input: touchscreen: mxs-lradc: Add support for touchscreen (d81ca730) · Commits · 戴 / test

drivers/input/touchscreen/Kconfig

+10 −0

Original line number	Diff line number	Diff line
		@@ -829,6 +829,16 @@ config TOUCHSCREEN_USB_COMPOSITE
		To compile this driver as a module, choose M here: the
		module will be called usbtouchscreen.

		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_MX25
		tristate "Freescale i.MX25 touchscreen input driver"
		depends on MFD_MX25_TSADC

drivers/input/touchscreen/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -45,6 +45,7 @@ obj-$(CONFIG_TOUCHSCREEN_INEXIO) += inexio.o
		obj-$(CONFIG_TOUCHSCREEN_IPROC) += bcm_iproc_tsc.o
		obj-$(CONFIG_TOUCHSCREEN_LPC32XX) += lpc32xx_ts.o
		obj-$(CONFIG_TOUCHSCREEN_MAX11801) += max11801_ts.o
		obj-$(CONFIG_TOUCHSCREEN_MXS_LRADC) += mxs-lradc-ts.o
		obj-$(CONFIG_TOUCHSCREEN_MX25) += fsl-imx25-tcq.o
		obj-$(CONFIG_TOUCHSCREEN_MC13783) += mc13783_ts.o
		obj-$(CONFIG_TOUCHSCREEN_MCS5000) += mcs5000_ts.o

drivers/input/touchscreen/mxs-lradc-ts.c

0 → 100644

+714 −0

Original line number	Diff line number	Diff line
		/*
		* Freescale MXS LRADC touchscreen driver
		*
		* Copyright (c) 2012 DENX Software Engineering, GmbH.
		* Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
		*
		* Authors:
		* Marek Vasut <marex@denx.de>
		* Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
		*
		* 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/device.h>
		#include <linux/err.h>
		#include <linux/input.h>
		#include <linux/interrupt.h>
		#include <linux/module.h>
		#include <linux/mfd/core.h>
		#include <linux/mfd/mxs-lradc.h>
		#include <linux/of.h>
		#include <linux/of_irq.h>
		#include <linux/platform_device.h>

		const char *mxs_lradc_ts_irq_names[] = {
		"mxs-lradc-touchscreen",
		"mxs-lradc-channel6",
		"mxs-lradc-channel7",
		};

		/*
		* 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;

		void __iomem *base;
		/*
		* 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 int ts_x_pos;
		unsigned int ts_y_pos;
		unsigned int ts_pressure;

		/* handle touchscreen's physical behaviour */
		/* samples per coordinate */
		unsigned int over_sample_cnt;
		/* time clocks between samples */
		unsigned int over_sample_delay;
		/* time in clocks to wait after the plates where switched */
		unsigned int settling_delay;
		spinlock_t lock;
		};

		struct state_info {
		u32 mask;
		u32 bit;
		u32 x_plate;
		u32 y_plate;
		u32 pressure;
		};

		static struct state_info info[] = {
		{LRADC_CTRL0_MX23_PLATE_MASK, LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE,
		LRADC_CTRL0_MX23_XP \| LRADC_CTRL0_MX23_XM,
		LRADC_CTRL0_MX23_YP \| LRADC_CTRL0_MX23_YM,
		LRADC_CTRL0_MX23_YP \| LRADC_CTRL0_MX23_XM},
		{LRADC_CTRL0_MX28_PLATE_MASK, LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE,
		LRADC_CTRL0_MX28_XPPSW \| LRADC_CTRL0_MX28_XNNSW,
		LRADC_CTRL0_MX28_YPPSW \| LRADC_CTRL0_MX28_YNNSW,
		LRADC_CTRL0_MX28_YPPSW \| LRADC_CTRL0_MX28_XNNSW}
		};

		static bool mxs_lradc_check_touch_event(struct mxs_lradc_ts *ts)
		{
		return !!(readl(ts->base + LRADC_STATUS) &
		LRADC_STATUS_TOUCH_DETECT_RAW);
		}

		static void mxs_lradc_map_ts_channel(struct mxs_lradc_ts *ts, unsigned int vch,
		unsigned int ch)
		{
		writel(LRADC_CTRL4_LRADCSELECT_MASK(vch),
		ts->base + LRADC_CTRL4 + STMP_OFFSET_REG_CLR);
		writel(LRADC_CTRL4_LRADCSELECT(vch, ch),
		ts->base + LRADC_CTRL4 + STMP_OFFSET_REG_SET);
		}

		static void mxs_lradc_setup_ts_channel(struct mxs_lradc_ts *ts, unsigned int 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."
		*/
		writel(LRADC_CH_ACCUMULATE \|
		LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1),
		ts->base + LRADC_CH(ch));

		/* from the datasheet:
		* "Software must clear this register in preparation for a
		* multi-cycle accumulation.
		*/
		writel(LRADC_CH_VALUE_MASK,
		ts->base + LRADC_CH(ch) + STMP_OFFSET_REG_CLR);

		/*
		* 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."
		*/
		writel(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),
		ts->base + LRADC_DELAY(3));

		writel(LRADC_CTRL1_LRADC_IRQ(ch),
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

		/*
		* 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.
		*/
		writel(LRADC_DELAY_TRIGGER(0) \| LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) \|
		LRADC_DELAY_KICK \| LRADC_DELAY_DELAY(ts->settling_delay),
		ts->base + 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 int ch1, unsigned int 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(ts->over_sample_cnt - 1);
		writel(reg, ts->base + LRADC_CH(ch1));
		writel(reg, ts->base + LRADC_CH(ch2));

		/* from the datasheet:
		* "Software must clear this register in preparation for a
		* multi-cycle accumulation.
		*/
		writel(LRADC_CH_VALUE_MASK,
		ts->base + LRADC_CH(ch1) + STMP_OFFSET_REG_CLR);
		writel(LRADC_CH_VALUE_MASK,
		ts->base + LRADC_CH(ch2) + STMP_OFFSET_REG_CLR);

		/* prepare the delay/loop unit according to the oversampling count */
		writel(LRADC_DELAY_TRIGGER(1 << ch1) \| LRADC_DELAY_TRIGGER(1 << ch2) \|
		LRADC_DELAY_TRIGGER_DELAYS(0) \|
		LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) \|
		LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
		ts->base + LRADC_DELAY(3));

		writel(LRADC_CTRL1_LRADC_IRQ(ch2),
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

		/*
		* 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.
		*/
		writel(LRADC_DELAY_TRIGGER(0) \| LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) \|
		LRADC_DELAY_KICK \| LRADC_DELAY_DELAY(ts->settling_delay),
		ts->base + LRADC_DELAY(2));
		}

		static unsigned int mxs_lradc_ts_read_raw_channel(struct mxs_lradc_ts *ts,
		unsigned int channel)
		{
		u32 reg;
		unsigned int num_samples, val;

		reg = readl(ts->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 int mxs_lradc_read_ts_pressure(struct mxs_lradc_ts *ts,
		unsigned int ch1, unsigned int ch2)
		{
		u32 reg, mask;
		unsigned int pressure, m1, m2;

		mask = LRADC_CTRL1_LRADC_IRQ(ch1) \| LRADC_CTRL1_LRADC_IRQ(ch2);
		reg = readl(ts->base + LRADC_CTRL1) & mask;

		while (reg != mask) {
		reg = readl(ts->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
		*/
		writel(info[lradc->soc].mask,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
		writel(info[lradc->soc].bit,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
		}

		/*
		* 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;

		writel(info[lradc->soc].mask,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
		writel(info[lradc->soc].x_plate,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);

		ts->cur_plate = LRADC_SAMPLE_X;
		mxs_lradc_map_ts_channel(ts, 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;

		writel(info[lradc->soc].mask,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
		writel(info[lradc->soc].y_plate,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);

		ts->cur_plate = LRADC_SAMPLE_Y;
		mxs_lradc_map_ts_channel(ts, 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;

		writel(info[lradc->soc].mask,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);
		writel(info[lradc->soc].pressure,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);

		ts->cur_plate = LRADC_SAMPLE_PRESSURE;
		mxs_lradc_map_ts_channel(ts, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
		mxs_lradc_map_ts_channel(ts, 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;
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ \| LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
		}

		static void mxs_lradc_start_touch_event(struct mxs_lradc_ts *ts)
		{
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
		writel(LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1),
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
		/*
		* 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)
		{
		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
		*/
		writel(0, ts->base + LRADC_CH(TOUCHSCREEN_VCHANNEL1));
		writel(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) \|
		LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2),
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
		writel(LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) \|
		LRADC_DELAY_KICK \| LRADC_DELAY_DELAY(10),
		ts->base + 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)
		{
		/* if it is still touched, report the sample */
		if (valid && mxs_lradc_check_touch_event(ts)) {
		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(ts)) {
		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;
		writel(0, ts->base + LRADC_DELAY(2));
		writel(0, ts->base + LRADC_DELAY(3));
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ \|
		LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) \|
		LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1),
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_SET);
		}

		/* touchscreen's state machine */
		static void mxs_lradc_handle_touch(struct mxs_lradc_ts *ts)
		{
		switch (ts->cur_plate) {
		case LRADC_TOUCH:
		if (mxs_lradc_check_touch_event(ts))
		mxs_lradc_start_touch_event(ts);
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
		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(ts->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);
		unsigned long flags;

		if (!(reg & mxs_lradc_irq_mask(lradc)))
		return IRQ_NONE;

		if (reg & ts_irq_mask) {
		spin_lock_irqsave(&ts->lock, flags);
		mxs_lradc_handle_touch(ts);
		spin_unlock_irqrestore(&ts->lock, flags);
		/* 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));
		writel(reg & clr_irq,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);
		}

		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_ts_stop(struct mxs_lradc_ts *ts)
		{
		int i;
		struct mxs_lradc *lradc = ts->lradc;

		/* stop all interrupts from firing */
		writel(LRADC_CTRL1_TOUCH_DETECT_IRQ_EN \|
		LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) \|
		LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2),
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

		/* Power-down touchscreen touch-detect circuitry. */
		writel(info[lradc->soc].mask,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);

		writel(lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
		ts->base + LRADC_CTRL1 + STMP_OFFSET_REG_CLR);

		for (i = 1; i < LRADC_MAX_DELAY_CHANS; i++)
		writel(0, ts->base + LRADC_DELAY(i));
		}

		static void mxs_lradc_ts_close(struct input_dev *dev)
		{
		struct mxs_lradc_ts *ts = input_get_drvdata(dev);

		mxs_lradc_ts_stop(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) {
		writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_CLR);

		if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
		writel(LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
		ts->base + LRADC_CTRL0 + STMP_OFFSET_REG_SET);
		}
		}

		static int mxs_lradc_ts_register(struct mxs_lradc_ts *ts)
		{
		struct input_dev *input = ts->ts_input;
		struct device *dev = ts->dev;

		input = devm_input_allocate_device(dev);
		if (!input)
		return -ENOMEM;

		input->name = "mxs-lradc-ts";
		input->id.bustype = BUS_HOST;
		input->open = mxs_lradc_ts_open;
		input->close = mxs_lradc_ts_close;

		__set_bit(INPUT_PROP_DIRECT, input->propbit);
		input_set_capability(input, EV_KEY, BTN_TOUCH);
		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_drvdata(dev->parent);
		struct mxs_lradc_ts *ts;
		struct resource *iores;
		int ret, irq, virq, i;
		u32 ts_wires = 0, adapt;

		ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
		if (!ts)
		return -ENOMEM;

		platform_set_drvdata(pdev, ts);

		ts->lradc = lradc;
		ts->dev = dev;
		spin_lock_init(&ts->lock);

		iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		ts->base = devm_ioremap(dev, iores->start, resource_size(iores));
		if (IS_ERR(ts->base))
		return PTR_ERR(ts->base);

		ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
		&ts_wires);
		if (ret)
		return ret;

		if (of_property_read_u32(node, "fsl,ave-ctrl", &adapt)) {
		ts->over_sample_cnt = 4;
		} else {
		if (adapt >= 1 \|\| adapt <= 32) {
		ts->over_sample_cnt = adapt;
		} else {
		dev_err(ts->dev, "Invalid sample count (%u)\n",
		adapt);
		return -EINVAL;
		}
		}

		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) {
		ts->over_sample_delay = adapt;
		} else {
		dev_err(ts->dev, "Invalid sample delay (%u)\n",
		adapt);
		return -EINVAL;
		}
		}

		if (of_property_read_u32(node, "fsl,settling", &adapt)) {
		ts->settling_delay = 10;
		} else {
		if (adapt >= 1 \|\| adapt <= LRADC_DELAY_DELAY_MASK) {
		ts->settling_delay = adapt;
		} else {
		dev_err(ts->dev, "Invalid settling delay (%u)\n",
		adapt);
		return -EINVAL;
		}
		}

		ret = stmp_reset_block(ts->base);
		if (ret)
		return ret;

		mxs_lradc_ts_hw_init(ts);

		for (i = 0; i < 3; i++) {
		irq = platform_get_irq_byname(pdev, mxs_lradc_ts_irq_names[i]);
		if (irq < 0)
		return irq;

		virq = irq_of_parse_and_map(node, irq);

		mxs_lradc_ts_stop(ts);

		ret = devm_request_irq(dev, virq,
		mxs_lradc_ts_handle_irq,
		0, mxs_lradc_ts_irq_names[i], ts);
		if (ret)
		return ret;
		}

		return mxs_lradc_ts_register(ts);
		}

		static struct platform_driver mxs_lradc_ts_driver = {
		.driver = {
		.name = "mxs-lradc-ts",
		},
		.probe = mxs_lradc_ts_probe,
		};
		module_platform_driver(mxs_lradc_ts_driver);

		MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
		MODULE_DESCRIPTION("Freescale MXS LRADC touchscreen driver");
		MODULE_LICENSE("GPL");
		MODULE_ALIAS("platform:mxs-lradc-ts");

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