RS485: fix inconsistencies in the meaning of some variables
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / mfd / mcp-core.c
blob84815f9ef636eb0e91c26c1869094bb5c83977d0
1 /*
2 * linux/drivers/mfd/mcp-core.c
4 * Copyright (C) 2001 Russell King
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.
10 * Generic MCP (Multimedia Communications Port) layer. All MCP locking
11 * is solely held within this file.
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>
22 #include <mach/dma.h>
23 #include <asm/system.h>
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)
29 static int mcp_bus_match(struct device *dev, struct device_driver *drv)
31 return 1;
34 static int mcp_bus_probe(struct device *dev)
36 struct mcp *mcp = to_mcp(dev);
37 struct mcp_driver *drv = to_mcp_driver(dev->driver);
39 return drv->probe(mcp);
42 static int mcp_bus_remove(struct device *dev)
44 struct mcp *mcp = to_mcp(dev);
45 struct mcp_driver *drv = to_mcp_driver(dev->driver);
47 drv->remove(mcp);
48 return 0;
51 static int mcp_bus_suspend(struct device *dev, pm_message_t state)
53 struct mcp *mcp = to_mcp(dev);
54 int ret = 0;
56 if (dev->driver) {
57 struct mcp_driver *drv = to_mcp_driver(dev->driver);
59 ret = drv->suspend(mcp, state);
61 return ret;
64 static int mcp_bus_resume(struct device *dev)
66 struct mcp *mcp = to_mcp(dev);
67 int ret = 0;
69 if (dev->driver) {
70 struct mcp_driver *drv = to_mcp_driver(dev->driver);
72 ret = drv->resume(mcp);
74 return ret;
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,
86 /**
87 * mcp_set_telecom_divisor - set the telecom divisor
88 * @mcp: MCP interface structure
89 * @div: SIB clock divisor
91 * Set the telecom divisor on the MCP interface. The resulting
92 * sample rate is SIBCLOCK/div.
94 void mcp_set_telecom_divisor(struct mcp *mcp, unsigned int div)
96 spin_lock_irq(&mcp->lock);
97 mcp->ops->set_telecom_divisor(mcp, div);
98 spin_unlock_irq(&mcp->lock);
100 EXPORT_SYMBOL(mcp_set_telecom_divisor);
103 * mcp_set_audio_divisor - set the audio divisor
104 * @mcp: MCP interface structure
105 * @div: SIB clock divisor
107 * Set the audio divisor on the MCP interface.
109 void mcp_set_audio_divisor(struct mcp *mcp, unsigned int div)
111 spin_lock_irq(&mcp->lock);
112 mcp->ops->set_audio_divisor(mcp, div);
113 spin_unlock_irq(&mcp->lock);
115 EXPORT_SYMBOL(mcp_set_audio_divisor);
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
123 * Write a device register. The MCP interface must be enabled
124 * to prevent this function hanging.
126 void mcp_reg_write(struct mcp *mcp, unsigned int reg, unsigned int val)
128 unsigned long flags;
130 spin_lock_irqsave(&mcp->lock, flags);
131 mcp->ops->reg_write(mcp, reg, val);
132 spin_unlock_irqrestore(&mcp->lock, flags);
134 EXPORT_SYMBOL(mcp_reg_write);
137 * mcp_reg_read - read a device register
138 * @mcp: MCP interface structure
139 * @reg: 4-bit register index
141 * Read a device register and return its value. The MCP interface
142 * must be enabled to prevent this function hanging.
144 unsigned int mcp_reg_read(struct mcp *mcp, unsigned int reg)
146 unsigned long flags;
147 unsigned int val;
149 spin_lock_irqsave(&mcp->lock, flags);
150 val = mcp->ops->reg_read(mcp, reg);
151 spin_unlock_irqrestore(&mcp->lock, flags);
153 return val;
155 EXPORT_SYMBOL(mcp_reg_read);
158 * mcp_enable - enable the MCP interface
159 * @mcp: MCP interface to enable
161 * Enable the MCP interface. Each call to mcp_enable will need
162 * a corresponding call to mcp_disable to disable the interface.
164 void mcp_enable(struct mcp *mcp)
166 spin_lock_irq(&mcp->lock);
167 if (mcp->use_count++ == 0)
168 mcp->ops->enable(mcp);
169 spin_unlock_irq(&mcp->lock);
171 EXPORT_SYMBOL(mcp_enable);
174 * mcp_disable - disable the MCP interface
175 * @mcp: MCP interface to disable
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.
181 void mcp_disable(struct mcp *mcp)
183 unsigned long flags;
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);
190 EXPORT_SYMBOL(mcp_disable);
192 static void mcp_release(struct device *dev)
194 struct mcp *mcp = container_of(dev, struct mcp, attached_device);
196 kfree(mcp);
199 struct mcp *mcp_host_alloc(struct device *parent, size_t size)
201 struct mcp *mcp;
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;
211 return mcp;
213 EXPORT_SYMBOL(mcp_host_alloc);
215 int mcp_host_register(struct mcp *mcp)
217 dev_set_name(&mcp->attached_device, "mcp0");
218 return device_register(&mcp->attached_device);
220 EXPORT_SYMBOL(mcp_host_register);
222 void mcp_host_unregister(struct mcp *mcp)
224 device_unregister(&mcp->attached_device);
226 EXPORT_SYMBOL(mcp_host_unregister);
228 int mcp_driver_register(struct mcp_driver *mcpdrv)
230 mcpdrv->drv.bus = &mcp_bus_type;
231 return driver_register(&mcpdrv->drv);
233 EXPORT_SYMBOL(mcp_driver_register);
235 void mcp_driver_unregister(struct mcp_driver *mcpdrv)
237 driver_unregister(&mcpdrv->drv);
239 EXPORT_SYMBOL(mcp_driver_unregister);
241 static int __init mcp_init(void)
243 return bus_register(&mcp_bus_type);
246 static void __exit mcp_exit(void)
248 bus_unregister(&mcp_bus_type);
251 module_init(mcp_init);
252 module_exit(mcp_exit);
254 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
255 MODULE_DESCRIPTION("Core multimedia communications port driver");
256 MODULE_LICENSE("GPL");