接上一个继续看spi.c。
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匹配设备 /* 名词解释of: OpenFirmware * 调用层次spi_match_device-->of_driver_match_device-->of_match_device--> * of_match_node * 用于驱动程序检查platform_device是否在其支持列表里 */ 80static int spi_match_device(struct device *dev, struct device_driver *drv) 81{ 82 const struct spi_device *spi = to_spi_device(dev); 83 const struct spi_driver *sdrv = to_spi_driver(drv); 84 85 /* Attempt an OF style match */ /* 不匹配返回0；匹配返回非0，指向struct of_device_id类型的指针 * dev:需要查找的设备; drv:驱动程序结构体 */ 86 if (of_driver_match_device(dev, drv)) 87 return 1; 88 /* 在驱动查找设备ID，找到返回真，否则假 */ 89 if (sdrv->id_table) 90 return !!spi_match_id(sdrv->id_table, spi); 91 /* 比较设备别名和驱动名称，匹配返回真 */ 92 return strcmp(spi->modalias, drv->name) == 0; 93} 94-------------------------------
uevent /* struct kobj_uevent_env 是内核用户空间的一个环境参数 * uevent是sysfs向用户空间发出的消息，这里实际上添加的是一串字符串消息。 * 关于uevent参考:http://blog.csdn.net/walkingman321/archive/2010/10/01/5917737.aspx */ 95static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) 96{ 97 const struct spi_device *spi = to_spi_device(dev); 98 99 add_uevent_var(env, "MODALIAS=%s%s", SPI_MODULE_PREFIX, spi->modalias); 100 return 0; 101}-------------------------------
电源管理 /* 配置了电源管理 * 现在不清楚suspend和resume函数哪里实现，等找到了再说 */ 103#ifdef CONFIG_PM 104 /* 挂起 */ 105static int spi_suspend(struct device *dev, pm_message_t message) 106{ 107 int value = 0; 108 struct spi_driver *drv = to_spi_driver(dev->driver); 109 110 /* suspend will stop irqs and dma; no more i/o */ /* 挂起将定制终端和DMA，没有输入输出 */ 111 if (drv) { /* 驱动实现了挂起操作函数 */ 112 if (drv->suspend) 113 value = drv->suspend(to_spi_device(dev), message); 114 else 115 dev_dbg(dev, "... can't suspend/n"); 116 } 117 return value; 118} 119 /* 恢复 */ 120static int spi_resume(struct device *dev) 121{ 122 int value = 0; 123 struct spi_driver *drv = to_spi_driver(dev->driver); 124 125 /* resume may restart the i/o queue */ /* 重新开始输入输出队列 */ 126 if (drv) { 127 if (drv->resume) 128 value = drv->resume(to_spi_device(dev)); 129 else 130 dev_dbg(dev, "... can't resume/n"); 131 } 132 return value; 133} 134 135#else /* 没有电源管理 */ 136#define spi_suspend NULL 137#define spi_resume NULL 138#endif-------------------------------
总线 /* 总线 参考:http://hi.baidu.com/xingzuzi/blog/item/d12c03f473b3c2a0a50f5260.html */ 140struct bus_type spi_bus_type = { 141 .name = "spi", 142 .dev_attrs = spi_dev_attrs, 143 .match = spi_match_device, 144 .uevent = spi_uevent, 145 .suspend = spi_suspend, 146 .resume = spi_resume, 147}; 148EXPORT_SYMBOL_GPL(spi_bus_type);-------------------------------
驱动注册、删除 /* 驱动注册 */ 151static int spi_drv_probe(struct device *dev) 152{ 153 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 154 155 return sdrv->probe(to_spi_device(dev)); 156} 157 /* 驱动删除 */ 158static int spi_drv_remove(struct device *dev) 159{ 160 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 161 162 return sdrv->remove(to_spi_device(dev)); 163} 164 /* 关闭 */ 165static void spi_drv_shutdown(struct device *dev) 166{ 167 const struct spi_driver *sdrv = to_spi_driver(dev->driver); 168 169 sdrv->shutdown(to_spi_device(dev)); 170}-------------------------------
注册SPI总线驱动 /* 注册SPI驱动 */ 172/** 173 * spi_register_driver - register a SPI driver 174 * @sdrv: the driver to register 175 * Context: can sleep 176 */ 177int spi_register_driver(struct spi_driver *sdrv) 178{ /* 初始化总线结构体 */ 179 sdrv->driver.bus = &spi_bus_type; /* 初始化驱动相关函数 */ 180 if (sdrv->probe) 181 sdrv->driver.probe = spi_drv_probe; 182 if (sdrv->remove) 183 sdrv->driver.remove = spi_drv_remove; 184 if (sdrv->shutdown) 185 sdrv->driver.shutdown = spi_drv_shutdown; /* 驱动注册 * 添加驱动到总线 * sysfs、uevent等创建、初始化 */ 186 return driver_register(&sdrv->driver); 187} 188EXPORT_SYMBOL_GPL(spi_register_driver);-------------------------------
今天先到这了。。。明天继续
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