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 #include <linux/mfd/mcp.h>
  21
  22 #include <asm/system.h>
  23
  24
  25 #define to_mcp(d)               container_of(d, struct mcp, attached_device)
  26 #define to_mcp_driver(d)        container_of(d, struct mcp_driver, drv)
  27
  28 static int mcp_bus_match(struct device *dev, struct device_driver *drv)
  29 {
  30         return 1;
  31 }
  32
  33 static int mcp_bus_probe(struct device *dev)
  34 {
  35         struct mcp *mcp = to_mcp(dev);
  36         struct mcp_driver *drv = to_mcp_driver(dev->driver);
  37
  38         return drv->probe(mcp);
  39 }
  40
  41 static int mcp_bus_remove(struct device *dev)
  42 {
  43         struct mcp *mcp = to_mcp(dev);
  44         struct mcp_driver *drv = to_mcp_driver(dev->driver);
  45
  46         drv->remove(mcp);
  47         return 0;
  48 }
  49
  50 static int mcp_bus_suspend(struct device *dev, pm_message_t state)
  51 {
  52         struct mcp *mcp = to_mcp(dev);
  53         int ret = 0;
  54
  55         if (dev->driver) {
  56                 struct mcp_driver *drv = to_mcp_driver(dev->driver);
  57
  58                 ret = drv->suspend(mcp, state);
  59         }
  60         return ret;
  61 }
  62
  63 static int mcp_bus_resume(struct device *dev)
  64 {
  65         struct mcp *mcp = to_mcp(dev);
  66         int ret = 0;
  67
  68         if (dev->driver) {
  69                 struct mcp_driver *drv = to_mcp_driver(dev->driver);
  70
  71                 ret = drv->resume(mcp);
  72         }
  73         return ret;
  74 }
  75
  76 static struct bus_type mcp_bus_type = {
  77         .name           = "mcp",
  78         .match          = mcp_bus_match,
  79         .probe          = mcp_bus_probe,
  80         .remove         = mcp_bus_remove,
  81         .suspend        = mcp_bus_suspend,
  82         .resume         = mcp_bus_resume,
  83 };
  84
  85 /**
  86  *      mcp_set_telecom_divisor - set the telecom divisor
  87  *      @mcp: MCP interface structure
  88  *      @div: SIB clock divisor
  89  *
  90  *      Set the telecom divisor on the MCP interface.  The resulting
  91  *      sample rate is SIBCLOCK/div.
  92  */
  93 void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div)
  94 {
  95         unsigned long flags;
  96
  97         spin_lock_irqsave(&mcp->lock, flags);
  98         mcp->ops->set_telecom_divisor(mcp, div);
  99         spin_unlock_irqrestore(&mcp->lock, flags);
 100 }
 101 EXPORT_SYMBOL(mcp_set_telecom_divisor);
 102
 103 /**
 104  *      mcp_set_audio_divisor - set the audio divisor
 105  *      @mcp: MCP interface structure
 106  *      @div: SIB clock divisor
 107  *
 108  *      Set the audio divisor on the MCP interface.
 109  */
 110 void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div)
 111 {
 112         unsigned long flags;
 113
 114         spin_lock_irqsave(&mcp->lock, flags);
 115         mcp->ops->set_audio_divisor(mcp, div);
 116         spin_unlock_irqrestore(&mcp->lock, flags);
 117 }
 118 EXPORT_SYMBOL(mcp_set_audio_divisor);
 119
 120 /**
 121  *      mcp_reg_write - write a device register
 122  *      @mcp: MCP interface structure
 123  *      @reg: 4-bit register index
 124  *      @val: 16-bit data value
 125  *
 126  *      Write a device register.  The MCP interface must be enabled
 127  *      to prevent this function hanging.
 128  */
 129 void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val)
 130 {
 131         unsigned long flags;
 132
 133         spin_lock_irqsave(&mcp->lock, flags);
 134         mcp->ops->reg_write(mcp, reg, val);
 135         spin_unlock_irqrestore(&mcp->lock, flags);
 136 }
 137 EXPORT_SYMBOL(mcp_reg_write);
 138
 139 /**
 140  *      mcp_reg_read - read a device register
 141  *      @mcp: MCP interface structure
 142  *      @reg: 4-bit register index
 143  *
 144  *      Read a device register and return its value.  The MCP interface
 145  *      must be enabled to prevent this function hanging.
 146  */
 147 unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg)
 148 {
 149         unsigned long flags;
 150         unsigned int val;
 151
 152         spin_lock_irqsave(&mcp->lock, flags);
 153         val = mcp->ops->reg_read(mcp, reg);
 154         spin_unlock_irqrestore(&mcp->lock, flags);
 155
 156         return val;
 157 }
 158 EXPORT_SYMBOL(mcp_reg_read);
 159
 160 /**
 161  *      mcp_enable - enable the MCP interface
 162  *      @mcp: MCP interface to enable
 163  *
 164  *      Enable the MCP interface.  Each call to mcp_enable will need
 165  *      a corresponding call to mcp_disable to disable the interface.
 166  */
 167 void mcp_enable(struct mcp *mcp)
 168 {
 169         unsigned long flags;
 170         spin_lock_irqsave(&mcp->lock, flags);
 171         if (mcp->use_count++ == 0)
 172                 mcp->ops->enable(mcp);
 173         spin_unlock_irqrestore(&mcp->lock, flags);
 174 }
 175 EXPORT_SYMBOL(mcp_enable);
 176
 177 /**
 178  *      mcp_disable - disable the MCP interface
 179  *      @mcp: MCP interface to disable
 180  *
 181  *      Disable the MCP interface.  The MCP interface will only be
 182  *      disabled once the number of calls to mcp_enable matches the
 183  *      number of calls to mcp_disable.
 184  */
 185 void mcp_disable(struct mcp *mcp)
 186 {
 187         unsigned long flags;
 188
 189         spin_lock_irqsave(&mcp->lock, flags);
 190         if (--mcp->use_count == 0)
 191                 mcp->ops->disable(mcp);
 192         spin_unlock_irqrestore(&mcp->lock, flags);
 193 }
 194 EXPORT_SYMBOL(mcp_disable);
 195
 196 static void mcp_release(struct device *dev)
 197 {
 198         struct mcp *mcp = container_of(dev, struct mcp, attached_device);
 199
 200         kfree(mcp);
 201 }
 202
 203 struct mcp *mcp_host_alloc(struct device *parent, size_t size)
 204 {
 205         struct mcp *mcp;
 206
 207         mcp = kzalloc(sizeof(struct mcp) + size, GFP_KERNEL);
 208         if (mcp) {
 209                 spin_lock_init(&mcp->lock);
 210                 device_initialize(&mcp->attached_device);
 211                 mcp->attached_device.parent = parent;
 212                 mcp->attached_device.bus = &mcp_bus_type;
 213                 mcp->attached_device.dma_mask = parent->dma_mask;
 214                 mcp->attached_device.release = mcp_release;
 215         }
 216         return mcp;
 217 }
 218 EXPORT_SYMBOL(mcp_host_alloc);
 219
 220 int mcp_host_add(struct mcp *mcp)
 221 {
 222         dev_set_name(&mcp->attached_device, "mcp0");
 223         return device_add(&mcp->attached_device);
 224 }
 225 EXPORT_SYMBOL(mcp_host_add);
 226
 227 void mcp_host_del(struct mcp *mcp)
 228 {
 229         device_del(&mcp->attached_device);
 230 }
 231 EXPORT_SYMBOL(mcp_host_del);
 232
 233 void mcp_host_free(struct mcp *mcp)
 234 {
 235         put_device(&mcp->attached_device);
 236 }
 237 EXPORT_SYMBOL(mcp_host_free);
 238
 239 int mcp_driver_register(struct mcp_driver *mcpdrv)
 240 {
 241         mcpdrv->drv.bus = &mcp_bus_type;
 242         return driver_register(&mcpdrv->drv);
 243 }
 244 EXPORT_SYMBOL(mcp_driver_register);
 245
 246 void mcp_driver_unregister(struct mcp_driver *mcpdrv)
 247 {
 248         driver_unregister(&mcpdrv->drv);
 249 }
 250 EXPORT_SYMBOL(mcp_driver_unregister);
 251
 252 static int __init mcp_init(void)
 253 {
 254         return bus_register(&mcp_bus_type);
 255 }
 256
 257 static void __exit mcp_exit(void)
 258 {
 259         bus_unregister(&mcp_bus_type);
 260 }
 261
 262 module_init(mcp_init);
 263 module_exit(mcp_exit);
 264
 265 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 266 MODULE_DESCRIPTION("Core multimedia communications port driver");
 267 MODULE_LICENSE("GPL");