linux 2.6 下基于yl2440板(s3c2440)touch screen 驱动移植过程

本移植是先从 Ben Dooks 的网站上下载了部分代码,同时在网下载了一个2410的
 touch screen 驱动程序,做了简单修改完成的.这个简单的触摸屏驱动程序还不是
 很完善,还需要改进.
 
简单触摸屏驱动移植过程如下:

一. 如果你的kernel里面没有 reg-adc.h 则需要到 Ben Dooks 的网站下载相关补丁
    文件位置在 include/asm-arm/arch-s3c2410/regs-adc.h, 并在其添加如下内容

#define S3C2410_ADCTSC_XY_PST_N     (0x0<<0)
#define S3C2410_ADCTSC_XY_PST_X     (0x1<<0)
#define S3C2410_ADCTSC_XY_PST_Y  (0x2<<0)
#define S3C2410_ADCTSC_XY_PST_W   (0x3<<0)

二.将下载的2410的驱动程序代码复制到 drivers/input/touchscreen/ 下名为
    s3c2440_ts.c .
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/init.h>
#include <linux/serio.h>
#include <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>

#include <asm/arch/regs-adc.h>
#include <asm/arch/regs-gpio.h>
#include <asm/arch/s3c2440_ts.h>
//#include <asm/hardware/clock.h>
#include <asm/arch/regs-clock.h>
#include <linux/clk.h>

/* For ts.dev.id.version */
#define S3C2440TSVERSION 0x0101

#define WAIT4INT(x)  (((x)<<8) | \
       S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
       S3C2410_ADCTSC_XY_PST_W)

#define AUTOPST      (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
       S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST_N)

#define DEBUG_LVL    KERN_INFO

#ifdef CONFIG_TOUCHSCREEN_S3C2440_DEBUG
#define DBG(x...)       printk(KERN_INFO x)
#else
#define DBG(x...)       do { } while (0)
#endif

/*
 * Definitions & global arrays.
 */

static char *s3c2440ts_name = "s3c2440 TouchScreen";

/*
 * Per-touchscreen data.
 */

struct s3c2440ts {
 struct input_dev *dev;
 long xp;
 long yp;
 int count;
 int shift;
 char phys[32];
};

static struct s3c2440ts ts;
static void __iomem *base_addr;

static void touch_timer_fire(unsigned long data)
{
   unsigned long data0;
   unsigned long data1;
 int updown;

   data0 = readl(base_addr+S3C2410_ADCDAT0);
   data1 = readl(base_addr+S3C2410_ADCDAT1);

  updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));
 
 DBG(" data0 = %x, data1 = %x updown = %d  %s : %s : line = %d\n", data0, data1, updown,
   __FUNCTION__, __FILE__, __LINE__);

  if (updown) {
   if (ts.count != 0) {
    ts.xp >>= ts.shift;
    ts.yp >>= ts.shift;
 
#ifdef CONFIG_TOUCHSCREEN_S3C2440_DEBUG
    {
     struct timeval tv;
     do_gettimeofday(&tv);
     printk(DEBUG_LVL "T: %06d, X: %03ld, Y: %03ld\n", (int)tv.tv_usec, ts.xp, ts.yp);
    }
#endif
   
    input_report_abs(ts.dev, ABS_X, ts.xp);
    input_report_abs(ts.dev, ABS_Y, ts.yp);
 
    input_report_key(ts.dev, BTN_TOUCH, 1);
    input_report_abs(ts.dev, ABS_PRESSURE, 1);
    input_sync(ts.dev);
   }
  
   ts.xp = 0;
   ts.yp = 0;
   ts.count = 0;
 
   writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC);
   writel(readl(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON);
  } else {
   ts.count = 0;
  
   input_report_key(ts.dev, BTN_TOUCH, 0);
   input_report_abs(ts.dev, ABS_PRESSURE, 0);
   input_sync(ts.dev);
  
   writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC);
  }
}