struct uart_port

最新推荐文章于 2025-03-31 14:48:46 发布

zdh_12

最新推荐文章于 2025-03-31 14:48:46 发布

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本文链接：https://blog.youkuaiyun.com/zdh_12/article/details/9421851

本文介绍了一个用于描述串行通信端口特性的结构体uart_port。该结构体包含了串口的基本配置参数、操作函数指针及状态信息等。通过对该结构体的详细解析，读者可以了解到串口设备在Linux内核中的抽象表示及其工作原理。

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include/linux/serial_core.h

struct uart_port {

   spinlock_t       lock;           /* port lock */
   unsigned long       iobase;           /* in/out[bwl] */
   unsigned char __iomem   *membase;       /* read/write[bwl] */
   unsigned int       (*serial_in)(struct uart_port *, int);
   void           (*serial_out)(struct uart_port *, int, int);
   void           (*set_termios)(struct uart_port *,
                               struct ktermios *new,
                               struct ktermios *old);
   void           (*pm)(struct uart_port *, unsigned int state,
                      unsigned int old);
   unsigned int       irq;           /* irq number */
   unsigned long       irqflags;       /* irq flags */
   unsigned int       uartclk;       /* base uart clock */
   unsigned int       fifosize;       /* tx fifo size */
   unsigned char       x_char;           /* xon/xoff char */
   unsigned char       regshift;       /* reg offset shift */
   unsigned char       iotype;           /* io access style */
   unsigned char       unused1;

#define UPIO_PORT       (0)
#define UPIO_HUB6       (1)
#define UPIO_MEM       (2)
#define UPIO_MEM32       (3)
#define UPIO_AU           (4)           /* Au1x00 type IO */
#define UPIO_TSI       (5)           /* Tsi108/109 type IO */
#define UPIO_DWAPB       (6)           /* DesignWare APB UART */
#define UPIO_RM9000       (7)           /* RM9000 type IO */
#define UPIO_DWAPB32       (8)           /* DesignWare APB UART (32 bit accesses) */

   unsigned int       read_status_mask;   /* driver specific */
   unsigned int       ignore_status_mask;   /* driver specific */
   struct uart_state   *state;           /* pointer to parent state */
   struct uart_icount   icount;           /* statistics */

   struct console       *cons;           /* struct console, if any */
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
   unsigned long       sysrq;           /* sysrq timeout */
#endif

   upf_t           flags;

#define UPF_FOURPORT       ((__force upf_t) (1 << 1))
#define UPF_SAK           ((__force upf_t) (1 << 2))
#define UPF_SPD_MASK       ((__force upf_t) (0x1030))
#define UPF_SPD_HI       ((__force upf_t) (0x0010))
#define UPF_SPD_VHI       ((__force upf_t) (0x0020))
#define UPF_SPD_CUST       ((__force upf_t) (0x0030))
#define UPF_SPD_SHI       ((__force upf_t) (0x1000))
#define UPF_SPD_WARP       ((__force upf_t) (0x1010))
#define UPF_SKIP_TEST       ((__force upf_t) (1 << 6))
#define UPF_AUTO_IRQ       ((__force upf_t) (1 << 7))
#define UPF_HARDPPS_CD       ((__force upf_t) (1 << 11))
#define UPF_LOW_LATENCY       ((__force upf_t) (1 << 13))
#define UPF_BUGGY_UART       ((__force upf_t) (1 << 14))
#define UPF_NO_TXEN_TEST   ((__force upf_t) (1 << 15))
#define UPF_MAGIC_MULTIPLIER   ((__force upf_t) (1 << 16))
#define UPF_CONS_FLOW       ((__force upf_t) (1 << 23))
#define UPF_SHARE_IRQ       ((__force upf_t) (1 << 24))
/* The exact UART type is known and should not be probed. */
#define UPF_FIXED_TYPE       ((__force upf_t) (1 << 27))
#define UPF_BOOT_AUTOCONF   ((__force upf_t) (1 << 28))
#define UPF_FIXED_PORT       ((__force upf_t) (1 << 29))
#define UPF_DEAD       ((__force upf_t) (1 << 30))
#define UPF_IOREMAP       ((__force upf_t) (1 << 31))

#define UPF_CHANGE_MASK       ((__force upf_t) (0x17fff))
#define UPF_USR_MASK       ((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))

   unsigned int       mctrl;           /* current modem ctrl settings */
   unsigned int       timeout;       /* character-based timeout */
   unsigned int       type;           /* port type */
   const struct uart_ops   *ops;
   unsigned int       custom_divisor;
   unsigned int       line;           /* port index */
   resource_size_t       mapbase;       /* for ioremap */
   struct device       *dev;           /* parent device */
   unsigned char       hub6;           /* this should be in the 8250 driver */
   unsigned char       suspended;
   unsigned char       irq_wake;
   unsigned char       unused[2];
   void           *private_data;       /* generic platform data pointer */
};