[Linux驱动之路] 驱动设计的思想_面向对象_分层_分离—程序扩展

韦东山老师的Linux驱动设计基础课程的p128 5_101
驱动设计的思想_面向对象_分层_分离这课在开发板上实作练习，可控制imx6ull_pro板子的LED开关。

基于韦老师代码的基础上，更改如下代码：

led_resource.h

#ifndef _LED_RESOURCE_H
#define _LED_RESOURCE_H

/* GPIO3_0 */
/* bit[31:16] = group */
/* bit[15:0]  = which pin */
#define GROUP(x) (x>>16)
#define PIN(x)   (x&0xFFFF)
#define GROUP_PIN(g,p) ((g<<16) | (p))

#define GPIO5_IO3 1

/* GPIO3_0 */
// BIT[31:16] == group
// bit[15:0]  == pin number
struct led_resource {
	int pin;
};

struct led_resource *get_led_resource(void);


#endif

board_A_led.c

#include "led_resource.h"

static struct led_resource board_A_led = {
	.pin = GROUP_PIN(5,3), //GPIO5_IO3
};

struct led_resource *get_led_resource(void)
{
	return &board_A_led;
}

chip_demo_gpio.c

#include <linux/module.h>

#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/tty.h>
#include <linux/kmod.h>
#include <linux/gfp.h>
#include <asm/io.h>
#include "led_opr.h"
#include "led_resource.h"

static struct led_resource *led_rsc;

#ifdef GPIO5_IO3
static volatile unsigned int *CCM_CCGR1 = NULL;
static volatile unsigned int *IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER3 = NULL;
static volatile unsigned int *GPIO5_GDIR = NULL;
static volatile unsigned int *GPIO5_DR = NULL;
#endif

/*******内部函数************/
static int _board_demo_led_init (int which) /* 初始化LED, which-哪个LED */	   
{
	unsigned int value;
	printk("%s %s line %d, led %d\n", __FILE__, __FUNCTION__, __LINE__, which);
	if(which == 0)
	{
		if(!CCM_CCGR1)
		{
			CCM_CCGR1 								= ioremap(0x20C406C, 4);
			IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER3 = ioremap(0x2290014, 4);
			GPIO5_GDIR								= ioremap(0x020AC000 + 0x4 , 4);
			GPIO5_DR 								= ioremap(0x020AC000, 4);
		}

		/* GPIO5_IO03 */ 
		/* a. 使能 GPIO5 
		* set CCM to enable GPIO5 
		* CCM_CCGR1[CG15] 0x20C406C 
		* bit[31:30] = 0b11 
		*/
		*CCM_CCGR1 |= (0x3 << 30); 

		/* b. 设置 GPIO5_IO03 用于 GPIO 
		* set IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER3 
		* to configure GPIO5_IO03 as GPIO 
		* IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER3 0x2290014 
		* bit[3:0] = 0b0101 alt5 
		*/
		value = *IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER3;
		value &= ~0xF; 
		value |= 0x5; 
		*IOMUXC_SNVS_SW_MUX_CTL_PAD_SNVS_TAMPER3 = value;
		

		/* c. 设置 GPIO5_IO03 作为 output 引脚 
		* set GPIO5_GDIR to configure GPIO5_IO03 as output 
		* GPIO5_GDIR 0x020AC000 + 0x4 
		* bit[3] = 0b1 
		*/ 
		*GPIO5_GDIR |= (1 << 3);
	}

	
	return 0;
}

static int _board_demo_led_ctl (int which, char status) /* 控制LED, which-哪个LED, status:1-亮,0-灭 */
{
	printk("%s %s line %d, led %d, %s\n", __FILE__, __FUNCTION__, __LINE__, which, status ? "on" : "off");
	if(which == 0)
	{
		if(status) //on
		{
			/* d. 设置 GPIO5_DR 输出低电平 
			* set GPIO5_DR to configure GPIO5_IO03 output 0 
			* GPIO5_DR 0x020AC000 + 0 
			* bit[3] = 0b0 
			*/ 
			*GPIO5_DR &= ~(1 << 3); 
			
		}
		else
		{
			/* e. 设置 GPIO5_IO3 输出高电平 
			* set GPIO5_DR to configure GPIO5_IO03 output 1 
			* GPIO5_DR 0x020AC000 + 0 
			* bit[3] = 0b1 
			*/
			*GPIO5_DR |= (1 << 3); 

		}
	
	}
	return 0;
}

/************外部函数******************/

static int board_demo_led_init (int which) /* 初始化LED, which-哪个LED */	   
{
	unsigned int value;
	
	if (!led_rsc)
	{
		led_rsc = get_led_resource();
	}
	
	printk("init gpio: group %d, pin %d\n", GROUP(led_rsc->pin), PIN(led_rsc->pin));
	switch(GROUP(led_rsc->pin))
	{
		case 0:
		{
			printk("init pin of group 0 ...\n");
			break;
		}
		case 1:
		{
			printk("init pin of group 1 ...\n");
			break;
		}
		case 2:
		{
			printk("init pin of group 2 ...\n");
			break;
		}
		case 3:
		{
			printk("init pin of group 3 ...\n");
			break;
		}
		case 4:
		{
			printk("init pin of group 4 ...\n");
			break;
		}
		case 5:
		{
			printk("init pin of group 5 ...\n");
			_board_demo_led_init(which);
			break;			
		}
	
	return 0;
}
}
	

static int board_demo_led_ctl (int which, char status) /* 控制LED, which-哪个LED, status:1-亮,0-灭 */
{
	printk("set led %s: group %d, pin %d\n", status ? "on" : "off", GROUP(led_rsc->pin), PIN(led_rsc->pin));
	switch(GROUP(led_rsc->pin))
	{
		case 0:
		{
			printk("set pin of group 0 ...\n");
			_board_demo_led_ctl(PIN(led_rsc->pin), status);
			break;
		}
		case 1:
		{
			printk("set pin of group 1 ...\n");
			break;
		}
		case 2:
		{
			printk("set pin of group 2 ...\n");
			break;
		}
		case 3:
		{
			printk("set pin of group 3 ...\n");
			break;
		}
		case 4:
		{
			printk("init pin of group 4 ...\n");
			break;
		}
		case 5:
		{
			printk("init pin of group 5 ...\n");
			_board_demo_led_ctl(which, status);
			break;			
		}
	}
	return 0;
}

static struct led_operations board_demo_led_opr = {
	.num = 1,
	.init = board_demo_led_init,
	.ctl  = board_demo_led_ctl,
};

struct led_operations *get_board_led_opr(void)
{
	return &board_demo_led_opr;
}