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

chenzhufly

  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
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
//#include
#include  
#include  
/* For ts.dev.id.version */
#define S3C2440TSVERSION 0x0101
#define WAIT4INT(x)  (((x)>= 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);
  }
}
static struct timer_list touch_timer = TIMER_INITIALIZER(touch_timer_fire, 0, 0);
static irqreturn_t stylus_updown(int irq, void *dev_id, struct pt_regs *regs)
{
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("\n data0 = %x, data1 = %x updown = %d  %s : %s : line = %d\n", data0, data1, updown,
   __FUNCTION__, __FILE__, __LINE__);
/* TODO we should never get an interrupt with updown set while
  * the timer is running, but maybe we ought to verify that the
  * timer isn't running anyways. */
  
if (updown)
  touch_timer_fire(0);
return IRQ_HANDLED;
}
static irqreturn_t stylus_action(int irq, void *dev_id, struct pt_regs *regs)
{
unsigned long data0;
unsigned long data1;

data0 = readl(base_addr+S3C2410_ADCDAT0);
data1 = readl(base_addr+S3C2410_ADCDAT1);
ts.xp += data0 & S3C2410_ADCDAT0_XPDATA_MASK;
ts.yp += data1 & S3C2410_ADCDAT1_YPDATA_MASK;
ts.count++;
    if (ts.count platform_data;
if (!info)
{
  printk(KERN_ERR "Hm... too bad : no platform data for ts\n");
  return -EINVAL;
}

#ifdef CONFIG_TOUCHSCREEN_S3C2440_DEBUG
printk(DEBUG_LVL "Entering s3c2440ts_init\n");
#endif
memset(&ts, 0, sizeof(struct s3c2440ts));
ts.dev = input_allocate_device();
if (!ts.dev)
{
  printk(KERN_ERR "%s:%s allocate_device\n", __FUNCTION__, __FILE__);
  return -ENOMEM;
}
adc_clock = clk_get(NULL, "adc");
if (!adc_clock) {
  printk(KERN_ERR "failed to get adc clock source\n");
  return -ENOENT;
}
//clk_use(adc_clock);
clk_enable(adc_clock);
#ifdef CONFIG_TOUCHSCREEN_S3C2440_DEBUG
printk(DEBUG_LVL "got and enabled clock\n");
#endif
base_addr = ioremap(S3C2410_PA_ADC, 0x20);
if (base_addr == NULL) {
  printk(KERN_ERR "Failed to remap register block\n");
  return -ENOMEM;
}
  
if ((info->presc&0xff) > 0)
  writel(S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(info->presc&0xFF), base_addr + S3C2410_ADCCON);
else
  writel(0,base_addr + S3C2410_ADCCON);
/* Initialise registers */
if ((info->delay&0xffff) > 0)
  writel(info->delay & 0xffff,  base_addr + S3C2410_ADCDLY);

writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC);

/* Initialise input stuff */
//memset(&ts, 0, sizeof(struct s3c2440ts));
//init_input_dev(&ts.dev);
ts.dev->evbit[0] = ts.dev->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
ts.dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
input_set_abs_params(ts.dev, ABS_X, 0, 0x3FF, 0, 0);
input_set_abs_params(ts.dev, ABS_Y, 0, 0x3FF, 0, 0);
input_set_abs_params(ts.dev, ABS_PRESSURE, 0, 1, 0, 0);
sprintf(ts.phys, "ts0");
ts.dev->private = &ts;
ts.dev->name = s3c2440ts_name;
ts.dev->phys = ts.phys;
ts.dev->id.bustype = BUS_RS232;
ts.dev->id.vendor = 0xDEAD;
ts.dev->id.product = 0xBEEF;
ts.dev->id.version = S3C2440TSVERSION;
ts.shift = info->oversampling_shift;
/* Get irqs */
if (request_irq(IRQ_ADC, stylus_action, SA_SAMPLE_RANDOM, "s3c2440_action", ts.dev)) {
  printk(KERN_ERR "s3c2440_ts.c: Could not allocate ts IRQ_ADC !\n");
  iounmap(base_addr);
  return -EIO;
}
if (request_irq(IRQ_TC, stylus_updown, SA_SAMPLE_RANDOM, "s3c2440_updown", ts.dev)) {
  printk(KERN_ERR "s3c2440_ts.c: Could not allocate ts IRQ_TC !\n");
  disable_irq(IRQ_ADC);
  free_irq(IRQ_ADC, ts.dev);
  iounmap(base_addr);
  return -EIO;
}
printk(KERN_INFO "%s successfully loaded\n", s3c2440ts_name);
/* All went ok, so register to the input system */
input_register_device(ts.dev);

return 0;
}
static int s3c2440ts_remove(struct device *dev)
{
disable_irq(IRQ_ADC);
disable_irq(IRQ_TC);
free_irq(IRQ_TC, ts.dev);
free_irq(IRQ_ADC, ts.dev);
if (adc_clock) {
  clk_disable(adc_clock);
  //clk_unuse(adc_clock);
  clk_put(adc_clock);
  adc_clock = NULL;
}

input_unregister_device(ts.dev);
iounmap(base_addr);
return 0;
}
static struct device_driver s3c2440ts_driver = {
       .name           = "s3c2440-ts",
       .bus            = &platform_bus_type,
       .probe          = s3c2440ts_probe,
       .remove         = s3c2440ts_remove,
};
int __init s3c2440ts_init(void)
{
return driver_register(&s3c2440ts_driver);
}
void __exit s3c2440ts_exit(void)
{
driver_unregister(&s3c2440ts_driver);
}
module_init(s3c2440ts_init);
module_exit(s3c2440ts_exit);
MODULE_AUTHOR("Arnaud Patard ");
MODULE_DESCRIPTION("s3c2440 touchscreen driver");
MODULE_LICENSE("GPL");

三.将s3c2440_ts.h文件拷贝到include/asm/arch-s3c2410/目录下，其内容为：
#ifndef __ASM_ARM_S3C2440_TS_H
#define __ASM_ARM_S3C2440_TS_H
struct s3c2440_ts_mach_info {
       int             delay;
       int             presc;
       int             oversampling_shift;
};
void __init set_s3c2440ts_info(struct s3c2440_ts_mach_info *hard_s3c2440ts_info);
#endif /* __ASM_ARM_S3C2440_TS_H */
四.在 arch/arm/mach-s3c2410/devs.c文件中添加如下几行
#include
/* Touchscreen */
static struct s3c2440_ts_mach_info s3c2440ts_info;
void __init set_s3c2440ts_info(struct s3c2440_ts_mach_info *hard_s3c2440ts_info)
{
memcpy(&s3c2440ts_info, hard_s3c2440ts_info, sizeof(struct s3c2440_ts_mach_info));
}
EXPORT_SYMBOL(set_s3c2440ts_info);
struct platform_device s3c_device_ts = {
.name    = "s3c2440-ts",
.id    = -1,
.dev              = {
   .platform_data = &s3c2440ts_info,
}
};
EXPORT_SYMBOL(s3c_device_ts);
五.在arch/arm/mach-s3c2410/devs.h文件中添加：
extern struct platform_device s3c_device_ts;
六.在arch/arm/mach-s3c2410/mach-smdk2410.c中添加：
#include
static struct s3c2440_ts_mach_info s3c2440_ts_cfg __initdata = {
.delay = 10000,
//.delay = 200000,
.presc = 49,
.oversampling_shift = 2,
};
在 smdk2440_devices[] 增加 &s3c_device_ts,
在 smdk2440_machine_init()函数中调用 set_s3c2440ts_info(&s3c2440_ts_cfg);
七.在drivers/input/touchscreen/Kconfig中添加
config TOUCHSCREEN_S3C2440
tristate "Samsung S3C2440 touchscreen input driver"
depends on ARCH_S3C2440 && INPUT && INPUT_TOUCHSCREEN
select SERIO
help
   Say Y here if you have the s3c2440 touchscreen.
   If unsure, say N.
   To compile this driver as a module, choose M here: the
   module will be called s3c2440_ts.
config TOUCHSCREEN_S3C2440_DEBUG
boolean "Samsung S3C2440 touchscreen debug messages"
depends on TOUCHSCREEN_S3C2440
help
   Select this if you want debug messages
八.在drivers/input/touchscreen/Makefile中添加：
obj-$(CONFIG_TOUCHSCREEN_S3C2440) += s3c2440_ts.o
九.配置编译内核


十.创建设备文件
根据你的配置情况创建相应的设备文件例如:
mknod -m 666 ts -c 13 128 等

注: 因为这个驱动相对校简单,在实际应用中需要对其准确性和效率需要自己验证和改进.


本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u1/41638/showart_437530.html