哪做网站最好,做网站的价,网站站群 硬盘扩容 申请报告,网络营销网站建设步骤一、核心数据结构串口驱动有3个核心数据结构#xff0c;它们都定义在1、uart_driveruart_driver包含了串口设备名、串口驱动名、主次设备号、串口控制台(可选)等信息#xff0c;还封装了tty_driver(底层串口驱动无需关心tty_driver)。struct uart_driver {struct module …一、核心数据结构串口驱动有3个核心数据结构它们都定义在1、uart_driveruart_driver包含了串口设备名、串口驱动名、主次设备号、串口控制台(可选)等信息还封装了tty_driver(底层串口驱动无需关心tty_driver)。struct uart_driver {struct module *owner; /* 拥有该uart_driver的模块,一般为THIS_MODULE */const char *driver_name; /* 串口驱动名串口设备文件名以驱动名为基础 */const char *dev_name; /* 串口设备名 */int major; /* 主设备号 */int minor; /* 次设备号 */int nr; /* 该uart_driver支持的串口个数(最大) */struct console *cons; /* 其对应的console.若该uart_driver支持serial console,否则为NULL *//** these are private; the low level driver should not* touch these; they should be initialised to NULL*/struct uart_state *state;struct tty_driver *tty_driver;};2、uart_portuart_port用于描述串口端口的I/O端口或I/O内存地址、FIFO大小、端口类型、串口时钟等信息。实际上一个uart_port实例对应一个串口设备struct uart_port {spinlock_t lock; /* 串口端口锁 */unsigned int iobase; /* IO端口基地址 */unsigned char __iomem *membase; /* IO内存基地址,经映射(如ioremap)后的IO内存虚拟基地址 */unsigned int irq; /* 中断号 */unsigned int uartclk; /* 串口时钟 */unsigned int fifosize; /* 串口FIFO缓冲大小 */unsigned char x_char; /* xon/xoff字符 */unsigned char regshift; /* 寄存器位移 */unsigned char iotype; /* IO访问方式 */unsigned char unused1;#define UPIO_PORT (0) /* IO端口 */#define UPIO_HUB6 (1)#define UPIO_MEM (2) /* IO内存 */#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 */unsigned int read_status_mask; /* 关心的Rx error status */unsigned int ignore_status_mask;/* 忽略的Rx error status */struct uart_info *info; /* pointer to parent info */struct uart_icount icount; /* 计数器 */struct console *cons; /* console结构体 */#ifdef CONFIG_SERIAL_CORE_CONSOLEunsigned long sysrq; /* sysrq timeout */#endifupf_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_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))#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; /* 当前的moden设置 */unsigned int timeout; /* character-based timeout */unsigned int type; /* 端口类型 */const struct uart_ops *ops; /* 串口端口操作函数集 */unsigned int custom_divisor;unsigned int line; /* 端口索引 */resource_size_t mapbase; /* IO内存物理基地址可用于ioremap */struct device *dev; /* 父设备 */unsigned char hub6; /* this should be in the 8250 driver */unsigned char suspended;unsigned char unused[2];void *private_data; /* 端口私有数据,一般为platform数据指针 */};uart_iconut为串口信息计数器包含了发送字符计数、接收字符计数等。在串口的发送中断处理函数和接收中断处理函数中我们需要管理这些计数。struct uart_icount {__u32 cts;__u32 dsr;__u32 rng;__u32 dcd;__u32 rx;/* 发送字符计数 */__u32 tx;/* 接受字符计数 */__u32 frame;/* 帧错误计数 */__u32 overrun;/* Rx FIFO溢出计数 */__u32 parity;/* 帧校验错误计数 */__u32 brk;/* break计数 */__u32 buf_overrun;};uart_info有两个成员在底层串口驱动会用到xmit和tty。用户空间程序通过串口发送数据时上层驱动将用户数据保存在xmit而串口发送中断处理函数就是通过xmit获取到用户数据并将它们发送出去。串口接收中断处理函数需要通过tty将接收到的数据传递给行规则层。/* uart_info实例仅在串口端口打开时有效它可能在串口关闭时被串口核心层释放。因此在使用uart_port的uart_info成员时必须保证串口已打开。底层驱动和核心层驱动都可以修改uart_info实例。* This is the state information which is only valid when the port* is open; it may be freed by the core driver once the device has* been closed. Either the low level driver or the core can modify* stuff here.*/struct uart_info {struct tty_struct *tty;struct circ_buf xmit;uif_t flags;/** Definitions for info-flags. These are _private_ to serial_core, and* are specific to this structure. They may be queried by low level drivers.*/#define UIF_CHECK_CD ((__force uif_t) (1 25))#define UIF_CTS_FLOW ((__force uif_t) (1 26))#define UIF_NORMAL_ACTIVE ((__force uif_t) (1 29))#define UIF_INITIALIZED ((__force uif_t) (1 31))#define UIF_SUSPENDED ((__force uif_t) (1 30))int blocked_open;struct tasklet_struct tlet;wait_queue_head_t open_wait;wait_queue_head_t delta_msr_wait;};3、uart_opsuart_ops涵盖了串口驱动可对串口设备进行的所有操作。/** This structure describes all the operations that can be* done on the physical hardware.*/struct uart_ops {unsigned int (*tx_empty)(struct uart_port *); /* 串口的Tx FIFO缓存是否为空 */void (*set_mctrl)(struct uart_port *, unsigned int mctrl);/* 设置串口modem控制 */unsigned int (*get_mctrl)(struct uart_port *);/* 获取串口modem控制 */void (*stop_tx)(struct uart_port *);/* 禁止串口发送数据 */void (*start_tx)(struct uart_port *);/* 使能串口发送数据 */void (*send_xchar)(struct uart_port *, char ch);/* 发送xChar */void (*stop_rx)(struct uart_port *);/* 禁止串口接收数据 */void (*enable_ms)(struct uart_port *);/* 使能modem的状态信号 */void (*break_ctl)(struct uart_port *, int ctl);/* 设置break信号 */int (*startup)(struct uart_port *);/* 启动串口,应用程序打开串口设备文件时,该函数会被调用 */void (*shutdown)(struct uart_port *);/* 关闭串口,应用程序关闭串口设备文件时,该函数会被调用 */void (*set_termios)(struct uart_port *, struct ktermios *new, struct ktermios *old);/* 设置串口参数 */void (*pm)(struct uart_port *, unsigned int state,unsigned int oldstate);/* 串口电源管理 */int (*set_wake)(struct uart_port *, unsigned int state);/* */const char *(*type)(struct uart_port *);/* 返回一描述串口类型的字符串 */void (*release_port)(struct uart_port *);/* 释放串口已申请的IO端口/IO内存资源,必要时还需iounmap */int (*request_port)(struct uart_port *);/* 申请必要的IO端口/IO内存资源,必要时还可以重新映射串口端口 */void (*config_port)(struct uart_port *, int);/* 执行串口所需的自动配置 */int (*verify_port)(struct uart_port *, struct serial_struct *);/* 核实新串口的信息 */int (*ioctl)(struct uart_port *, unsigned int, unsigned long);/* IO控制 */};二、串口驱动API1、uart_register_driver/* 功能 uart_register_driver用于将串口驱动uart_driver注册到内核(串口核心层)中通常在模块初始化函数调用该函数。* 参数 drv要注册的uart_driver* 返回值 成功返回0否则返回错误码*/int uart_register_driver(struct uart_driver *drv)2、uart_unregister_driver/* 功能 uart_unregister_driver用于注销我们已注册的uart_driver通常在模块卸载函数调用该函数*参数 drv要注销的uart_driver* 返回值 成功返回0否则返回错误码*/void uart_unregister_driver(struct uart_driver *drv)3、uart_add_one_port/* 功能 uart_add_one_port用于为串口驱动添加一个串口端口通常在探测到设备后(驱动的设备probe方法)调用该函数* 参数 drv串口驱动* port:要添加的串口端口* 返回值成功返回0否则返回错误码*/int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)4、uart_remove_one_port/* 功能 uart_remove_one_port用于删除一个已添加到串口驱动中的串口端口通常在驱动卸载时调用该函数* 参数 drv 串口驱动* port: 要删除的串口端口* 返回值 成功返回0否则返回错误码*/int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)5、uart_write_wakeup/* 功能 uart_write_wakeup唤醒上层因向串口端口写数据而阻塞的进程通常在串口发送中断处理函数中调用该函数* 参数 port需要唤醒写阻塞进程的串口端口*/void uart_write_wakeup(struct uart_port *port)6、uart_suspend_port/* 功能 uart_suspend_port用于挂起特定的串口端口* 参数drv 要挂起的串口端口所属的串口驱动* port要挂起的串口端口* 返回值 成功返回0否则返回错误码*/int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)7、uart_resume_port/* 功能 uart_resume_port用于恢复某一已挂起的串口* 参数drv 要恢复的串口端口所属的串口驱动* port要恢复的串口端口* 返回值 成功返回0否则返回错误码*/int uart_resume_port(struct uart_driver *drv, struct uart_port *port)8、uart_get_baud_rate/* 功能 uart_get_baud_rate通过解码termios结构体来获取指定串口的波特率* 参数 port 要获取波特率的串口端口* termios当前期望的termios配置(包含串口波特率)* old 以前的termios配置可以为NULL* min 可接受的最小波特率* max 可接受的最大波特率* 返回值 串口的波特率*/unsigned intuart_get_baud_rate(struct uart_port *port, struct ktermios *termios,struct ktermios *old, unsigned int min, unsigned int max)9、uart_get_divisor/* 功能 uart_get_divisor用于计算某一波特率的串口时钟分频数(串口波特率除数)* 参数 port要计算时钟分频数的串口端口* baud期望的波特率*返回值 串口时钟分频数*/unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud)10、uart_update_timeout/* 功能 uart_update_timeout用于更新(设置)串口FIFO超时时间* 参数 port 要更新超时时间的串口端口* cflagtermios结构体的cflag值* baud 串口的波特率*/void uart_update_timeout(struct uart_port *port, unsigned intcflag, unsigned int baud)11、uart_match_port/* 功能uart_match_port用于判断两串口端口是否为同一端口* 参数 port1、port2要判断的串口端口* 返回值不同返回0否则返回非0*/int uart_match_port(struct uart_port *port1, struct uart_port *port2)12、uart_console_write/* 功能 uart_console_write用于向串口端口写一控制台信息* 参数 port: 要写信息的串口端口* s: 要写的信息* count: 信息的大小* putchar: 用于向串口端口写字符的函数该函数函数有两个参数串口端口和要写的字符*/void uart_console_write(struct uart_port *port, const char *s,unsigned int count,void (*putchar)(struct uart_port *, int))三、串口驱动例子该串口驱动例子是我针对s3c2410处理器的串口2(uart2)独立开发的。因为我通过博创2410s开发板的GRPS扩展板来测试该驱动(已通过测试)所以我叫该串口为gprs_uart。该驱动将串口看作平台(platform)设备。platform可以看作一伪总线用于将集成于片上系统的轻量级设备与Linux设备驱动模型联系到一起它包含以下两部分(有关platform的声明都在#include ,具体实现在drivers/base/platform.c)1、platform设备。我们需要为每个设备定义一个platform_device实例struct platform_device {const char *name;/* 设备名 */int id;/* 设备的id号 */struct device dev;/* 其对应的device */u32 num_resources;/* 该设备用有的资源数 */struct resource *resource;/* 资源数组 */};为我们的设备创建platform_device实例有两种方法填充一个platform_device结构体后用platform_device_register(一次注册一个)或platform_add_devices(一次可以注册多个platform设备)将platform_device注册到内核更简单的是使用platform_device_register_simple来建立并注册我们的platform_device。2、platform驱动。platform设备由platform驱动进行管理。当设备加入到系统中时platform_driver的probe方法会被调用来见对应的设备添加或者注册到内核当设备从系统中移除时platform_driver的remove方法会被调用来做一些清理工作如移除该设备的一些实例、注销一些已注册到系统中去的东西。struct platform_driver {int (*probe)(struct platform_device *);int (*remove)(struct platform_device *);void (*shutdown)(struct platform_device *);int (*suspend)(struct platform_device *, pm_message_t state);int (*suspend_late)(struct platform_device *, pm_message_t state);int (*resume_early)(struct platform_device *);int (*resume)(struct platform_device *);struct device_driver driver;};更详细platform资料可参考网上相关文章。例子驱动中申请和释放IO内存区的整个过程如下insmod gprs_uart.ko→gprs_init_module()→uart_register_driver()→gprs_uart_probe()→uart_add_one_port()→gprs_uart_config_port()→gprs_uart_request_port()→request_mem_region()rmmod gprs_uart.ko→gprs_exit_module()→uart_unregister_driver()→gprs_uart_remove()→uart_remove_one_port()→gprs_uart_release_port()→release_mem_region()例子驱动中申请和释放IRQ资源的整个过程如下open /dev/gprs_uart→gprs_uart_startup()→request_irq()close /dev/gprs_uart→gprs_uart_shutdown()→free_irq()想了解更详细的调用过程可以在驱动模块各函数头插入printk(KERN_DEBUG %s\n, __FUNCTION__);并在函数尾插入printk(KERN_DEBUG %s done\n, __FUNCTION__);下面是串口驱动例子和其GPRS测试程序源码下载地址#include #include #include /* printk() */#include /* kmalloc() */#include /* everything... */#include /* error codes */#include /* size_t */#include /* O_ACCMODE */#include /* cli(), *_flags */#include /* copy_*_user */#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DEV_NAME gprs_uart /* 设备名 *//* 这里将串口的主设备号设为0,则串口设备编号由内核动态分配;你也可指定串口的设备编号 */#define GPRS_UART_MAJOR 0 /* 主设备号 */#define GPRS_UART_MINOR 0 /* 次设备号 */#define GPRS_UART_FIFO_SIZE 16 /* 串口FIFO的大小 */#define RXSTAT_DUMMY_READ (0x10000000)#define MAP_SIZE (0x100) /* 要映射的串口IO内存区大小 *//* 串口发送中断号 */#define TX_IRQ(port) ((port)-irq 1)/* 串口接收中断号 */#define RX_IRQ(port) ((port)-irq)/* 允许串口接收字符的标志 */#define tx_enabled(port) ((port)-unused[0])/* 允许串口发送字符的标志 */#define rx_enabled(port) ((port)-unused[1])/* 获取寄存器地址 */#define portaddr(port, reg) ((port)-membase (reg))/* 读8位宽的寄存器 */#define rd_regb(port, reg) (ioread8(portaddr(port, reg)))/* 读32位宽的寄存器 */#define rd_regl(port, reg) (ioread32(portaddr(port, reg)))/* 写8位宽的寄存器 */#define wr_regb(port, reg, val) \do { iowrite8(val, portaddr(port, reg)); } while(0)/* 写32位宽的寄存器 */#define wr_regl(port, reg, val) \do { iowrite32(val, portaddr(port, reg)); } while(0)/* 禁止串口发送数据 */static void gprs_uart_stop_tx(struct uart_port *port){if (tx_enabled(port)) /* 若串口已启动发送 */{disable_irq(TX_IRQ(port)); /* 禁止发送中断 */tx_enabled(port) 0; /* 设置串口为未启动发送 */}}/* 使能串口发送数据 */static void gprs_uart_start_tx(struct uart_port *port){if (!tx_enabled(port)) /* 若串口未启动发送 */{enable_irq(TX_IRQ(port)); /* 使能发送中断 */tx_enabled(port) 1; /* 设置串口为已启动发送 */}}/* 禁止串口接收数据 */static void gprs_uart_stop_rx(struct uart_port *port){if (rx_enabled(port)) /* 若串口已启动接收 */{disable_irq(RX_IRQ(port)); /* 禁止接收中断 */rx_enabled(port) 0; /* 设置串口为未启动接收 */}}/* 使能modem的状态信号 */static void gprs_uart_enable_ms(struct uart_port *port){}/* 串口的Tx FIFO缓存是否为空 */static unsigned int gprs_uart_tx_empty(struct uart_port *port){int ret 1;unsigned long ufstat rd_regl(port, S3C2410_UFSTAT);unsigned long ufcon rd_regl(port, S3C2410_UFCON);if (ufcon S3C2410_UFCON_FIFOMODE) /* 若使能了FIFO */{if ((ufstat S3C2410_UFSTAT_TXMASK) ! 0 || /* 0 (ufstat S3C2410_UFSTAT_TXFULL)) /* FIFO满 */ret 0;}else /* 若未使能了FIFO,则判断发送缓存和发送移位寄存器是否均为空 */{ret rd_regl(port, S3C2410_UTRSTAT) S3C2410_UTRSTAT_TXE;}return ret;}/* 获取串口modem控制,因为uart2无modem控制,所以CTS、DSR直接返回有效 */static unsigned int gprs_uart_get_mctrl(struct uart_port *port){return (TIOCM_CTS | TIOCM_DSR | TIOCM_CAR);}/* 设置串口modem控制 */static void gprs_uart_set_mctrl(struct uart_port *port, unsigned int mctrl){}/* 设置break信号 */static void gprs_uart_break_ctl(struct uart_port *port, int break_state){unsigned long flags;unsigned int ucon;spin_lock_irqsave(port-lock, flags);ucon rd_regl(port, S3C2410_UCON);if (break_state)ucon | S3C2410_UCON_SBREAK;elseucon ~S3C2410_UCON_SBREAK;wr_regl(port, S3C2410_UCON, ucon);spin_unlock_irqrestore(port-lock, flags);}/* 返回Rx FIFO已存多少数据 */static int gprs_uart_rx_fifocnt(unsigned long ufstat){/* 若Rx FIFO已满,返回FIFO的大小 */if (ufstat S3C2410_UFSTAT_RXFULL)return GPRS_UART_FIFO_SIZE;/* 若FIFO未满,返回Rx FIFO已存了多少字节数据 */return (ufstat S3C2410_UFSTAT_RXMASK) S3C2410_UFSTAT_RXSHIFT;}#define S3C2410_UERSTAT_PARITY (0x1000)/* 串口接收中断处理函数,获取串口接收到的数据,并将这些数据递交给行规则层 */static irqreturn_t gprs_uart_rx_chars(int irq, void *dev_id){struct uart_port *port dev_id;struct tty_struct *tty port-info-tty;unsigned int ufcon, ch, flag, ufstat, uerstat;int max_count 64;/* 循环接收数据,最多一次中断接收64字节数据 */while (max_count-- 0){ufcon rd_regl(port, S3C2410_UFCON);ufstat rd_regl(port, S3C2410_UFSTAT);/* 若Rx FIFO无数据了,跳出循环 */if (gprs_uart_rx_fifocnt(ufstat) 0)break;/* 读取Rx error状态寄存器 */uerstat rd_regl(port, S3C2410_UERSTAT);/* 读取已接受到的数据 */ch rd_regb(port, S3C2410_URXH);/* insert the character into the buffer *//* 先将tty标志设为正常 */flag TTY_NORMAL;/* 递增接收字符计数器 */port-icount.rx;/* 判断是否存在Rx error* if (unlikely(uerstat S3C2410_UERSTAT_ANY))等同于* if (uerstat S3C2410_UERSTAT_ANY)* 只是unlikely表示uerstat S3C2410_UERSTAT_ANY的值为假的可能性大一些* 另外还有一个likely(value)表示value的值为真的可能性更大一些*/if (unlikely(uerstat S3C2410_UERSTAT_ANY)){/* 若break错误,递增icount.brk计算器 */if (uerstat S3C2410_UERSTAT_BREAK){port-icount.brk;if (uart_handle_break(port))goto ignore_char;}/* 若frame错误,递增icount.frame计算器 */if (uerstat S3C2410_UERSTAT_FRAME)port-icount.frame;/* 若overrun错误,递增icount.overrun计算器 */if (uerstat S3C2410_UERSTAT_OVERRUN)port-icount.overrun;/* 查看我们是否关心该Rx error* port-read_status_mask保存着我们感兴趣的Rx error status*/uerstat port-read_status_mask;/* 若我们关心该Rx error,则将flag设置为对应的error flag */if (uerstat S3C2410_UERSTAT_BREAK)flag TTY_BREAK;else if (uerstat S3C2410_UERSTAT_PARITY)flag TTY_PARITY;else if (uerstat ( S3C2410_UERSTAT_FRAME | S3C2410_UERSTAT_OVERRUN))flag TTY_FRAME;}/* 处理sys字符 */if (uart_handle_sysrq_char(port, ch))goto ignore_char;/* 将接收到的字符插入到tty设备的flip缓冲 */uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN, ch, flag);ignore_char:continue;}/* 刷新tty设备的flip缓冲,将接受到的数据传给行规则层 */tty_flip_buffer_push(tty);return IRQ_HANDLED;}/* 串口发送中断处理函数,将用户空间的数据(保存在环形缓冲xmit里)发送出去 */static irqreturn_t gprs_uart_tx_chars(int irq, void *dev_id){struct uart_port *port dev_id;struct circ_buf *xmit port-info-xmit; /* 获取环线缓冲 */int count 256;/* 若设置了xChar字符 */if (port-x_char){/* 将该xChar发送出去 */wr_regb(port, S3C2410_UTXH, port-x_char);/* 递增发送计数 */port-icount.tx;/* 清除xChar */port-x_char 0;/* 退出中断处理 */goto out;}/* 如果没有更多的字符需要发送(环形缓冲为空)* 或者uart Tx已停止* 则停止uart并退出中断处理函数*/if (uart_circ_empty(xmit) || uart_tx_stopped(port)){gprs_uart_stop_tx(port);goto out;}/* 循环发送数据,直到环形缓冲为空,最多一次中断发送256字节数据 */while (!uart_circ_empty(xmit) count-- 0){/* 若Tx FIFO已满,退出循环 */if (rd_regl(port, S3C2410_UFSTAT) S3C2410_UFSTAT_TXFULL)break;/* 将要发送的数据写入Tx FIFO */wr_regb(port, S3C2410_UTXH, xmit-buf[xmit-tail]);/* 移向循环缓冲中下一要发送的数据 */xmit-tail (xmit-tail 1) (UART_XMIT_SIZE - 1);port-icount.tx;}/* 如果环形缓冲区中剩余的字符少于WAKEUP_CHARS唤醒上层 */if (uart_circ_chars_pending(xmit) WAKEUP_CHARS)uart_write_wakeup(port);/* 如果环形缓冲为空则停止发送 */if (uart_circ_empty(xmit))gprs_uart_stop_tx(port);out:return IRQ_HANDLED;}/* 启动串口端口,在打开该驱动的设备文件时会调用该函数来申请串口中断,并设置串口为可接受,也可发送 */static int gprs_uart_startup(struct uart_port *port){unsigned long flags;int ret;const char *portname to_platform_device(port-dev)-name;/* 设置串口为不可接受,也不可发送 */rx_enabled(port) 0;tx_enabled(port) 0;spin_lock_irqsave(port-lock, flags);/* 申请接收中断 */ret request_irq(RX_IRQ(port), gprs_uart_rx_chars, 0, portname, port);if (ret ! 0){printk(KERN_ERR cannot get irq %d\n, RX_IRQ(port));return ret;}/* 设置串口为允许接收 */rx_enabled(port) 1;/* 申请发送中断 */ret request_irq(TX_IRQ(port), gprs_uart_tx_chars, 0, portname, port);if (ret){printk(KERN_ERR cannot get irq %d\n, TX_IRQ(port));rx_enabled(port) 0;free_irq(RX_IRQ(port), port);goto err;}/* 设置串口为允许发送 */tx_enabled(port) 1;err:spin_unlock_irqrestore(port-lock, flags);return ret;}/* 关闭串口,在关闭驱动的设备文件时会调用该函数,释放串口中断 */static void gprs_uart_shutdown(struct uart_port *port){rx_enabled(port) 0; /* 设置串口为不允许接收 */free_irq(RX_IRQ(port), port); /* 释放接收中断 */tx_enabled(port) 0; /* 设置串口为不允许发送 */free_irq(TX_IRQ(port), port); /* 释放发送中断 */}/* 设置串口参数 */static void gprs_uart_set_termios(struct uart_port *port,struct ktermios *termios,struct ktermios *old){unsigned long flags;unsigned int baud, quot;unsigned int ulcon, ufcon 0;/* 不支持moden控制信号线* HUPCL: 关闭时挂断moden* CMSPAR: mark or space (stick) parity* CLOCAL: 忽略任何moden控制线*/termios-c_cflag ~(HUPCL | CMSPAR);termios-c_cflag | CLOCAL;/* 获取用户设置的串口波特率,并计算分频数(串口波特率除数quot) */baud uart_get_baud_rate(port, termios, old, 0, 115200*8);if (baud 38400 (port-flags UPF_SPD_MASK) UPF_SPD_CUST)quot port-custom_divisor;elsequot port-uartclk / baud / 16 - 1;/* 设置数据字长 */switch (termios-c_cflag CSIZE){case CS5:ulcon S3C2410_LCON_CS5;break;case CS6:ulcon S3C2410_LCON_CS6;break;case CS7:ulcon S3C2410_LCON_CS7;break;case CS8:default:ulcon S3C2410_LCON_CS8;break;}/* 是否要求设置两个停止位(CSTOPB) */if (termios-c_cflag CSTOPB)ulcon | S3C2410_LCON_STOPB;/* 是否使用奇偶检验 */if (termios-c_cflag PARENB){if (termios-c_cflag PARODD) /* 奇校验 */ulcon | S3C2410_LCON_PODD;else /* 偶校验 */ulcon | S3C2410_LCON_PEVEN;}else /* 无校验 */{ulcon | S3C2410_LCON_PNONE;}if (port-fifosize 1)ufcon | S3C2410_UFCON_FIFOMODE | S3C2410_UFCON_RXTRIG8;spin_lock_irqsave(port-lock, flags);/* 设置FIFO控制寄存器、线控制寄存器和波特率除数寄存器 */wr_regl(port, S3C2410_UFCON, ufcon);wr_regl(port, S3C2410_ULCON, ulcon);wr_regl(port, S3C2410_UBRDIV, quot);/* 更新串口FIFO的超时时限 */uart_update_timeout(port, termios-c_cflag, baud);/* 设置我们感兴趣的Rx error */port-read_status_mask S3C2410_UERSTAT_OVERRUN;if (termios-c_iflag INPCK)port-read_status_mask | S3C2410_UERSTAT_FRAME | S3C2410_UERSTAT_PARITY;/* 设置我们忽略的Rx error */port-ignore_status_mask 0;if (termios-c_iflag IGNPAR)port-ignore_status_mask | S3C2410_UERSTAT_OVERRUN;if (termios-c_iflag IGNBRK termios-c_iflag IGNPAR)port-ignore_status_mask | S3C2410_UERSTAT_FRAME;/* 若未设置CREAD(使用接收器),则忽略所有Rx error*/if ((termios-c_cflag CREAD) 0)port-ignore_status_mask | RXSTAT_DUMMY_READ;spin_unlock_irqrestore(port-lock, flags);}/* 获取串口类型 */static const char *gprs_uart_type(struct uart_port *port){/* 返回描述串口类型的字符串指针 */return port-type PORT_S3C2410 ? gprs_uart:s3c2410_uart2 : NULL;}/* 申请串口一些必要的资源,如IO端口/IO内存资源,必要时还可以重新映射串口端口 */static int gprs_uart_request_port(struct uart_port *port){struct resource *res;const char *name to_platform_device(port-dev)-name;/* request_mem_region请求分配IO内存,从开始port-mapbase,大小MAP_SIZE* port-mapbase保存当前串口的寄存器基地址(物理)* uart2: 0x50008000*/res request_mem_region(port-mapbase, MAP_SIZE, name);if (res NULL){printk(KERN_ERRrequest_mem_region error: %p\n, res);return -EBUSY;}return 0;}/* 释放串口已申请的IO端口/IO内存资源,必要时还需iounmap */static void gprs_uart_release_port(struct uart_port *port){/* 释放已分配IO内存 */release_mem_region(port-mapbase, MAP_SIZE);}/* 执行串口所需的自动配置 */static void gprs_uart_config_port(struct uart_port *port, int flags){int retval;/* 请求串口 */retval gprs_uart_request_port(port);/* 设置串口类型 */if (flags UART_CONFIG_TYPE retval 0)port-type PORT_S3C2410;}/* The UART operations structure */static struct uart_ops gprs_uart_ops {.start_tx gprs_uart_start_tx, /* Start transmitting */.stop_tx gprs_uart_stop_tx, /* Stop transmission */.stop_rx gprs_uart_stop_rx, /* Stop reception */.enable_ms gprs_uart_enable_ms, /* Enable modem status signals */.tx_empty gprs_uart_tx_empty, /* Transmitter busy? */.get_mctrl gprs_uart_get_mctrl, /* Get modem control */.set_mctrl gprs_uart_set_mctrl, /* Set modem control */.break_ctl gprs_uart_break_ctl, /* Set break signal */.startup gprs_uart_startup, /* App opens GPRS_UART */.shutdown gprs_uart_shutdown, /* App closes GPRS_UART */.set_termios gprs_uart_set_termios, /* Set termios */.type gprs_uart_type, /* Get UART type */.request_port gprs_uart_request_port, /* Claim resources associated with a GPRS_UART port */.release_port gprs_uart_release_port, /* Release resources associated with a GPRS_UART port */.config_port gprs_uart_config_port, /* Configure when driver adds a GPRS_UART port */};/* Uart driver for GPRS_UART */static struct uart_driver gprs_uart_driver {.owner THIS_MODULE, /* Owner */.driver_name DEV_NAME, /* Driver name */.dev_name DEV_NAME, /* Device node name */.major GPRS_UART_MAJOR, /* Major number */.minor GPRS_UART_MINOR, /* Minor number start */.nr 1, /* Number of UART ports */};/* Uart port for GPRS_UART port */static struct uart_port gprs_uart_port {.irq IRQ_S3CUART_RX2, /* IRQ */.fifosize GPRS_UART_FIFO_SIZE, /* Size of the FIFO */.iotype UPIO_MEM, /* IO memory */.flags UPF_BOOT_AUTOCONF, /* UART port flag */.ops gprs_uart_ops, /* UART operations */.line 0, /* UART port number */.lock __SPIN_LOCK_UNLOCKED(gprs_uart_port.lock),};/* 初始化指定串口端口 */static int gprs_uart_init_port(struct uart_port *port, struct platform_device *platdev){unsigned long flags;unsigned int gphcon;if (platdev NULL)return -ENODEV;port-dev platdev-dev;/* 设置串口波特率时钟频率 */port-uartclk clk_get_rate(clk_get(platdev-dev, pclk));/* 设置串口的寄存器基地址(物理): 0x50008000 */port-mapbase S3C2410_PA_UART2;/* 设置当前串口的寄存器基地址(虚拟): 0xF5008000 */port-membase S3C24XX_VA_UART (S3C2410_PA_UART2 - S3C24XX_PA_UART);spin_lock_irqsave(port-lock, flags);wr_regl(port, S3C2410_UCON, S3C2410_UCON_DEFAULT);wr_regl(port, S3C2410_ULCON, S3C2410_LCON_CS8 | S3C2410_LCON_PNONE);wr_regl(port, S3C2410_UFCON, S3C2410_UFCON_FIFOMODE| S3C2410_UFCON_RXTRIG8 | S3C2410_UFCON_RESETBOTH);/* 将I/O port H的gph6和gph7设置为TXD2和RXD2 */gphcon readl(S3C2410_GPHCON);gphcon ~((0x5) 12);writel(gphcon, S3C2410_GPHCON);spin_unlock_irqrestore(port-lock, flags);return 0;}/* Platform driver probe */static int __init gprs_uart_probe(struct platform_device *dev){int ret;/* 初始化串口 */ret gprs_uart_init_port(gprs_uart_port, dev);if (ret 0){printk(KERN_ERRgprs_uart_probe: gprs_uart_init_port error: %d\n, ret);return ret;}/* 添加串口 */ret uart_add_one_port(gprs_uart_driver, gprs_uart_port);if (ret 0){printk(KERN_ERRgprs_uart_probe: uart_add_one_port error: %d\n, ret);return ret;}/* 将串口uart_port结构体保存在platform_device-dev-driver_data中 */platform_set_drvdata(dev, gprs_uart_port);return 0;}/* Called when the platform driver is unregistered */static int gprs_uart_remove(struct platform_device *dev){platform_set_drvdata(dev, NULL);/* 移除串口 */uart_remove_one_port(gprs_uart_driver, gprs_uart_port);return 0;}/* Suspend power management event */static int gprs_uart_suspend(struct platform_device *dev, pm_message_t state){uart_suspend_port(gprs_uart_driver, gprs_uart_port);return 0;}/* Resume after a previous suspend */static int gprs_uart_resume(struct platform_device *dev){uart_resume_port(gprs_uart_driver, gprs_uart_port);return 0;}/* Platform driver for GPRS_UART */static struct platform_driver gprs_plat_driver {.probe gprs_uart_probe, /* Probe method */.remove __exit_p(gprs_uart_remove), /* Detach method */.suspend gprs_uart_suspend, /* Power suspend */.resume gprs_uart_resume, /* Resume after a suspend */.driver {.owner THIS_MODULE,.name DEV_NAME, /* Driver name */},};/* Platform device for GPRS_UART */struct platform_device *gprs_plat_device;static int __init gprs_init_module(void){int retval;/* Register uart_driver for GPRS_UART */retval uart_register_driver(gprs_uart_driver);if (0 ! retval){printk(KERN_ERR gprs_init_module: cant register the GPRS_UART driver %d\n, retval);return retval;}/* Register platform device for GPRS_UART. Usually calledduring architecture-specific setup */gprs_plat_device platform_device_register_simple(DEV_NAME, 0, NULL, 0);if (IS_ERR(gprs_plat_device)){retval PTR_ERR(gprs_plat_device);printk(KERN_ERR gprs_init_module: cant register platform device %d\n, retval);goto fail_reg_plat_dev;}/* Announce a matching driver for the platformdevices registered above */retval platform_driver_register(gprs_plat_driver);if (0 ! retval){printk(KERN_ERR gprs_init_module: cant register platform driver %d\n, retval);goto fail_reg_plat_drv;}return 0; /* succeed */fail_reg_plat_drv:platform_device_unregister(gprs_plat_device);fail_reg_plat_dev:uart_unregister_driver(gprs_uart_driver);return retval;}static void __exit gprs_exit_module(void){/* The order of unregistration is important. Unregistering theUART driver before the platform driver will crash the system *//* Unregister the platform driver */platform_driver_unregister(gprs_plat_driver);/* Unregister the platform devices */platform_device_unregister(gprs_plat_device);/* Unregister the GPRS_UART driver */uart_unregister_driver(gprs_uart_driver);}module_init(gprs_init_module);module_exit(gprs_exit_module);MODULE_AUTHOR(lingd);MODULE_LICENSE(Dual BSD/GPL);
