83         .resume         = mcp_bus_resume,
  84 };
  85
  86 /**
  87  *      mcp_set_telecom_divisor - set the telecom divisor
  88  *      @mcp: MCP interface structure
  89  *      @div: SIB clock divisor
  90  *
  91  *      Set the telecom divisor on the MCP interface.  The resulting
  92  *      sample rate is SIBCLOCK/div.
  93  */
  94 void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div)
  95 {
  96         spin_lock_irq(&mcp->lock);
  97         mcp->ops->set_telecom_divisor(mcp, div);
  98         spin_unlock_irq(&mcp->lock);
  99 }
 100 EXPORT_SYMBOL(mcp_set_telecom_divisor);
 101
 102 /**
 103  *      mcp_set_audio_divisor - set the audio divisor
 104  *      @mcp: MCP interface structure
 105  *      @div: SIB clock divisor
 106  *
 107  *      Set the audio divisor on the MCP interface.
 108  */
 109 void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div)
 110 {
 111         spin_lock_irq(&mcp->lock);
 112         mcp->ops->set_audio_divisor(mcp, div);
 113         spin_unlock_irq(&mcp->lock);
 114 }
 115 EXPORT_SYMBOL(mcp_set_audio_divisor);
 116
 117 /**
 118  *      mcp_reg_write - write a device register
 119  *      @mcp: MCP interface structure
 120  *      @reg: 4-bit register index
 121  *      @val: 16-bit data value
 122  *
 123  *      Write a device register.  The MCP interface must be enabled
 124  *      to prevent this function hanging.
 125  */
 126 void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val)
 127 {
 128         unsigned long flags;
 129
 130         spin_lock_irqsave(&mcp->lock, flags);
 131         mcp->ops->reg_write(mcp, reg, val);
 132         spin_unlock_irqrestore(&mcp->lock, flags);
 133 }
 134 EXPORT_SYMBOL(mcp_reg_write);
 135
 136 /**
 137  *      mcp_reg_read - read a device register
 138  *      @mcp: MCP interface structure
 139  *      @reg: 4-bit register index
 140  *
 141  *      Read a device register and return its value.  The MCP interface
 142  *      must be enabled to prevent this function hanging.
 143  */
 144 unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg)
 145 {
 146         unsigned long flags;
 147         unsigned int val;
 148
 149         spin_lock_irqsave(&mcp->lock, flags);
 150         val = mcp->ops->reg_read(mcp, reg);
 151         spin_unlock_irqrestore(&mcp->lock, flags);
 152
 153         return val;
 154 }
 155 EXPORT_SYMBOL(mcp_reg_read);
 156
 157 /**
 158  *      mcp_enable - enable the MCP interface
 159  *      @mcp: MCP interface to enable
 160  *
 161  *      Enable the MCP interface.  Each call to mcp_enable will need
 162  *      a corresponding call to mcp_disable to disable the interface.
 163  */
 164 void mcp_enable(struct mcp *mcp)
 165 {
 166         spin_lock_irq(&mcp->lock);
 167         if (mcp->use_count++ == 0)
 168                 mcp->ops->enable(mcp);
 169         spin_unlock_irq(&mcp->lock);
 170 }
 171 EXPORT_SYMBOL(mcp_enable);
 172
 173 /**
 174  *      mcp_disable - disable the MCP interface
 175  *      @mcp: MCP interface to disable
 176  *
 177  *      Disable the MCP interface.  The MCP interface will only be
 178  *      disabled once the number of calls to mcp_enable matches the
 179  *      number of calls to mcp_disable.
 180  */
 181 void mcp_disable(struct mcp *mcp)
 182 {
 183         unsigned long flags;
 184
 185         spin_lock_irqsave(&mcp->lock, flags);
 186         if (--mcp->use_count == 0)
 187                 mcp->ops->disable(mcp);
 188         spin_unlock_irqrestore(&mcp->lock, flags);
 189 }
 190 EXPORT_SYMBOL(mcp_disable);
 191
 192 static void mcp_release(struct device *dev)
 193 {
 194         struct mcp *mcp = container_of(dev, struct mcp, attached_device);
 195
 196         kfree(mcp);
 197 }
 198
 199 struct mcp *mcp_host_alloc(struct device *parent, size_t size)
 200 {
 201         struct mcp *mcp;
 202
 203         mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL);
 204         if (mcp) {
 205                 spin_lock_init(&mcp->lock);
 206                 mcp->attached_device.parent = parent;
 207                 mcp->attached_device.bus = &mcp_bus_type;
 208                 mcp->attached_device.dma_mask = parent->dma_mask;
 209                 mcp->attached_device.release = mcp_release;
 210         }
 211         return mcp;
 212 }
 213 EXPORT_SYMBOL(mcp_host_alloc);
 214
 215 int mcp_host_register(struct mcp *mcp)
 216 {
 217         strcpy(mcp->attached_device.bus_id, "mcp0");
 218         return device_register(&mcp->attached_device);
 219 }
 220 EXPORT_SYMBOL(mcp_host_register);
 221
 222 void mcp_host_unregister(struct mcp *mcp)
 223 {
 224         device_unregister(&mcp->attached_device);
 225 }
 226 EXPORT_SYMBOL(mcp_host_unregister);
 227
 228 int mcp_driver_register(struct mcp_driver *mcpdrv)
 229 {
 230         mcpdrv->drv.bus = &mcp_bus_type;
 231         return driver_register(&mcpdrv->drv);
 232 }
 233 EXPORT_SYMBOL(mcp_driver_register);
 234
 235 void mcp_driver_unregister(struct mcp_driver *mcpdrv)
 236 {
 237         driver_unregister(&mcpdrv->drv);
 238 }
 239 EXPORT_SYMBOL(mcp_driver_unregister);
 240
 241 static int __init mcp_init(void)
 242 {
 243         return bus_register(&mcp_bus_type);
 244 }
 245
 246 static void __exit mcp_exit(void)
 247 {
 248         bus_unregister(&mcp_bus_type);
 249 }
 250
 251 module_init(mcp_init);
 252 module_exit(mcp_exit);
 253
 254 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 255 MODULE_DESCRIPTION("Core multimedia communications port driver");
 256 MODULE_LICENSE("GPL");