Original Source:
http://blog.chinaunix.net/uid-22030783-id-3391515.html
First introduced the Samsung S3C24XX platform BSP definition peripheral registers and GPIO related header file to linux-3.4 system as an example, linux2.6.37 system is similar, just keep the directory is different
The header files of the platform are stored in the arch/arm/mach-s3c24xx/include/mach/directory
Memory Map definitions defines the 8-bank address of the Samsung platform, the register base address and size of each peripheral controller, and often uses file names when creating resource for Platform_data: arch/arm/ Mach-s3c24xx/include/mach/map.h such as: #define S3C2410_CS4 (0x20000000)
#define S3C2410_PA_LCD (0x4d000000)
#define S3C24XX_SZ_LCD sz_1m
IRQ definitions defines the interrupt number of the Samsung platform and is often used when creating platform_data resource arch/arm/mach-s3c24xx/include/mach/irqs.h such as: #define Irq_ EINT0 S3C2410_IRQ (0)
#define IRQ_RTC S3C2410_IRQ (30)
s3c2410 GPIO Register definitions defines the Samsung platform GPIO related registers base address and each pin's functional configuration arch/arm/mach-s3c24xx/include/mach/regs-gpio.h such as: #de Fine S3c2410_gpgcon S3c2410_gpioreg (0x60)
#define S3C2410_GPGDAT S3c2410_gpioreg (0x64)
#define S3C2410_GPB0_TOUT0 (0x02 << 0)
S3c2410-gpio Bank numbering arch/arm/mach-s3c24xx/include/mach/gpio-nrs.h such as: #define S3C2410_GPF (_NR) (S3C2410_GPIO_F _start + (_NR))
s3c2440 GPIO J Register definitions arch/arm/mach-s3c24xx/include/mach/regs-gpioj.h such as: #define S3C2413_GPJCON S 3c2410_gpioreg (0x80)
#define S3C2440_GPJ5_OUTP (0x01 << 10)
#define S3C2440_GPJ5_CAMDATA5 (0x02 << 10)
Other header files define a macro such as an IRQ, CLK, LCD, MEM, Power, SDI, and other peripheral registers such as Regs-irq.h regs-lcd.h regs-mem.h
Here's how to do this gpio, either using a generic Gpio library or using the GPIIO library provided by Samsung
The api:drivers/gpio/gpio-samsung.c of Samsung Gpiolib
S3C Platform-gpio pin configuration arch/arm/plat-samsung/include/plat/gpio-cfg.h declares GPIO API functions, such as using Samsung's GPIO API, Need to include this file declaration configuration pin Input output, whether can pull up macros such as: #define S3c_gpio_input
#define S3c_gpio_output
#define S3C_GPIO_PULL_UP
Kernel Help Documentation: Documentation/arm/samsung-s3c24xx/gpio.txt
Configure PIN function: int s3c_gpio_cfgpin (unsigned int pin, unsigned int config) example: set GPB1 to TOUT1 function S3c_gpio_cfgpin (1), S3C2410_GPB1_TOUT1);
where S3C2410_GPB (1) is defined in Gpio-nrs.h, S3C2410_GPB1_TOUT1 defines the set output function in Regs-gpio.h as: s3c_gpio_output setting the input function as: s3c_gpio_input
Set PIN Pull: int s3c_gpio_setpull (unsigned int pin, samsung_gpio_pull_t pull) Example: Set GPG5 pin to pull s3c_gpio_setpull (5) , s3c_gpio_pull_up);
Set output level: void S3c2410_gpio_setpin (unsigned int pin, unsigned int to) example: Set GPF1 pin output High level S3c2410_gpio_setpin (S3C2410_GPF (1), 1);
Detection input level: unsigned int s3c2410_gpio_getpin (unsigned int pin) Example: Detection GPF7 pin level state value = S3c2410_gpio_getpin (S3C2410_GPF (7));
Generic GPIOLIB:DRIVERS/GPIO/GPIOLIB.C need to contain linux/gpio.h when used
Request Gpio:int gpio_request (unsigned gpio, const char *label)
Free gpio:void gpio_free (unsigned GPIO)
Set to output and specify the default level: int gpio_direction_output (unsigned gpio, int value)
Set to input: int gpio_direction_input (unsigned gpio)
Set output level: void __gpio_set_value (unsigned gpio, int value)
Detection input Level:
int __gpio_get_value (unsigned gpio)
