[PATCH v6 6/8] input: touchscreen: imx25 tcq driver

[Markus Pargmann <mpa@pengutronix.de>]

This is a driver for the imx25 ADC/TSC module. It controls the
touchscreen conversion queue and creates a touchscreen input device.
The driver currently only supports 4 wire touchscreens. The driver uses
a simple conversion queue of precharge, touch detection, X measurement,
Y measurement, precharge and another touch detection.

This driver uses the regmap from the parent to setup some touch specific
settings in the core driver and setup a idle configuration with touch
detection.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Denis Carikli <denis@eukrea.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
---
 drivers/input/touchscreen/Kconfig         |   6 +
 drivers/input/touchscreen/Makefile        |   1 +
 drivers/input/touchscreen/fsl-imx25-tcq.c | 587 ++++++++++++++++++++++++++++++
 3 files changed, 594 insertions(+)
 create mode 100644 drivers/input/touchscreen/fsl-imx25-tcq.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 58917525126e..f1534a0cd23f 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -748,6 +748,12 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MX25
+	tristate "Freescale i.MX25 touchscreen input driver"
+	depends on MFD_MX25_TSADC
+	help
+	  Enable support for touchscreen connected to your i.MX25.
+
 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 0242fea2102a..bbb55a69c33c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)	+= intel-mid-touch.o
 obj-$(CONFIG_TOUCHSCREEN_LPC32XX)	+= lpc32xx_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MAX11801)	+= max11801_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MX25)		+= fsl-imx25-tcq.o
 obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o
diff --git a/drivers/input/touchscreen/fsl-imx25-tcq.c b/drivers/input/touchscreen/fsl-imx25-tcq.c
new file mode 100644
index 000000000000..2eb3bd00d56c
--- /dev/null
+++ b/drivers/input/touchscreen/fsl-imx25-tcq.c
@@ -0,0 +1,587 @@
+/*
+ * Copyright 2014 Markus Pargmann, Pengutronix <mpa@pengutronix.de>
+ * Based on driver from 2011:
+ *   Juergen Beisert, Pengutronix <kernel@pengutronix.de>
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * This is the driver for the imx25 TCQ (Touchscreen Conversion Queue)
+ * connected to the imx25 ADC.
+ */
+
+#include <linux/clk.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/imx25-tsadc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static const char mx25_tcq_name[] = "mx25-tcq";
+
+enum mx25_tcq_mode {
+	MX25_TS_4WIRE,
+};
+
+struct mx25_tcq_priv {
+	struct regmap *regs;
+	struct regmap *core_regs;
+	struct input_dev *idev;
+	enum mx25_tcq_mode mode;
+	unsigned int pen_threshold;
+	unsigned int sample_count;
+	unsigned int expected_samples;
+	unsigned int pen_debounce;
+	unsigned int settling_time;
+	struct clk *clk;
+	int irq;
+};
+
+static struct regmap_config mx25_tcq_regconfig = {
+	.fast_io = true,
+	.max_register = 0x5c,
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+};
+
+static struct of_device_id mx25_tcq_ids[] = {
+	{ .compatible = "fsl,imx25-tcq", },
+	{ /* Sentinel */ }
+};
+
+#define TSC_4WIRE_PRE_INDEX 0
+#define TSC_4WIRE_X_INDEX 1
+#define TSC_4WIRE_Y_INDEX 2
+#define TSC_4WIRE_POST_INDEX 3
+#define TSC_4WIRE_LEAVE 4
+
+#define MX25_TSC_DEF_THRESHOLD 80
+#define TSC_MAX_SAMPLES 16
+
+#define MX25_TSC_REPEAT_WAIT 14
+
+enum mx25_adc_configurations {
+	MX25_CFG_PRECHARGE = 0,
+	MX25_CFG_TOUCH_DETECT,
+	MX25_CFG_X_MEASUREMENT,
+	MX25_CFG_Y_MEASUREMENT,
+};
+
+#define MX25_PRECHARGE_VALUE (\
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_HIGH | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_IGS)
+
+#define MX25_TOUCH_DETECT_VALUE (\
+			MX25_ADCQ_CFG_YNLR | \
+			MX25_ADCQ_CFG_YPLL_OFF | \
+			MX25_ADCQ_CFG_XNUR_OFF | \
+			MX25_ADCQ_CFG_XPUL_OFF | \
+			MX25_ADCQ_CFG_REFP_INT | \
+			MX25_ADCQ_CFG_IN_XP | \
+			MX25_ADCQ_CFG_REFN_NGND2 | \
+			MX25_ADCQ_CFG_PENIACK)
+
+static void imx25_setup_queue_cfgs(struct mx25_tcq_priv *priv,
+				   unsigned int settling_time)
+{
+	u32 precharge_cfg =
+			MX25_PRECHARGE_VALUE |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+	u32 touch_detect_cfg =
+			MX25_TOUCH_DETECT_VALUE |
+			MX25_ADCQ_CFG_NOS(1) |
+			MX25_ADCQ_CFG_SETTLING_TIME(settling_time);
+
+	regmap_write(priv->core_regs, MX25_TSC_TICR, precharge_cfg);
+
+	/* PRECHARGE */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_PRECHARGE),
+		     precharge_cfg);
+
+	/* TOUCH_DETECT */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_TOUCH_DETECT),
+		     touch_detect_cfg);
+
+	/* X Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_X_MEASUREMENT),
+		     MX25_ADCQ_CFG_YPLL_OFF |
+		     MX25_ADCQ_CFG_XNUR_LOW |
+		     MX25_ADCQ_CFG_XPUL_HIGH |
+		     MX25_ADCQ_CFG_REFP_XP |
+		     MX25_ADCQ_CFG_IN_YP |
+		     MX25_ADCQ_CFG_REFN_XN |
+		     MX25_ADCQ_CFG_NOS(priv->sample_count) |
+		     MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Y Measurement */
+	regmap_write(priv->regs, MX25_ADCQ_CFG(MX25_CFG_Y_MEASUREMENT),
+		     MX25_ADCQ_CFG_YNLR |
+		     MX25_ADCQ_CFG_YPLL_HIGH |
+		     MX25_ADCQ_CFG_XNUR_OFF |
+		     MX25_ADCQ_CFG_XPUL_OFF |
+		     MX25_ADCQ_CFG_REFP_YP |
+		     MX25_ADCQ_CFG_IN_XP |
+		     MX25_ADCQ_CFG_REFN_YN |
+		     MX25_ADCQ_CFG_NOS(priv->sample_count) |
+		     MX25_ADCQ_CFG_SETTLING_TIME(settling_time));
+
+	/* Enable the touch detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, touch_detect_cfg |
+		     MX25_ADCQ_CFG_IGS);
+}
+
+static int imx25_setup_queue_4wire(struct mx25_tcq_priv *priv,
+				   unsigned settling_time, int *items)
+{
+	imx25_setup_queue_cfgs(priv, settling_time);
+
+	/* Setup the conversion queue */
+	regmap_write(priv->regs, MX25_ADCQ_ITEM_7_0,
+		     MX25_ADCQ_ITEM(0, MX25_CFG_PRECHARGE) |
+		     MX25_ADCQ_ITEM(1, MX25_CFG_TOUCH_DETECT) |
+		     MX25_ADCQ_ITEM(2, MX25_CFG_X_MEASUREMENT) |
+		     MX25_ADCQ_ITEM(3, MX25_CFG_Y_MEASUREMENT) |
+		     MX25_ADCQ_ITEM(4, MX25_CFG_PRECHARGE) |
+		     MX25_ADCQ_ITEM(5, MX25_CFG_TOUCH_DETECT));
+
+	/* We measure X/Y with 'sample_count' number of samples and execute a
+	 * touch detection twice, with 1 sample each */
+	priv->expected_samples = priv->sample_count * 2 + 2;
+	*items = 6;
+
+	return 0;
+}
+
+static void mx25_tcq_disable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK,
+			   MX25_ADCQ_CR_PDMSK);
+}
+
+static void mx25_tcq_enable_touch_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_PDMSK, 0);
+}
+
+static void mx25_tcq_disable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ,
+			   MX25_ADCQ_MR_FDRY_IRQ);
+}
+
+static void mx25_tcq_enable_fifo_irq(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_FDRY_IRQ, 0);
+}
+
+static void mx25_tcq_force_queue_start(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_FQS,
+			   MX25_ADCQ_CR_FQS);
+}
+
+static void mx25_tcq_force_queue_stop(struct mx25_tcq_priv *priv)
+{
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_FQS, 0);
+}
+
+static void mx25_tcq_fifo_reset(struct mx25_tcq_priv *priv)
+{
+	u32 tcqcr;
+
+	regmap_read(priv->regs, MX25_ADCQ_CR, &tcqcr);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST,
+			   MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_FRST, 0);
+	regmap_write(priv->regs, MX25_ADCQ_CR, tcqcr);
+}
+
+static void mx25_tcq_re_enable_touch_detection(struct mx25_tcq_priv *priv)
+{
+	/* stop the queue from looping */
+	mx25_tcq_force_queue_stop(priv);
+
+	/* for a clean touch detection, preload the X plane */
+	regmap_write(priv->core_regs, MX25_TSC_TICR, MX25_PRECHARGE_VALUE);
+
+	/* waste some time now to pre-load the X plate to high voltage */
+	mx25_tcq_fifo_reset(priv);
+
+	/* re-enable the detection right now */
+	regmap_write(priv->core_regs, MX25_TSC_TICR,
+		     MX25_TOUCH_DETECT_VALUE | MX25_ADCQ_CFG_IGS);
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_PD,
+			   MX25_ADCQ_SR_PD);
+
+	/* enable the pen down event to be a source for the interrupt */
+	regmap_update_bits(priv->regs, MX25_ADCQ_MR, MX25_ADCQ_MR_PD_IRQ, 0);
+
+	/* lets fire the next IRQ if someone touches the touchscreen */
+	mx25_tcq_enable_touch_irq(priv);
+}
+
+static int mx25_tcq_create_event_for_4wire(struct mx25_tcq_priv *priv,
+					   u32 *sample_buf,
+					   unsigned int samples)
+{
+	unsigned int x_pos = 0;
+	unsigned int y_pos = 0;
+	unsigned int touch_pre = 0;
+	unsigned int touch_post = 0;
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < samples; i++) {
+		unsigned int index = MX25_ADCQ_FIFO_ID(sample_buf[i]);
+		unsigned int val = MX25_ADCQ_FIFO_DATA(sample_buf[i]);
+
+		switch (index) {
+		case 1:
+			touch_pre = val;
+			break;
+		case 2:
+			x_pos = val;
+			break;
+		case 3:
+			y_pos = val;
+			break;
+		case 5:
+			touch_post = val;
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	if (ret == 0 && samples != 0) {
+		/*
+		 * only if both touch measures are below a threshold,
+		 * the position is valid
+		 */
+		if (touch_pre < priv->pen_threshold &&
+		    touch_post < priv->pen_threshold) {
+			/* valid samples, generate a report */
+			x_pos /= priv->sample_count;
+			y_pos /= priv->sample_count;
+			input_report_abs(priv->idev, ABS_X, x_pos);
+			input_report_abs(priv->idev, ABS_Y, y_pos);
+			input_report_key(priv->idev, BTN_TOUCH, 1);
+			input_sync(priv->idev);
+
+			/* get next sample */
+			mx25_tcq_enable_fifo_irq(priv);
+		} else if (touch_pre >= priv->pen_threshold &&
+			   touch_post >= priv->pen_threshold) {
+			/*
+			 * if both samples are invalid,
+			 * generate a release report
+			 */
+			input_report_key(priv->idev, BTN_TOUCH, 0);
+			input_sync(priv->idev);
+			mx25_tcq_re_enable_touch_detection(priv);
+		} else {
+			/*
+			 * if only one of both touch measurements are
+			 * below the threshold, still some bouncing
+			 * happens. Take additional samples in this
+			 * case to be sure
+			 */
+			mx25_tcq_enable_fifo_irq(priv);
+		}
+	}
+
+	return ret;
+}
+
+static irqreturn_t mx25_tcq_irq_thread(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = dev_id;
+	u32 sample_buf[TSC_MAX_SAMPLES];
+	unsigned int samples = 0;
+
+	/* read all samples */
+	while (1) {
+		u32 stats;
+
+		regmap_read(priv->regs, MX25_ADCQ_SR, &stats);
+		if (stats & MX25_ADCQ_SR_EMPT)
+			break;
+
+		if (samples < TSC_MAX_SAMPLES) {
+			regmap_read(priv->regs, MX25_ADCQ_FIFO,
+				    &sample_buf[samples]);
+			++samples;
+		} else {
+			u32 discarded;
+			/* discard samples */
+			regmap_read(priv->regs, MX25_ADCQ_FIFO, &discarded);
+		}
+	}
+
+	mx25_tcq_create_event_for_4wire(priv, sample_buf, samples);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t mx25_tcq_irq(int irq, void *dev_id)
+{
+	struct mx25_tcq_priv *priv = dev_id;
+	u32 stat;
+	int ret = IRQ_HANDLED;
+
+	regmap_read(priv->regs, MX25_ADCQ_SR, &stat);
+
+	if (stat & (MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR))
+		mx25_tcq_fifo_reset(priv);
+
+	if (stat & MX25_ADCQ_SR_PD) {
+		mx25_tcq_disable_touch_irq(priv);
+		mx25_tcq_force_queue_start(priv);
+		mx25_tcq_enable_fifo_irq(priv);
+	}
+
+	if (stat & MX25_ADCQ_SR_FDRY) {
+		mx25_tcq_disable_fifo_irq(priv);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_SR, MX25_ADCQ_SR_FRR |
+			   MX25_ADCQ_SR_FUR | MX25_ADCQ_SR_FOR |
+			   MX25_ADCQ_SR_PD | MX25_ADCQ_SR_EOQ,
+			   MX25_ADCQ_SR_FRR | MX25_ADCQ_SR_FUR |
+			   MX25_ADCQ_SR_FOR | MX25_ADCQ_SR_PD |
+			   MX25_ADCQ_SR_EOQ);
+
+	return ret;
+}
+
+/* configure the statemachine for a 4-wire touchscreen */
+static int mx25_tcq_init(struct mx25_tcq_priv *priv)
+{
+	u32 tgcr;
+	unsigned int ipg_div;
+	unsigned int adc_period;
+	unsigned int debounce_cnt;
+	unsigned int settling_time;
+	int itemct;
+	int ret;
+
+	regmap_read(priv->core_regs, MX25_TSC_TGCR, &tgcr);
+	ipg_div = max_t(unsigned int, 4, MX25_TGCR_GET_ADCCLK(tgcr));
+	adc_period = clk_get_rate(priv->clk) / (ipg_div * 2 + 2);
+	debounce_cnt = DIV_ROUND_UP(priv->pen_debounce, adc_period * 8) - 1;
+	settling_time = DIV_ROUND_UP(priv->settling_time, adc_period);
+
+	/* Reset */
+	regmap_write(priv->regs, MX25_ADCQ_CR,
+		     MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST);
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_QRST | MX25_ADCQ_CR_FRST, 0);
+
+	/* up to 128 * 8 ADC clocks are possible */
+	if (debounce_cnt > 127)
+		debounce_cnt = 127;
+
+	ret = imx25_setup_queue_4wire(priv, settling_time, &itemct);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_LITEMID_MASK | MX25_ADCQ_CR_WMRK_MASK,
+			   MX25_ADCQ_CR_LITEMID(itemct - 1) |
+			   MX25_ADCQ_CR_WMRK(priv->expected_samples - 1));
+
+	/* setup debounce count */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR,
+			   MX25_TGCR_PDBTIME_MASK,
+			   MX25_TGCR_PDBTIME(debounce_cnt));
+
+	/* enable debounce */
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDBEN,
+			   MX25_TGCR_PDBEN);
+	regmap_update_bits(priv->core_regs, MX25_TSC_TGCR, MX25_TGCR_PDEN,
+			   MX25_TGCR_PDEN);
+
+	/* enable the engine on demand */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR, MX25_ADCQ_CR_QSM_MASK,
+			   MX25_ADCQ_CR_QSM_FQS);
+
+	/* Enable repeat and repeat wait */
+	regmap_update_bits(priv->regs, MX25_ADCQ_CR,
+			   MX25_ADCQ_CR_RPT | MX25_ADCQ_CR_RWAIT_MASK,
+			   MX25_ADCQ_CR_RPT |
+			   MX25_ADCQ_CR_RWAIT(MX25_TSC_REPEAT_WAIT));
+
+	mx25_tcq_re_enable_touch_detection(priv);
+
+	return 0;
+}
+
+static int mx25_tcq_parse_dt(struct platform_device *pdev,
+			     struct mx25_tcq_priv *priv)
+{
+	struct device_node *np = pdev->dev.of_node;
+	u32 wires;
+	int ret;
+
+	/* Setup defaults */
+	priv->pen_threshold = 500;
+	priv->sample_count = 3;
+	priv->pen_debounce = 1000000;
+	priv->settling_time = 250000;
+
+	ret = of_property_read_u32(np, "fsl,wires", &wires);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to find fsl,wires properties\n");
+		return ret;
+	}
+
+	if (wires == 4) {
+		priv->mode = MX25_TS_4WIRE;
+	} else {
+		dev_err(&pdev->dev, "%u-wire mode not supported\n", wires);
+		return -EINVAL;
+	}
+
+	/* These are optional, we don't care about the return values */
+	of_property_read_u32(np, "fsl,pen-threshold", &priv->pen_threshold);
+	of_property_read_u32(np, "fsl,settling-time", &priv->settling_time);
+	of_property_read_u32(np, "fsl,pen-debounce", &priv->pen_debounce);
+
+	return 0;
+}
+
+static int mx25_tcq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct input_dev *idev;
+	struct mx25_tcq_priv *priv;
+	struct mx25_tsadc *tsadc = dev_get_drvdata(pdev->dev.parent);
+	struct resource *res;
+	void __iomem *mem;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mem = devm_ioremap_resource(dev, res);
+	if (!mem)
+		return -ENOMEM;
+
+	ret = mx25_tcq_parse_dt(pdev, priv);
+	if (ret)
+		return ret;
+
+	priv->regs = devm_regmap_init_mmio(dev, mem, &mx25_tcq_regconfig);
+	if (IS_ERR(priv->regs)) {
+		dev_err(dev, "Failed to initialize regmap\n");
+		return PTR_ERR(priv->regs);
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq <= 0) {
+		dev_err(dev, "Failed to get IRQ\n");
+		return priv->irq;
+	}
+
+	idev = devm_input_allocate_device(dev);
+	if (!idev) {
+		dev_err(dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	idev->name = mx25_tcq_name;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
+
+	idev->id.bustype = BUS_HOST;
+
+	ret = input_register_device(idev);
+	if (ret) {
+		dev_err(dev, "Failed to register input device\n");
+		return ret;
+	}
+
+	priv->idev = idev;
+
+	priv->core_regs = tsadc->regs;
+	if (!priv->core_regs)
+		return -EINVAL;
+
+	priv->clk = tsadc->clk;
+	if (!priv->clk)
+		return -EINVAL;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable ipg clock\n");
+		return ret;
+	}
+
+	ret = request_threaded_irq(priv->irq, mx25_tcq_irq, mx25_tcq_irq_thread,
+				   IRQF_ONESHOT, pdev->name, priv);
+	if (ret) {
+		dev_err(dev, "Failed requesting IRQ\n");
+		goto err_clk_unprepare;
+	}
+
+	ret = mx25_tcq_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to init tcq\n");
+		goto error_free_irq;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+
+error_free_irq:
+	free_irq(priv->irq, priv);
+err_clk_unprepare:
+	clk_disable_unprepare(priv->clk);
+	return ret;
+}
+
+static int mx25_tcq_remove(struct platform_device *pdev)
+{
+	struct mx25_tcq_priv *priv = platform_get_drvdata(pdev);
+
+	free_irq(priv->irq, priv);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static struct platform_driver mx25_tcq_driver = {
+	.driver		= {
+		.name	= "mx25-tcq",
+		.of_match_table = mx25_tcq_ids,
+	},
+	.probe		= mx25_tcq_probe,
+	.remove		= mx25_tcq_remove,
+};
+module_platform_driver(mx25_tcq_driver);
+
+MODULE_DESCRIPTION("TS input driver for Freescale mx25");
+MODULE_AUTHOR("Markus Pargmann <mpa@pengutronix.de>");
+MODULE_LICENSE("GPL v2");
-- 
2.1.4