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    Subject[PATCH 3/3] input: touchscreen: mxs-lradc: Add support for touchscreen
    Date
    Add mxs-lradc touchscreen driver.

    Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
    ---
    drivers/input/touchscreen/Kconfig | 14 +-
    drivers/input/touchscreen/Makefile | 1 +
    drivers/input/touchscreen/mxs-lradc-ts.c | 729 +++++++++++++++++++++++++++++++
    3 files changed, 742 insertions(+), 2 deletions(-)
    create mode 100644 drivers/input/touchscreen/mxs-lradc-ts.c

    diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
    index 8ecdc38..d614d248 100644
    --- a/drivers/input/touchscreen/Kconfig
    +++ b/drivers/input/touchscreen/Kconfig
    @@ -566,7 +566,7 @@ config TOUCHSCREEN_HP600
    depends on SH_HP6XX && SH_ADC
    help
    Say Y here if you have a HP Jornada 620/660/680/690 and want to
    - support the built-in touchscreen.
    + support the built-in touchscreen.

    To compile this driver as a module, choose M here: the
    module will be called hp680_ts_input.
    @@ -685,7 +685,7 @@ config TOUCHSCREEN_UCB1400
    This enables support for the Philips UCB1400 touchscreen interface.
    The UCB1400 is an AC97 audio codec. The touchscreen interface
    will be initialized only after the ALSA subsystem has been
    - brought up and the UCB1400 detected. You therefore have to
    + brought up and the UCB1400 detected. You therefore have to
    configure ALSA support as well (either built-in or modular,
    independently of whether this driver is itself built-in or
    modular) for this driver to work.
    @@ -842,6 +842,16 @@ config TOUCHSCREEN_MX25
    To compile this driver as a module, choose M here: the
    module will be called fsl-imx25-tcq.

    +config TOUCHSCREEN_MXS_LRADC
    + tristate "Freescale i.MX23/i.MX28 LRADC touchscreen"
    + depends on MFD_MXS_LRADC
    + help
    + Say Y here if you have a touchscreen connected to the low-resolution
    + analog-to-digital converter (LRADC) on an i.MX23 or i.MX28 processor.
    +
    + To compile this driver as a module, choose M here: the module will be
    + called mxs-lradc-ts.
    +
    config TOUCHSCREEN_MC13783
    tristate "Freescale MC13783 touchscreen input driver"
    depends on MFD_MC13XXX
    diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
    index f42975e..513a6ff 100644
    --- a/drivers/input/touchscreen/Makefile
    +++ b/drivers/input/touchscreen/Makefile
    @@ -54,6 +54,7 @@ obj-$(CONFIG_TOUCHSCREEN_MIGOR) += migor_ts.o
    obj-$(CONFIG_TOUCHSCREEN_MMS114) += mms114.o
    obj-$(CONFIG_TOUCHSCREEN_MTOUCH) += mtouch.o
    obj-$(CONFIG_TOUCHSCREEN_MK712) += mk712.o
    +obj-$(CONFIG_TOUCHSCREEN_MXS_LRADC) += mxs-lradc-ts.o
    obj-$(CONFIG_TOUCHSCREEN_HP600) += hp680_ts_input.o
    obj-$(CONFIG_TOUCHSCREEN_HP7XX) += jornada720_ts.o
    obj-$(CONFIG_TOUCHSCREEN_IPAQ_MICRO) += ipaq-micro-ts.o
    diff --git a/drivers/input/touchscreen/mxs-lradc-ts.c b/drivers/input/touchscreen/mxs-lradc-ts.c
    new file mode 100644
    index 0000000..27abb8e
    --- /dev/null
    +++ b/drivers/input/touchscreen/mxs-lradc-ts.c
    @@ -0,0 +1,729 @@
    +/*
    + * Freescale MXS LRADC driver
    + *
    + * Copyright (c) 2012 DENX Software Engineering, GmbH.
    + * Marek Vasut <marex@denx.de>
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License as published by
    + * the Free Software Foundation; either version 2 of the License, or
    + * (at your option) any later version.
    + *
    + * This program is distributed in the hope that it will be useful,
    + * but WITHOUT ANY WARRANTY; without even the implied warranty of
    + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    + * GNU General Public License for more details.
    + */
    +
    +#include <linux/module.h>
    +#include <linux/mfd/mxs-lradc.h>
    +#include <linux/platform_device.h>
    +
    +/*
    + * Touchscreen handling
    + */
    +enum mxs_lradc_ts_plate {
    + LRADC_TOUCH = 0,
    + LRADC_SAMPLE_X,
    + LRADC_SAMPLE_Y,
    + LRADC_SAMPLE_PRESSURE,
    + LRADC_SAMPLE_VALID,
    +};
    +
    +struct mxs_lradc_ts {
    + struct mxs_lradc *lradc;
    + struct device *dev;
    + /*
    + * When the touchscreen is enabled, we give it two private virtual
    + * channels: #6 and #7. This means that only 6 virtual channels (instead
    + * of 8) will be available for buffered capture.
    + */
    +#define TOUCHSCREEN_VCHANNEL1 7
    +#define TOUCHSCREEN_VCHANNEL2 6
    +
    + struct input_dev *ts_input;
    +
    + enum mxs_lradc_ts_plate cur_plate; /* state machine */
    + 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;
    +};
    +
    +static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
    +{
    + if (lradc->soc == IMX23_LRADC)
    + return LRADC_CTRL0_MX23_PLATE_MASK;
    + return LRADC_CTRL0_MX28_PLATE_MASK;
    +}
    +
    +static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
    +{
    + if (lradc->soc == IMX23_LRADC)
    + return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
    + return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
    +}
    +
    +static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
    +{
    + if (lradc->soc == IMX23_LRADC)
    + return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
    + return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
    +}
    +
    +static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
    +{
    + if (lradc->soc == IMX23_LRADC)
    + return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
    + return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
    +}
    +
    +static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
    +{
    + if (lradc->soc == IMX23_LRADC)
    + return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
    + 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_map_ts_channel(struct mxs_lradc *lradc, unsigned vch,
    + unsigned ch)
    +{
    + mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(vch),
    + LRADC_CTRL4);
    + mxs_lradc_reg_set(lradc, LRADC_CTRL4_LRADCSELECT(vch, ch), LRADC_CTRL4);
    +}
    +
    +static void mxs_lradc_setup_ts_channel(struct mxs_lradc_ts *ts, unsigned ch)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + /*
    + * 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(ts->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
    + *
    + * from the datasheet:
    + * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
    + * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
    + * the LRADC will not trigger the delay group."
    + */
    + mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
    + LRADC_DELAY_TRIGGER_DELAYS(0) |
    + LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
    + LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
    + LRADC_DELAY(3));
    +
    + mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(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(BIT(3)) | /* trigger DELAY unit#3 */
    + LRADC_DELAY_KICK |
    + LRADC_DELAY_DELAY(ts->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_ts *ts, unsigned ch1,
    + unsigned ch2)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    + 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(ts->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(ts->over_sample_cnt - 1) |
    + LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
    + LRADC_DELAY(3));
    +
    + mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(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(BIT(3)) | /* trigger DELAY unit#3 */
    + LRADC_DELAY_KICK |
    + LRADC_DELAY_DELAY(ts->settling_delay), LRADC_DELAY(2));
    +}
    +
    +static unsigned mxs_lradc_ts_read_raw_channel(struct mxs_lradc_ts *ts,
    + unsigned channel)
    +{
    + u32 reg;
    + unsigned num_samples, val;
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + reg = readl(lradc->base + LRADC_CH(channel));
    + if (reg & LRADC_CH_ACCUMULATE)
    + num_samples = ts->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_ts *ts,
    + unsigned ch1, unsigned ch2)
    +{
    + u32 reg, mask;
    + unsigned pressure, m1, m2;
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + 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(ts->dev, "One channel is still busy: %X\n", reg);
    + }
    +
    + m1 = mxs_lradc_ts_read_raw_channel(ts, ch1);
    + m2 = mxs_lradc_ts_read_raw_channel(ts, ch2);
    +
    + if (m2 == 0) {
    + dev_warn(ts->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(ts->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
    +
    +/*
    + * YP(open)--+-------------+
    + * | |--+
    + * | | |
    + * YM(-)--+-------------+ |
    + * +--------------+
    + * | |
    + * XP(weak+) XM(open)
    + *
    + * "weak+" means 200k Ohm VDDIO
    + * (-) means GND
    + */
    +static void mxs_lradc_setup_touch_detection(struct mxs_lradc_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->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_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->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);
    +
    + ts->cur_plate = LRADC_SAMPLE_X;
    + mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
    + mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
    +}
    +
    +/*
    + * YP(+)--+-------------+
    + * | |--+
    + * | | |
    + * YM(-)--+-------------+ |
    + * +--------------+
    + * | |
    + * XP(open) XM(meas)
    + *
    + * (+) means here 1.85 V
    + * (-) means here GND
    + */
    +static void mxs_lradc_prepare_y_pos(struct mxs_lradc_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->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);
    +
    + ts->cur_plate = LRADC_SAMPLE_Y;
    + mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
    + mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
    +}
    +
    +/*
    + * YP(+)--+-------------+
    + * | |--+
    + * | | |
    + * YM(meas)--+-------------+ |
    + * +--------------+
    + * | |
    + * XP(meas) XM(-)
    + *
    + * (+) means here 1.85 V
    + * (-) means here GND
    + */
    +static void mxs_lradc_prepare_pressure(struct mxs_lradc_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->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);
    +
    + ts->cur_plate = LRADC_SAMPLE_PRESSURE;
    + mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
    + mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
    + mxs_lradc_setup_ts_pressure(ts, TOUCHSCREEN_VCHANNEL2,
    + TOUCHSCREEN_VCHANNEL1);
    +}
    +
    +static void mxs_lradc_enable_touch_detection(struct mxs_lradc_ts *ts)
    +{
    + mxs_lradc_setup_touch_detection(ts);
    +
    + ts->cur_plate = LRADC_TOUCH;
    + mxs_lradc_reg_clear(ts->lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
    + LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
    + mxs_lradc_reg_set(ts->lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
    + LRADC_CTRL1);
    +}
    +
    +static void mxs_lradc_start_touch_event(struct mxs_lradc_ts *ts)
    +{
    + mxs_lradc_reg_clear(ts->lradc,
    + LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
    + LRADC_CTRL1);
    + mxs_lradc_reg_set(ts->lradc,
    + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1),
    + LRADC_CTRL1);
    + /*
    + * start with the Y-pos, because it uses nearly the same plate
    + * settings like the touch detection
    + */
    + mxs_lradc_prepare_y_pos(ts);
    +}
    +
    +static void mxs_lradc_report_ts_event(struct mxs_lradc_ts *ts)
    +{
    + input_report_abs(ts->ts_input, ABS_X, ts->ts_x_pos);
    + input_report_abs(ts->ts_input, ABS_Y, ts->ts_y_pos);
    + input_report_abs(ts->ts_input, ABS_PRESSURE, ts->ts_pressure);
    + input_report_key(ts->ts_input, BTN_TOUCH, 1);
    + input_sync(ts->ts_input);
    +}
    +
    +static void mxs_lradc_complete_touch_event(struct mxs_lradc_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + mxs_lradc_setup_touch_detection(ts);
    + ts->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(TOUCHSCREEN_VCHANNEL1));
    + mxs_lradc_reg_clear(lradc,
    + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
    + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2),
    + LRADC_CTRL1);
    + mxs_lradc_reg_wrt(
    + lradc,
    + LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
    + 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_ts *ts, bool valid)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + /* if it is still touched, report the sample */
    + if (valid && mxs_lradc_check_touch_event(lradc)) {
    + ts->ts_valid = true;
    + mxs_lradc_report_ts_event(ts);
    + }
    +
    + /* if it is even still touched, continue with the next measurement */
    + if (mxs_lradc_check_touch_event(lradc)) {
    + mxs_lradc_prepare_y_pos(ts);
    + return;
    + }
    +
    + if (ts->ts_valid) {
    + /* signal the release */
    + ts->ts_valid = false;
    + input_report_key(ts->ts_input, BTN_TOUCH, 0);
    + input_sync(ts->ts_input);
    + }
    +
    + /* if it is released, wait for the next touch via IRQ */
    + ts->cur_plate = LRADC_TOUCH;
    + mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
    + mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
    + mxs_lradc_reg_clear(lradc,
    + LRADC_CTRL1_TOUCH_DETECT_IRQ |
    + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
    + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1),
    + 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_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + switch (ts->cur_plate) {
    + case LRADC_TOUCH:
    + if (mxs_lradc_check_touch_event(lradc))
    + mxs_lradc_start_touch_event(ts);
    + mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
    + LRADC_CTRL1);
    + return;
    +
    + case LRADC_SAMPLE_Y:
    + ts->ts_y_pos =
    + mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
    + mxs_lradc_prepare_x_pos(ts);
    + return;
    +
    + case LRADC_SAMPLE_X:
    + ts->ts_x_pos =
    + mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
    + mxs_lradc_prepare_pressure(ts);
    + return;
    +
    + case LRADC_SAMPLE_PRESSURE:
    + ts->ts_pressure =
    + mxs_lradc_read_ts_pressure(ts,
    + TOUCHSCREEN_VCHANNEL2,
    + TOUCHSCREEN_VCHANNEL1);
    + mxs_lradc_complete_touch_event(ts);
    + return;
    +
    + case LRADC_SAMPLE_VALID:
    + mxs_lradc_finish_touch_event(ts, 1);
    + break;
    + }
    +}
    +
    +/*
    + * IRQ Handling
    + */
    +static irqreturn_t mxs_lradc_ts_handle_irq(int irq, void *data)
    +{
    + struct mxs_lradc_ts *ts = data;
    + struct mxs_lradc *lradc = ts->lradc;
    + unsigned long reg = readl(lradc->base + LRADC_CTRL1);
    + u32 clr_irq = mxs_lradc_irq_mask(lradc);
    + const u32 ts_irq_mask =
    + LRADC_CTRL1_TOUCH_DETECT_IRQ |
    + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
    + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
    +
    + if (!(reg & mxs_lradc_irq_mask(lradc)))
    + return IRQ_NONE;
    +
    + if (lradc->use_touchscreen && (reg & ts_irq_mask)) {
    + mxs_lradc_handle_touch(ts);
    +
    + /* Make sure we don't clear the next conversion's interrupt. */
    + clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
    + LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
    + mxs_lradc_reg_clear(lradc, reg & clr_irq, LRADC_CTRL1);
    + }
    +
    + return IRQ_HANDLED;
    +}
    +
    +static int mxs_lradc_ts_open(struct input_dev *dev)
    +{
    + struct mxs_lradc_ts *ts = input_get_drvdata(dev);
    +
    + /* Enable the touch-detect circuitry. */
    + mxs_lradc_enable_touch_detection(ts);
    +
    + return 0;
    +}
    +
    +static void mxs_lradc_disable_ts(struct mxs_lradc_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + /* stop all interrupts from firing */
    + mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
    + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
    + LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), 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_ts *ts = input_get_drvdata(dev);
    +
    + mxs_lradc_disable_ts(ts);
    +}
    +
    +static void mxs_lradc_ts_hw_init(struct mxs_lradc_ts *ts)
    +{
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + /* Configure the touchscreen type */
    + if (lradc->soc == IMX28_LRADC) {
    + mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
    + LRADC_CTRL0);
    +
    + if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
    + mxs_lradc_reg_set(lradc,
    + LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
    + LRADC_CTRL0);
    + }
    +}
    +
    +static void mxs_lradc_ts_hw_stop(struct mxs_lradc_ts *ts)
    +{
    + int i;
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + mxs_lradc_reg_clear(lradc,
    + lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
    + LRADC_CTRL1);
    +
    + for (i = 1; i < LRADC_MAX_DELAY_CHANS; i++)
    + mxs_lradc_reg_wrt(ts->lradc, 0, LRADC_DELAY(i));
    +}
    +
    +static int mxs_lradc_ts_register(struct mxs_lradc_ts *ts)
    +{
    + struct input_dev *input = ts->ts_input;
    + struct device *dev = ts->dev;
    + struct mxs_lradc *lradc = ts->lradc;
    +
    + if (!lradc->use_touchscreen)
    + return 0;
    +
    + input->name = DRIVER_NAME_TS;
    + input->id.bustype = BUS_HOST;
    + input->dev.parent = dev;
    + input->open = mxs_lradc_ts_open;
    + input->close = mxs_lradc_ts_close;
    +
    + __set_bit(EV_ABS, input->evbit);
    + __set_bit(EV_KEY, input->evbit);
    + __set_bit(BTN_TOUCH, input->keybit);
    + __set_bit(INPUT_PROP_DIRECT, input->propbit);
    + input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
    + input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
    + input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
    + 0, 0);
    +
    + ts->ts_input = input;
    + input_set_drvdata(input, ts);
    +
    + return input_register_device(input);
    +}
    +
    +static int mxs_lradc_ts_probe(struct platform_device *pdev)
    +{
    + struct device *dev = &pdev->dev;
    + struct device_node *node = dev->parent->of_node;
    + struct mxs_lradc *lradc = dev_get_platdata(dev);
    + struct mxs_lradc_ts *ts;
    + struct input_dev *input;
    + int touch_ret, ret, i;
    + u32 ts_wires = 0, adapt;
    +
    + ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
    + input = devm_input_allocate_device(dev);
    + if (!ts || !input)
    + return -ENOMEM;
    +
    + ts->lradc = lradc;
    + ts->dev = dev;
    + ts->ts_input = input;
    + platform_set_drvdata(pdev, ts);
    + input_set_drvdata(input, ts);
    +
    + touch_ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
    + &ts_wires);
    +
    + if (of_property_read_u32(node, "fsl,ave-ctrl", &adapt)) {
    + ts->over_sample_cnt = 4;
    + } else {
    + if (adapt < 1 || adapt > 32) {
    + dev_err(ts->dev, "Invalid sample count (%u)\n",
    + adapt);
    + touch_ret = -EINVAL;
    + } else {
    + ts->over_sample_cnt = adapt;
    + }
    + }
    +
    + if (of_property_read_u32(node, "fsl,ave-delay", &adapt)) {
    + ts->over_sample_delay = 2;
    + } else {
    + if (adapt < 2 || adapt > LRADC_DELAY_DELAY_MASK + 1) {
    + dev_err(ts->dev, "Invalid sample delay (%u)\n",
    + adapt);
    + touch_ret = -EINVAL;
    + } else {
    + ts->over_sample_delay = adapt;
    + }
    + }
    +
    + if (of_property_read_u32(node, "fsl,settling", &adapt)) {
    + ts->settling_delay = 10;
    + } else {
    + if (adapt < 1 || adapt > LRADC_DELAY_DELAY_MASK) {
    + dev_err(ts->dev, "Invalid settling delay (%u)\n",
    + adapt);
    + touch_ret = -EINVAL;
    + } else {
    + ts->settling_delay = adapt;
    + }
    + }
    +
    + mxs_lradc_ts_hw_init(ts);
    + for (i = 0; i < lradc->irq_count; i++) {
    + ret = devm_request_irq(dev, lradc->irq[i],
    + mxs_lradc_ts_handle_irq,
    + IRQF_SHARED, lradc->irq_name[i], ts);
    + if (ret)
    + return ret;
    + }
    +
    + if (!touch_ret) {
    + ret = mxs_lradc_ts_register(ts);
    + if (!ret)
    + goto err_ts_register;
    + }
    +
    + return 0;
    +
    +err_ts_register:
    + mxs_lradc_ts_hw_stop(ts);
    + return ret;
    +}
    +
    +static int mxs_lradc_ts_remove(struct platform_device *pdev)
    +{
    + struct mxs_lradc_ts *ts = platform_get_drvdata(pdev);
    +
    + mxs_lradc_ts_hw_stop(ts);
    +
    + return 0;
    +}
    +
    +static struct platform_driver mxs_lradc_ts_driver = {
    + .driver = {
    + .name = DRIVER_NAME_TS,
    + },
    + .probe = mxs_lradc_ts_probe,
    + .remove = mxs_lradc_ts_remove,
    +};
    +module_platform_driver(mxs_lradc_ts_driver);
    +
    +MODULE_LICENSE("GPL v2");
    --
    1.9.1
    \
     
     \ /
      Last update: 2016-04-29 14:21    [W:8.584 / U:0.020 seconds]
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