linux uart驅動——uart platfrom 註冊（三）

一：註冊platform device

註冊一個platfrom device通常須要初始化兩個內容，設備佔用的資源resource和設備私有數據dev.platfrom_data。設備的resource佔用的資源主要包含兩個方面：IO內存和IRQ資源信息，有時也包含DMA。

resource結構：

   1:  struct resource {

   2:      resource_size_t start;//定義資源的起始地址 

   3:      resource_size_t end;//定義資源的結束地址

   4:      const char *name;//定義資源的名稱 

   5:      unsigned long flags;//定義資源的類型，好比MEM，IO，IRQ，DMA類型

   6:      struct resource *parent, *sibling, *child;//資源鏈表指針 

   7:  };

筆者當前的君正board有三個串口：

   1:  #ifdef CONFIG_SERIAL_JZ47XX_UART0

   2:  /* UART ( uart controller) */

   3:  static struct resource jz_uart0_resources[] = {

   4:      [0] = {

   5:          .start          = UART0_IOBASE,

   6:          .end            = UART0_IOBASE + 0x1000 - 1,

   7:          .flags          = IORESOURCE_MEM,

   8:      },

   9:      [1] = {

  10:          .start          = IRQ_UART0,

  11:          .end            = IRQ_UART0,

  12:          .flags          = IORESOURCE_IRQ,

  13:      },

  14:  #ifdef CONFIG_SERIAL_JZ47XX_UART0_DMA

  15:      [2] = {

  16:          .start          = JZDMA_REQ_UART0,

  17:          .flags          = IORESOURCE_DMA,

  18:      },

  19:  #endif

  20:  };

  21:   

  22:  struct platform_device jz_uart0_device = {

  23:      .name = "jz-uart",

  24:      .id = 0,

  25:      .num_resources  = ARRAY_SIZE(jz_uart0_resources),

  26:      .resource       = jz_uart0_resources,

  27:  };

  28:  #endif

  29:  #ifdef CONFIG_SERIAL_JZ47XX_UART1

  30:  static struct resource jz_uart1_resources[] = {

  31:      [0] = {

  32:          .start          = UART1_IOBASE,

  33:          .end            = UART1_IOBASE + 0x1000 - 1,

  34:          .flags          = IORESOURCE_MEM,

  35:      },

  36:      [1] = {

  37:          .start          = IRQ_UART1,

  38:          .end            = IRQ_UART1,

  39:          .flags          = IORESOURCE_IRQ,

  40:      },

  41:  #ifdef CONFIG_SERIAL_JZ47XX_UART1_DMA

  42:      [2] = {

  43:          .start          = JZDMA_REQ_UART1,

  44:          .flags          = IORESOURCE_DMA,

  45:      },

  46:  #endif

  47:  };

  48:  struct platform_device jz_uart1_device = {

  49:      .name = "jz-uart",

  50:      .id = 1,

  51:      .num_resources  = ARRAY_SIZE(jz_uart1_resources),

  52:      .resource       = jz_uart1_resources,

  53:  };

  54:  #endif

  55:  #ifdef CONFIG_SERIAL_JZ47XX_UART2

  56:  static struct resource jz_uart2_resources[] = {

  57:      [0] = {

  58:          .start          = UART2_IOBASE,

  59:          .end            = UART2_IOBASE + 0x1000 - 1,

  60:          .flags          = IORESOURCE_MEM,

  61:      },

  62:      [1] = {

  63:          .start          = IRQ_UART2,

  64:          .end            = IRQ_UART2,

  65:          .flags          = IORESOURCE_IRQ,

  66:      },

  67:  #ifdef CONFIG_SERIAL_JZ47XX_UART2_DMA

  68:      [2] = {

  69:          .start          = JZDMA_REQ_UART2,

  70:          .flags          = IORESOURCE_DMA,

  71:      },

  72:  #endif

  73:  };

  74:   

  75:  struct platform_device jz_uart2_device = {

  76:      .name = "jz-uart",

  77:      .id = 2,

  78:      .num_resources  = ARRAY_SIZE(jz_uart2_resources),

  79:      .resource       = jz_uart2_resources,

  80:  };

  81:  #endif

platform_device_register(&jz_uartXX_device);

註冊成功後：（多個device）

ls /sys/bus/platform/devices/
jz-uart.0/  jz-uart.2/

 

二：註冊platfrom driver

   1:  /* serial platfrom driver */

   2:  static struct platform_driver serial_jz47xx_driver = {

   3:      .probe          = serial_jz47xx_probe,

   4:      .remove         = serial_jz47xx_remove,

   5:   

   6:      .driver        = {

   7:          .name    = "jz-uart",

   8:          .owner    = THIS_MODULE,

   9:  #ifdef CONFIG_PM

  10:          .pm    = &serial_jz47xx_pm_ops,

  11:  #endif

  12:      },

  13:  };

  14:   

  15:  int __init serial_jz47xx_init(void)

  16:  {

  17:      int ret;

  18:      /* 功能：uart_register_driver用於將串口驅動uart_driver註冊到內核(串口核心層)中，

  19:                  一般在模塊初始化函數調用該函數。

  20:        * 參數 drv：要註冊的uart_driver

  21:        * 返回值：  成功，返回0；不然返回錯誤碼

  22:       */

  23:      ret = uart_register_driver(&serial_jz47xx_reg);

  24:      if (ret != 0)

  25:          return ret;

  26:   

  27:      /* 註冊serial platfrom驅動 */

  28:      ret = platform_driver_register(&serial_jz47xx_driver); 

  29:      if (ret != 0)

  30:          uart_unregister_driver(&serial_jz47xx_reg);

  31:   

  32:      return ret;

  33:  }

  34:   

  35:  void __exit serial_jz47xx_exit(void)

  36:  {

  37:      platform_driver_unregister(&serial_jz47xx_driver);

  38:      uart_unregister_driver(&serial_jz47xx_reg);

  39:  }

  40:   

  41:   

  42:  #ifdef CONFIG_EARLY_INIT_RUN

  43:  rootfs_initcall(serial_jz47xx_init);/*先於module註冊*/

  44:   

  45:  #else

  46:  module_init(serial_jz47xx_init);

  47:   

  48:  #endif

  49:   

  50:  module_exit(serial_jz47xx_exit);

  51:   

  52:  MODULE_LICENSE("GPL");

  53:  MODULE_ALIAS("platform:jz47xx-uart");

註冊成功後：（一個driver對應多個device）

ls /sys/bus/platform/drivers/jz-uart/
bind       jz-uart.0  jz-uart.2  uevent     unbind