- Factor the ADC conversion. - Include a FIFO that gives us more flexibility in the interrupt handlers.
- Changed timer function. Now we can have more states for the touchscreen. The new states make the logic easier to understand. The state TS_STATE_PRESSED_PENDING will be useful to filter short clicks that fail to provide a valid point. We can check this with an additional filter. The state TS_STATE_RELEASE_PENDING helps us ignore short UP events. - Integrate Jitter Detection (preserving the threshold chosen by Tick -- 1/16 sec) http://lists.openmoko.org/pipermail/devel/2008-October/002822.html - Fix trivial compilation warning in a ts_filter_create_chain call. Signed-off-by: Nelson Castillo <[EMAIL PROTECTED]> --- drivers/input/touchscreen/s3c2410_ts.c | 248 +++++++++++++++++++++++--------- 1 files changed, 181 insertions(+), 67 deletions(-) diff --git a/drivers/input/touchscreen/s3c2410_ts.c b/drivers/input/touchscreen/s3c2410_ts.c index 253dc5b..9904088 100644 --- a/drivers/input/touchscreen/s3c2410_ts.c +++ b/drivers/input/touchscreen/s3c2410_ts.c @@ -49,6 +49,8 @@ #include <linux/input.h> #include <linux/init.h> #include <linux/serio.h> +#include <linux/timer.h> +#include <linux/kfifo.h> #include <linux/delay.h> #include <linux/platform_device.h> #include <linux/clk.h> @@ -89,13 +91,16 @@ MODULE_LICENSE("GPL"); * Definitions & global arrays. */ -#define TOUCH_STANDBY_FLAG 0 -#define TOUCH_PRESSED_FLAG 1 -#define TOUCH_RELEASE_FLAG 2 +static char *s3c2410ts_name = "s3c2410 TouchScreen"; -#define TOUCH_RELEASE_TIMEOUT (HZ >> 4) +#define TS_RELEASE_TIMEOUT (HZ >> 4) /* ~ 60 milliseconds */ +#define TS_EVENT_FIFO_SIZE (2 << 6) /* must be a power of 2 */ -static char *s3c2410ts_name = "s3c2410 TouchScreen"; +#define TS_STATE_STANDBY 0 /* initial state */ +#define TS_STATE_PRESSED_PENDING 1 +#define TS_STATE_PRESSED 2 +#define TS_STATE_RELEASE_PENDING 3 +#define TS_STATE_RELEASE 4 /* * Per-touchscreen data. @@ -106,7 +111,8 @@ struct s3c2410ts { struct ts_filter *tsf[MAX_TS_FILTER_CHAIN]; int coords[2]; /* just X and Y for us */ int is_down; - int need_to_send_first_touch; + int state; + struct kfifo *event_fifo; }; static struct s3c2410ts ts; @@ -122,74 +128,151 @@ static inline void s3c2410_ts_connect(void) s3c2410_gpio_cfgpin(S3C2410_GPG15, S3C2410_GPG15_nYPON); } +static void s3c2410_ts_start_adc_conversion(void) +{ + 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); +} + +/* + * Just send the input events. + */ + enum ts_input_event {IE_DOWN = 0, IE_UP, IE_UPDATE}; -static void ts_input_report(int event) +static void ts_input_report(int event, int coords[]) { +#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG + static char *s[] = {"down", "up", "update"}; + struct timeval tv; + + do_gettimeofday(&tv); +#endif + if (event == IE_DOWN || event == IE_UPDATE) { - input_report_abs(ts.dev, ABS_X, ts.coords[0]); - input_report_abs(ts.dev, ABS_Y, ts.coords[1]); + input_report_abs(ts.dev, ABS_X, coords[0]); + input_report_abs(ts.dev, ABS_Y, coords[1]); input_report_key(ts.dev, BTN_TOUCH, 1); input_report_abs(ts.dev, ABS_PRESSURE, 1); + +#ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG + printk(DEBUG_LVL "T:%06d %6s (X:%03d, Y:%03d)\n", + (int)tv.tv_usec, s[event], coords[0], coords[1]); +#endif } else { input_report_key(ts.dev, BTN_TOUCH, 0); input_report_abs(ts.dev, ABS_PRESSURE, 0); - } - - input_sync(ts.dev); #ifdef CONFIG_TOUCHSCREEN_S3C2410_DEBUG - { - static char *s[] = {"down", "up", "update"}; - struct timeval tv; - do_gettimeofday(&tv); - printk(DEBUG_LVL "T:%06d %6s (X:%03d, Y:%03d)\n", - (int)tv.tv_usec, s[event], ts.coords[0], ts.coords[1]); - } + printk(DEBUG_LVL "T:%06d %6s\n", + (int)tv.tv_usec, s[event]); #endif + } + + input_sync(ts.dev); } -static void touch_timer_fire(unsigned long data); -static struct timer_list touch_timer = - TIMER_INITIALIZER(touch_timer_fire, 0, 0); +/* + * Manage state of the touchscreen and send events. + */ + + +static void event_send_timer_f(unsigned long data); + +static struct timer_list event_send_timer = + TIMER_INITIALIZER(event_send_timer_f, 0, 0); -static void touch_timer_fire(unsigned long data) +static void event_send_timer_f(unsigned long data) { - if (ts.tsf[0]) - (ts.tsf[0]->api->scale)(ts.tsf[0], &ts.coords[0]); + static unsigned long running; + static int noop_counter; + int event_type; + + if (unlikely(test_and_set_bit(0, &running))) { + mod_timer(&event_send_timer, + jiffies + TS_RELEASE_TIMEOUT); + return; + } + + while (__kfifo_get(ts.event_fifo, (unsigned char *)&event_type, + sizeof(int))) { + int buf[2]; + + switch (event_type) { + case 'D': + if (ts.state == TS_STATE_RELEASE_PENDING) + /* Ignore short UP event */ + ts.state = TS_STATE_PRESSED; + else + /* Defer PRESSED until we get a valid point */ + ts.state = TS_STATE_PRESSED_PENDING; + break; + + case 'U': + ts.state = TS_STATE_RELEASE_PENDING; + break; + + case 'P': + if (ts.is_down) /* stylus_action needs a conversion */ + s3c2410_ts_start_adc_conversion(); + + if (unlikely(__kfifo_get(ts.event_fifo, + (unsigned char *)buf, + sizeof(int) * 2) + != sizeof(int) * 2)) + goto ts_exit_error; + + if (ts.state == TS_STATE_PRESSED_PENDING) + ts_input_report(IE_DOWN, buf); + else + ts_input_report(IE_UPDATE, buf); + + ts.state = TS_STATE_PRESSED; - if (ts.is_down && ts.need_to_send_first_touch == TOUCH_RELEASE_FLAG) - ts.need_to_send_first_touch = TOUCH_PRESSED_FLAG; - - if ( ts.is_down ) { - if ( ts.need_to_send_first_touch == TOUCH_STANDBY_FLAG ) - ts_input_report(IE_DOWN); - else - ts_input_report(IE_UPDATE); - ts.need_to_send_first_touch = TOUCH_PRESSED_FLAG; - } else if (ts.need_to_send_first_touch == TOUCH_RELEASE_FLAG) - ts_input_report(IE_UP); - else { - ts.need_to_send_first_touch = TOUCH_RELEASE_FLAG; - mod_timer(&touch_timer, jiffies + TOUCH_RELEASE_TIMEOUT); - } - - if (ts.is_down) { - 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); + break; + + default: + goto ts_exit_error; + } + + noop_counter = 0; + } + + if (noop_counter++ >= 1) { + noop_counter = 0; + if (ts.state == TS_STATE_RELEASE_PENDING) { + /* We delay the UP event for a + * while to avoid jitter. If we get a DOWN + * event we do not send it. */ + ts_input_report(IE_UP, NULL); + ts.state = TS_STATE_STANDBY; + + if (ts.tsf[0]) + (ts.tsf[0]->api->clear)(ts.tsf[0]); + } } else { - if (ts.tsf[0]) - (ts.tsf[0]->api->clear)(ts.tsf[0]); - writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC); + mod_timer(&event_send_timer, jiffies + TS_RELEASE_TIMEOUT); } + + clear_bit(0, &running); + + return; + +ts_exit_error: /* should not happen unless we have a bug */ + printk(KERN_ERR __FILE__ ": event_send_timer_f failed\n"); } +/* + * Manage interrupts. + */ + static irqreturn_t stylus_updown(int irq, void *dev_id) { unsigned long data0; unsigned long data1; + int event_type; data0 = readl(base_addr+S3C2410_ADCDAT0); data1 = readl(base_addr+S3C2410_ADCDAT1); @@ -197,18 +280,26 @@ static irqreturn_t stylus_updown(int irq, void *dev_id) ts.is_down = (!(data0 & S3C2410_ADCDAT0_UPDOWN)) && (!(data1 & S3C2410_ADCDAT0_UPDOWN)); - if (ts.is_down) { - 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); - } + event_type = ts.is_down ? 'D' : 'U'; + + if (unlikely(__kfifo_put(ts.event_fifo, (unsigned char *)&event_type, + sizeof(int)) != sizeof(int))) /* should not happen */ + printk(KERN_ERR __FILE__": stylus_updown lost event!\n"); + + if (ts.is_down) + s3c2410_ts_start_adc_conversion(); + else + writel(WAIT4INT(0), base_addr+S3C2410_ADCTSC); + + mod_timer(&event_send_timer, jiffies + 1); return IRQ_HANDLED; } static irqreturn_t stylus_action(int irq, void *dev_id) { + int buf[3]; + /* grab the ADC results */ ts.coords[0] = readl(base_addr + S3C2410_ADCDAT0) & S3C2410_ADCDAT0_XPDATA_MASK; @@ -226,15 +317,27 @@ static irqreturn_t stylus_action(int irq, void *dev_id) * no real sample came out of processing yet, * get another raw result to feed it */ - 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); + + s3c2410_ts_start_adc_conversion(); + return IRQ_HANDLED; real_sample: - mod_timer(&touch_timer, jiffies + 1); + + if (ts.tsf[0]) + (ts.tsf[0]->api->scale)(ts.tsf[0], &ts.coords[0]); + + buf[0] = 'P'; + buf[1] = ts.coords[0]; + buf[2] = ts.coords[1]; + + if (unlikely(__kfifo_put(ts.event_fifo, (unsigned char *)buf, + sizeof(int) * 3) != sizeof(int) * 3)) + /* should not happen */ + printk(KERN_ERR __FILE__": stylus_action lost event!\n"); + writel(WAIT4INT(1), base_addr + S3C2410_ADCTSC); + mod_timer(&event_send_timer, jiffies + 1); return IRQ_HANDLED; } @@ -325,12 +428,12 @@ static int __init s3c2410ts_probe(struct platform_device *pdev) ts.dev->id.vendor = 0xDEAD; ts.dev->id.product = 0xBEEF; ts.dev->id.version = S3C2410TSVERSION; - ts.need_to_send_first_touch = TOUCH_STANDBY_FLAG; + ts.state = TS_STATE_STANDBY; /* create the filter chain set up for the 2 coordinates we produce */ ret = ts_filter_create_chain( (struct ts_filter_api **)&info->filter_sequence, - &info->filter_config, ts.tsf, ARRAY_SIZE(ts.coords)); + (void *)&info->filter_config, ts.tsf, ARRAY_SIZE(ts.coords)); if (ret) dev_info(&pdev->dev, "%d filter(s) initialized\n", ret); else /* this is OK, just means there won't be any filtering */ @@ -358,22 +461,31 @@ static int __init s3c2410ts_probe(struct platform_device *pdev) goto bail4; } + ts.event_fifo = kfifo_alloc(TS_EVENT_FIFO_SIZE, GFP_KERNEL, NULL); + + if (IS_ERR(ts.event_fifo)) { + ret = -EIO; + goto bail5; + } + dev_info(&pdev->dev, "successfully loaded\n"); /* All went ok, so register to the input system */ rc = input_register_device(ts.dev); if (rc) { - free_irq(IRQ_TC, ts.dev); - free_irq(IRQ_ADC, ts.dev); - clk_disable(adc_clock); - iounmap(base_addr); ret = -EIO; - goto bail5; + goto bail6; } return 0; +bail6: + kfifo_free(ts.event_fifo); bail5: + free_irq(IRQ_TC, ts.dev); + free_irq(IRQ_ADC, ts.dev); + clk_disable(adc_clock); + iounmap(base_addr); disable_irq(IRQ_TC); bail4: disable_irq(IRQ_ADC); @@ -406,6 +518,8 @@ static int s3c2410ts_remove(struct platform_device *pdev) ts_filter_destroy_chain(ts.tsf); + kfifo_free(ts.event_fifo); + return 0; }
