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