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 23 static int mcp_bus_match(struct device *dev, struct device_driver *drv) 24 { 25 return 1; 26 } 27 28 static 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 36 static 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 45 static 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 */ 60 void 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 } 68 EXPORT_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 */ 77 void 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 } 85 EXPORT_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 */ 96 void 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 } 104 EXPORT_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 */ 114 unsigned 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 } 125 EXPORT_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 */ 134 void 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 } 143 EXPORT_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 */ 153 void 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 } 162 EXPORT_SYMBOL(mcp_disable); 163 164 static void mcp_release(struct device *dev) 165 { 166 struct mcp *mcp = container_of(dev, struct mcp, attached_device); 167 168 kfree(mcp); 169 } 170 171 struct 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 } 186 EXPORT_SYMBOL(mcp_host_alloc); 187 188 int 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 } 194 EXPORT_SYMBOL(mcp_host_add); 195 196 void mcp_host_del(struct mcp *mcp) 197 { 198 device_del(&mcp->attached_device); 199 } 200 EXPORT_SYMBOL(mcp_host_del); 201 202 void mcp_host_free(struct mcp *mcp) 203 { 204 put_device(&mcp->attached_device); 205 } 206 EXPORT_SYMBOL(mcp_host_free); 207 208 int mcp_driver_register(struct mcp_driver *mcpdrv) 209 { 210 mcpdrv->drv.bus = &mcp_bus_type; 211 return driver_register(&mcpdrv->drv); 212 } 213 EXPORT_SYMBOL(mcp_driver_register); 214 215 void mcp_driver_unregister(struct mcp_driver *mcpdrv) 216 { 217 driver_unregister(&mcpdrv->drv); 218 } 219 EXPORT_SYMBOL(mcp_driver_unregister); 220 221 static int __init mcp_init(void) 222 { 223 return bus_register(&mcp_bus_type); 224 } 225 226 static void __exit mcp_exit(void) 227 { 228 bus_unregister(&mcp_bus_type); 229 } 230 231 module_init(mcp_init); 232 module_exit(mcp_exit); 233 234 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); 235 MODULE_DESCRIPTION("Core multimedia communications port driver"); 236 MODULE_LICENSE("GPL"); 237