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=%p\n", 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) %d\n", dev, info, probe_index);
ourport = &s3c24xx_serial_ports[probe_index];
probe_index++;
如下，在Samsung.c (linux2.6.28\drivers\serial)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;
/* s3c24xx_serial_init_port
* initialise a single serial port from the platform device given
*/
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 (linux2.6.28\arch\arm\plat-s3c64xx)中有如下定义：
/* uart devices */
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=%p\n", 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：
/* configuration structure for per-machine configurations for the
* serial port
*
* the pointer is setup by the machine specific initialisation from the
* arch/arm/mach-s3c2410/ directory.
*/
struct s3c2410_uartcfg {
unsigned char
hwport; /* hardware port number */
unsigned char
unused;
unsigned short flags;
#if !defined(CONFIG_CPU_S3C6400) && !defined(CONFIG_CPU_S3C6410) && !defined(CONFIG_CPU_S5PC100)
upf_t uart_flags; /* default uart flags */
#else
unsigned long uart_flags; /* default uart flags */
#endif
unsigned long
ucon; /* value of ucon for port */
unsigned long
ulcon; /* value of ulcon for port */
unsigned long
ufcon; /* value of ufcon for port */
struct s3c24xx_uart_clksrc *clocks;
unsigned int
clocks_size;
};
这个结构体的实例在：Mach-smdk6410.c (linux2.6.28\arch\arm\mach-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) {
.......
}
/* setup info for port */
port->dev
= &platdev->dev;
ourport->info
= info;
/* copy the info in from provided structure */
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) {
.......
}
/* sort our the physical and virtual addresses for each UART */
res = platform_get_resource(platdev, IORESOURCE_MEM, 0);
if (res == NULL) {
printk(KERN_ERR "failed to find memory resource for uart\n");
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 (linux2.6.28\arch\arm\plat-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 (linux2.6.28\arch\arm\plat-s3c64xx)文件中有如下函数：
/* uart registration process */
void __init s3c6400_common_init_uarts(struct s3c2410_uartcfg *cfg, int no)
{
s3c24xx_init_uartdevs("s3c6400-uart", s3c64xx_uart_resources, cfg, no);
}
/* s3c24xx_init_uartdevs
*
* copy the specified platform data and configuration into our central
* set of devices, before the data is thrown away after the init process.
*
* This also fills in the array passed to the serial driver for the
* early initialisation of the console.
*/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=%d\n",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=%08x, mem=%08x, irq=%d (%d,%d), clock=%ld\n",
port->mapbase, port->membase, port->irq,
ourport->rx_irq, ourport->tx_irq, port->uartclk);
/* reset the fifos (and setup the uart) */
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 port\n", __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 notifier\n");
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！