Input: touchscreen - add imx6ul_tsc driver support
authorHaibo Chen <haibo.chen@freescale.com>
Sat, 5 Sep 2015 18:31:21 +0000 (11:31 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Sat, 5 Sep 2015 18:49:33 +0000 (11:49 -0700)
Freescale i.MX6UL contains a internal touchscreen controller,
this patch add a driver to support this controller.

Signed-off-by: Haibo Chen <haibo.chen@freescale.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt [new file with mode: 0644]
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/imx6ul_tsc.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt b/Documentation/devicetree/bindings/input/touchscreen/imx6ul_tsc.txt
new file mode 100644 (file)
index 0000000..853dff9
--- /dev/null
@@ -0,0 +1,36 @@
+* Freescale i.MX6UL Touch Controller
+
+Required properties:
+- compatible: must be "fsl,imx6ul-tsc".
+- reg: this touch controller address and the ADC2 address.
+- interrupts: the interrupt of this touch controller and ADC2.
+- clocks: the root clock of touch controller and ADC2.
+- clock-names; must be "tsc" and "adc".
+- xnur-gpio: the X- gpio this controller connect to.
+  This xnur-gpio returns to low once the finger leave the touch screen (The
+  last touch event the touch controller capture).
+
+Optional properties:
+- measure-delay-time: the value of measure delay time.
+  Before X-axis or Y-axis measurement, the screen need some time before
+  even potential distribution ready.
+  This value depends on the touch screen.
+- pre-charge-time: the touch screen need some time to precharge.
+  This value depends on the touch screen.
+
+Example:
+       tsc: tsc@02040000 {
+               compatible = "fsl,imx6ul-tsc";
+               reg = <0x02040000 0x4000>, <0x0219c000 0x4000>;
+               interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>,
+                            <GIC_SPI 101 IRQ_TYPE_LEVEL_HIGH>;
+               clocks = <&clks IMX6UL_CLK_IPG>,
+                        <&clks IMX6UL_CLK_ADC2>;
+               clock-names = "tsc", "adc";
+               pinctrl-names = "default";
+               pinctrl-0 = <&pinctrl_tsc>;
+               xnur-gpio = <&gpio1 3 GPIO_ACTIVE_LOW>;
+               measure-delay-time = <0xfff>;
+               pre-charge-time = <0xffff>;
+               status = "okay";
+       };
index a6d7a4d..600dcce 100644 (file)
@@ -479,6 +479,18 @@ config TOUCHSCREEN_MTOUCH
          To compile this driver as a module, choose M here: the
          module will be called mtouch.
 
+config TOUCHSCREEN_IMX6UL_TSC
+       tristate "Freescale i.MX6UL touchscreen controller"
+       depends on (OF && GPIOLIB) || COMPILE_TEST
+       help
+         Say Y here if you have a Freescale i.MX6UL, and want to
+         use the internal touchscreen controller.
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called imx6ul_tsc.
+
 config TOUCHSCREEN_INEXIO
        tristate "iNexio serial touchscreens"
        select SERIO
index fb27f7e..1b79cc0 100644 (file)
@@ -38,6 +38,7 @@ obj-$(CONFIG_TOUCHSCREEN_EGALAX)      += egalax_ts.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)      += fujitsu_ts.o
 obj-$(CONFIG_TOUCHSCREEN_GOODIX)       += goodix.o
 obj-$(CONFIG_TOUCHSCREEN_ILI210X)      += ili210x.o
+obj-$(CONFIG_TOUCHSCREEN_IMX6UL_TSC)   += imx6ul_tsc.o
 obj-$(CONFIG_TOUCHSCREEN_INEXIO)       += inexio.o
 obj-$(CONFIG_TOUCHSCREEN_INTEL_MID)    += intel-mid-touch.o
 obj-$(CONFIG_TOUCHSCREEN_IPROC)                += bcm_iproc_tsc.o
diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
new file mode 100644 (file)
index 0000000..ff0b758
--- /dev/null
@@ -0,0 +1,523 @@
+/*
+ * Freescale i.MX6UL touchscreen controller driver
+ *
+ * Copyright (C) 2015 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/gpio/consumer.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/of.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+/* ADC configuration registers field define */
+#define ADC_AIEN               (0x1 << 7)
+#define ADC_CONV_DISABLE       0x1F
+#define ADC_CAL                        (0x1 << 7)
+#define ADC_CALF               0x2
+#define ADC_12BIT_MODE         (0x2 << 2)
+#define ADC_IPG_CLK            0x00
+#define ADC_CLK_DIV_8          (0x03 << 5)
+#define ADC_SHORT_SAMPLE_MODE  (0x0 << 4)
+#define ADC_HARDWARE_TRIGGER   (0x1 << 13)
+#define SELECT_CHANNEL_4       0x04
+#define SELECT_CHANNEL_1       0x01
+#define DISABLE_CONVERSION_INT (0x0 << 7)
+
+/* ADC registers */
+#define REG_ADC_HC0            0x00
+#define REG_ADC_HC1            0x04
+#define REG_ADC_HC2            0x08
+#define REG_ADC_HC3            0x0C
+#define REG_ADC_HC4            0x10
+#define REG_ADC_HS             0x14
+#define REG_ADC_R0             0x18
+#define REG_ADC_CFG            0x2C
+#define REG_ADC_GC             0x30
+#define REG_ADC_GS             0x34
+
+#define ADC_TIMEOUT            msecs_to_jiffies(100)
+
+/* TSC registers */
+#define REG_TSC_BASIC_SETING   0x00
+#define REG_TSC_PRE_CHARGE_TIME        0x10
+#define REG_TSC_FLOW_CONTROL   0x20
+#define REG_TSC_MEASURE_VALUE  0x30
+#define REG_TSC_INT_EN         0x40
+#define REG_TSC_INT_SIG_EN     0x50
+#define REG_TSC_INT_STATUS     0x60
+#define REG_TSC_DEBUG_MODE     0x70
+#define REG_TSC_DEBUG_MODE2    0x80
+
+/* TSC configuration registers field define */
+#define DETECT_4_WIRE_MODE     (0x0 << 4)
+#define AUTO_MEASURE           0x1
+#define MEASURE_SIGNAL         0x1
+#define DETECT_SIGNAL          (0x1 << 4)
+#define VALID_SIGNAL           (0x1 << 8)
+#define MEASURE_INT_EN         0x1
+#define MEASURE_SIG_EN         0x1
+#define VALID_SIG_EN           (0x1 << 8)
+#define DE_GLITCH_2            (0x2 << 29)
+#define START_SENSE            (0x1 << 12)
+#define TSC_DISABLE            (0x1 << 16)
+#define DETECT_MODE            0x2
+
+struct imx6ul_tsc {
+       struct device *dev;
+       struct input_dev *input;
+       void __iomem *tsc_regs;
+       void __iomem *adc_regs;
+       struct clk *tsc_clk;
+       struct clk *adc_clk;
+       struct gpio_desc *xnur_gpio;
+
+       int measure_delay_time;
+       int pre_charge_time;
+
+       struct completion completion;
+};
+
+/*
+ * TSC module need ADC to get the measure value. So
+ * before config TSC, we should initialize ADC module.
+ */
+static void imx6ul_adc_init(struct imx6ul_tsc *tsc)
+{
+       int adc_hc = 0;
+       int adc_gc;
+       int adc_gs;
+       int adc_cfg;
+       int timeout;
+
+       reinit_completion(&tsc->completion);
+
+       adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
+       adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
+       adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
+       adc_cfg &= ~ADC_HARDWARE_TRIGGER;
+       writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
+
+       /* enable calibration interrupt */
+       adc_hc |= ADC_AIEN;
+       adc_hc |= ADC_CONV_DISABLE;
+       writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
+
+       /* start ADC calibration */
+       adc_gc = readl(tsc->adc_regs + REG_ADC_GC);
+       adc_gc |= ADC_CAL;
+       writel(adc_gc, tsc->adc_regs + REG_ADC_GC);
+
+       timeout = wait_for_completion_timeout
+                       (&tsc->completion, ADC_TIMEOUT);
+       if (timeout == 0)
+               dev_err(tsc->dev, "Timeout for adc calibration\n");
+
+       adc_gs = readl(tsc->adc_regs + REG_ADC_GS);
+       if (adc_gs & ADC_CALF)
+               dev_err(tsc->dev, "ADC calibration failed\n");
+
+       /* TSC need the ADC work in hardware trigger */
+       adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
+       adc_cfg |= ADC_HARDWARE_TRIGGER;
+       writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
+}
+
+/*
+ * This is a TSC workaround. Currently TSC misconnect two
+ * ADC channels, this function remap channel configure for
+ * hardware trigger.
+ */
+static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
+{
+       int adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
+
+       adc_hc0 = DISABLE_CONVERSION_INT;
+       writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
+
+       adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
+       writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
+
+       adc_hc2 = DISABLE_CONVERSION_INT;
+       writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
+
+       adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
+       writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
+
+       adc_hc4 = DISABLE_CONVERSION_INT;
+       writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
+}
+
+/*
+ * TSC setting, confige the pre-charge time and measure delay time.
+ * different touch screen may need different pre-charge time and
+ * measure delay time.
+ */
+static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
+{
+       int basic_setting = 0;
+       int start;
+
+       basic_setting |= tsc->measure_delay_time << 8;
+       basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
+       writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
+
+       writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
+
+       writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
+       writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
+       writel(MEASURE_SIG_EN | VALID_SIG_EN,
+               tsc->tsc_regs + REG_TSC_INT_SIG_EN);
+
+       /* start sense detection */
+       start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
+       start |= START_SENSE;
+       start &= ~TSC_DISABLE;
+       writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
+}
+
+static void imx6ul_tsc_init(struct imx6ul_tsc *tsc)
+{
+       imx6ul_adc_init(tsc);
+       imx6ul_tsc_channel_config(tsc);
+       imx6ul_tsc_set(tsc);
+}
+
+static void imx6ul_tsc_disable(struct imx6ul_tsc *tsc)
+{
+       int tsc_flow;
+       int adc_cfg;
+
+       /* TSC controller enters to idle status */
+       tsc_flow = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
+       tsc_flow |= TSC_DISABLE;
+       writel(tsc_flow, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
+
+       /* ADC controller enters to stop mode */
+       adc_cfg = readl(tsc->adc_regs + REG_ADC_HC0);
+       adc_cfg |= ADC_CONV_DISABLE;
+       writel(adc_cfg, tsc->adc_regs + REG_ADC_HC0);
+}
+
+/* Delay some time (max 2ms), wait the pre-charge done. */
+static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
+{
+       unsigned long timeout = jiffies + msecs_to_jiffies(2);
+       int state_machine;
+       int debug_mode2;
+
+       do {
+               if (time_after(jiffies, timeout))
+                       return false;
+
+               usleep_range(200, 400);
+               debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
+               state_machine = (debug_mode2 >> 20) & 0x7;
+       } while (state_machine != DETECT_MODE);
+
+       usleep_range(200, 400);
+       return true;
+}
+
+static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
+{
+       struct imx6ul_tsc *tsc = dev_id;
+       int status;
+       int value;
+       int x, y;
+       int start;
+
+       status = readl(tsc->tsc_regs + REG_TSC_INT_STATUS);
+
+       /* write 1 to clear the bit measure-signal */
+       writel(MEASURE_SIGNAL | DETECT_SIGNAL,
+               tsc->tsc_regs + REG_TSC_INT_STATUS);
+
+       /* It's a HW self-clean bit. Set this bit and start sense detection */
+       start = readl(tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
+       start |= START_SENSE;
+       writel(start, tsc->tsc_regs + REG_TSC_FLOW_CONTROL);
+
+       if (status & MEASURE_SIGNAL) {
+               value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
+               x = (value >> 16) & 0x0fff;
+               y = value & 0x0fff;
+
+               /*
+                * In detect mode, we can get the xnur gpio value,
+                * otherwise assume contact is stiull active.
+                */
+               if (!tsc_wait_detect_mode(tsc) ||
+                   gpiod_get_value_cansleep(tsc->xnur_gpio)) {
+                       input_report_key(tsc->input, BTN_TOUCH, 1);
+                       input_report_abs(tsc->input, ABS_X, x);
+                       input_report_abs(tsc->input, ABS_Y, y);
+               } else {
+                       input_report_key(tsc->input, BTN_TOUCH, 0);
+               }
+
+               input_sync(tsc->input);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static irqreturn_t adc_irq_fn(int irq, void *dev_id)
+{
+       struct imx6ul_tsc *tsc = dev_id;
+       int coco;
+       int value;
+
+       coco = readl(tsc->adc_regs + REG_ADC_HS);
+       if (coco & 0x01) {
+               value = readl(tsc->adc_regs + REG_ADC_R0);
+               complete(&tsc->completion);
+       }
+
+       return IRQ_HANDLED;
+}
+
+static int imx6ul_tsc_open(struct input_dev *input_dev)
+{
+       struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
+       int err;
+
+       err = clk_prepare_enable(tsc->adc_clk);
+       if (err) {
+               dev_err(tsc->dev,
+                       "Could not prepare or enable the adc clock: %d\n",
+                       err);
+               return err;
+       }
+
+       err = clk_prepare_enable(tsc->tsc_clk);
+       if (err) {
+               dev_err(tsc->dev,
+                       "Could not prepare or enable the tsc clock: %d\n",
+                       err);
+               clk_disable_unprepare(tsc->adc_clk);
+               return err;
+       }
+
+       imx6ul_tsc_init(tsc);
+
+       return 0;
+}
+
+static void imx6ul_tsc_close(struct input_dev *input_dev)
+{
+       struct imx6ul_tsc *tsc = input_get_drvdata(input_dev);
+
+       imx6ul_tsc_disable(tsc);
+
+       clk_disable_unprepare(tsc->tsc_clk);
+       clk_disable_unprepare(tsc->adc_clk);
+}
+
+static int imx6ul_tsc_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct imx6ul_tsc *tsc;
+       struct input_dev *input_dev;
+       struct resource *tsc_mem;
+       struct resource *adc_mem;
+       int err;
+       int tsc_irq;
+       int adc_irq;
+
+       tsc = devm_kzalloc(&pdev->dev, sizeof(struct imx6ul_tsc), GFP_KERNEL);
+       if (!tsc)
+               return -ENOMEM;
+
+       input_dev = devm_input_allocate_device(&pdev->dev);
+       if (!input_dev)
+               return -ENOMEM;
+
+       input_dev->name = "iMX6UL TouchScreen Controller";
+       input_dev->id.bustype = BUS_HOST;
+
+       input_dev->open = imx6ul_tsc_open;
+       input_dev->close = imx6ul_tsc_close;
+
+       input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+       input_set_abs_params(input_dev, ABS_X, 0, 0xFFF, 0, 0);
+       input_set_abs_params(input_dev, ABS_Y, 0, 0xFFF, 0, 0);
+
+       input_set_drvdata(input_dev, tsc);
+
+       tsc->dev = &pdev->dev;
+       tsc->input = input_dev;
+       init_completion(&tsc->completion);
+
+       tsc->xnur_gpio = devm_gpiod_get(&pdev->dev, "xnur", GPIOD_IN);
+       if (IS_ERR(tsc->xnur_gpio)) {
+               err = PTR_ERR(tsc->xnur_gpio);
+               dev_err(&pdev->dev,
+                       "failed to request GPIO tsc_X- (xnur): %d\n", err);
+               return err;
+       }
+
+       tsc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       tsc->tsc_regs = devm_ioremap_resource(&pdev->dev, tsc_mem);
+       if (IS_ERR(tsc->tsc_regs)) {
+               err = PTR_ERR(tsc->tsc_regs);
+               dev_err(&pdev->dev, "failed to remap tsc memory: %d\n", err);
+               return err;
+       }
+
+       adc_mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+       tsc->adc_regs = devm_ioremap_resource(&pdev->dev, adc_mem);
+       if (IS_ERR(tsc->adc_regs)) {
+               err = PTR_ERR(tsc->adc_regs);
+               dev_err(&pdev->dev, "failed to remap adc memory: %d\n", err);
+               return err;
+       }
+
+       tsc->tsc_clk = devm_clk_get(&pdev->dev, "tsc");
+       if (IS_ERR(tsc->tsc_clk)) {
+               err = PTR_ERR(tsc->tsc_clk);
+               dev_err(&pdev->dev, "failed getting tsc clock: %d\n", err);
+               return err;
+       }
+
+       tsc->adc_clk = devm_clk_get(&pdev->dev, "adc");
+       if (IS_ERR(tsc->adc_clk)) {
+               err = PTR_ERR(tsc->adc_clk);
+               dev_err(&pdev->dev, "failed getting adc clock: %d\n", err);
+               return err;
+       }
+
+       tsc_irq = platform_get_irq(pdev, 0);
+       if (tsc_irq < 0) {
+               dev_err(&pdev->dev, "no tsc irq resource?\n");
+               return tsc_irq;
+       }
+
+       adc_irq = platform_get_irq(pdev, 1);
+       if (adc_irq <= 0) {
+               dev_err(&pdev->dev, "no adc irq resource?\n");
+               return adc_irq;
+       }
+
+       err = devm_request_threaded_irq(tsc->dev, tsc_irq,
+                                       NULL, tsc_irq_fn, IRQF_ONESHOT,
+                                       dev_name(&pdev->dev), tsc);
+       if (err) {
+               dev_err(&pdev->dev,
+                       "failed requesting tsc irq %d: %d\n",
+                       tsc_irq, err);
+               return err;
+       }
+
+       err = devm_request_irq(tsc->dev, adc_irq, adc_irq_fn, 0,
+                               dev_name(&pdev->dev), tsc);
+       if (err) {
+               dev_err(&pdev->dev,
+                       "failed requesting adc irq %d: %d\n",
+                       adc_irq, err);
+               return err;
+       }
+
+       err = of_property_read_u32(np, "measure-delay-time",
+                                  &tsc->measure_delay_time);
+       if (err)
+               tsc->measure_delay_time = 0xffff;
+
+       err = of_property_read_u32(np, "pre-charge-time",
+                                  &tsc->pre_charge_time);
+       if (err)
+               tsc->pre_charge_time = 0xfff;
+
+       err = input_register_device(tsc->input);
+       if (err) {
+               dev_err(&pdev->dev,
+                       "failed to register input device: %d\n", err);
+               return err;
+       }
+
+       platform_set_drvdata(pdev, tsc);
+       return 0;
+}
+
+static int __maybe_unused imx6ul_tsc_suspend(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
+       struct input_dev *input_dev = tsc->input;
+
+       mutex_lock(&input_dev->mutex);
+
+       if (input_dev->users) {
+               imx6ul_tsc_disable(tsc);
+
+               clk_disable_unprepare(tsc->tsc_clk);
+               clk_disable_unprepare(tsc->adc_clk);
+       }
+
+       mutex_unlock(&input_dev->mutex);
+
+       return 0;
+}
+
+static int __maybe_unused imx6ul_tsc_resume(struct device *dev)
+{
+       struct platform_device *pdev = to_platform_device(dev);
+       struct imx6ul_tsc *tsc = platform_get_drvdata(pdev);
+       struct input_dev *input_dev = tsc->input;
+       int retval = 0;
+
+       mutex_lock(&input_dev->mutex);
+
+       if (input_dev->users) {
+               retval = clk_prepare_enable(tsc->adc_clk);
+               if (retval)
+                       goto out;
+
+               retval = clk_prepare_enable(tsc->tsc_clk);
+               if (retval) {
+                       clk_disable_unprepare(tsc->adc_clk);
+                       goto out;
+               }
+
+               imx6ul_tsc_init(tsc);
+       }
+
+out:
+       mutex_unlock(&input_dev->mutex);
+       return retval;
+}
+
+static SIMPLE_DEV_PM_OPS(imx6ul_tsc_pm_ops,
+                        imx6ul_tsc_suspend, imx6ul_tsc_resume);
+
+static const struct of_device_id imx6ul_tsc_match[] = {
+       { .compatible = "fsl,imx6ul-tsc", },
+       { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx6ul_tsc_match);
+
+static struct platform_driver imx6ul_tsc_driver = {
+       .driver         = {
+               .name   = "imx6ul-tsc",
+               .of_match_table = imx6ul_tsc_match,
+               .pm     = &imx6ul_tsc_pm_ops,
+       },
+       .probe          = imx6ul_tsc_probe,
+};
+module_platform_driver(imx6ul_tsc_driver);
+
+MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>");
+MODULE_DESCRIPTION("Freescale i.MX6UL Touchscreen controller driver");
+MODULE_LICENSE("GPL v2");