//*********************************************************************************************/ //* Purpose:this is a s3c2410 touch screen drive //* //* Author: alvin.zhang //* //* Date: 2008/04/06 //* //* Revision: 2009/01/12 //* //* Description : the code about s3c2410 touch screen , you can reference it in your code //**********************************************************************************************/
#include <linux/platform_device.h> //#include <linux/config.h> #include <linux/errno.h> #include <linux/kernel.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/s3c2410_ts.h> #include <asm/arch/regs-clock.h> #include <linux/clk.h>
/* 定义版本*/ #define S3C2410TSVERSION 0x0101 /*IT4INT(1) 为UP_INT WAIT4INT(0)为 DOWN_INT*/ #define WAIT4INT(x) (((x)<<8) | S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | S3C2410_ADCTSC_XY_PST(3)) /* 设置触摸屏的模式为AUTOPST */ #define AUTOPST (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST(0))
#define DEBUG_LVL KERN_DEBUG #define DEBUG 1 MODULE_AUTHOR(“Arnaud Patard <arnaud.patard@rtp-net.org>”); MODULE_DESCRIPTION(“s3c2410 touchscreen driver”); MODULE_LICENSE(“GPL”);
/* * Definitions & global arrays. */
static char *s3c2410ts_name = “s3c2410 TouchScreen”;
/* * Per-touchscreen data. */
struct s3c2410ts { /*修改前 struct input_dev dev; */
/*add by alvin*/ struct input_dev *dev; /*add by alvin*/ long xp; long yp; int count; /*驱动内取样的频率定义在oversampling_shift 作法是取樣 (1<<oversampling_shift) 次，然後取平均值當作最後抓到的座標。 */ int shift; char phys[32]; };
static struct s3c2410ts ts; static void __iomem *base_addr; /* 配置GPIO PIN*/ static inline void s3c2410_ts_connect(void) { s3c2410_gpio_cfgpin(S3C2410_GPG12, S3C2410_GPG12_XMON); s3c2410_gpio_cfgpin(S3C2410_GPG13, S3C2410_GPG13_nXPON); s3c2410_gpio_cfgpin(S3C2410_GPG14, S3C2410_GPG14_YMON); s3c2410_gpio_cfgpin(S3C2410_GPG15, S3C2410_GPG15_nYPON); } /* * touch_timer_fire这个函数主要实现以下功能： * 1、stylus down的时候，在中断函数stylus_updown里面被调用， * 此时缓存区没有数据，ts.count为0，所以只是简单的设 * 置ad转换的模式，然后开启ad转换。 * 2、但ADC中断函数stylus_action把缓冲区填满的时候，作为中 断后半段函数稍后被调用，此时ts.count为4，算出其平 均值后，交给事件处理层(Event Handler)处理，主要是填写 缓冲，然后唤醒等待输入数据的进程。 * 3、stylus抬起，等到缓冲区填满后(可能会包含一些无用的数据)被调用， * 这时候判断出stylus up，报告stylus up事件，重新等待stylus down。 */ 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_ADCDAT1_UPDOWN)); if (updown) {//注意updown变量只在stylus_updown中更新 if (ts.count != 0) {/*<功能2>*/ ts.xp >>= ts.shift; ts.yp >>= ts.shift; #ifdef CONFIG_TOUCHSCREEN_S3C2410_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); printk(KERN_INFO “T: %06d, X: %03ld, Y: %03ld/n”, (int)tv.tv_usec, ts.xp, ts.yp); } #endif /* 报告x、y的绝对坐标值 */ input_report_abs(ts.dev/*&ts.dev*/, ABS_X, ts.xp); input_report_abs(ts.dev/*&ts.dev*/, ABS_Y, ts.yp); /* 报告按键事件，键值为1(代表触摸屏对应的按键被按下) */ input_report_key(ts.dev/*&ts.dev*/, BTN_TOUCH, 1); /* 报告触摸屏的状态，1表明触摸屏被按下 */ input_report_abs(ts.dev/*&ts.dev*/, ABS_PRESSURE, 1); /* 等待接收方受到数据后回复确认，用于同步 */ input_sync(ts.dev/*&ts.dev*/); } /*<功能1>*/ ts.xp = 0; ts.yp = 0; ts.count = 0; /* 设置触摸屏的模式为AUTOPST */ writel(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC); /* 启动ADC转换 */ writel(readl(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON); } else {/*<功能3>*/ ts.count = 0; input_report_key(ts.dev/*&ts.dev*/, BTN_TOUCH, 0); input_report_abs(ts.dev/*&ts.dev*/, ABS_PRESSURE, 0); input_sync(ts.dev/*&ts.dev*/); writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC); } } /*这里初始化定时器,并把中断处理函数指向touch_timer_fire*/ 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; /********************************debug************************************/ printk(KERN_INFO “You touch the screen/n”); /*************************************************************************/ data0 = readl(base_addr+S3C2410_ADCDAT0); data1 = readl(base_addr+S3C2410_ADCDAT1); /*更新stylus状态寄变量updown： 1 = down 0 = up */ updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT1_UPDOWN)); /* 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; }
/*ADC中断服务程序*/ 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 < (1<<ts.shift)) {/* 缓冲区未满，再次激活ADC转换 */ 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 {/* 缓冲区满，激活下半部处理程序touch_timer_fire，处理接收数据 */ mod_timer(&touch_timer, jiffies+1);//修改定时器的expire writel(WAIT4INT(1), base_addr+S3C2410_ADCTSC);//等待提笔中断 } return IRQ_HANDLED; }
static struct clk *adc_clock;
/* * The functions for inserting/removing us as a module. */
static int __init s3c2410ts_probe(struct device *dev) { struct s3c2410_ts_mach_info *info; /*s3c2410_ts_mach_info这个结构需要我们去填充，里面存放的是触摸屏需要的一些配置参数，见下面的附录部分*/ info = ( struct s3c2410_ts_mach_info *)dev->platform_data; if (!info) { printk(KERN_ERR “Hm… too bad : no platform data for ts/n”); return -EINVAL; } #ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG printk(DEBUG_LVL “Entering s3c2410ts_init/n”); #endif adc_clock = clk_get(NULL, “adc”);//可以获得adc时钟 if (!adc_clock) { printk(KERN_ERR “failed to get adc clock source/n”); return -ENOENT; } //clk_use(adc_clock);//这个在高版本下已经不需要了 clk_enable(adc_clock);// 使能时钟 #ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG printk(DEBUG_LVL “got and enabled clock/n”); #endif base_addr=ioremap(S3C2410_PA_ADC,0x20);//映射触摸屏的控制寄存器 if (base_addr == NULL) { printk(KERN_ERR “Failed to remap register block/n”); return -ENOMEM; } /* Configure GPIOs */ s3c2410_ts_connect(); /* Set the prscvl*/ 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 the adcdly 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 s3c2410ts));
/* 以下配置2.6内核划分出来的输入设备 */ /* 修改前 init_input_dev(&ts.dev);//这是低版本linux函数,新版本中已经被取替 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 = s3c2410ts_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 = S3C2410TSVERSION; */
/*add by alvin*/ // int err;
if (ts.dev) { return -ENODEV; /* already initialized */ }
ts.dev = input_allocate_device(); if (!ts.dev) return -ENOMEM; /* evbit字段用来定义该输入设备可以支持的（产生和响应）的事件的类型， 在此触摸屏设置为支持同步(EN_SYN)、按键(EN_KEY)、绝对坐标(EV_ABS)事件*/ ts.dev->evbit[0] = ts.dev->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS); /* 设置所支持的按键(键值)，触摸屏可以看成只有一个按键的设备 */ ts.dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH); /* 设置绝对坐标x和y的最小最大值，在这是0-0x3FF */ input_set_abs_params(ts.dev, ABS_X, 0, 320/*0x3FF*/, 0, 0); input_set_abs_params(ts.dev, ABS_Y, 0, 240/*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 = s3c2410ts_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 = S3C2410TSVERSION; /*add by alvin*/
ts.shift = info->oversampling_shift; /* 这个比较重要，配置输入数据的缓存区大小， 在这里oversampling_shift设为2，也就是缓存区的大小为4(1<<2) */ /* Get irqs */ /* ADC转换中断，转换结束后触发 */ if (request_irq(IRQ_ADC, stylus_action, SA_SAMPLE_RANDOM, “s3c2410_action”, ts.dev/*&ts.dev*/)) { printk(KERN_ERR “s3c2410_ts.c: Could not allocate ts IRQ_ADC !/n”); iounmap(base_addr); return -EIO; } /* 触摸屏的中断,按下或提笔触发*/ if (request_irq(IRQ_TC, stylus_updown, SA_SAMPLE_RANDOM, “s3c2410_action”, ts.dev/*&ts.dev*/)) { printk(KERN_ERR “s3c2410_ts.c: Could not allocate ts IRQ_TC !/n”); iounmap(base_addr); return -EIO; } printk(KERN_INFO “%s successfully loaded/n”, s3c2410ts_name); /* All went ok, so register to the input system */ input_register_device(ts.dev/*&ts.dev*/); return 0; }
static int s3c2410ts_remove(struct device *dev) { disable_irq(IRQ_ADC); disable_irq(IRQ_TC); free_irq(IRQ_TC,ts.dev/*&ts.dev*/); free_irq(IRQ_ADC,ts.dev/*&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/*&ts.dev*/); iounmap(base_addr); return 0; }
static struct device_driver s3c2410ts_driver = { .name = “s3c2410-ts”, .bus = &platform_bus_type, .probe = s3c2410ts_probe, .remove = s3c2410ts_remove, };
int __init s3c2410ts_init(void) { return driver_register(&s3c2410ts_driver); }
void __exit s3c2410ts_exit(void) { driver_unregister(&s3c2410ts_driver); }
module_init(s3c2410ts_init); module_exit(s3c2410ts_exit); /* mach-smdk2410.c中 static struct s3c2410_ts_mach_info s3c2410_ts_cfg __initdata = { .delay = 10000, .presc = 49, .oversampling_shift = 2, };
在devs.c中定义 struct platform_device s3c_device_ts = { .name = “s3c2410-ts”, .id = -1, .dev = { .platform_data = &s3c2410ts_info, } };
*/
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/alvin_518/archive/2009/01/12/3754989.aspx
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