s3c6410的UART设备驱动(5)

原文地址：s3c6410的UART设备驱动(5)作者：晃煽褐疟犯 

s3c6410的UART设备驱动(1)的链接

s3c6410的UART设备驱动(2)的链接

s3c6410的UART设备驱动(3)的链接地址

s3c6410的UART设备驱动(4)的链接地址

上一篇中说到了这个函数，源码如下：
static int
s3c6400_serial_probe(struct platform_device *dev)
{
 dbg("s3c6400_serial_probe:
dev=%pn", dev);
 return s3c24xx_serial_probe(dev,
&s3c6400_uart_inf);
}

现在接着往下说：
int s3c24xx_serial_probe(struct
platform_device *dev,

 struct s3c24xx_uart_info *info)

{

struct s3c24xx_uart_port *ourport;

int ret;

dbg("s3c24xx_serial_probe(%p, %p)
%dn", dev, info, probe_index);

ourport = &s3c24xx_serial_ports[probe_index];
   
   
 probe_index++;

如下，在Samsung.c
(linux2.6.28driversserial)文件中有如下定义：在struct s3c24xx_uart_port结构体重有struct
uart_port结构体。
static struct
s3c24xx_uart_port s3c24xx_serial_ports[CONFIG_SERIAL_SAMSUNG_UARTS]
= {

[0] = {

.port = {

.lock =
__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[0].port.lock),

.iotype = UPIO_MEM,

.irq = IRQ_S3CUART_RX0,

.uartclk = 0,

.fifosize = 16,

.ops = &s3c24xx_serial_ops,

.flags = UPF_BOOT_AUTOCONF,

.line = 0,

}

},

[1] = {

.port = {

.lock =
__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[1].port.lock),

.iotype = UPIO_MEM,

.irq = IRQ_S3CUART_RX1,

.uartclk = 0,

.fifosize = 16,

.ops = &s3c24xx_serial_ops,

.flags = UPF_BOOT_AUTOCONF,

.line = 1,

}

},

#if CONFIG_SERIAL_SAMSUNG_UARTS > 2

[2] = {

.port = {

.lock =
__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[2].port.lock),

.iotype = UPIO_MEM,

.irq = IRQ_S3CUART_RX2,

.uartclk = 0,

.fifosize = 16,

.ops = &s3c24xx_serial_ops,

.flags = UPF_BOOT_AUTOCONF,

.line = 2,

}

},

#endif

#if CONFIG_SERIAL_SAMSUNG_UARTS > 3

[3] = {

.port = {

.lock =
__SPIN_LOCK_UNLOCKED(s3c24xx_serial_ports[3].port.lock),

.iotype = UPIO_MEM,

.irq = IRQ_S3CUART_RX3,

.uartclk = 0,

.fifosize = 16,

.ops = &s3c24xx_serial_ops,

//---->modify by phantom

///#ifdef TE6410

#if 1

.flags = UPF_BOOT_AUTOCONF | UPF_CONS_FLOW,

#else

.flags = UPF_BOOT_AUTOCONF,

#endif

//<----

.line = 3,

}

}

#endif

};

dbg("%s: initialising port
%p...n", __func__, ourport);

ret =
s3c24xx_serial_init_port(ourport, info, dev);

if (ret < 0)

goto probe_err;
 

此函数传入的参数中有个struct platform_device结构体，在那里定义的呢？

在Dev-uart.c
(linux2.6.28archarmplat-s3c64xx)中有如下定义：

static struct platform_device s3c24xx_uart_device0 = {

.id = 0,

};

static struct platform_device s3c24xx_uart_device1 = {

.id = 1,

};

static struct platform_device s3c24xx_uart_device2 = {

.id = 2,

};

static struct platform_device s3c24xx_uart_device3 = {

.id = 3,

};

struct platform_device *s3c24xx_uart_src[4] = {

&s3c24xx_uart_device0,

&s3c24xx_uart_device1,

&s3c24xx_uart_device2,

&s3c24xx_uart_device3,

};
static int s3c24xx_serial_init_port(struct
s3c24xx_uart_port *ourport,

    struct
s3c24xx_uart_info *info,

    struct platform_device *platdev)

{

struct uart_port *port =
&ourport->port;

struct s3c2410_uartcfg *cfg;

struct resource *res;

int ret;

dbg("s3c24xx_serial_init_port: port=%p,
platdev=%pn", port, platdev);

if (platdev == NULL)

return -ENODEV;

cfg =
s3c24xx_dev_to_cfg(&platdev->dev);

     
  #define s3c24xx_dev_to_cfg(__dev) (struct
s3c2410_uartcfg
*)((__dev)->platform_data)

这里有关的一个结构体是：

struct s3c2410_uartcfg {

unsigned char    hwport;
 

unsigned char    unused;

unsigned short   flags;

#if !defined(CONFIG_CPU_S3C6400) &&
!defined(CONFIG_CPU_S3C6410) &&
!defined(CONFIG_CPU_S5PC100) 

     
  upf_t    
     
   uart_f
4000
lags;
 

#else

     
  unsigned long   uart_flags;
     

#endif

unsigned long    ucon;
 

unsigned long    ulcon;
 

unsigned long    ufcon;
 

struct s3c24xx_uart_clksrc *clocks;

unsigned int   
 clocks_size;

};
这个结构体的实例在：Mach-smdk6410.c
(linux2.6.28archarmmach-s3c6410)文件中，
static struct
s3c2410_uartcfg smdk6410_uartcfgs[] __initdata = {

[0] = {

.hwport     = 0,

.flags     = 0,

.ucon     =
S3C64XX_UCON_DEFAULT,

.ulcon     =
S3C64XX_ULCON_DEFAULT,

.ufcon     =
S3C64XX_UFCON_DEFAULT,

},

[1] = {

.hwport     = 1,

.flags     = 0,

.ucon     =
S3C64XX_UCON_DEFAULT,

.ulcon     =
S3C64XX_ULCON_DEFAULT,

.ufcon     =
S3C64XX_UFCON_DEFAULT,

},

[2] = {

.hwport     = 2,

.flags     = 0,

.ucon     =
S3C64XX_UCON_DEFAULT,

.ulcon     =
S3C64XX_ULCON_DEFAULT,

.ufcon     =
S3C64XX_UFCON_DEFAULT,

},

[3] = {

.hwport     = 3,

.flags     = 0,

.ucon     =
S3C64XX_UCON_DEFAULT,

.ulcon     =
S3C64XX_ULCON_DEFAULT,

.ufcon     =
S3C64XX_UFCON_DEFAULT,

},

};

if (port->mapbase != 0)

return 0;

if (cfg->hwport >
CONFIG_SERIAL_SAMSUNG_UARTS) {

.......

}

port->dev =
&platdev->dev;

ourport->info = info;

ourport->port.fifosize =
info->fifosize;

dbg("s3c24xx_serial_init_port: %p (hw
%d)...n", port,
cfg->hwport);

port->uartclk = 1;

if (cfg->uart_flags & UPF_CONS_FLOW)
{

.......

}

res = platform_get_resource(platdev,
IORESOURCE_MEM, 0);

if (res == NULL) {

printk(KERN_ERR "failed to find memory resource
for uartn");

return -EINVAL;

}

大家应该都知道在struct platform_device结构体中有个struct resource*
resource指针，可以存放相应的资源。但是在上面的static
struct platform_device
s3c24xx_uart_device2结构中并没有有关资源的赋值，那在那里赋的值呢？
static struct
platform_device s3c24xx_uart_device2 = {
.id= 2,
};
struct platform_device {

const char * name;

int id;

struct device dev;

u32 num_resources;

struct resource* resource;

};

在Dev-uart.c
(linux2.6.28archarmplat-s3c64xx)文件中有下面这两个结构，我们只列出了其中的一部分。
struct
s3c24xx_uart_resources s3c64xx_uart_resources[] __initdata =
{
[0] = {
.resources=
s3c64xx_uart0_resource,
.nr_resources= ARRAY_SIZE(s3c64xx_uart0_resource),
}
static struct resource s3c64xx_uart0_resource[] =
{

[0] = {

.start = S3C_PA_UART0,

.end = S3C_PA_UART0 + S3C_SZ_UART,

.flags = IORESOURCE_MEM,

},

[1] = {

.start = IRQ_S3CUART_RX0,

.end = IRQ_S3CUART_RX0,

.flags = IORESOURCE_IRQ,

}, 

[2] = {

.start = IRQ_S3CUART_TX0,

.end = IRQ_S3CUART_TX0,

.flags = IORESOURCE_IRQ,

},

[3] = {

.start = IRQ_S3CUART_ERR0,

.end = IRQ_S3CUART_ERR0,

.flags = IORESOURCE_IRQ,

}

};

那么这些结构怎样联系起来的呢？
在S3c6400-init.c
(linux2.6.28archarmplat-s3c64xx)文件中有如下函数：

void __init s3c6400_common_init_uarts(struct s3c2410_uartcfg *cfg,
int no)

{
s3c24xx_init_uartdevs("s3c6400-uart",
s3c64xx_uart_resources, cfg, no);

}
注：这个函数是在系统初始化是执行的。

void __init
s3c24xx_init_uartdevs(char *name,

  struct s3c24xx_uart_resources
*res,

  struct s3c2410_uartcfg *cfg,
int no)

{

struct platform_device *platdev;

struct s3c2410_uartcfg *cfgptr = uart_cfgs;

struct s3c24xx_uart_resources *resp;

int uart;

//printk("iiiiiiiiiiiiiiiiiiii=%dn",no);

memcpy(cfgptr, cfg, sizeof(struct s3c2410_uartcfg) * no);

for (uart = 0; uart < no;
uart++,
cfg++,
cfgptr++) {

platdev = s3c24xx_uart_src[cfgptr->hwport];

resp = res + cfgptr->hwport;

s3c24xx_uart_devs[uart] = platdev;

platdev->name =
name;

platdev->resource =
resp->resources;

platdev->num_resources =
resp->nr_resources;

platdev->dev.platform_data =
cfgptr;
看到这些应该，明白了吧！
}

nr_uarts = no;

}此函数到此结束

dbg("resource %p (%lx..%lx)n",
res, res->start, res->end);

port->mapbase = res->start;

port->membase = S3C_VA_UART +
res->start - (S3C_PA_UART &
0xfff00000);
ret = platform_get_irq(platdev,
0);这个应该不用说了。

if (ret < 0)

port->irq = 0;

else {

port->irq = ret;

ourport->rx_irq = ret;

ourport->tx_irq = ret + 1;

}

ret = platform_get_irq(platdev, 1);

if (ret > 0)

ourport->tx_irq = ret;

ourport->clk =
clk_get(&platdev->dev,
"uart");

dbg("port: map=x, mem=x, irq=%d (%d,%d),
clock=%ldn",

  
 port->mapbase,
port->membase, port->irq,

  
 ourport->rx_irq,
ourport->tx_irq,
port->uartclk);

s3c24xx_serial_resetport(port,
cfg);
return 0;
}s3c24xx_serial_init_port函数到这里就完了。下面接着分析s3c24xx_serial_probe函数：

dbg("%s: adding portn",
__func__);
uart_add_one_port(&s3c24xx_uart_drv,
&ourport->port);
这个函数应该很面熟，上一篇说过。
platform_set_drvdata(dev,
&ourport->port);是个宏，展开后为：
#define
platform_set_drvdata(_dev,data)dev_set_drvdata(&(_dev)->dev,
(data))
static inline void
dev_set_drvdata(struct device *dev, void *data)

{

dev->driver_data = data;

}
应该明白了吧。

ret = device_create_file(&dev->dev,
&dev_attr_clock_source);与sysfs文件系统有关。

if (ret < 0)

printk(KERN_ERR "%s: failed to add clksrc
attr.n", __func__);

ret = s3c24xx_serial_cpufreq_register(ourport);

if (ret < 0)

dev_err(&dev->dev,
"failed to add cpufreq
notifiern");

return 0;

 probe_err:

return ret;

}

好了，终于走完了这个函数的旅途，但以后的还很长啊！再接再厉！
 
 

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