iio: adc: Move mxs-lradc out of staging

Move mxs-lradc driver from drivers/staging/iio/adc to drivers/iio/adc.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 1790 insertions, 0 deletions

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index fd8b53e37bf0..ce152261b438 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -295,6 +295,20 @@ config MEN_Z188_ADC
           This driver can also be built as a module. If so, the module will be
           called men_z188_adc.
 
+config MXS_LRADC
+        tristate "Freescale i.MX23/i.MX28 LRADC"
+        depends on (ARCH_MXS || COMPILE_TEST) && HAS_IOMEM
+        depends on INPUT
+        select STMP_DEVICE
+        select IIO_BUFFER
+        select IIO_TRIGGERED_BUFFER
+        help
+          Say yes here to build support for i.MX23/i.MX28 LRADC convertor
+          built into these chips.
+
+          To compile this driver as a module, choose M here: the
+          module will be called mxs-lradc.
+
 config NAU7802
         tristate "Nuvoton NAU7802 ADC driver"
         depends on I2C
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index a3820fa54004..76c008158fa9 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_MAX1363) += max1363.o
 obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
 obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
+obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
 obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
 obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
diff --git a/drivers/iio/adc/mxs-lradc.c b/drivers/iio/adc/mxs-lradc.c
new file mode 100644
index 000000000000..33051b87aac2
--- /dev/null
+++ b/drivers/iio/adc/mxs-lradc.c
@@ -0,0 +1,1775 @@
+/*
+ * 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/bitops.h>
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/stmp_device.h>
+#include <linux/sysfs.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/sysfs.h>
+
+#define DRIVER_NAME             "mxs-lradc"
+
+#define LRADC_MAX_DELAY_CHANS   4
+#define LRADC_MAX_MAPPED_CHANS  8
+#define LRADC_MAX_TOTAL_CHANS   16
+
+#define LRADC_DELAY_TIMER_HZ    2000
+
+/*
+ * Make this runtime configurable if necessary. Currently, if the buffered mode
+ * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before
+ * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000)
+ * seconds. The result is that the samples arrive every 500mS.
+ */
+#define LRADC_DELAY_TIMER_PER   200
+#define LRADC_DELAY_TIMER_LOOP  5
+
+/*
+ * Once the pen touches the touchscreen, the touchscreen switches from
+ * IRQ-driven mode to polling mode to prevent interrupt storm. The polling
+ * is realized by worker thread, which is called every 20 or so milliseconds.
+ * This gives the touchscreen enough fluency and does not strain the system
+ * too much.
+ */
+#define LRADC_TS_SAMPLE_DELAY_MS        5
+
+/*
+ * The LRADC reads the following amount of samples from each touchscreen
+ * channel and the driver then computes average of these.
+ */
+#define LRADC_TS_SAMPLE_AMOUNT          4
+
+enum mxs_lradc_id {
+        IMX23_LRADC,
+        IMX28_LRADC,
+};
+
+static const char * const mx23_lradc_irq_names[] = {
+        "mxs-lradc-touchscreen",
+        "mxs-lradc-channel0",
+        "mxs-lradc-channel1",
+        "mxs-lradc-channel2",
+        "mxs-lradc-channel3",
+        "mxs-lradc-channel4",
+        "mxs-lradc-channel5",
+        "mxs-lradc-channel6",
+        "mxs-lradc-channel7",
+};
+
+static const char * const mx28_lradc_irq_names[] = {
+        "mxs-lradc-touchscreen",
+        "mxs-lradc-thresh0",
+        "mxs-lradc-thresh1",
+        "mxs-lradc-channel0",
+        "mxs-lradc-channel1",
+        "mxs-lradc-channel2",
+        "mxs-lradc-channel3",
+        "mxs-lradc-channel4",
+        "mxs-lradc-channel5",
+        "mxs-lradc-channel6",
+        "mxs-lradc-channel7",
+        "mxs-lradc-button0",
+        "mxs-lradc-button1",
+};
+
+struct mxs_lradc_of_config {
+        const int               irq_count;
+        const char * const      *irq_name;
+        const u32               *vref_mv;
+};
+
+#define VREF_MV_BASE 1850
+
+static const u32 mx23_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
+        VREF_MV_BASE,           /* CH0 */
+        VREF_MV_BASE,           /* CH1 */
+        VREF_MV_BASE,           /* CH2 */
+        VREF_MV_BASE,           /* CH3 */
+        VREF_MV_BASE,           /* CH4 */
+        VREF_MV_BASE,           /* CH5 */
+        VREF_MV_BASE * 2,       /* CH6 VDDIO */
+        VREF_MV_BASE * 4,       /* CH7 VBATT */
+        VREF_MV_BASE,           /* CH8 Temp sense 0 */
+        VREF_MV_BASE,           /* CH9 Temp sense 1 */
+        VREF_MV_BASE,           /* CH10 */
+        VREF_MV_BASE,           /* CH11 */
+        VREF_MV_BASE,           /* CH12 USB_DP */
+        VREF_MV_BASE,           /* CH13 USB_DN */
+        VREF_MV_BASE,           /* CH14 VBG */
+        VREF_MV_BASE * 4,       /* CH15 VDD5V */
+};
+
+static const u32 mx28_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
+        VREF_MV_BASE,           /* CH0 */
+        VREF_MV_BASE,           /* CH1 */
+        VREF_MV_BASE,           /* CH2 */
+        VREF_MV_BASE,           /* CH3 */
+        VREF_MV_BASE,           /* CH4 */
+        VREF_MV_BASE,           /* CH5 */
+        VREF_MV_BASE,           /* CH6 */
+        VREF_MV_BASE * 4,       /* CH7 VBATT */
+        VREF_MV_BASE,           /* CH8 Temp sense 0 */
+        VREF_MV_BASE,           /* CH9 Temp sense 1 */
+        VREF_MV_BASE * 2,       /* CH10 VDDIO */
+        VREF_MV_BASE,           /* CH11 VTH */
+        VREF_MV_BASE * 2,       /* CH12 VDDA */
+        VREF_MV_BASE,           /* CH13 VDDD */
+        VREF_MV_BASE,           /* CH14 VBG */
+        VREF_MV_BASE * 4,       /* CH15 VDD5V */
+};
+
+static const struct mxs_lradc_of_config mxs_lradc_of_config[] = {
+        [IMX23_LRADC] = {
+                .irq_count      = ARRAY_SIZE(mx23_lradc_irq_names),
+                .irq_name       = mx23_lradc_irq_names,
+                .vref_mv        = mx23_vref_mv,
+        },
+        [IMX28_LRADC] = {
+                .irq_count      = ARRAY_SIZE(mx28_lradc_irq_names),
+                .irq_name       = mx28_lradc_irq_names,
+                .vref_mv        = mx28_vref_mv,
+        },
+};
+
+enum mxs_lradc_ts {
+        MXS_LRADC_TOUCHSCREEN_NONE = 0,
+        MXS_LRADC_TOUCHSCREEN_4WIRE,
+        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,
+};
+
+enum mxs_lradc_divbytwo {
+        MXS_LRADC_DIV_DISABLED = 0,
+        MXS_LRADC_DIV_ENABLED,
+};
+
+struct mxs_lradc_scale {
+        unsigned int            integer;
+        unsigned int            nano;
+};
+
+struct mxs_lradc {
+        struct device           *dev;
+        void __iomem            *base;
+        int                     irq[13];
+
+        struct clk              *clk;
+
+        u32                     *buffer;
+        struct iio_trigger      *trig;
+
+        struct mutex            lock;
+
+        struct completion       completion;
+
+        const u32               *vref_mv;
+        struct mxs_lradc_scale  scale_avail[LRADC_MAX_TOTAL_CHANS][2];
+        unsigned long           is_divided;
+
+        /*
+         * 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
+#define BUFFER_VCHANS_LIMITED           0x3f
+#define BUFFER_VCHANS_ALL               0xff
+        u8                      buffer_vchans;
+
+        /*
+         * Furthermore, certain LRADC channels are shared between touchscreen
+         * and/or touch-buttons and generic LRADC block. Therefore when using
+         * either of these, these channels are not available for the regular
+         * sampling. The shared channels are as follows:
+         *
+         * CH0 -- Touch button #0
+         * CH1 -- Touch button #1
+         * CH2 -- Touch screen XPUL
+         * CH3 -- Touch screen YPLL
+         * CH4 -- Touch screen XNUL
+         * CH5 -- Touch screen YNLR
+         * CH6 -- Touch screen WIPER (5-wire only)
+         *
+         * The bit fields below represents which parts of the LRADC block are
+         * switched into special mode of operation. These channels can not
+         * be sampled as regular LRADC channels. The driver will refuse any
+         * attempt to sample these channels.
+         */
+#define CHAN_MASK_TOUCHBUTTON           (BIT(1) | BIT(0))
+#define CHAN_MASK_TOUCHSCREEN_4WIRE     (0xf << 2)
+#define CHAN_MASK_TOUCHSCREEN_5WIRE     (0x1f << 2)
+        enum mxs_lradc_ts       use_touchscreen;
+        bool                    use_touchbutton;
+
+        struct input_dev        *ts_input;
+
+        enum mxs_lradc_id       soc;
+        enum 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;
+};
+
+#define LRADC_CTRL0                             0x00
+# define LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE   BIT(23)
+# define LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE     BIT(22)
+# define LRADC_CTRL0_MX28_YNNSW /* YM */        BIT(21)
+# define LRADC_CTRL0_MX28_YPNSW /* YP */        BIT(20)
+# define LRADC_CTRL0_MX28_YPPSW /* YP */        BIT(19)
+# define LRADC_CTRL0_MX28_XNNSW /* XM */        BIT(18)
+# define LRADC_CTRL0_MX28_XNPSW /* XM */        BIT(17)
+# define LRADC_CTRL0_MX28_XPPSW /* XP */        BIT(16)
+
+# define LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE   BIT(20)
+# define LRADC_CTRL0_MX23_YM                    BIT(19)
+# define LRADC_CTRL0_MX23_XM                    BIT(18)
+# define LRADC_CTRL0_MX23_YP                    BIT(17)
+# define LRADC_CTRL0_MX23_XP                    BIT(16)
+
+# define LRADC_CTRL0_MX28_PLATE_MASK \
+                (LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE | \
+                LRADC_CTRL0_MX28_YNNSW | LRADC_CTRL0_MX28_YPNSW | \
+                LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW | \
+                LRADC_CTRL0_MX28_XNPSW | LRADC_CTRL0_MX28_XPPSW)
+
+# define LRADC_CTRL0_MX23_PLATE_MASK \
+                (LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE | \
+                LRADC_CTRL0_MX23_YM | LRADC_CTRL0_MX23_XM | \
+                LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XP)
+
+#define LRADC_CTRL1                             0x10
+#define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN         BIT(24)
+#define LRADC_CTRL1_LRADC_IRQ_EN(n)             (1 << ((n) + 16))
+#define LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK      (0x1fff << 16)
+#define LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK      (0x01ff << 16)
+#define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET         16
+#define LRADC_CTRL1_TOUCH_DETECT_IRQ            BIT(8)
+#define LRADC_CTRL1_LRADC_IRQ(n)                (1 << (n))
+#define LRADC_CTRL1_MX28_LRADC_IRQ_MASK         0x1fff
+#define LRADC_CTRL1_MX23_LRADC_IRQ_MASK         0x01ff
+#define LRADC_CTRL1_LRADC_IRQ_OFFSET            0
+
+#define LRADC_CTRL2                             0x20
+#define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET        24
+#define LRADC_CTRL2_TEMPSENSE_PWD               BIT(15)
+
+#define LRADC_STATUS                            0x40
+#define LRADC_STATUS_TOUCH_DETECT_RAW           BIT(0)
+
+#define LRADC_CH(n)                             (0x50 + (0x10 * (n)))
+#define LRADC_CH_ACCUMULATE                     BIT(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         (0xffUL << 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                        BIT(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))
+#define LRADC_CTRL4_LRADCSELECT_OFFSET(n)       ((n) * 4)
+#define LRADC_CTRL4_LRADCSELECT(n, x) \
+                                (((x) << LRADC_CTRL4_LRADCSELECT_OFFSET(n)) & \
+                                LRADC_CTRL4_LRADCSELECT_MASK(n))
+
+#define LRADC_RESOLUTION                        12
+#define LRADC_SINGLE_SAMPLE_MASK                ((1 << LRADC_RESOLUTION) - 1)
+
+static void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+        writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
+}
+
+static void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+        writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
+}
+
+static void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+        writel(val, lradc->base + reg);
+}
+
+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_irq_en_mask(struct mxs_lradc *lradc)
+{
+        if (lradc->soc == IMX23_LRADC)
+                return LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK;
+        return LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK;
+}
+
+static u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
+{
+        if (lradc->soc == IMX23_LRADC)
+                return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;
+        return LRADC_CTRL1_MX28_LRADC_IRQ_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_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 *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
+         *
+         * 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(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(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(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(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(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
+
+/*
+ * 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_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
+        mxs_lradc_setup_ts_channel(lradc, 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 *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_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
+        mxs_lradc_setup_ts_channel(lradc, 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 *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_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
+        mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
+        mxs_lradc_setup_ts_pressure(lradc, TOUCHSCREEN_VCHANNEL2,
+                                    TOUCHSCREEN_VCHANNEL1);
+}
+
+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_start_touch_event(struct mxs_lradc *lradc)
+{
+        mxs_lradc_reg_clear(lradc,
+                            LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+                            LRADC_CTRL1);
+        mxs_lradc_reg_set(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(lradc);
+}
+
+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(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 *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 */
+        lradc->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 *lradc)
+{
+        switch (lradc->cur_plate) {
+        case LRADC_TOUCH:
+                if (mxs_lradc_check_touch_event(lradc))
+                        mxs_lradc_start_touch_event(lradc);
+                mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
+                                    LRADC_CTRL1);
+                return;
+
+        case LRADC_SAMPLE_Y:
+                lradc->ts_y_pos =
+                    mxs_lradc_read_raw_channel(lradc,
+                                               TOUCHSCREEN_VCHANNEL1);
+                mxs_lradc_prepare_x_pos(lradc);
+                return;
+
+        case LRADC_SAMPLE_X:
+                lradc->ts_x_pos =
+                    mxs_lradc_read_raw_channel(lradc,
+                                               TOUCHSCREEN_VCHANNEL1);
+                mxs_lradc_prepare_pressure(lradc);
+                return;
+
+        case LRADC_SAMPLE_PRESSURE:
+                lradc->ts_pressure =
+                    mxs_lradc_read_ts_pressure(lradc,
+                                               TOUCHSCREEN_VCHANNEL2,
+                                               TOUCHSCREEN_VCHANNEL1);
+                mxs_lradc_complete_touch_event(lradc);
+                return;
+
+        case LRADC_SAMPLE_VALID:
+                mxs_lradc_finish_touch_event(lradc, 1);
+                break;
+        }
+}
+
+/*
+ * Raw I/O operations
+ */
+static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
+{
+        struct mxs_lradc *lradc = iio_priv(iio_dev);
+        int ret;
+
+        /*
+         * See if there is no buffered operation in progress. If there is, simply
+         * bail out. This can be improved to support both buffered and raw IO at
+         * the same time, yet the code becomes horribly complicated. Therefore I
+         * applied KISS principle here.
+         */
+        ret = mutex_trylock(&lradc->lock);
+        if (!ret)
+                return -EBUSY;
+
+        reinit_completion(&lradc->completion);
+
+        /*
+         * No buffered operation in progress, map the channel and trigger it.
+         * Virtual channel 0 is always used here as the others are always not
+         * used if doing raw sampling.
+         */
+        if (lradc->soc == IMX28_LRADC)
+                mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0),
+                                    LRADC_CTRL1);
+        mxs_lradc_reg_clear(lradc, 0x1, LRADC_CTRL0);
+
+        /* Enable / disable the divider per requirement */
+        if (test_bit(chan, &lradc->is_divided))
+                mxs_lradc_reg_set(lradc,
+                                  1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+                                  LRADC_CTRL2);
+        else
+                mxs_lradc_reg_clear(lradc,
+                                    1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
+                                    LRADC_CTRL2);
+
+        /* Clean the slot's previous content, then set new one. */
+        mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0),
+                            LRADC_CTRL4);
+        mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4);
+
+        mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0));
+
+        /* Enable the IRQ and start sampling the channel. */
+        mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
+        mxs_lradc_reg_set(lradc, BIT(0), LRADC_CTRL0);
+
+        /* Wait for completion on the channel, 1 second max. */
+        ret = wait_for_completion_killable_timeout(&lradc->completion, HZ);
+        if (!ret)
+                ret = -ETIMEDOUT;
+        if (ret < 0)
+                goto err;
+
+        /* Read the data. */
+        *val = readl(lradc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK;
+        ret = IIO_VAL_INT;
+
+err:
+        mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
+
+        mutex_unlock(&lradc->lock);
+
+        return ret;
+}
+
+static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
+{
+        int ret, min, max;
+
+        ret = mxs_lradc_read_single(iio_dev, 8, &min);
+        if (ret != IIO_VAL_INT)
+                return ret;
+
+        ret = mxs_lradc_read_single(iio_dev, 9, &max);
+        if (ret != IIO_VAL_INT)
+                return ret;
+
+        *val = max - min;
+
+        return IIO_VAL_INT;
+}
+
+static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
+                              const struct iio_chan_spec *chan,
+                              int *val, int *val2, long m)
+{
+        struct mxs_lradc *lradc = iio_priv(iio_dev);
+
+        switch (m) {
+        case IIO_CHAN_INFO_RAW:
+                if (chan->type == IIO_TEMP)
+                        return mxs_lradc_read_temp(iio_dev, val);
+
+                return mxs_lradc_read_single(iio_dev, chan->channel, val);
+
+        case IIO_CHAN_INFO_SCALE:
+                if (chan->type == IIO_TEMP) {
+                        /*
+                         * From the datasheet, we have to multiply by 1.012 and
+                         * divide by 4
+                         */
+                        *val = 0;
+                        *val2 = 253000;
+                        return IIO_VAL_INT_PLUS_MICRO;
+                }
+
+                *val = lradc->vref_mv[chan->channel];
+                *val2 = chan->scan_type.realbits -
+                        test_bit(chan->channel, &lradc->is_divided);
+                return IIO_VAL_FRACTIONAL_LOG2;
+
+        case IIO_CHAN_INFO_OFFSET:
+                if (chan->type == IIO_TEMP) {
+                        /*
+                         * The calculated value from the ADC is in Kelvin, we
+                         * want Celsius for hwmon so the offset is -273.15
+                         * The offset is applied before scaling so it is
+                         * actually -213.15 * 4 / 1.012 = -1079.644268
+                         */
+                        *val = -1079;
+                        *val2 = 644268;
+
+                        return IIO_VAL_INT_PLUS_MICRO;
+                }
+
+                return -EINVAL;
+
+        default:
+                break;
+        }
+
+        return -EINVAL;
+}
+
+static int mxs_lradc_write_raw(struct iio_dev *iio_dev,
+                               const struct iio_chan_spec *chan,
+                               int val, int val2, long m)
+{
+        struct mxs_lradc *lradc = iio_priv(iio_dev);
+        struct mxs_lradc_scale *scale_avail =
+                        lradc->scale_avail[chan->channel];
+        int ret;
+
+        ret = mutex_trylock(&lradc->lock);
+        if (!ret)
+                return -EBUSY;
+
+        switch (m) {
+        case IIO_CHAN_INFO_SCALE:
+                ret = -EINVAL;
+                if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
+                    val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
+                        /* divider by two disabled */
+                        clear_bit(chan->channel, &lradc->is_divided);
+                        ret = 0;
+                } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
+                           val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
+                        /* divider by two enabled */
+                        set_bit(chan->channel, &lradc->is_divided);
+                        ret = 0;
+                }
+
+                break;
+        default:
+                ret = -EINVAL;
+                break;
+        }
+
+        mutex_unlock(&lradc->lock);
+
+        return ret;
+}
+
+static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
+                                       const struct iio_chan_spec *chan,
+                                       long m)
+{
+        return IIO_VAL_INT_PLUS_NANO;
+}
+
+static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
+                                                 struct device_attribute *attr,
+                                                 char *buf,
+                                                 int ch)
+{
+        struct iio_dev *iio = dev_to_iio_dev(dev);
+        struct mxs_lradc *lradc = iio_priv(iio);
+        int i, len = 0;
+
+        for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
+                len += sprintf(buf + len, "%u.%09u ",
+                               lradc->scale_avail[ch][i].integer,
+                               lradc->scale_avail[ch][i].nano);
+
+        len += sprintf(buf + len, "\n");
+
+        return len;
+}
+
+static ssize_t mxs_lradc_show_scale_available(struct device *dev,
+                                              struct device_attribute *attr,
+                                              char *buf)
+{
+        struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
+
+        return mxs_lradc_show_scale_available_ch(dev, attr, buf,
+                                                 iio_attr->address);
+}
+
+#define SHOW_SCALE_AVAILABLE_ATTR(ch)                                   \
+static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO,       \
+                       mxs_lradc_show_scale_available, NULL, ch)
+
+SHOW_SCALE_AVAILABLE_ATTR(0);
+SHOW_SCALE_AVAILABLE_ATTR(1);
+SHOW_SCALE_AVAILABLE_ATTR(2);
+SHOW_SCALE_AVAILABLE_ATTR(3);
+SHOW_SCALE_AVAILABLE_ATTR(4);
+SHOW_SCALE_AVAILABLE_ATTR(5);
+SHOW_SCALE_AVAILABLE_ATTR(6);
+SHOW_SCALE_AVAILABLE_ATTR(7);
+SHOW_SCALE_AVAILABLE_ATTR(10);
+SHOW_SCALE_AVAILABLE_ATTR(11);
+SHOW_SCALE_AVAILABLE_ATTR(12);
+SHOW_SCALE_AVAILABLE_ATTR(13);
+SHOW_SCALE_AVAILABLE_ATTR(14);
+SHOW_SCALE_AVAILABLE_ATTR(15);
+
+static struct attribute *mxs_lradc_attributes[] = {
+        &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
+        &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group mxs_lradc_attribute_group = {
+        .attrs = mxs_lradc_attributes,
+};
+
+static const struct iio_info mxs_lradc_iio_info = {
+        .driver_module          = THIS_MODULE,
+        .read_raw               = mxs_lradc_read_raw,
+        .write_raw              = mxs_lradc_write_raw,
+        .write_raw_get_fmt      = mxs_lradc_write_raw_get_fmt,
+        .attrs                  = &mxs_lradc_attribute_group,
+};
+
+static int mxs_lradc_ts_open(struct input_dev *dev)
+{
+        struct mxs_lradc *lradc = input_get_drvdata(dev);
+
+        /* Enable the touch-detect circuitry. */
+        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(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 *lradc = input_get_drvdata(dev);
+
+        mxs_lradc_disable_ts(lradc);
+}
+
+static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
+{
+        struct input_dev *input;
+        struct device *dev = lradc->dev;
+        int ret;
+
+        if (!lradc->use_touchscreen)
+                return 0;
+
+        input = input_allocate_device();
+        if (!input)
+                return -ENOMEM;
+
+        input->name = DRIVER_NAME;
+        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);
+        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);
+
+        lradc->ts_input = input;
+        input_set_drvdata(input, lradc);
+        ret = input_register_device(input);
+        if (ret)
+                input_free_device(lradc->ts_input);
+
+        return ret;
+}
+
+static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
+{
+        if (!lradc->use_touchscreen)
+                return;
+
+        mxs_lradc_disable_ts(lradc);
+        input_unregister_device(lradc->ts_input);
+}
+
+/*
+ * IRQ Handling
+ */
+static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
+{
+        struct iio_dev *iio = data;
+        struct mxs_lradc *lradc = iio_priv(iio);
+        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(lradc);
+
+                /* 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));
+        }
+
+        if (iio_buffer_enabled(iio)) {
+                if (reg & lradc->buffer_vchans)
+                        iio_trigger_poll(iio->trig);
+        } else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
+                complete(&lradc->completion);
+        }
+
+        mxs_lradc_reg_clear(lradc, reg & clr_irq, LRADC_CTRL1);
+
+        return IRQ_HANDLED;
+}
+
+/*
+ * Trigger handling
+ */
+static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
+{
+        struct iio_poll_func *pf = p;
+        struct iio_dev *iio = pf->indio_dev;
+        struct mxs_lradc *lradc = iio_priv(iio);
+        const u32 chan_value = LRADC_CH_ACCUMULATE |
+                ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
+        unsigned int i, j = 0;
+
+        for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
+                lradc->buffer[j] = readl(lradc->base + LRADC_CH(j));
+                mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(j));
+                lradc->buffer[j] &= LRADC_CH_VALUE_MASK;
+                lradc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
+                j++;
+        }
+
+        iio_push_to_buffers_with_timestamp(iio, lradc->buffer, pf->timestamp);
+
+        iio_trigger_notify_done(iio->trig);
+
+        return IRQ_HANDLED;
+}
+
+static int mxs_lradc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+        struct iio_dev *iio = iio_trigger_get_drvdata(trig);
+        struct mxs_lradc *lradc = iio_priv(iio);
+        const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
+
+        mxs_lradc_reg_wrt(lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
+
+        return 0;
+}
+
+static const struct iio_trigger_ops mxs_lradc_trigger_ops = {
+        .owner = THIS_MODULE,
+        .set_trigger_state = &mxs_lradc_configure_trigger,
+};
+
+static int mxs_lradc_trigger_init(struct iio_dev *iio)
+{
+        int ret;
+        struct iio_trigger *trig;
+        struct mxs_lradc *lradc = iio_priv(iio);
+
+        trig = iio_trigger_alloc("%s-dev%i", iio->name, iio->id);
+        if (!trig)
+                return -ENOMEM;
+
+        trig->dev.parent = lradc->dev;
+        iio_trigger_set_drvdata(trig, iio);
+        trig->ops = &mxs_lradc_trigger_ops;
+
+        ret = iio_trigger_register(trig);
+        if (ret) {
+                iio_trigger_free(trig);
+                return ret;
+        }
+
+        lradc->trig = trig;
+
+        return 0;
+}
+
+static void mxs_lradc_trigger_remove(struct iio_dev *iio)
+{
+        struct mxs_lradc *lradc = iio_priv(iio);
+
+        iio_trigger_unregister(lradc->trig);
+        iio_trigger_free(lradc->trig);
+}
+
+static int mxs_lradc_buffer_preenable(struct iio_dev *iio)
+{
+        struct mxs_lradc *lradc = iio_priv(iio);
+        int ret = 0, chan, ofs = 0;
+        unsigned long enable = 0;
+        u32 ctrl4_set = 0;
+        u32 ctrl4_clr = 0;
+        u32 ctrl1_irq = 0;
+        const u32 chan_value = LRADC_CH_ACCUMULATE |
+                ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
+        const int len = bitmap_weight(iio->active_scan_mask,
+                        LRADC_MAX_TOTAL_CHANS);
+
+        if (!len)
+                return -EINVAL;
+
+        /*
+         * Lock the driver so raw access can not be done during buffered
+         * operation. This simplifies the code a lot.
+         */
+        ret = mutex_trylock(&lradc->lock);
+        if (!ret)
+                return -EBUSY;
+
+        lradc->buffer = kmalloc_array(len, sizeof(*lradc->buffer), GFP_KERNEL);
+        if (!lradc->buffer) {
+                ret = -ENOMEM;
+                goto err_mem;
+        }
+
+        if (lradc->soc == IMX28_LRADC)
+                mxs_lradc_reg_clear(
+                        lradc,
+                        lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+                        LRADC_CTRL1);
+        mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
+
+        for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
+                ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
+                ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
+                ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
+                mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs));
+                bitmap_set(&enable, ofs, 1);
+                ofs++;
+        }
+
+        mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+                            LRADC_DELAY_KICK, LRADC_DELAY(0));
+        mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4);
+        mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4);
+        mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1);
+        mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
+                          LRADC_DELAY(0));
+
+        return 0;
+
+err_mem:
+        mutex_unlock(&lradc->lock);
+        return ret;
+}
+
+static int mxs_lradc_buffer_postdisable(struct iio_dev *iio)
+{
+        struct mxs_lradc *lradc = iio_priv(iio);
+
+        mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
+                            LRADC_DELAY_KICK, LRADC_DELAY(0));
+
+        mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
+        if (lradc->soc == IMX28_LRADC)
+                mxs_lradc_reg_clear(
+                        lradc,
+                        lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+                        LRADC_CTRL1);
+
+        kfree(lradc->buffer);
+        mutex_unlock(&lradc->lock);
+
+        return 0;
+}
+
+static bool mxs_lradc_validate_scan_mask(struct iio_dev *iio,
+                                         const unsigned long *mask)
+{
+        struct mxs_lradc *lradc = iio_priv(iio);
+        const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS);
+        int rsvd_chans = 0;
+        unsigned long rsvd_mask = 0;
+
+        if (lradc->use_touchbutton)
+                rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
+        if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE)
+                rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
+        if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
+                rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
+
+        if (lradc->use_touchbutton)
+                rsvd_chans++;
+        if (lradc->use_touchscreen)
+                rsvd_chans += 2;
+
+        /* Test for attempts to map channels with special mode of operation. */
+        if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS))
+                return false;
+
+        /* Test for attempts to map more channels then available slots. */
+        if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
+                return false;
+
+        return true;
+}
+
+static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
+        .preenable = &mxs_lradc_buffer_preenable,
+        .postenable = &iio_triggered_buffer_postenable,
+        .predisable = &iio_triggered_buffer_predisable,
+        .postdisable = &mxs_lradc_buffer_postdisable,
+        .validate_scan_mask = &mxs_lradc_validate_scan_mask,
+};
+
+/*
+ * Driver initialization
+ */
+
+#define MXS_ADC_CHAN(idx, chan_type, name) {                    \
+        .type = (chan_type),                                    \
+        .indexed = 1,                                           \
+        .scan_index = (idx),                                    \
+        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |          \
+                              BIT(IIO_CHAN_INFO_SCALE),         \
+        .channel = (idx),                                       \
+        .address = (idx),                                       \
+        .scan_type = {                                          \
+                .sign = 'u',                                    \
+                .realbits = LRADC_RESOLUTION,                   \
+                .storagebits = 32,                              \
+        },                                                      \
+        .datasheet_name = (name),                               \
+}
+
+static const struct iio_chan_spec mx23_lradc_chan_spec[] = {
+        MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
+        MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
+        MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
+        MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
+        MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
+        MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
+        MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"),
+        MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
+        /* Combined Temperature sensors */
+        {
+                .type = IIO_TEMP,
+                .indexed = 1,
+                .scan_index = 8,
+                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                                      BIT(IIO_CHAN_INFO_OFFSET) |
+                                      BIT(IIO_CHAN_INFO_SCALE),
+                .channel = 8,
+                .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
+                .datasheet_name = "TEMP_DIE",
+        },
+        /* Hidden channel to keep indexes */
+        {
+                .type = IIO_TEMP,
+                .indexed = 1,
+                .scan_index = -1,
+                .channel = 9,
+        },
+        MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL),
+        MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL),
+        MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"),
+        MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"),
+        MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
+        MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
+};
+
+static const struct iio_chan_spec mx28_lradc_chan_spec[] = {
+        MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
+        MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
+        MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
+        MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
+        MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
+        MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
+        MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"),
+        MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
+        /* Combined Temperature sensors */
+        {
+                .type = IIO_TEMP,
+                .indexed = 1,
+                .scan_index = 8,
+                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                                      BIT(IIO_CHAN_INFO_OFFSET) |
+                                      BIT(IIO_CHAN_INFO_SCALE),
+                .channel = 8,
+                .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
+                .datasheet_name = "TEMP_DIE",
+        },
+        /* Hidden channel to keep indexes */
+        {
+                .type = IIO_TEMP,
+                .indexed = 1,
+                .scan_index = -1,
+                .channel = 9,
+        },
+        MXS_ADC_CHAN(10, IIO_VOLTAGE, "VDDIO"),
+        MXS_ADC_CHAN(11, IIO_VOLTAGE, "VTH"),
+        MXS_ADC_CHAN(12, IIO_VOLTAGE, "VDDA"),
+        MXS_ADC_CHAN(13, IIO_VOLTAGE, "VDDD"),
+        MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
+        MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
+};
+
+static int mxs_lradc_hw_init(struct mxs_lradc *lradc)
+{
+        /* The ADC always uses DELAY CHANNEL 0. */
+        const u32 adc_cfg =
+                (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
+                (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);
+
+        int ret = stmp_reset_block(lradc->base);
+
+        if (ret)
+                return ret;
+
+        /* Configure DELAY CHANNEL 0 for generic ADC sampling. */
+        mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
+
+        /* Disable remaining DELAY CHANNELs */
+        mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(1));
+        mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
+        mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
+
+        /* 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);
+        }
+
+        /* Start internal temperature sensing. */
+        mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
+
+        return 0;
+}
+
+static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
+{
+        int i;
+
+        mxs_lradc_reg_clear(lradc, mxs_lradc_irq_en_mask(lradc), LRADC_CTRL1);
+
+        for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
+                mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(i));
+}
+
+static const struct of_device_id mxs_lradc_dt_ids[] = {
+        { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
+        { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
+
+static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
+                                       struct device_node *lradc_node)
+{
+        int ret;
+        u32 ts_wires = 0, adapt;
+
+        ret = of_property_read_u32(lradc_node, "fsl,lradc-touchscreen-wires",
+                                   &ts_wires);
+        if (ret)
+                return -ENODEV; /* touchscreen feature disabled */
+
+        switch (ts_wires) {
+        case 4:
+                lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
+                break;
+        case 5:
+                if (lradc->soc == IMX28_LRADC) {
+                        lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
+                        break;
+                }
+                /* fall through an error message for i.MX23 */
+        default:
+                dev_err(lradc->dev,
+                        "Unsupported number of touchscreen wires (%d)\n",
+                        ts_wires);
+                return -EINVAL;
+        }
+
+        if (of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt)) {
+                lradc->over_sample_cnt = 4;
+        } else {
+                if (adapt < 1 || adapt > 32) {
+                        dev_err(lradc->dev, "Invalid sample count (%u)\n",
+                                adapt);
+                        return -EINVAL;
+                }
+                lradc->over_sample_cnt = adapt;
+        }
+
+        if (of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt)) {
+                lradc->over_sample_delay = 2;
+        } else {
+                if (adapt < 2 || adapt > LRADC_DELAY_DELAY_MASK + 1) {
+                        dev_err(lradc->dev, "Invalid sample delay (%u)\n",
+                                adapt);
+                        return -EINVAL;
+                }
+                lradc->over_sample_delay = adapt;
+        }
+
+        if (of_property_read_u32(lradc_node, "fsl,settling", &adapt)) {
+                lradc->settling_delay = 10;
+        } else {
+                if (adapt < 1 || adapt > LRADC_DELAY_DELAY_MASK) {
+                        dev_err(lradc->dev, "Invalid settling delay (%u)\n",
+                                adapt);
+                        return -EINVAL;
+                }
+                lradc->settling_delay = adapt;
+        }
+
+        return 0;
+}
+
+static int mxs_lradc_probe(struct platform_device *pdev)
+{
+        const struct of_device_id *of_id =
+                of_match_device(mxs_lradc_dt_ids, &pdev->dev);
+        const struct mxs_lradc_of_config *of_cfg =
+                &mxs_lradc_of_config[(enum mxs_lradc_id)of_id->data];
+        struct device *dev = &pdev->dev;
+        struct device_node *node = dev->of_node;
+        struct mxs_lradc *lradc;
+        struct iio_dev *iio;
+        struct resource *iores;
+        int ret = 0, touch_ret;
+        int i, s;
+        u64 scale_uv;
+
+        /* Allocate the IIO device. */
+        iio = devm_iio_device_alloc(dev, sizeof(*lradc));
+        if (!iio) {
+                dev_err(dev, "Failed to allocate IIO device\n");
+                return -ENOMEM;
+        }
+
+        lradc = iio_priv(iio);
+        lradc->soc = (enum mxs_lradc_id)of_id->data;
+
+        /* Grab the memory area */
+        iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        lradc->dev = &pdev->dev;
+        lradc->base = devm_ioremap_resource(dev, iores);
+        if (IS_ERR(lradc->base))
+                return PTR_ERR(lradc->base);
+
+        lradc->clk = devm_clk_get(&pdev->dev, NULL);
+        if (IS_ERR(lradc->clk)) {
+                dev_err(dev, "Failed to get the delay unit clock\n");
+                return PTR_ERR(lradc->clk);
+        }
+        ret = clk_prepare_enable(lradc->clk);
+        if (ret != 0) {
+                dev_err(dev, "Failed to enable the delay unit clock\n");
+                return ret;
+        }
+
+        touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
+
+        if (touch_ret == 0)
+                lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
+        else
+                lradc->buffer_vchans = BUFFER_VCHANS_ALL;
+
+        /* Grab all IRQ sources */
+        for (i = 0; i < of_cfg->irq_count; i++) {
+                lradc->irq[i] = platform_get_irq(pdev, i);
+                if (lradc->irq[i] < 0) {
+                        ret = lradc->irq[i];
+                        goto err_clk;
+                }
+
+                ret = devm_request_irq(dev, lradc->irq[i],
+                                       mxs_lradc_handle_irq, 0,
+                                       of_cfg->irq_name[i], iio);
+                if (ret)
+                        goto err_clk;
+        }
+
+        lradc->vref_mv = of_cfg->vref_mv;
+
+        platform_set_drvdata(pdev, iio);
+
+        init_completion(&lradc->completion);
+        mutex_init(&lradc->lock);
+
+        iio->name = pdev->name;
+        iio->dev.parent = &pdev->dev;
+        iio->info = &mxs_lradc_iio_info;
+        iio->modes = INDIO_DIRECT_MODE;
+        iio->masklength = LRADC_MAX_TOTAL_CHANS;
+
+        if (lradc->soc == IMX23_LRADC) {
+                iio->channels = mx23_lradc_chan_spec;
+                iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec);
+        } else {
+                iio->channels = mx28_lradc_chan_spec;
+                iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
+        }
+
+        ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
+                                         &mxs_lradc_trigger_handler,
+                                         &mxs_lradc_buffer_ops);
+        if (ret)
+                goto err_clk;
+
+        ret = mxs_lradc_trigger_init(iio);
+        if (ret)
+                goto err_trig;
+
+        /* Populate available ADC input ranges */
+        for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
+                for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
+                        /*
+                         * [s=0] = optional divider by two disabled (default)
+                         * [s=1] = optional divider by two enabled
+                         *
+                         * The scale is calculated by doing:
+                         *   Vref >> (realbits - s)
+                         * which multiplies by two on the second component
+                         * of the array.
+                         */
+                        scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
+                                   (LRADC_RESOLUTION - s);
+                        lradc->scale_avail[i][s].nano =
+                                        do_div(scale_uv, 100000000) * 10;
+                        lradc->scale_avail[i][s].integer = scale_uv;
+                }
+        }
+
+        /* Configure the hardware. */
+        ret = mxs_lradc_hw_init(lradc);
+        if (ret)
+                goto err_dev;
+
+        /* Register the touchscreen input device. */
+        if (touch_ret == 0) {
+                ret = mxs_lradc_ts_register(lradc);
+                if (ret)
+                        goto err_ts_register;
+        }
+
+        /* Register IIO device. */
+        ret = iio_device_register(iio);
+        if (ret) {
+                dev_err(dev, "Failed to register IIO device\n");
+                goto err_ts;
+        }
+
+        return 0;
+
+err_ts:
+        mxs_lradc_ts_unregister(lradc);
+err_ts_register:
+        mxs_lradc_hw_stop(lradc);
+err_dev:
+        mxs_lradc_trigger_remove(iio);
+err_trig:
+        iio_triggered_buffer_cleanup(iio);
+err_clk:
+        clk_disable_unprepare(lradc->clk);
+        return ret;
+}
+
+static int mxs_lradc_remove(struct platform_device *pdev)
+{
+        struct iio_dev *iio = platform_get_drvdata(pdev);
+        struct mxs_lradc *lradc = iio_priv(iio);
+
+        iio_device_unregister(iio);
+        mxs_lradc_ts_unregister(lradc);
+        mxs_lradc_hw_stop(lradc);
+        mxs_lradc_trigger_remove(iio);
+        iio_triggered_buffer_cleanup(iio);
+
+        clk_disable_unprepare(lradc->clk);
+
+        return 0;
+}
+
+static struct platform_driver mxs_lradc_driver = {
+        .driver = {
+                .name   = DRIVER_NAME,
+                .of_match_table = mxs_lradc_dt_ids,
+        },
+        .probe  = mxs_lradc_probe,
+        .remove = mxs_lradc_remove,
+};
+
+module_platform_driver(mxs_lradc_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Freescale MXS LRADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);