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Staging/iio/adc/touchscreen/MXS: add interrupt driven touch detection

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For battery driven systems it is a very bad idea to collect the touchscreen
data within a kernel busy loop.

This change uses the features of the hardware to delay and accumulate samples in
hardware to avoid a high interrupt and CPU load.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Tested-by: Marek Vasut <marex@denx.de>
Acked-by: Marek Vasut <marex@denx.de>
Tested-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

CC: linux-arm-kernel@lists.infradead.org
CC: linux-input@vger.kernel.org
CC: devel@driverdev.osuosl.org
CC: Marek Vasut <marex@denx.de>
CC: Fabio Estevam <fabio.estevam@freescale.com>
CC: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: linux-input@vger.kernel.org
This commit is contained in:
Juergen Beisert 2013-09-23 15:36:00 +01:00 committed by Jonathan Cameron
parent 8c06f71444
commit dee05308f6
1 changed files with 476 additions and 54 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

530
drivers/staging/iio/adc/mxs-lradc.c
View File

@ -130,6 +130,17 @@ enum mxs_lradc_ts {
MXS_LRADC_TOUCHSCREEN_5WIRE,
};
/*
* Touchscreen handling
*/
enum lradc_ts_plate {
LRADC_TOUCH = 0,
LRADC_SAMPLE_X,
LRADC_SAMPLE_Y,
LRADC_SAMPLE_PRESSURE,
LRADC_SAMPLE_VALID,
};
struct mxs_lradc {
struct device *dev;
void __iomem *base;
@ -172,13 +183,25 @@ struct mxs_lradc {
#define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2)
#define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2)
enum mxs_lradc_ts use_touchscreen;
bool stop_touchscreen;
bool use_touchbutton;
struct input_dev *ts_input;
struct work_struct ts_work;
enum mxs_lradc_id soc;
enum lradc_ts_plate cur_plate; /* statemachine */
bool ts_valid;
unsigned ts_x_pos;
unsigned ts_y_pos;
unsigned ts_pressure;
/* handle touchscreen's physical behaviour */
/* samples per coordinate */
unsigned over_sample_cnt;
/* time clocks between samples */
unsigned over_sample_delay;
/* time in clocks to wait after the plates where switched */
unsigned settling_delay;
};
#define LRADC_CTRL0 0x00
@ -230,19 +253,33 @@ struct mxs_lradc {
#define LRADC_CH_ACCUMULATE (1 << 29)
#define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24)
#define LRADC_CH_NUM_SAMPLES_OFFSET 24
#define LRADC_CH_NUM_SAMPLES(x) \
((x) << LRADC_CH_NUM_SAMPLES_OFFSET)
#define LRADC_CH_VALUE_MASK 0x3ffff
#define LRADC_CH_VALUE_OFFSET 0
#define LRADC_DELAY(n) (0xd0 + (0x10 * (n)))
#define LRADC_DELAY_TRIGGER_LRADCS_MASK (0xff << 24)
#define LRADC_DELAY_TRIGGER_LRADCS_OFFSET 24
#define LRADC_DELAY_TRIGGER(x) \
(((x) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) & \
LRADC_DELAY_TRIGGER_LRADCS_MASK)
#define LRADC_DELAY_KICK (1 << 20)
#define LRADC_DELAY_TRIGGER_DELAYS_MASK (0xf << 16)
#define LRADC_DELAY_TRIGGER_DELAYS_OFFSET 16
#define LRADC_DELAY_TRIGGER_DELAYS(x) \
(((x) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) & \
LRADC_DELAY_TRIGGER_DELAYS_MASK)
#define LRADC_DELAY_LOOP_COUNT_MASK (0x1f << 11)
#define LRADC_DELAY_LOOP_COUNT_OFFSET 11
#define LRADC_DELAY_LOOP(x) \
(((x) << LRADC_DELAY_LOOP_COUNT_OFFSET) & \
LRADC_DELAY_LOOP_COUNT_MASK)
#define LRADC_DELAY_DELAY_MASK 0x7ff
#define LRADC_DELAY_DELAY_OFFSET 0
#define LRADC_DELAY_DELAY(x) \
(((x) << LRADC_DELAY_DELAY_OFFSET) & \
LRADC_DELAY_DELAY_MASK)
#define LRADC_CTRL4 0x140
#define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
@ -322,6 +359,404 @@ static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
}
static bool mxs_lradc_check_touch_event(struct mxs_lradc *lradc)
{
return !!(readl(lradc->base + LRADC_STATUS) &
LRADC_STATUS_TOUCH_DETECT_RAW);
}
static void mxs_lradc_setup_ts_channel(struct mxs_lradc *lradc, unsigned ch)
{
/*
* prepare for oversampling conversion
*
* from the datasheet:
* "The ACCUMULATE bit in the appropriate channel register
* HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
* otherwise, the IRQs will not fire."
*/
mxs_lradc_reg_wrt(lradc, LRADC_CH_ACCUMULATE |
LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1),
LRADC_CH(ch));
/* from the datasheet:
* "Software must clear this register in preparation for a
* multi-cycle accumulation.
*/
mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
/* prepare the delay/loop unit according to the oversampling count */
mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
LRADC_DELAY_TRIGGER_DELAYS(0) |
LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
LRADC_DELAY(3));
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(2) |
LRADC_CTRL1_LRADC_IRQ(3) | LRADC_CTRL1_LRADC_IRQ(4) |
LRADC_CTRL1_LRADC_IRQ(5), LRADC_CTRL1);
/* wake us again, when the complete conversion is done */
mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(ch), LRADC_CTRL1);
/*
* after changing the touchscreen plates setting
* the signals need some initial time to settle. Start the
* SoC's delay unit and start the conversion later
* and automatically.
*/
mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
LRADC_DELAY_TRIGGER_DELAYS(1 << 3) | /* trigger DELAY unit#3 */
LRADC_DELAY_KICK |
LRADC_DELAY_DELAY(lradc->settling_delay),
LRADC_DELAY(2));
}
/*
* Pressure detection is special:
* We want to do both required measurements for the pressure detection in
* one turn. Use the hardware features to chain both conversions and let the
* hardware report one interrupt if both conversions are done
*/
static void mxs_lradc_setup_ts_pressure(struct mxs_lradc *lradc, unsigned ch1,
unsigned ch2)
{
u32 reg;
/*
* prepare for oversampling conversion
*
* from the datasheet:
* "The ACCUMULATE bit in the appropriate channel register
* HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
* otherwise, the IRQs will not fire."
*/
reg = LRADC_CH_ACCUMULATE |
LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1);
mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch1));
mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch2));
/* from the datasheet:
* "Software must clear this register in preparation for a
* multi-cycle accumulation.
*/
mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
/* prepare the delay/loop unit according to the oversampling count */
mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch1) |
LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
LRADC_DELAY_TRIGGER_DELAYS(0) |
LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
LRADC_DELAY(3));
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(2) |
LRADC_CTRL1_LRADC_IRQ(3) | LRADC_CTRL1_LRADC_IRQ(4) |
LRADC_CTRL1_LRADC_IRQ(5), LRADC_CTRL1);
/* wake us again, when the conversions are done */
mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(ch2), LRADC_CTRL1);
/*
* after changing the touchscreen plates setting
* the signals need some initial time to settle. Start the
* SoC's delay unit and start the conversion later
* and automatically.
*/
mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
LRADC_DELAY_TRIGGER_DELAYS(1 << 3) | /* trigger DELAY unit#3 */
LRADC_DELAY_KICK |
LRADC_DELAY_DELAY(lradc->settling_delay), LRADC_DELAY(2));
}
static unsigned mxs_lradc_read_raw_channel(struct mxs_lradc *lradc,
unsigned channel)
{
u32 reg;
unsigned num_samples, val;
reg = readl(lradc->base + LRADC_CH(channel));
if (reg & LRADC_CH_ACCUMULATE)
num_samples = lradc->over_sample_cnt;
else
num_samples = 1;
val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
return val / num_samples;
}
static unsigned mxs_lradc_read_ts_pressure(struct mxs_lradc *lradc,
unsigned ch1, unsigned ch2)
{
u32 reg, mask;
unsigned pressure, m1, m2;
mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
reg = readl(lradc->base + LRADC_CTRL1) & mask;
while (reg != mask) {
reg = readl(lradc->base + LRADC_CTRL1) & mask;
dev_dbg(lradc->dev, "One channel is still busy: %X\n", reg);
}
m1 = mxs_lradc_read_raw_channel(lradc, ch1);
m2 = mxs_lradc_read_raw_channel(lradc, ch2);
if (m2 == 0) {
dev_warn(lradc->dev, "Cannot calculate pressure\n");
return 1 << (LRADC_RESOLUTION - 1);
}
/* simply scale the value from 0 ... max ADC resolution */
pressure = m1;
pressure *= (1 << LRADC_RESOLUTION);
pressure /= m2;
dev_dbg(lradc->dev, "Pressure = %u\n", pressure);
return pressure;
}
#define TS_CH_XP 2
#define TS_CH_YP 3
#define TS_CH_XM 4
#define TS_CH_YM 5
static int mxs_lradc_read_ts_channel(struct mxs_lradc *lradc)
{
u32 reg;
int val;
reg = readl(lradc->base + LRADC_CTRL1);
/* only channels 3 to 5 are of interest here */
if (reg & LRADC_CTRL1_LRADC_IRQ(TS_CH_YP)) {
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(TS_CH_YP) |
LRADC_CTRL1_LRADC_IRQ(TS_CH_YP), LRADC_CTRL1);
val = mxs_lradc_read_raw_channel(lradc, TS_CH_YP);
} else if (reg & LRADC_CTRL1_LRADC_IRQ(TS_CH_XM)) {
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(TS_CH_XM) |
LRADC_CTRL1_LRADC_IRQ(TS_CH_XM), LRADC_CTRL1);
val = mxs_lradc_read_raw_channel(lradc, TS_CH_XM);
} else if (reg & LRADC_CTRL1_LRADC_IRQ(TS_CH_YM)) {
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(TS_CH_YM) |
LRADC_CTRL1_LRADC_IRQ(TS_CH_YM), LRADC_CTRL1);
val = mxs_lradc_read_raw_channel(lradc, TS_CH_YM);
} else {
return -EIO;
}
mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
return val;
}
/*
* YP(open)--+-------------+
* | |--+
* | | |
* YM(-)--+-------------+ |
* +--------------+
* | |
* XP(weak+) XM(open)
*
* "weak+" means 200k Ohm VDDIO
* (-) means GND
*/
static void mxs_lradc_setup_touch_detection(struct mxs_lradc *lradc)
{
/*
* In order to detect a touch event the 'touch detect enable' bit
* enables:
* - a weak pullup to the X+ connector
* - a strong ground at the Y- connector
*/
mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
LRADC_CTRL0);
}
/*
* YP(meas)--+-------------+
* | |--+
* | | |
* YM(open)--+-------------+ |
* +--------------+
* | |
* XP(+) XM(-)
*
* (+) means here 1.85 V
* (-) means here GND
*/
static void mxs_lradc_prepare_x_pos(struct mxs_lradc *lradc)
{
mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
mxs_lradc_reg_set(lradc, mxs_lradc_drive_x_plate(lradc), LRADC_CTRL0);
lradc->cur_plate = LRADC_SAMPLE_X;
mxs_lradc_setup_ts_channel(lradc, TS_CH_YP);
}
/*
* YP(+)--+-------------+
* | |--+
* | | |
* YM(-)--+-------------+ |
* +--------------+
* | |
* XP(open) XM(meas)
*
* (+) means here 1.85 V
* (-) means here GND
*/
static void mxs_lradc_prepare_y_pos(struct mxs_lradc *lradc)
{
mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
mxs_lradc_reg_set(lradc, mxs_lradc_drive_y_plate(lradc), LRADC_CTRL0);
lradc->cur_plate = LRADC_SAMPLE_Y;
mxs_lradc_setup_ts_channel(lradc, TS_CH_XM);
}
/*
* YP(+)--+-------------+
* | |--+
* | | |
* YM(meas)--+-------------+ |
* +--------------+
* | |
* XP(meas) XM(-)
*
* (+) means here 1.85 V
* (-) means here GND
*/
static void mxs_lradc_prepare_pressure(struct mxs_lradc *lradc)
{
mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
mxs_lradc_reg_set(lradc, mxs_lradc_drive_pressure(lradc), LRADC_CTRL0);
lradc->cur_plate = LRADC_SAMPLE_PRESSURE;
mxs_lradc_setup_ts_pressure(lradc, TS_CH_XP, TS_CH_YM);
}
static void mxs_lradc_enable_touch_detection(struct mxs_lradc *lradc)
{
mxs_lradc_setup_touch_detection(lradc);
lradc->cur_plate = LRADC_TOUCH;
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
}
static void mxs_lradc_report_ts_event(struct mxs_lradc *lradc)
{
input_report_abs(lradc->ts_input, ABS_X, lradc->ts_x_pos);
input_report_abs(lradc->ts_input, ABS_Y, lradc->ts_y_pos);
input_report_abs(lradc->ts_input, ABS_PRESSURE, lradc->ts_pressure);
input_report_key(lradc->ts_input, BTN_TOUCH, 1);
input_sync(lradc->ts_input);
}
static void mxs_lradc_complete_touch_event(struct mxs_lradc *lradc)
{
mxs_lradc_setup_touch_detection(lradc);
lradc->cur_plate = LRADC_SAMPLE_VALID;
/*
* start a dummy conversion to burn time to settle the signals
* note: we are not interested in the conversion's value
*/
mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(5));
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(5), LRADC_CTRL1);
mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(5), LRADC_CTRL1);
mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << 5) |
LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
LRADC_DELAY(2));
}
/*
* in order to avoid false measurements, report only samples where
* the surface is still touched after the position measurement
*/
static void mxs_lradc_finish_touch_event(struct mxs_lradc *lradc, bool valid)
{
/* if it is still touched, report the sample */
if (valid && mxs_lradc_check_touch_event(lradc)) {
lradc->ts_valid = true;
mxs_lradc_report_ts_event(lradc);
}
/* if it is even still touched, continue with the next measurement */
if (mxs_lradc_check_touch_event(lradc)) {
mxs_lradc_prepare_y_pos(lradc);
return;
}
if (lradc->ts_valid) {
/* signal the release */
lradc->ts_valid = false;
input_report_key(lradc->ts_input, BTN_TOUCH, 0);
input_sync(lradc->ts_input);
}
/* if it is released, wait for the next touch via IRQ */
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ, LRADC_CTRL1);
mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
}
/* touchscreen's state machine */
static void mxs_lradc_handle_touch(struct mxs_lradc *lradc)
{
int val;
switch (lradc->cur_plate) {
case LRADC_TOUCH:
/*
* start with the Y-pos, because it uses nearly the same plate
* settings like the touch detection
*/
if (mxs_lradc_check_touch_event(lradc)) {
mxs_lradc_reg_clear(lradc,
LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
LRADC_CTRL1);
mxs_lradc_prepare_y_pos(lradc);
}
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
LRADC_CTRL1);
return;
case LRADC_SAMPLE_Y:
val = mxs_lradc_read_ts_channel(lradc);
if (val < 0) {
mxs_lradc_enable_touch_detection(lradc); /* re-start */
return;
}
lradc->ts_y_pos = val;
mxs_lradc_prepare_x_pos(lradc);
return;
case LRADC_SAMPLE_X:
val = mxs_lradc_read_ts_channel(lradc);
if (val < 0) {
mxs_lradc_enable_touch_detection(lradc); /* re-start */
return;
}
lradc->ts_x_pos = val;
mxs_lradc_prepare_pressure(lradc);
return;
case LRADC_SAMPLE_PRESSURE:
lradc->ts_pressure =
mxs_lradc_read_ts_pressure(lradc, TS_CH_XP, TS_CH_YM);
mxs_lradc_complete_touch_event(lradc);
return;
case LRADC_SAMPLE_VALID:
val = mxs_lradc_read_ts_channel(lradc); /* ignore the value */
mxs_lradc_finish_touch_event(lradc, 1);
break;
}
}
/*
* Raw I/O operations
*/
@ -395,15 +830,6 @@ static const struct iio_info mxs_lradc_iio_info = {
.read_raw = mxs_lradc_read_raw,
};
/*
* Touchscreen handling
*/
enum lradc_ts_plate {
LRADC_SAMPLE_X,
LRADC_SAMPLE_Y,
LRADC_SAMPLE_PRESSURE,
};
static int mxs_lradc_ts_touched(struct mxs_lradc *lradc)
{
uint32_t reg;
@ -561,10 +987,6 @@ static void mxs_lradc_ts_work(struct work_struct *ts_work)
input_report_key(lradc->ts_input, BTN_TOUCH, 0);
input_sync(lradc->ts_input);
/* Do not restart the TS IRQ if the driver is shutting down. */
if (lradc->stop_touchscreen)
return;
/* Restart the touchscreen interrupts. */
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ, LRADC_CTRL1);
mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
@ -574,36 +996,29 @@ static int mxs_lradc_ts_open(struct input_dev *dev)
{
struct mxs_lradc *lradc = input_get_drvdata(dev);
/* The touchscreen is starting. */
lradc->stop_touchscreen = false;
/* Enable the touch-detect circuitry. */
mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
LRADC_CTRL0);
/* Enable the touch-detect IRQ. */
mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
mxs_lradc_enable_touch_detection(lradc);
return 0;
}
static void mxs_lradc_disable_ts(struct mxs_lradc *lradc)
{
/* stop all interrupts from firing */
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
LRADC_CTRL1_LRADC_IRQ_EN(2) | LRADC_CTRL1_LRADC_IRQ_EN(3) |
LRADC_CTRL1_LRADC_IRQ_EN(4) | LRADC_CTRL1_LRADC_IRQ_EN(5),
LRADC_CTRL1);
/* Power-down touchscreen touch-detect circuitry. */
mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
}
static void mxs_lradc_ts_close(struct input_dev *dev)
{
struct mxs_lradc *lradc = input_get_drvdata(dev);
/* Indicate the touchscreen is stopping. */
lradc->stop_touchscreen = true;
mb();
/* Wait until touchscreen thread finishes any possible remnants. */
cancel_work_sync(&lradc->ts_work);
/* Disable touchscreen touch-detect IRQ. */
mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
LRADC_CTRL1);
/* Power-down touchscreen touch-detect circuitry. */
mxs_lradc_reg_clear(lradc, mxs_lradc_touch_detect_bit(lradc), LRADC_CTRL0);
mxs_lradc_disable_ts(lradc);
}
static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
@ -649,8 +1064,7 @@ static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
if (!lradc->use_touchscreen)
return;
cancel_work_sync(&lradc->ts_work);
mxs_lradc_disable_ts(lradc);
input_unregister_device(lradc->ts_input);
}
@ -663,22 +1077,17 @@ static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
struct mxs_lradc *lradc = iio_priv(iio);
unsigned long reg = readl(lradc->base + LRADC_CTRL1);
const uint32_t ts_irq_mask =
LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
LRADC_CTRL1_TOUCH_DETECT_IRQ;
LRADC_CTRL1_TOUCH_DETECT_IRQ |
LRADC_CTRL1_LRADC_IRQ(2) |
LRADC_CTRL1_LRADC_IRQ(3) |
LRADC_CTRL1_LRADC_IRQ(4) |
LRADC_CTRL1_LRADC_IRQ(5);
if (!(reg & mxs_lradc_irq_mask(lradc)))
return IRQ_NONE;
/*
* Touchscreen IRQ handling code has priority and therefore
* is placed here. In case touchscreen IRQ arrives, disable
* it ASAP
*/
if (reg & LRADC_CTRL1_TOUCH_DETECT_IRQ) {
mxs_lradc_reg_clear(lradc, ts_irq_mask, LRADC_CTRL1);
if (!lradc->stop_touchscreen)
schedule_work(&lradc->ts_work);
}
if (lradc->use_touchscreen && (reg & ts_irq_mask))
mxs_lradc_handle_touch(lradc);
if (iio_buffer_enabled(iio))
iio_trigger_poll(iio->trig, iio_get_time_ns());
@ -975,6 +1384,17 @@ static const struct of_device_id mxs_lradc_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
struct device_node *lradc_node)
{
/* TODO retrieve from device tree */
lradc->over_sample_cnt = 4;
lradc->over_sample_delay = 2;
lradc->settling_delay = 10;
return 0;
}
static int mxs_lradc_probe(struct platform_device *pdev)
{
const struct of_device_id *of_id =
@ -987,7 +1407,7 @@ static int mxs_lradc_probe(struct platform_device *pdev)
struct iio_dev *iio;
struct resource *iores;
uint32_t ts_wires = 0;
int ret = 0;
int ret = 0, touch_ret;
int i;
/* Allocate the IIO device. */
@ -1018,7 +1438,7 @@ static int mxs_lradc_probe(struct platform_device *pdev)
return ret;
}
INIT_WORK(&lradc->ts_work, mxs_lradc_ts_work);
touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
/* Check if touchscreen is enabled in DT. */
ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
@ -1081,9 +1501,11 @@ static int mxs_lradc_probe(struct platform_device *pdev)
goto err_dev;
/* Register the touchscreen input device. */
ret = mxs_lradc_ts_register(lradc);
if (ret)
goto err_ts_register;
if (touch_ret == 0) {
ret = mxs_lradc_ts_register(lradc);
if (ret)
goto err_ts_register;
}
/* Register IIO device. */
ret = iio_device_register(iio);