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authorAmaury Pouly <amaury.pouly@gmail.com>2013-06-18 15:34:54 +0200
committerAmaury Pouly <amaury.pouly@gmail.com>2013-06-18 15:34:54 +0200
commit57bb7b2d2704166b5d4dd307d3ae8d8ae99afbbd (patch)
tree20dd540c994744341c1a88b614699fb414b55f99 /firmware/target/arm/imx233/touchscreen-imx233.c
parent0173f6edf58c3ee377cd2d6a10540787cb847524 (diff)
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imx233: rework touchscreen driver
The old driver didn't behave nicely because it waiting for stability which could never arrive on some gestures. The new one uses a fixed delay and averaging. Change-Id: I8ff80f373b6792e6d5fc3cfe41b709642e61c38b
Diffstat (limited to 'firmware/target/arm/imx233/touchscreen-imx233.c')
-rw-r--r--firmware/target/arm/imx233/touchscreen-imx233.c84
1 files changed, 37 insertions, 47 deletions
diff --git a/firmware/target/arm/imx233/touchscreen-imx233.c b/firmware/target/arm/imx233/touchscreen-imx233.c
index e76d7a49e3..c4d2f4d726 100644
--- a/firmware/target/arm/imx233/touchscreen-imx233.c
+++ b/firmware/target/arm/imx233/touchscreen-imx233.c
@@ -46,28 +46,53 @@ enum touch_state_t
TOUCH_STATE_VERIFY, /* verify touch */
};
-#define DEBOUNCE_THRESHOLD 100
-#define SAMPLES_THRESHOLD 4
+#define NR_SAMPLES 10
+#define DELAY 1
static enum touch_state_t touch_state;
static int touch_chan = -1;
static int touch_delay = -1;
-static int touch_x, touch_y, nr_samples;
+static int touch_x, touch_y;
/* once a touch is confirmed, the parameters are copied to these value for
* instant readout by button code. */
static bool old_touch_detect = false;
static int old_touch_x, old_touch_y;
-static void kick_measure(bool pull_x, bool pull_y, bool detect, int lradc_phys)
+static void process(void);
+
+void INT_TOUCH_DETECT(void)
+{
+ process();
+}
+
+static void touch_channel_irq(int chan)
{
+ imx233_icoll_enable_interrupt(INT_SRC_LRADC_CHx(chan), false);
+ imx233_lradc_enable_channel_irq(chan, false);
+ process();
+}
+
+static void kick_measure(bool pull_x, bool pull_y, bool detect, int src)
+{
+ if(touch_chan >= 0)
+ imx233_lradc_release_channel(touch_chan);
+ touch_chan = imx233_lradc_acquire_channel(src, TIMEOUT_NOBLOCK);
+ if(touch_chan < 0)
+ panicf("touchscreen: cannot get adc channel");
+ /* enable interrupt */
+ imx233_lradc_set_channel_irq_callback(touch_chan, &touch_channel_irq);
+ imx233_icoll_enable_interrupt(INT_SRC_LRADC_CHx(touch_chan), true);
+ imx233_lradc_enable_channel_irq(touch_chan, true);
/* setup measurement: x- pull down and x+ pull up */
imx233_lradc_setup_touch(pull_x, pull_y, pull_x, pull_y, detect);
imx233_lradc_enable_touch_detect_irq(false);
imx233_lradc_enable_channel_irq(touch_chan, true);
/* measure channel, no accumulation */
- imx233_lradc_setup_channel(touch_chan, false, false, 0, lradc_phys);
+ imx233_lradc_setup_channel(touch_chan, false, true, NR_SAMPLES - 1, src);
+ imx233_lradc_clear_channel(touch_chan);
/* use a delay */
- imx233_lradc_setup_delay(touch_delay, 1 << touch_chan, 0, 0, 8);
+ imx233_lradc_setup_delay(touch_delay, 1 << touch_chan, 1 << touch_delay,
+ NR_SAMPLES -1, DELAY);
imx233_lradc_kick_delay(touch_delay);
}
@@ -78,7 +103,6 @@ static void enter_state(enum touch_state_t state)
{
case TOUCH_STATE_WAIT:
imx233_lradc_setup_touch(false, false, false, false, true);
- imx233_lradc_enable_channel_irq(touch_chan, false);
imx233_lradc_enable_touch_detect_irq(true);
break;
case TOUCH_STATE_MEASURE_X:
@@ -95,7 +119,6 @@ static void enter_state(enum touch_state_t state)
static void process(void)
{
- int val;
switch(touch_state)
{
case TOUCH_STATE_WAIT:
@@ -110,32 +133,12 @@ static void process(void)
}
break;
case TOUCH_STATE_MEASURE_X:
- /* read value */
- val = imx233_lradc_read_channel(touch_chan);
- /* if value is too far from average, restart */
- if(nr_samples > 0 && abs(val - touch_x) > DEBOUNCE_THRESHOLD)
- nr_samples = 0;
- touch_x = (touch_x * nr_samples + val) / (nr_samples + 1);
- nr_samples++;
- /* if we have enough samples, measure Y */
- if(nr_samples > SAMPLES_THRESHOLD)
- enter_state(TOUCH_STATE_MEASURE_Y);
- else
- imx233_lradc_kick_delay(touch_delay);
+ touch_x = imx233_lradc_read_channel(touch_chan) / NR_SAMPLES;
+ enter_state(TOUCH_STATE_MEASURE_Y);
break;
case TOUCH_STATE_MEASURE_Y:
- /* read value */
- val = imx233_lradc_read_channel(touch_chan);
- /* if value is too far from average, restart */
- if(nr_samples > 0 && abs(val - touch_y) > DEBOUNCE_THRESHOLD)
- nr_samples = 0;
- touch_y = (touch_y * nr_samples + val) / (nr_samples + 1);
- nr_samples++;
- /* if we have enough samples, verify touch */
- if(nr_samples > SAMPLES_THRESHOLD)
+ touch_y = imx233_lradc_read_channel(touch_chan) / NR_SAMPLES;
enter_state(TOUCH_STATE_VERIFY);
- else
- imx233_lradc_kick_delay(touch_delay);
break;
case TOUCH_STATE_VERIFY:
if(imx233_lradc_read_touch_detect())
@@ -154,31 +157,18 @@ static void process(void)
}
}
-void INT_TOUCH_DETECT(void)
-{
- process();
-}
-
-static void touch_channel_irq(int chan)
-{
- (void) chan;
- process();
-}
-
void imx233_touchscreen_init(void)
{
- touch_chan = imx233_lradc_acquire_channel(LRADC_SRC_XPLUS, TIMEOUT_NOBLOCK);
touch_delay = imx233_lradc_acquire_delay(TIMEOUT_NOBLOCK);
- if(touch_chan < 0 || touch_delay < 0)
+ if(touch_delay < 0)
panicf("Cannot acquire channel and delays for touchscreen measurement");
imx233_touchscreen_enable(false);
}
void imx233_touchscreen_enable(bool enable)
{
- enter_state(TOUCH_STATE_WAIT);
- imx233_lradc_set_channel_irq_callback(touch_chan, &touch_channel_irq);
- imx233_icoll_enable_interrupt(INT_SRC_LRADC_CHx(touch_chan), enable);
+ if(enable)
+ enter_state(TOUCH_STATE_WAIT);
imx233_icoll_enable_interrupt(INT_SRC_TOUCH_DETECT, enable);
}