mini 2440タッチスクリーン駆動における信号量作用に関する最新の解釈

8086 ワード

ここ数日タッチスクリーンドライバを詳しく分析し、タッチスクリーンドライバstylus_Action関数のmod_timer()がよくわからなかったので、タッチパネルドライバにdebug情報を付けてテストしました.Debug情報を追加したドライバ除去コードは次のとおりです.
/*************************************

NAME:gt2440.c
COPYRIGHT:www.e-online.cc

*************************************/

#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 <linux/platform_device.h>
#include <linux/clk.h>
#include <asm/io.h>
#include <asm/irq.h>

#include <plat/regs-adc.h>
#include <mach/regs-gpio.h>

/* For ts.dev.id.version */
#define TSDEBUG
#ifdef TSDEBUG
#define TPDEBUG(fmt,args...) printk("gt2440 ts:" fmt,##args)
#else
#define TPDEBUG(fmt,args...)
#endif

#define S3C2410TSVERSION	0x0101

#define WAIT4INT(x)  (((x)<<8) | \
		     S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
		     S3C2410_ADCTSC_XY_PST(3))

#define AUTOPST	     (S3C2410_ADCTSC_YM_SEN | S3C2410_ADCTSC_YP_SEN | S3C2410_ADCTSC_XP_SEN | \
		     S3C2410_ADCTSC_AUTO_PST | S3C2410_ADCTSC_XY_PST(0))

static char *gt2440ts_name = "GT2440 TouchScreen";

static	struct input_dev *dev;
static	long xp;
static	long yp;
static	int count;

extern struct semaphore ADC_LOCK;
static int OwnADC = 0;

static void __iomem *base_addr;

static inline void gt2440_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);
}

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

  	data0 = ioread32(base_addr+S3C2410_ADCDAT0);
  	data1 = ioread32(base_addr+S3C2410_ADCDAT1);

 	updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN));

 	if (updown) {
 		if (count != 0)
 		{
                        xp >>= 2;
                        yp >>= 2;

 			input_report_abs(dev, ABS_X, xp);
 			input_report_abs(dev, ABS_Y, yp);

 			input_report_key(dev, BTN_TOUCH, 1);
 			input_report_abs(dev, ABS_PRESSURE, 1);
 			input_sync(dev);
			TPDEBUG("touch_timer_fire func report key:%d,%d
",xp,yp); } xp = 0; yp = 0; count = 0; iowrite32(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC); iowrite32(ioread32(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON); TPDEBUG("touch_timer_fire func start ADC
"); } else { count = 0; input_report_key(dev, BTN_TOUCH, 0); input_report_abs(dev, ABS_PRESSURE, 0); input_sync(dev); iowrite32(WAIT4INT(0), base_addr+S3C2410_ADCTSC); if (OwnADC) { OwnADC = 0; up(&ADC_LOCK); } TPDEBUG("touch_timer_fire func stylus up
"); } } static struct timer_list touch_timer = TIMER_INITIALIZER(touch_timer_fire, 0, 0); static irqreturn_t stylus_updown(int irq, void *dev_id) { unsigned long data0; unsigned long data1; int updown; TPDEBUG("stylus_updown func init
"); if (down_trylock(&ADC_LOCK) == 0) { OwnADC = 1; data0 = ioread32(base_addr+S3C2410_ADCDAT0); data1 = ioread32(base_addr+S3C2410_ADCDAT1); updown = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN)); if (updown) { TPDEBUG("stylus_updown func:stylus down
"); touch_timer_fire(0); } else { TPDEBUG("stylus_updown func:stylus up
"); OwnADC = 0; up(&ADC_LOCK); } } return IRQ_HANDLED; } static irqreturn_t stylus_action(int irq, void *dev_id) { unsigned long data0; unsigned long data1; if (OwnADC) { data0 = ioread32(base_addr+S3C2410_ADCDAT0); data1 = ioread32(base_addr+S3C2410_ADCDAT1); xp += data0 & S3C2410_ADCDAT0_XPDATA_MASK; yp += data1 & S3C2410_ADCDAT1_YPDATA_MASK; count++; if (count < (1<<4)) { iowrite32(S3C2410_ADCTSC_PULL_UP_DISABLE | AUTOPST, base_addr+S3C2410_ADCTSC); iowrite32(ioread32(base_addr+S3C2410_ADCCON) | S3C2410_ADCCON_ENABLE_START, base_addr+S3C2410_ADCCON); TPDEBUG("stylus_action func still adc
"); } else { TPDEBUG("stylus_action func report key
"); mod_timer(&touch_timer, jiffies+1); iowrite32(WAIT4INT(1), base_addr+S3C2410_ADCTSC); TPDEBUG("stylus_action func wait interrupt
"); } } return IRQ_HANDLED; } static struct clk *adc_clock; static int __init gt2440ts_init(void) { struct input_dev *input_dev; adc_clock = clk_get(NULL, "adc"); if (!adc_clock) { printk(KERN_ERR "failed to get adc clock source
"); return -ENOENT; } clk_enable(adc_clock); base_addr=ioremap(S3C2410_PA_ADC,0x20); if (base_addr == NULL) { printk(KERN_ERR "Failed to remap register block
"); return -ENOMEM; } /* Configure GPIOs */ //gt2440_ts_connect(); iowrite32(S3C2410_ADCCON_PRSCEN | S3C2410_ADCCON_PRSCVL(100),base_addr+S3C2410_ADCCON); iowrite32(0x4fff, base_addr+S3C2410_ADCDLY); iowrite32(WAIT4INT(0), base_addr+S3C2410_ADCTSC); /* Initialise input stuff */ input_dev = input_allocate_device(); if (!input_dev) { printk(KERN_ERR "Unable to allocate the input device !!
"); return -ENOMEM; } dev = input_dev; dev->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS); dev->keybit[BITS_TO_LONGS(BTN_TOUCH)] = BIT(BTN_TOUCH); input_set_abs_params(dev, ABS_X, 0, 0x3FF, 0, 0); input_set_abs_params(dev, ABS_Y, 0, 0x3FF, 0, 0); input_set_abs_params(dev, ABS_PRESSURE, 0, 1, 0, 0); dev->name = gt2440ts_name; dev->id.bustype = BUS_RS232; dev->id.vendor = 0xDEAD; dev->id.product = 0xBEEF; dev->id.version = S3C2410TSVERSION; if (request_irq(IRQ_ADC, stylus_action, IRQF_SHARED|IRQF_SAMPLE_RANDOM, gt2440ts_name, dev)) { printk(KERN_ERR "gt2440_ts.c: Could not allocate ts IRQ_ADC !
"); iounmap(base_addr); return -EIO; } if (request_irq(IRQ_TC, stylus_updown, IRQF_SAMPLE_RANDOM, gt2440ts_name, dev)) { printk(KERN_ERR "gt2440_ts.c: Could not allocate ts IRQ_ADC !
"); iounmap(base_addr); return -EIO; } printk(KERN_INFO "%s successfully loaded
", gt2440ts_name); input_register_device(dev); return 0; } static void __exit gt2440ts_exit(void) { disable_irq(IRQ_ADC); disable_irq(IRQ_TC); free_irq(IRQ_TC,dev); free_irq(IRQ_ADC,dev); if (adc_clock) { clk_disable(adc_clock); clk_put(adc_clock); adc_clock = NULL; } input_unregister_device(dev); iounmap(base_addr); } module_init(gt2440ts_init); module_exit(gt2440ts_exit);

ドライバテスト結果入力:
gt2440 ts: stylus_updown func init
gt2440 ts: stylus_updown func:stylus down
gt2440 ts: touch_timer_fire func start ADC
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func still adc
gt2440 ts: stylus_action func report key
gt2440 ts: stylus_action func wait interrupt
gt2440 ts: stylus_updown func ini
gt2440 ts: touch_timer_fire func report key 676,,4347 

次の3つの出力結果に基づいて、プログラムstylusを分析します.updown()->touch_timer_fire()->stylus_action()->stylus_updown()->touch_timer_fire()、だからstylus_updown関数のif(down_trylock(&ADC_LOCK)==0)は、いつでも1つのドライバだけがADCを使用することを保証するだけでなく、タッチスクリーンが押されている間に端末に入ってタイマ関数をトリガーしないことを保証する重要な役割もあります.