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