2.6.33+2440 led 灯 驱动程序 代码分析 （三）

代码查看：
我们直接看代码

1.

#define S3C2410_GPBCON S3C2410_GPIOREG(0x10)
#define S3C2410_GPBDAT S3C2410_GPIOREG(0x14)
#define S3C2410_GPBUP S3C2410_GPIOREG(0x18)

等同于：

 #define S3C2410_GPBCON (*(volatile unsigned long *)0x56000010)
 #define S3C2410_GPBDAT (*(volatile unsigned long *)0x56000014)
 #define S3C2410_GPBUP (*(volatile unsigned long *)0x56000018)

  这里，我们自己定义  3 个寄存器的地址
      S3C2410_GPIOREG定义在    

#define S3C2410_GPIOREG(x) ((x) + )
#define S3C24XX_GPIOREG2(x) ((x) + S3C24XX_VA_GPIO2)

S3C24XX_VA_GPIO：定义在linux/include/asm-arm/plat-s3c24xx/map.h

72 #define S3C2410_PA_GPIO    (0x56000000)

而在 S3C2440手册中，我们定义了

Register            Address            R/W                         Description                       Reset Value

GPBCON             0x56000010           R/W      Configures the pins of port B                             0x0

GPBDAT            0x56000014           R/W      The data register for port B                             Undef.

GPBUP             0x56000018           R/W      Pull-up disable register for port B

#define S3C2410_GPBCON S3C2410_GPIOREG(0x10)

等同于
  #define S3C2410_GPBCON (*volatile unsigned long *)(0x56000000+0x10)

2.设置管脚

#define S3C2410_GPB5 S3C2410_GPIONO(S3C2410_GPIO_BANKB, 5)
#define S3C2410_GPB6 S3C2410_GPIONO(S3C2410_GPIO_BANKB, 6)
#define S3C2410_GPB7 S3C2410_GPIONO(S3C2410_GPIO_BANKB, 7)
#define S3C2410_GPB8 S3C2410_GPIONO(S3C2410_GPIO_BANKB, 8)

S3C2410_GPIONO 定义在：

17#define S3C2410_GPIONO(bank,offset) ((bank) + (offset))
18
19#define S3C2410_GPIO_BANKA   (32*0)
20#define S3C2410_GPIO_BANKB   (32*1)   有疑问？？

3. 设置输出管脚

#define S3C2410_GPB5_OUTP (0x01 << 10)
#define S3C2410_GPB6_OUTP (0x01 << 12)
#define S3C2410_GPB7_OUTP (0x01 << 14)
#define S3C2410_GPB8_OUTP (0x01 << 16)

在 S3C2440 手册中定义了，当为 01 时，表示输出功能

GPB8                [17:16]        00 = Input                01 = Output
             10 = nXDREQ1               11 = Reserved

GPB7                [15:14]        00 = Input                01 = Output
             10 = nXDACK1               11 = Reserved

GPB6                [13:12]        00 = Input                01 = Output
             10 = nXBREQ                11 = reserved

GPB5                [11:10]        00 = Input                01 = Output
             10 = nXBACK                11 = reserved

4.设置

static unsigned long gpio_table [] =
{
   
S3C2410_GPB(5),
   
S3C2410_GPB(6),
   
S3C2410_GPB(7),
   
S3C2410_GPB(8),
};

在哪里定义了 S3C2410_GPB(5)呢？？

60    /* S3C2410 GPIO number definitions. */
61
62    #define S3C2410_GPA(_nr)        (S3C2410_GPIO_A_START + (_nr))
63    #define S3C2410_GPB(_nr)        (S3C2410_GPIO_B_START + (_nr))

     enum s3c_gpio_number {
48          S3C2410_GPIO_A_START = 0,  ？？ 是虚拟内存，映射实现？？ 第一个地址 0
49          S3C2410_GPIO_B_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_A),  32+0吗？？
50          S3C2410_GPIO_C_START = S3C2410_GPIO_NEXT(S3C2410_GPIO_B),

 S3C2410_GPB(5) () 0x56000010+


5 管脚设置

s3c2410_gpio_setpin(gpio_table[arg], 0);

::::
  s3c2410_gpio_setpin( S3C2410_GPB(5),0);

s3c2410_gpio_setpin 定义在：

99   extern int s3c2410_gpio_getpull(unsigned int pin);
100
101  extern void s3c2410_gpio_setpin(unsigned int pin, unsigned int to);
102
103  extern unsigned int s3c2410_gpio_getpin(unsigned int pin);

s3c2410_gpio_setpin 代码实现在：

       void s3c2410_gpio_setpin(unsigned int pin, unsigned int to)
 140   {
 141             void __iomem *base = S3C24XX_GPIO_BASE(pin);
 142             unsigned long offs = S3C2410_GPIO_OFFSET(pin);
 143             unsigned long flags;
 144             unsigned long dat;
 145
 146             local_irq_save(flags);
 147
 148             dat = __raw_readl(base + 0x04);
 149             dat &= ~(1 << offs);
 150             dat |= to << offs;
 151             __raw_writel(dat, base + 0x04);
 152
 153            local_irq_restore(flags);
 154  }
 155
 156  EXPORT_SYMBOL(s3c2410_gpio_setpin);

不知道 怎么实现的 ？？？？





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