[PATCH v4 0/4] mxs-lradc: Split driver into MFD

[PATCH v4 0/4] mxs-lradc: Split driver into MFD

[Ksenija Stanojevic]

Split existing driver mxs-lradc into MFD with touchscreen and
IIO part.

Tested on I.MX28.

Ksenija Stanojevic (4):
  mfd: mxs-lradc: Add support for mxs-lradc MFD
  iio: adc: mxs-lradc: Add support for adc driver
  input: touchscreen: mxs-lradc: Add support for touchscreen
  iio: adc: mxs-lradc: Remove driver

 drivers/iio/adc/Kconfig                  |   27 +-
 drivers/iio/adc/Makefile                 |    2 +-
 drivers/iio/adc/mxs-lradc-adc.c          |  833 ++++++++++++++
 drivers/iio/adc/mxs-lradc.c              | 1775 ------------------------------
 drivers/input/touchscreen/Kconfig        |   10 +
 drivers/input/touchscreen/Makefile       |    1 +
 drivers/input/touchscreen/mxs-lradc-ts.c |  736 +++++++++++++
 drivers/mfd/Kconfig                      |   17 +
 drivers/mfd/Makefile                     |    1 +
 drivers/mfd/mxs-lradc.c                  |  259 +++++
 include/linux/mfd/mxs-lradc.h            |  198 ++++
 11 files changed, 2069 insertions(+), 1790 deletions(-)
 create mode 100644 drivers/iio/adc/mxs-lradc-adc.c
 delete mode 100644 drivers/iio/adc/mxs-lradc.c
 create mode 100644 drivers/input/touchscreen/mxs-lradc-ts.c
 create mode 100644 drivers/mfd/mxs-lradc.c
 create mode 100644 include/linux/mfd/mxs-lradc.h

-- 
1.9.1

[PATCH v4 1/4] mfd: mxs-lradc: Add support for mxs-lradc MFD

[Ksenija Stanojevic]

Add core files for mxs-lradc MFD driver.

Note:  this patch won't compile in iio/testing without this patch:
a8f447be8056 ("mfd: Add resource managed APIs for mfd_add_devices")

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
Changes in v4:
 - update copyright
 - use DEFINE_RES_IRQ_NAMED
 - remove mxs_lradc_add_device function
 - use struct mfd_cell in static form
 - improve spacing
 - remove unnecessary comment
 - remove platform_get_irq
 - remove touch_ret and use ret instead
 - rename use_touchscreen to touchscreen_wire
 - use goto statements
 - remove irq[13], irq_count and irq_name from struct mxs_lradc
 - remove all defines from inside the struct definition

Changes in v3:
 - add note to commit message
 - move switch statement into if(touch_ret == 0) branch
 - add MODULE_AUTHOR

Changes in v2:
 - do not change spacing in Kconfig
 - make struct mfd_cell part of struct mxs_lradc
 - use switch instead of if in mxs_lradc_irq_mask
 - use only necessary header files in mxs_lradc.h
 - use devm_mfd_add_device
 - use separate function to register mfd device
 - change licence to GPL
 - add copyright

 drivers/mfd/Kconfig           |  17 +++
 drivers/mfd/Makefile          |   1 +
 drivers/mfd/mxs-lradc.c       | 259 ++++++++++++++++++++++++++++++++++++++++++
 include/linux/mfd/mxs-lradc.h | 198 ++++++++++++++++++++++++++++++++
 4 files changed, 475 insertions(+)
 create mode 100644 drivers/mfd/mxs-lradc.c
 create mode 100644 include/linux/mfd/mxs-lradc.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 9ca66de..ffe14ef 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -271,6 +271,23 @@ config MFD_MC13XXX_I2C
 	help
 	  Select this if your MC13xxx is connected via an I2C bus.
 
+config MFD_MXS_LRADC
+	tristate "Freescale i.MX23/i.MX28 LRADC"
+	depends on ARCH_MXS || COMPILE_TEST
+	select MFD_CORE
+	select STMP_DEVICE
+	help
+	  Say yes here to build support for the Low Resolution
+	  Analog-to-Digital Converter (LRADC) found on the i.MX23 and i.MX28
+	  processors. This driver provides common support for accessing the
+	  device, additional drivers must be enabled in order to use the
+	  functionality of the device:
+		mxs-lradc-adc for ADC readings
+		mxs-lradc-ts  for touchscreen support
+
+	  This driver can also be built as a module. If so, the module will be
+	  called mxs-lradc.
+
 config MFD_HI6421_PMIC
 	tristate "HiSilicon Hi6421 PMU/Codec IC"
 	depends on OF
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 0f230a6..ecf6399 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -198,3 +198,4 @@ intel-soc-pmic-objs		:= intel_soc_pmic_core.o intel_soc_pmic_crc.o
 intel-soc-pmic-$(CONFIG_INTEL_PMC_IPC)	+= intel_soc_pmic_bxtwc.o
 obj-$(CONFIG_INTEL_SOC_PMIC)	+= intel-soc-pmic.o
 obj-$(CONFIG_MFD_MT6397)	+= mt6397-core.o
+obj-$(CONFIG_MFD_MXS_LRADC)	+= mxs-lradc.o
diff --git a/drivers/mfd/mxs-lradc.c b/drivers/mfd/mxs-lradc.c
new file mode 100644
index 0000000..ff221f3
--- /dev/null
+++ b/drivers/mfd/mxs-lradc.c
@@ -0,0 +1,259 @@
+/*
+ * Freescale MXS LRADC driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ *
+ * Authors:
+ * Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
+ * Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
+ *
+ * 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/clk.h>
+#include <linux/device.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mxs-lradc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+enum mx23_lradc_irqs {
+	MX23_LRADC_TS_IRQ = 0,
+	MX23_LRADC_CH0_IRQ,
+	MX23_LRADC_CH1_IRQ,
+	MX23_LRADC_CH2_IRQ,
+	MX23_LRADC_CH3_IRQ,
+	MX23_LRADC_CH4_IRQ,
+	MX23_LRADC_CH5_IRQ,
+	MX23_LRADC_CH6_IRQ,
+	MX23_LRADC_CH7_IRQ,
+};
+
+enum mx28_lradc_irqs {
+	MX28_LRADC_TS_IRQ = 0,
+	MX28_LRADC_TRESH0_IRQ,
+	MX28_LRADC_TRESH1_IRQ,
+	MX28_LRADC_CH0_IRQ,
+	MX28_LRADC_CH1_IRQ,
+	MX28_LRADC_CH2_IRQ,
+	MX28_LRADC_CH3_IRQ,
+	MX28_LRADC_CH4_IRQ,
+	MX28_LRADC_CH5_IRQ,
+	MX28_LRADC_CH6_IRQ,
+	MX28_LRADC_CH7_IRQ,
+	MX28_LRADC_BUTTON0_IRQ,
+	MX28_LRADC_BUTTON1_IRQ,
+};
+
+static struct resource mx23_adc_resources[] = {
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
+};
+
+static struct resource mx23_touchscreen_resources[] = {
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
+	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
+};
+
+static struct resource mx28_adc_resources[] = {
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"),
+};
+
+static struct resource mx28_touchscreen_resources[] = {
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
+	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
+};
+
+static struct mfd_cell mx23_cells[] = {
+	{
+		.name = "mxs-lradc-adc",
+		.resources = mx23_adc_resources,
+		.num_resources = ARRAY_SIZE(mx23_adc_resources),
+	},
+	{
+		.name = "mxs-lradc-ts",
+		.resources = mx23_touchscreen_resources,
+		.num_resources = ARRAY_SIZE(mx23_touchscreen_resources),
+	},
+};
+
+static struct mfd_cell mx28_cells[] = {
+	{
+		.name = "mxs-lradc-adc",
+		.resources = mx28_adc_resources,
+		.num_resources = ARRAY_SIZE(mx28_adc_resources),
+	},
+	{
+		.name = "mxs-lradc-ts",
+		.resources = mx28_touchscreen_resources,
+		.num_resources = ARRAY_SIZE(mx28_touchscreen_resources),
+	}
+};
+
+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(struct platform_device *pdev)
+{
+	const struct of_device_id *of_id;
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct mxs_lradc *lradc;
+	struct resource *iores;
+	struct mfd_cell *cells = NULL;
+	int ret = 0;
+	u32 ts_wires = 0;
+
+	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
+	if (!lradc)
+		return -ENOMEM;
+
+	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
+	lradc->soc = (enum mxs_lradc_id)of_id->data;
+
+	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	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;
+	}
+
+	ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
+					 &ts_wires);
+
+	if (ret == 0) {
+		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
+
+		switch (ts_wires) {
+		case 4:
+			lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;
+			break;
+		case 5:
+			if (lradc->soc == IMX28_LRADC) {
+				lradc->touchscreen_wire =
+					MXS_LRADC_TOUCHSCREEN_5WIRE;
+				break;
+			}
+			/* fall through to an error message for i.MX23 */
+		default:
+			dev_err(&pdev->dev,
+				"Unsupported number of touchscreen wires (%d)\n"
+				, ts_wires);
+			ret = -EINVAL;
+			goto err_clk;
+		}
+	} else {
+		lradc->buffer_vchans = BUFFER_VCHANS_ALL;
+	}
+
+	platform_set_drvdata(pdev, lradc);
+
+	ret = stmp_reset_block(lradc->base);
+	if (ret)
+		goto err_clk;
+
+	switch (lradc->soc) {
+	case IMX23_LRADC:
+		cells = mx23_cells;
+		break;
+	case IMX28_LRADC:
+		cells = mx28_cells;
+		break;
+	default:
+		ret = -EINVAL;
+		goto err_clk;
+	}
+
+	cells[0].platform_data = lradc;
+	cells[0].pdata_size = sizeof(*lradc);
+
+	ret = devm_mfd_add_devices(&pdev->dev, -1, &cells[0], 1, NULL, 0, NULL);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
+		goto err_clk;
+	}
+
+	if (!lradc->touchscreen_wire)
+		return 0;
+
+	cells[1].platform_data = lradc;
+	cells[1].pdata_size = sizeof(*lradc);
+
+	ret = devm_mfd_add_devices(&pdev->dev, -1, &cells[1], 1, NULL, 0, NULL);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"Failed to add the touchscreen subdevice\n");
+		goto err_clk;
+	}
+
+	return 0;
+
+err_clk:
+	clk_disable_unprepare(lradc->clk);
+
+	return ret;
+}
+
+static int mxs_lradc_remove(struct platform_device *pdev)
+{
+	struct mxs_lradc *lradc = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(lradc->clk);
+
+	return 0;
+}
+
+static struct platform_driver mxs_lradc_driver = {
+	.driver = {
+		.name = "mxs-lradc",
+		.of_match_table = mxs_lradc_dt_ids,
+	},
+	.probe = mxs_lradc_probe,
+	.remove = mxs_lradc_remove,
+};
+module_platform_driver(mxs_lradc_driver);
+
+MODULE_AUTHOR("Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>");
+MODULE_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-lradc");
diff --git a/include/linux/mfd/mxs-lradc.h b/include/linux/mfd/mxs-lradc.h
new file mode 100644
index 0000000..88f6c15
--- /dev/null
+++ b/include/linux/mfd/mxs-lradc.h
@@ -0,0 +1,198 @@
+/*
+ * Freescale MXS LRADC driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ *
+ * Author: Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
+ *
+ * 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.
+ */
+
+#ifndef __MFD_MXS_LRADC_H
+#define __MFD_MXS_LRADC_H
+
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/stmp_device.h>
+
+#define LRADC_MAX_DELAY_CHANS	4
+#define LRADC_MAX_MAPPED_CHANS	8
+#define LRADC_MAX_TOTAL_CHANS	16
+
+#define LRADC_DELAY_TIMER_HZ	2000
+
+#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)
+
+#define BUFFER_VCHANS_LIMITED           0x3f
+#define BUFFER_VCHANS_ALL               0xff
+
+#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_id {
+	IMX23_LRADC,
+	IMX28_LRADC,
+};
+
+enum mxs_lradc_ts_wires {
+	MXS_LRADC_TOUCHSCREEN_NONE = 0,
+	MXS_LRADC_TOUCHSCREEN_4WIRE,
+	MXS_LRADC_TOUCHSCREEN_5WIRE,
+};
+
+struct mxs_lradc {
+	enum mxs_lradc_id	soc;
+
+	void __iomem		*base;
+	struct clk		*clk;
+
+	u8			buffer_vchans;
+
+	/*
+	 * 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.
+	 */
+
+	enum mxs_lradc_ts_wires	touchscreen_wire;
+	bool			use_touchbutton;
+};
+
+static inline void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+	writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
+}
+
+static inline void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val,
+				       u32 reg)
+{
+	writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
+}
+
+static inline void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
+{
+	writel(val, lradc->base + reg);
+}
+
+static inline u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
+{
+	switch (lradc->soc) {
+	case IMX23_LRADC:
+		return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;
+	case IMX28_LRADC:
+		return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;
+	default:
+		return 0;
+	}
+}
+
+#endif /* __MXS_LRADC_H */
-- 
1.9.1

Re: [PATCH v4 1/4] mfd: mxs-lradc: Add support for mxs-lradc MFD

[Alexander Stein]

On Thursday 04 August 2016 15:28:18, Ksenija Stanojevic wrote:
> Add core files for mxs-lradc MFD driver.
> 
> Note:  this patch won't compile in iio/testing without this patch:
> a8f447be8056 ("mfd: Add resource managed APIs for mfd_add_devices")
> 
> Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
> ---
> [...]
> +static int mxs_lradc_probe(struct platform_device *pdev)
> +{
> +	const struct of_device_id *of_id;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	struct mxs_lradc *lradc;
> +	struct resource *iores;
> +	struct mfd_cell *cells = NULL;
> +	int ret = 0;
> +	u32 ts_wires = 0;
> +
> +	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
> +	if (!lradc)
> +		return -ENOMEM;
> +
> +	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
> +	lradc->soc = (enum mxs_lradc_id)of_id->data;
> +
> +	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	lradc->base = devm_ioremap_resource(dev, iores);

Out of couriosity: Is it common to pass already ioremapped addresses to (MFD 
cell) platform drivers? I would have expected, and done myself, that ioremap 
is done in the driver itself, same as the IRQ.

Best regards,
Alexander

Re: [PATCH v4 1/4] mfd: mxs-lradc: Add support for mxs-lradc MFD

[Lee Jones]

On Thu, 04 Aug 2016, Alexander Stein wrote:

> On Thursday 04 August 2016 15:28:18, Ksenija Stanojevic wrote:
> > Add core files for mxs-lradc MFD driver.
> > 
> > Note:  this patch won't compile in iio/testing without this patch:
> > a8f447be8056 ("mfd: Add resource managed APIs for mfd_add_devices")
> > 
> > Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
> > ---
> > [...]
> > +static int mxs_lradc_probe(struct platform_device *pdev)
> > +{
> > +	const struct of_device_id *of_id;
> > +	struct device *dev = &pdev->dev;
> > +	struct device_node *node = dev->of_node;
> > +	struct mxs_lradc *lradc;
> > +	struct resource *iores;
> > +	struct mfd_cell *cells = NULL;
> > +	int ret = 0;
> > +	u32 ts_wires = 0;
> > +
> > +	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
> > +	if (!lradc)
> > +		return -ENOMEM;
> > +
> > +	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
> > +	lradc->soc = (enum mxs_lradc_id)of_id->data;
> > +
> > +	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	lradc->base = devm_ioremap_resource(dev, iores);
> 
> Out of couriosity: Is it common to pass already ioremapped addresses to (MFD 
> cell) platform drivers? I would have expected, and done myself, that ioremap 
> is done in the driver itself, same as the IRQ.

Yes, this is exactly what should happen.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v4 1/4] mfd: mxs-lradc: Add support for mxs-lradc MFD

[Jonathan Cameron]

On 05/08/16 08:02, Lee Jones wrote:
> On Thu, 04 Aug 2016, Alexander Stein wrote:
> 
>> On Thursday 04 August 2016 15:28:18, Ksenija Stanojevic wrote:
>>> Add core files for mxs-lradc MFD driver.
>>>
>>> Note:  this patch won't compile in iio/testing without this patch:
>>> a8f447be8056 ("mfd: Add resource managed APIs for mfd_add_devices")
>>>
>>> Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
>>> ---
>>> [...]
>>> +static int mxs_lradc_probe(struct platform_device *pdev)
>>> +{
>>> +	const struct of_device_id *of_id;
>>> +	struct device *dev = &pdev->dev;
>>> +	struct device_node *node = dev->of_node;
>>> +	struct mxs_lradc *lradc;
>>> +	struct resource *iores;
>>> +	struct mfd_cell *cells = NULL;
>>> +	int ret = 0;
>>> +	u32 ts_wires = 0;
>>> +
>>> +	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
>>> +	if (!lradc)
>>> +		return -ENOMEM;
>>> +
>>> +	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
>>> +	lradc->soc = (enum mxs_lradc_id)of_id->data;
>>> +
>>> +	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>>> +	lradc->base = devm_ioremap_resource(dev, iores);
>>
>> Out of couriosity: Is it common to pass already ioremapped addresses to (MFD 
>> cell) platform drivers? I would have expected, and done myself, that ioremap 
>> is done in the driver itself, same as the IRQ.
> 
> Yes, this is exactly what should happen.
> 
Lee, you've confused me with this answer.  Yes, it is common or Yes it
should have been done the way Alexander suggested?

Jonathan

Re: [PATCH v4 1/4] mfd: mxs-lradc: Add support for mxs-lradc MFD

[Lee Jones]

On Mon, 15 Aug 2016, Jonathan Cameron wrote:

> On 05/08/16 08:02, Lee Jones wrote:
> > On Thu, 04 Aug 2016, Alexander Stein wrote:
> > 
> >> On Thursday 04 August 2016 15:28:18, Ksenija Stanojevic wrote:
> >>> Add core files for mxs-lradc MFD driver.
> >>>
> >>> Note:  this patch won't compile in iio/testing without this patch:
> >>> a8f447be8056 ("mfd: Add resource managed APIs for mfd_add_devices")
> >>>
> >>> Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> >>> ---
> >>> [...]
> >>> +static int mxs_lradc_probe(struct platform_device *pdev)
> >>> +{
> >>> +	const struct of_device_id *of_id;
> >>> +	struct device *dev = &pdev->dev;
> >>> +	struct device_node *node = dev->of_node;
> >>> +	struct mxs_lradc *lradc;
> >>> +	struct resource *iores;
> >>> +	struct mfd_cell *cells = NULL;
> >>> +	int ret = 0;
> >>> +	u32 ts_wires = 0;
> >>> +
> >>> +	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
> >>> +	if (!lradc)
> >>> +		return -ENOMEM;
> >>> +
> >>> +	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
> >>> +	lradc->soc = (enum mxs_lradc_id)of_id->data;
> >>> +
> >>> +	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >>> +	lradc->base = devm_ioremap_resource(dev, iores);
> >>
> >> Out of couriosity: Is it common to pass already ioremapped addresses to (MFD 
> >> cell) platform drivers? I would have expected, and done myself, that ioremap 
> >> is done in the driver itself, same as the IRQ.
> > 
> > Yes, this is exactly what should happen.
> > 
> Lee, you've confused me with this answer.  Yes, it is common or Yes it
> should have been done the way Alexander suggested?

The remapping and IRQ obtainment should be done in the leaf driver.

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH v4 4/4] iio: adc: mxs-lradc: Remove driver

[Ksenija Stanojevic]

Since the driver has been split into mfd there is no reason for it to
stay, so remove it.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Acked-by: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
---
Changes in v4:
 - nothing

Changes in v3:
 - nothing

Changes in v2:
 - nothing

 drivers/iio/adc/Kconfig     |   14 -
 drivers/iio/adc/Makefile    |    1 -
 drivers/iio/adc/mxs-lradc.c | 1775 -------------------------------------------
 3 files changed, 1790 deletions(-)
 delete mode 100644 drivers/iio/adc/mxs-lradc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 4ef3ad1..5aba3fe 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -310,20 +310,6 @@ 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 9bb35c4..b2382ab 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -30,7 +30,6 @@ obj-$(CONFIG_MCP320X) += mcp320x.o
 obj-$(CONFIG_MCP3422) += mcp3422.o
 obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
 obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-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
deleted file mode 100644
index 33051b8..0000000
--- a/drivers/iio/adc/mxs-lradc.c
+++ /dev/null
@@ -1,1775 +0,0 @@
-/*
- * Freescale MXS LRADC driver
- *
- * Copyright (c) 2012 DENX Software Engineering, GmbH.
- * Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
- *
- * 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-ynQEQJNshbs@public.gmane.org>");
-MODULE_DESCRIPTION("Freescale MXS LRADC driver");
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("platform:" DRIVER_NAME);
-- 
1.9.1

[PATCH v4 2/4] iio: adc: mxs-lradc: Add support for adc driver

[Ksenija Stanojevic]

Add support for sixteen-channel 12-bit resolution ADC and its functions,
which include general-purpose ADC readings, battery voltage measurement,
and die temperature measurement.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
---
Changes in v4:
 - update copyright
 - use platform_get_irq_byname
 - use irq_of_parse_and_map

Changes in v3:
 - nothing

Changes in v2:
 - improve commit message
 - do not change spacing in Kconfig
 - impove formating
 - remove wrapper show_scale_avail
 - use correct syntax for comments
 - use devm_iio_trigger_alloc
 - do not allocate buffer dynamically 
 - use iio_device_claim_*_mode helpers
 - add spinlock in struct mxs_lradc_ts to enable locking in interrupt handler
 - only grab irqs that are relevant to adc
 - remove blank line at the end of the file
 - change licence to GPL
 - add copyright

 drivers/iio/adc/Kconfig         |  13 +
 drivers/iio/adc/Makefile        |   1 +
 drivers/iio/adc/mxs-lradc-adc.c | 833 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 847 insertions(+)
 create mode 100644 drivers/iio/adc/mxs-lradc-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 932de1f..4ef3ad1 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -194,6 +194,19 @@ config EXYNOS_ADC
 	  To compile this driver as a module, choose M here: the module will be
 	  called exynos_adc.
 
+config MXS_LRADC_ADC
+	tristate "Freescale i.MX23/i.MX28 LRADC ADC"
+	depends on MFD_MXS_LRADC
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  Say yes here to build support for the ADC functions of the
+	  i.MX23/i.MX28 LRADC. This includes general-purpose ADC readings,
+	  battery voltage measurement, and die temperature measurement.
+
+	  This driver can also be built as a module. If so, the module will be
+	  called mxs-lradc-adc.
+
 config HI8435
 	tristate "Holt Integrated Circuits HI-8435 threshold detector"
 	select IIO_TRIGGERED_EVENT
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index b1aa456..9bb35c4 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-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
 obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
 obj-$(CONFIG_NAU7802) += nau7802.o
 obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
diff --git a/drivers/iio/adc/mxs-lradc-adc.c b/drivers/iio/adc/mxs-lradc-adc.c
new file mode 100644
index 0000000..9c362ae
--- /dev/null
+++ b/drivers/iio/adc/mxs-lradc-adc.c
@@ -0,0 +1,833 @@
+/*
+ * Freescale MXS LRADC ADC driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ *
+ * Authors:
+ * Marek Vasut <marex@denx.de>
+ * Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mxs-lradc.h>
+#include <linux/module.h>
+#include <linux/of_irq.h>
+#include <linux/platform_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>
+
+/*
+ * 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
+
+#define VREF_MV_BASE 1850
+
+const char *mx23_lradc_adc_irq_names[] = {
+	"mxs-lradc-channel0",
+	"mxs-lradc-channel1",
+	"mxs-lradc-channel2",
+	"mxs-lradc-channel3",
+	"mxs-lradc-channel4",
+	"mxs-lradc-channel5",
+};
+
+const char *mx28_lradc_adc_irq_names[] = {
+	"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-button0",
+	"mxs-lradc-button1",
+};
+
+static const u32 mxs_lradc_adc_vref_mv[][LRADC_MAX_TOTAL_CHANS] = {
+	[IMX23_LRADC] = {
+		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 */
+	},
+	[IMX28_LRADC] = {
+		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 */
+	},
+};
+
+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_adc {
+	struct mxs_lradc	*lradc;
+	struct device		*dev;
+
+	u32			buffer[10];
+	struct iio_trigger	*trig;
+	struct completion	completion;
+	spinlock_t		lock;
+
+	const u32		*vref_mv;
+	struct mxs_lradc_scale	scale_avail[LRADC_MAX_TOTAL_CHANS][2];
+	unsigned long		is_divided;
+};
+
+
+/* Raw I/O operations */
+static int mxs_lradc_adc_read_single(struct iio_dev *iio_dev, int chan,
+				     int *val)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
+	struct mxs_lradc *lradc = adc->lradc;
+	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 = iio_device_claim_direct_mode(iio_dev);
+	if (ret)
+		return ret;
+
+	reinit_completion(&adc->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, &adc->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(&adc->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);
+
+	iio_device_release_direct_mode(iio_dev);
+
+	return ret;
+}
+
+static int mxs_lradc_adc_read_temp(struct iio_dev *iio_dev, int *val)
+{
+	int ret, min, max;
+
+	ret = mxs_lradc_adc_read_single(iio_dev, 8, &min);
+	if (ret != IIO_VAL_INT)
+		return ret;
+
+	ret = mxs_lradc_adc_read_single(iio_dev, 9, &max);
+	if (ret != IIO_VAL_INT)
+		return ret;
+
+	*val = max - min;
+
+	return IIO_VAL_INT;
+}
+
+static int mxs_lradc_adc_read_raw(struct iio_dev *iio_dev,
+			      const struct iio_chan_spec *chan,
+			      int *val, int *val2, long m)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
+
+	switch (m) {
+	case IIO_CHAN_INFO_RAW:
+		if (chan->type == IIO_TEMP)
+			return mxs_lradc_adc_read_temp(iio_dev, val);
+
+		return mxs_lradc_adc_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 = adc->vref_mv[chan->channel];
+		*val2 = chan->scan_type.realbits -
+			test_bit(chan->channel, &adc->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_adc_write_raw(struct iio_dev *iio_dev,
+				   const struct iio_chan_spec *chan,
+				   int val, int val2, long m)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
+	struct mxs_lradc_scale *scale_avail =
+			adc->scale_avail[chan->channel];
+	int ret;
+
+	ret = iio_device_claim_direct_mode(iio_dev);
+	if (ret)
+		return ret;
+
+	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, &adc->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, &adc->is_divided);
+			ret = 0;
+		}
+
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	iio_device_release_direct_mode(iio_dev);
+
+	return ret;
+}
+
+static int mxs_lradc_adc_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_adc_show_scale_avail(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct iio_dev *iio = dev_to_iio_dev(dev);
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+	struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
+	int i, ch, len = 0;
+
+	ch = iio_attr->address;
+	for (i = 0; i < ARRAY_SIZE(adc->scale_avail[ch]); i++)
+		len += sprintf(buf + len, "%u.%09u ",
+			       adc->scale_avail[ch][i].integer,
+			       adc->scale_avail[ch][i].nano);
+
+	len += sprintf(buf + len, "\n");
+
+	return len;
+}
+
+#define SHOW_SCALE_AVAILABLE_ATTR(ch)					\
+static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO,	\
+		       mxs_lradc_adc_show_scale_avail, 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_adc_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_adc_attribute_group = {
+	.attrs = mxs_lradc_adc_attributes,
+};
+
+static const struct iio_info mxs_lradc_adc_iio_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= mxs_lradc_adc_read_raw,
+	.write_raw		= mxs_lradc_adc_write_raw,
+	.write_raw_get_fmt	= mxs_lradc_adc_write_raw_get_fmt,
+	.attrs			= &mxs_lradc_adc_attribute_group,
+};
+
+/* IRQ Handling */
+static irqreturn_t mxs_lradc_adc_handle_irq(int irq, void *data)
+{
+	struct iio_dev *iio = data;
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+	struct mxs_lradc *lradc = adc->lradc;
+	unsigned long reg = readl(lradc->base + LRADC_CTRL1);
+	unsigned long flags;
+
+	if (!(reg & mxs_lradc_irq_mask(lradc)))
+		return IRQ_NONE;
+
+	if (iio_buffer_enabled(iio)) {
+		if (reg & lradc->buffer_vchans) {
+			spin_lock_irqsave(&adc->lock, flags);
+			iio_trigger_poll(iio->trig);
+			spin_unlock_irqrestore(&adc->lock, flags);
+		}
+	} else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
+		complete(&adc->completion);
+	}
+
+	mxs_lradc_reg_clear(lradc, reg & mxs_lradc_irq_mask(lradc),
+			    LRADC_CTRL1);
+
+	return IRQ_HANDLED;
+}
+
+
+/* Trigger handling */
+static irqreturn_t mxs_lradc_adc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *iio = pf->indio_dev;
+	struct mxs_lradc_adc *adc = 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) {
+		adc->buffer[j] = readl(adc->lradc->base + LRADC_CH(j));
+		mxs_lradc_reg_wrt(adc->lradc, chan_value, LRADC_CH(j));
+		adc->buffer[j] &= LRADC_CH_VALUE_MASK;
+		adc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
+		j++;
+	}
+
+	iio_push_to_buffers_with_timestamp(iio, adc->buffer, pf->timestamp);
+
+	iio_trigger_notify_done(iio->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int mxs_lradc_adc_configure_trigger(struct iio_trigger *trig, bool state)
+{
+	struct iio_dev *iio = iio_trigger_get_drvdata(trig);
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+	const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
+
+	mxs_lradc_reg_wrt(adc->lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
+
+	return 0;
+}
+
+static const struct iio_trigger_ops mxs_lradc_adc_trigger_ops = {
+	.owner = THIS_MODULE,
+	.set_trigger_state = &mxs_lradc_adc_configure_trigger,
+};
+
+static int mxs_lradc_adc_trigger_init(struct iio_dev *iio)
+{
+	int ret;
+	struct iio_trigger *trig;
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+
+	trig = devm_iio_trigger_alloc(&iio->dev, "%s-dev%i", iio->name,
+				      iio->id);
+
+	trig->dev.parent = adc->dev;
+	iio_trigger_set_drvdata(trig, iio);
+	trig->ops = &mxs_lradc_adc_trigger_ops;
+
+	ret = iio_trigger_register(trig);
+	if (ret)
+		return ret;
+
+	adc->trig = trig;
+
+	return 0;
+}
+
+static void mxs_lradc_adc_trigger_remove(struct iio_dev *iio)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+
+	iio_trigger_unregister(adc->trig);
+}
+
+static int mxs_lradc_adc_buffer_preenable(struct iio_dev *iio)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+	struct mxs_lradc *lradc = adc->lradc;
+	int 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);
+
+	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;
+}
+
+static int mxs_lradc_adc_buffer_postdisable(struct iio_dev *iio)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+	struct mxs_lradc *lradc = adc->lradc;
+
+	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);
+
+	return 0;
+}
+
+static bool mxs_lradc_adc_validate_scan_mask(struct iio_dev *iio,
+					     const unsigned long *mask)
+{
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+	struct mxs_lradc *lradc = adc->lradc;
+	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->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_4WIRE)
+		rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
+	if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
+		rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
+
+	if (lradc->use_touchbutton)
+		rsvd_chans++;
+	if (lradc->touchscreen_wire)
+		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_adc_buffer_ops = {
+	.preenable = &mxs_lradc_adc_buffer_preenable,
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = &iio_triggered_buffer_predisable,
+	.postdisable = &mxs_lradc_adc_buffer_postdisable,
+	.validate_scan_mask = &mxs_lradc_adc_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 void mxs_lradc_adc_hw_init(struct mxs_lradc_adc *adc)
+{
+	struct mxs_lradc *lradc = adc->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);
+
+	/* Configure DELAY CHANNEL 0 for generic ADC sampling. */
+	mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
+
+	/*
+	 * Start internal temperature sensing by clearing bit
+	 * HW_LRADC_CTRL2_TEMPSENSE_PWD. This bit can be left cleared
+	 * after power up.
+	 */
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
+}
+
+static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc)
+{
+	mxs_lradc_reg_wrt(adc->lradc, 0, LRADC_DELAY(0));
+}
+
+static int mxs_lradc_adc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mxs_lradc *lradc = dev_get_platdata(dev);
+	struct mxs_lradc_adc *adc;
+	struct iio_dev *iio;
+	int ret, irq, virq, i, s, n;
+	u64 scale_uv;
+	const char **irq_name;
+
+	/* Allocate the IIO device. */
+	iio = devm_iio_device_alloc(dev, sizeof(*adc));
+	if (!iio) {
+		dev_err(dev, "Failed to allocate IIO device\n");
+		return -ENOMEM;
+	}
+
+	adc = iio_priv(iio);
+	adc->lradc = lradc;
+	adc->dev = dev;
+
+	init_completion(&adc->completion);
+	spin_lock_init(&adc->lock);
+
+	platform_set_drvdata(pdev, iio);
+
+	iio->name = pdev->name;
+	iio->dev.parent = dev;
+	iio->dev.of_node = dev->parent->of_node;
+	iio->info = &mxs_lradc_adc_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);
+		irq_name = mx23_lradc_adc_irq_names;
+		n = ARRAY_SIZE(mx23_lradc_adc_irq_names);
+	} else {
+		iio->channels = mx28_lradc_chan_spec;
+		iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
+		irq_name = mx28_lradc_adc_irq_names;
+		n = ARRAY_SIZE(mx28_lradc_adc_irq_names);
+	}
+
+	for (i = 0; i < n; i++) {
+		irq = platform_get_irq_byname(pdev, irq_name[i]);
+		if (irq < 0)
+			return irq;
+
+		virq = irq_of_parse_and_map(dev->parent->of_node, irq);
+
+		ret = devm_request_irq(dev, virq, mxs_lradc_adc_handle_irq,
+				       0, irq_name[i], iio);
+		if (ret)
+			return ret;
+	}
+
+	ret = mxs_lradc_adc_trigger_init(iio);
+	if (ret)
+		goto err_trig;
+
+	ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
+					 &mxs_lradc_adc_trigger_handler,
+					 &mxs_lradc_adc_buffer_ops);
+	if (ret)
+		return ret;
+
+	adc->vref_mv = mxs_lradc_adc_vref_mv[lradc->soc];
+
+	/* Populate available ADC input ranges */
+	for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
+		for (s = 0; s < ARRAY_SIZE(adc->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)adc->vref_mv[i] * 100000000) >>
+				   (LRADC_RESOLUTION - s);
+			adc->scale_avail[i][s].nano =
+					do_div(scale_uv, 100000000) * 10;
+			adc->scale_avail[i][s].integer = scale_uv;
+		}
+	}
+
+	/* Configure the hardware. */
+	mxs_lradc_adc_hw_init(adc);
+
+	/* Register IIO device. */
+	ret = iio_device_register(iio);
+	if (ret) {
+		dev_err(dev, "Failed to register IIO device\n");
+		goto err_dev;
+	}
+
+	return 0;
+
+err_dev:
+	mxs_lradc_adc_hw_stop(adc);
+	mxs_lradc_adc_trigger_remove(iio);
+err_trig:
+	iio_triggered_buffer_cleanup(iio);
+	return ret;
+}
+
+static int mxs_lradc_adc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *iio = platform_get_drvdata(pdev);
+	struct mxs_lradc_adc *adc = iio_priv(iio);
+
+	iio_device_unregister(iio);
+	mxs_lradc_adc_hw_stop(adc);
+	mxs_lradc_adc_trigger_remove(iio);
+	iio_triggered_buffer_cleanup(iio);
+
+	return 0;
+}
+
+static struct platform_driver mxs_lradc_adc_driver = {
+	.driver = {
+		.name	= "mxs-lradc-adc",
+	},
+	.probe	= mxs_lradc_adc_probe,
+	.remove = mxs_lradc_adc_remove,
+};
+module_platform_driver(mxs_lradc_adc_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-lradc-adc");
-- 
1.9.1

Re: [PATCH v4 2/4] iio: adc: mxs-lradc: Add support for adc driver

[Jonathan Cameron]

On 04/08/16 14:29, Ksenija Stanojevic wrote:
> Add support for sixteen-channel 12-bit resolution ADC and its functions,
> which include general-purpose ADC readings, battery voltage measurement,
> and die temperature measurement.
> 
> Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Acked-by: Jonathan Cameron <jic23-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> 
> ---
> Changes in v4:
>  - update copyright
>  - use platform_get_irq_byname
>  - use irq_of_parse_and_map
> 
> Changes in v3:
>  - nothing
> 
> Changes in v2:
>  - improve commit message
>  - do not change spacing in Kconfig
>  - impove formating
>  - remove wrapper show_scale_avail
>  - use correct syntax for comments
>  - use devm_iio_trigger_alloc
>  - do not allocate buffer dynamically 
>  - use iio_device_claim_*_mode helpers
>  - add spinlock in struct mxs_lradc_ts to enable locking in interrupt handler
>  - only grab irqs that are relevant to adc
>  - remove blank line at the end of the file
>  - change licence to GPL
>  - add copyright
> 
>  drivers/iio/adc/Kconfig         |  13 +
>  drivers/iio/adc/Makefile        |   1 +
>  drivers/iio/adc/mxs-lradc-adc.c | 833 ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 847 insertions(+)
>  create mode 100644 drivers/iio/adc/mxs-lradc-adc.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 932de1f..4ef3ad1 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -194,6 +194,19 @@ config EXYNOS_ADC
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called exynos_adc.
>  
> +config MXS_LRADC_ADC
> +	tristate "Freescale i.MX23/i.MX28 LRADC ADC"
> +	depends on MFD_MXS_LRADC
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  Say yes here to build support for the ADC functions of the
> +	  i.MX23/i.MX28 LRADC. This includes general-purpose ADC readings,
> +	  battery voltage measurement, and die temperature measurement.
> +
> +	  This driver can also be built as a module. If so, the module will be
> +	  called mxs-lradc-adc.
> +
>  config HI8435
>  	tristate "Holt Integrated Circuits HI-8435 threshold detector"
>  	select IIO_TRIGGERED_EVENT
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index b1aa456..9bb35c4 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-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
>  obj-$(CONFIG_MXS_LRADC) += mxs-lradc.o
>  obj-$(CONFIG_NAU7802) += nau7802.o
>  obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
> diff --git a/drivers/iio/adc/mxs-lradc-adc.c b/drivers/iio/adc/mxs-lradc-adc.c
> new file mode 100644
> index 0000000..9c362ae
> --- /dev/null
> +++ b/drivers/iio/adc/mxs-lradc-adc.c
> @@ -0,0 +1,833 @@
> +/*
> + * Freescale MXS LRADC ADC driver
> + *
> + * Copyright (c) 2012 DENX Software Engineering, GmbH.
> + *
> + * Authors:
> + * Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>
> + * Ksenija Stanojevic <ksenija.stanojevic-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> + *
> + * 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/completion.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/core.h>
> +#include <linux/mfd/mxs-lradc.h>
> +#include <linux/module.h>
> +#include <linux/of_irq.h>
> +#include <linux/platform_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>
> +
> +/*
> + * 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
> +
> +#define VREF_MV_BASE 1850
> +
> +const char *mx23_lradc_adc_irq_names[] = {
> +	"mxs-lradc-channel0",
> +	"mxs-lradc-channel1",
> +	"mxs-lradc-channel2",
> +	"mxs-lradc-channel3",
> +	"mxs-lradc-channel4",
> +	"mxs-lradc-channel5",
> +};
> +
> +const char *mx28_lradc_adc_irq_names[] = {
> +	"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-button0",
> +	"mxs-lradc-button1",
> +};
> +
> +static const u32 mxs_lradc_adc_vref_mv[][LRADC_MAX_TOTAL_CHANS] = {
> +	[IMX23_LRADC] = {
> +		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 */
> +	},
> +	[IMX28_LRADC] = {
> +		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 */
> +	},
> +};
> +
> +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_adc {
> +	struct mxs_lradc	*lradc;
> +	struct device		*dev;
> +
> +	u32			buffer[10];
> +	struct iio_trigger	*trig;
> +	struct completion	completion;
> +	spinlock_t		lock;
> +
> +	const u32		*vref_mv;
> +	struct mxs_lradc_scale	scale_avail[LRADC_MAX_TOTAL_CHANS][2];
> +	unsigned long		is_divided;
> +};
> +
> +
> +/* Raw I/O operations */
> +static int mxs_lradc_adc_read_single(struct iio_dev *iio_dev, int chan,
> +				     int *val)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
> +	struct mxs_lradc *lradc = adc->lradc;
> +	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 = iio_device_claim_direct_mode(iio_dev);
> +	if (ret)
> +		return ret;
> +
> +	reinit_completion(&adc->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, &adc->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(&adc->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);
> +
> +	iio_device_release_direct_mode(iio_dev);
> +
> +	return ret;
> +}
> +
> +static int mxs_lradc_adc_read_temp(struct iio_dev *iio_dev, int *val)
> +{
> +	int ret, min, max;
> +
> +	ret = mxs_lradc_adc_read_single(iio_dev, 8, &min);
> +	if (ret != IIO_VAL_INT)
> +		return ret;
> +
> +	ret = mxs_lradc_adc_read_single(iio_dev, 9, &max);
> +	if (ret != IIO_VAL_INT)
> +		return ret;
> +
> +	*val = max - min;
> +
> +	return IIO_VAL_INT;
> +}
> +
> +static int mxs_lradc_adc_read_raw(struct iio_dev *iio_dev,
> +			      const struct iio_chan_spec *chan,
> +			      int *val, int *val2, long m)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_RAW:
> +		if (chan->type == IIO_TEMP)
> +			return mxs_lradc_adc_read_temp(iio_dev, val);
> +
> +		return mxs_lradc_adc_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 = adc->vref_mv[chan->channel];
> +		*val2 = chan->scan_type.realbits -
> +			test_bit(chan->channel, &adc->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_adc_write_raw(struct iio_dev *iio_dev,
> +				   const struct iio_chan_spec *chan,
> +				   int val, int val2, long m)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio_dev);
> +	struct mxs_lradc_scale *scale_avail =
> +			adc->scale_avail[chan->channel];
> +	int ret;
> +
> +	ret = iio_device_claim_direct_mode(iio_dev);
> +	if (ret)
> +		return ret;
> +
> +	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, &adc->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, &adc->is_divided);
> +			ret = 0;
> +		}
> +
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	iio_device_release_direct_mode(iio_dev);
> +
> +	return ret;
> +}
> +
> +static int mxs_lradc_adc_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_adc_show_scale_avail(struct device *dev,
> +						 struct device_attribute *attr,
> +						 char *buf)
> +{
> +	struct iio_dev *iio = dev_to_iio_dev(dev);
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +	struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
> +	int i, ch, len = 0;
> +
> +	ch = iio_attr->address;
> +	for (i = 0; i < ARRAY_SIZE(adc->scale_avail[ch]); i++)
> +		len += sprintf(buf + len, "%u.%09u ",
> +			       adc->scale_avail[ch][i].integer,
> +			       adc->scale_avail[ch][i].nano);
> +
> +	len += sprintf(buf + len, "\n");
> +
> +	return len;
> +}
> +
> +#define SHOW_SCALE_AVAILABLE_ATTR(ch)					\
> +static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO,	\
> +		       mxs_lradc_adc_show_scale_avail, 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_adc_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_adc_attribute_group = {
> +	.attrs = mxs_lradc_adc_attributes,
> +};
> +
> +static const struct iio_info mxs_lradc_adc_iio_info = {
> +	.driver_module		= THIS_MODULE,
> +	.read_raw		= mxs_lradc_adc_read_raw,
> +	.write_raw		= mxs_lradc_adc_write_raw,
> +	.write_raw_get_fmt	= mxs_lradc_adc_write_raw_get_fmt,
> +	.attrs			= &mxs_lradc_adc_attribute_group,
> +};
> +
> +/* IRQ Handling */
> +static irqreturn_t mxs_lradc_adc_handle_irq(int irq, void *data)
> +{
> +	struct iio_dev *iio = data;
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +	struct mxs_lradc *lradc = adc->lradc;
> +	unsigned long reg = readl(lradc->base + LRADC_CTRL1);
> +	unsigned long flags;
> +
> +	if (!(reg & mxs_lradc_irq_mask(lradc)))
> +		return IRQ_NONE;
> +
> +	if (iio_buffer_enabled(iio)) {
> +		if (reg & lradc->buffer_vchans) {
> +			spin_lock_irqsave(&adc->lock, flags);
> +			iio_trigger_poll(iio->trig);
> +			spin_unlock_irqrestore(&adc->lock, flags);
> +		}
> +	} else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
> +		complete(&adc->completion);
> +	}
> +
> +	mxs_lradc_reg_clear(lradc, reg & mxs_lradc_irq_mask(lradc),
> +			    LRADC_CTRL1);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +
> +/* Trigger handling */
> +static irqreturn_t mxs_lradc_adc_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *iio = pf->indio_dev;
> +	struct mxs_lradc_adc *adc = 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) {
> +		adc->buffer[j] = readl(adc->lradc->base + LRADC_CH(j));
> +		mxs_lradc_reg_wrt(adc->lradc, chan_value, LRADC_CH(j));
> +		adc->buffer[j] &= LRADC_CH_VALUE_MASK;
> +		adc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
> +		j++;
> +	}
> +
> +	iio_push_to_buffers_with_timestamp(iio, adc->buffer, pf->timestamp);
> +
> +	iio_trigger_notify_done(iio->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int mxs_lradc_adc_configure_trigger(struct iio_trigger *trig, bool state)
> +{
> +	struct iio_dev *iio = iio_trigger_get_drvdata(trig);
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +	const u32 st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
> +
> +	mxs_lradc_reg_wrt(adc->lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
> +
> +	return 0;
> +}
> +
> +static const struct iio_trigger_ops mxs_lradc_adc_trigger_ops = {
> +	.owner = THIS_MODULE,
> +	.set_trigger_state = &mxs_lradc_adc_configure_trigger,
> +};
> +
> +static int mxs_lradc_adc_trigger_init(struct iio_dev *iio)
> +{
> +	int ret;
> +	struct iio_trigger *trig;
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +
> +	trig = devm_iio_trigger_alloc(&iio->dev, "%s-dev%i", iio->name,
> +				      iio->id);
> +
> +	trig->dev.parent = adc->dev;
> +	iio_trigger_set_drvdata(trig, iio);
> +	trig->ops = &mxs_lradc_adc_trigger_ops;
> +
> +	ret = iio_trigger_register(trig);
> +	if (ret)
> +		return ret;
> +
> +	adc->trig = trig;
> +
> +	return 0;
> +}
> +
> +static void mxs_lradc_adc_trigger_remove(struct iio_dev *iio)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +
> +	iio_trigger_unregister(adc->trig);
> +}
> +
> +static int mxs_lradc_adc_buffer_preenable(struct iio_dev *iio)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +	struct mxs_lradc *lradc = adc->lradc;
> +	int 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);
> +
> +	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;
> +}
> +
> +static int mxs_lradc_adc_buffer_postdisable(struct iio_dev *iio)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +	struct mxs_lradc *lradc = adc->lradc;
> +
> +	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);
> +
> +	return 0;
> +}
> +
> +static bool mxs_lradc_adc_validate_scan_mask(struct iio_dev *iio,
> +					     const unsigned long *mask)
> +{
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +	struct mxs_lradc *lradc = adc->lradc;
> +	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->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_4WIRE)
> +		rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
> +	if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
> +		rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
> +
> +	if (lradc->use_touchbutton)
> +		rsvd_chans++;
> +	if (lradc->touchscreen_wire)
> +		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_adc_buffer_ops = {
> +	.preenable = &mxs_lradc_adc_buffer_preenable,
> +	.postenable = &iio_triggered_buffer_postenable,
> +	.predisable = &iio_triggered_buffer_predisable,
> +	.postdisable = &mxs_lradc_adc_buffer_postdisable,
> +	.validate_scan_mask = &mxs_lradc_adc_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 void mxs_lradc_adc_hw_init(struct mxs_lradc_adc *adc)
> +{
> +	struct mxs_lradc *lradc = adc->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);
> +
> +	/* Configure DELAY CHANNEL 0 for generic ADC sampling. */
> +	mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
> +
> +	/*
> +	 * Start internal temperature sensing by clearing bit
> +	 * HW_LRADC_CTRL2_TEMPSENSE_PWD. This bit can be left cleared
> +	 * after power up.
> +	 */
> +	mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
> +}
> +
> +static void mxs_lradc_adc_hw_stop(struct mxs_lradc_adc *adc)
> +{
> +	mxs_lradc_reg_wrt(adc->lradc, 0, LRADC_DELAY(0));
> +}
> +
> +static int mxs_lradc_adc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct mxs_lradc *lradc = dev_get_platdata(dev);
> +	struct mxs_lradc_adc *adc;
> +	struct iio_dev *iio;
> +	int ret, irq, virq, i, s, n;
> +	u64 scale_uv;
> +	const char **irq_name;
> +
> +	/* Allocate the IIO device. */
> +	iio = devm_iio_device_alloc(dev, sizeof(*adc));
> +	if (!iio) {
> +		dev_err(dev, "Failed to allocate IIO device\n");
> +		return -ENOMEM;
> +	}
> +
> +	adc = iio_priv(iio);
> +	adc->lradc = lradc;
> +	adc->dev = dev;
> +
> +	init_completion(&adc->completion);
> +	spin_lock_init(&adc->lock);
> +
> +	platform_set_drvdata(pdev, iio);
> +
> +	iio->name = pdev->name;
> +	iio->dev.parent = dev;
> +	iio->dev.of_node = dev->parent->of_node;
> +	iio->info = &mxs_lradc_adc_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);
> +		irq_name = mx23_lradc_adc_irq_names;
> +		n = ARRAY_SIZE(mx23_lradc_adc_irq_names);
> +	} else {
> +		iio->channels = mx28_lradc_chan_spec;
> +		iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
> +		irq_name = mx28_lradc_adc_irq_names;
> +		n = ARRAY_SIZE(mx28_lradc_adc_irq_names);
> +	}
> +
> +	for (i = 0; i < n; i++) {
> +		irq = platform_get_irq_byname(pdev, irq_name[i]);
> +		if (irq < 0)
> +			return irq;
> +
> +		virq = irq_of_parse_and_map(dev->parent->of_node, irq);
> +
> +		ret = devm_request_irq(dev, virq, mxs_lradc_adc_handle_irq,
> +				       0, irq_name[i], iio);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = mxs_lradc_adc_trigger_init(iio);
> +	if (ret)
> +		goto err_trig;
> +
> +	ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
> +					 &mxs_lradc_adc_trigger_handler,
> +					 &mxs_lradc_adc_buffer_ops);
> +	if (ret)
> +		return ret;
> +
> +	adc->vref_mv = mxs_lradc_adc_vref_mv[lradc->soc];
> +
> +	/* Populate available ADC input ranges */
> +	for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
> +		for (s = 0; s < ARRAY_SIZE(adc->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)adc->vref_mv[i] * 100000000) >>
> +				   (LRADC_RESOLUTION - s);
> +			adc->scale_avail[i][s].nano =
> +					do_div(scale_uv, 100000000) * 10;
> +			adc->scale_avail[i][s].integer = scale_uv;
> +		}
> +	}
> +
> +	/* Configure the hardware. */
> +	mxs_lradc_adc_hw_init(adc);
> +
> +	/* Register IIO device. */
> +	ret = iio_device_register(iio);
> +	if (ret) {
> +		dev_err(dev, "Failed to register IIO device\n");
> +		goto err_dev;
> +	}
> +
> +	return 0;
> +
> +err_dev:
> +	mxs_lradc_adc_hw_stop(adc);
> +	mxs_lradc_adc_trigger_remove(iio);
> +err_trig:
> +	iio_triggered_buffer_cleanup(iio);
> +	return ret;
> +}
> +
> +static int mxs_lradc_adc_remove(struct platform_device *pdev)
> +{
> +	struct iio_dev *iio = platform_get_drvdata(pdev);
> +	struct mxs_lradc_adc *adc = iio_priv(iio);
> +
> +	iio_device_unregister(iio);
> +	mxs_lradc_adc_hw_stop(adc);
> +	mxs_lradc_adc_trigger_remove(iio);
> +	iio_triggered_buffer_cleanup(iio);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver mxs_lradc_adc_driver = {
> +	.driver = {
> +		.name	= "mxs-lradc-adc",
> +	},
> +	.probe	= mxs_lradc_adc_probe,
> +	.remove = mxs_lradc_adc_remove,
> +};
> +module_platform_driver(mxs_lradc_adc_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marex-ynQEQJNshbs@public.gmane.org>");
> +MODULE_DESCRIPTION("Freescale MXS LRADC driver general purpose ADC driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:mxs-lradc-adc");
> 

[PATCH v4 3/4] input: touchscreen: mxs-lradc: Add support for touchscreen

[Ksenija Stanojevic]

Add 4-wire/5-wire touchscreen controller.

Signed-off-by: Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
---
Changes in v4:
 - update copyright
 - use platform_get_irq_byname
 - use irq_of_parse_and_map

Changes in v3:
 - add MODULE_*(ALIAS, AUTHOR, DESCRIPTION)

Changes in v2:
 - do not change spacing in Kconfig
 - remove dev.parent
 - rename err_ts_register to error
 - combine functions hw_stop and disable_ts so that mxs_lradc_ts_remove
   could be deleted.
 - add spinlock in struct mxs_lradc_ts to enable locking in interrupt handler.
 - only grab irqs that are relevant to touchscreen
 - use direct return instead assigning error to touch_ret in probe function.
 - change licence to GPL
 - add copyright

 drivers/input/touchscreen/Kconfig        |  10 +
 drivers/input/touchscreen/Makefile       |   1 +
 drivers/input/touchscreen/mxs-lradc-ts.c | 736 +++++++++++++++++++++++++++++++
 3 files changed, 747 insertions(+)
 create mode 100644 drivers/input/touchscreen/mxs-lradc-ts.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 66c6264..a34661d 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -305,6 +305,16 @@ config TOUCHSCREEN_EGALAX_SERIAL
 	  To compile this driver as a module, choose M here: the
 	  module will be called egalax_ts_serial.
 
+config TOUCHSCREEN_MXS_LRADC
+	tristate "Freescale i.MX23/i.MX28 LRADC touchscreen"
+	depends on MFD_MXS_LRADC
+	help
+	  Say Y here if you have a touchscreen connected to the low-resolution
+	  analog-to-digital converter (LRADC) on an i.MX23 or i.MX28 processor.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called mxs-lradc-ts.
+
 config TOUCHSCREEN_FT6236
 	tristate "FT6236 I2C touchscreen"
 	depends on I2C
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 968ff12..6319b5c 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MMS114)	+= mms114.o
 obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
+obj-$(CONFIG_TOUCHSCREEN_MXS_LRADC)	+= mxs-lradc-ts.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
 obj-$(CONFIG_TOUCHSCREEN_IPAQ_MICRO)	+= ipaq-micro-ts.o
diff --git a/drivers/input/touchscreen/mxs-lradc-ts.c b/drivers/input/touchscreen/mxs-lradc-ts.c
new file mode 100644
index 0000000..e2c0301
--- /dev/null
+++ b/drivers/input/touchscreen/mxs-lradc-ts.c
@@ -0,0 +1,736 @@
+/*
+ * Freescale MXS LRADC touchscreen driver
+ *
+ * Copyright (c) 2012 DENX Software Engineering, GmbH.
+ *
+ * Authors:
+ * Marek Vasut <marex@denx.de>
+ * Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/mxs-lradc.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+const char *mxs_lradc_ts_irq_names[] = {
+	"mxs-lradc-touchscreen",
+	"mxs-lradc-channel6",
+	"mxs-lradc-channel7",
+};
+
+/*
+ * Touchscreen handling
+ */
+enum mxs_lradc_ts_plate {
+	LRADC_TOUCH = 0,
+	LRADC_SAMPLE_X,
+	LRADC_SAMPLE_Y,
+	LRADC_SAMPLE_PRESSURE,
+	LRADC_SAMPLE_VALID,
+};
+
+struct mxs_lradc_ts {
+	struct mxs_lradc	*lradc;
+	struct device		*dev;
+	/*
+	 * When the touchscreen is enabled, we give it two private virtual
+	 * channels: #6 and #7. This means that only 6 virtual channels (instead
+	 * of 8) will be available for buffered capture.
+	 */
+#define TOUCHSCREEN_VCHANNEL1		7
+#define TOUCHSCREEN_VCHANNEL2		6
+
+	struct input_dev	*ts_input;
+
+	enum mxs_lradc_ts_plate	cur_plate; /* state machine */
+	bool			ts_valid;
+	unsigned int		ts_x_pos;
+	unsigned int		ts_y_pos;
+	unsigned int		ts_pressure;
+
+	/* handle touchscreen's physical behaviour */
+	/* samples per coordinate */
+	unsigned int		over_sample_cnt;
+	/* time clocks between samples */
+	unsigned int		over_sample_delay;
+	/* time in clocks to wait after the plates where switched */
+	unsigned int		settling_delay;
+	spinlock_t		lock;
+};
+
+static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
+{
+	if (lradc->soc == IMX23_LRADC)
+		return LRADC_CTRL0_MX23_PLATE_MASK;
+	return LRADC_CTRL0_MX28_PLATE_MASK;
+}
+
+static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
+{
+	if (lradc->soc == IMX23_LRADC)
+		return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
+	return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
+}
+
+static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
+{
+	if (lradc->soc == IMX23_LRADC)
+		return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
+	return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
+{
+	if (lradc->soc == IMX23_LRADC)
+		return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
+	return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
+}
+
+static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
+{
+	if (lradc->soc == IMX23_LRADC)
+		return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
+	return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
+}
+
+static bool mxs_lradc_check_touch_event(struct mxs_lradc *lradc)
+{
+	return !!(readl(lradc->base + LRADC_STATUS) &
+					LRADC_STATUS_TOUCH_DETECT_RAW);
+}
+
+static void mxs_lradc_map_ts_channel(struct mxs_lradc *lradc, unsigned int vch,
+				     unsigned int ch)
+{
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(vch),
+			    LRADC_CTRL4);
+	mxs_lradc_reg_set(lradc, LRADC_CTRL4_LRADCSELECT(vch, ch), LRADC_CTRL4);
+}
+
+static void mxs_lradc_setup_ts_channel(struct mxs_lradc_ts *ts, unsigned int ch)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	/*
+	 * prepare for oversampling conversion
+	 *
+	 * from the datasheet:
+	 * "The ACCUMULATE bit in the appropriate channel register
+	 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+	 * otherwise, the IRQs will not fire."
+	 */
+	mxs_lradc_reg_wrt(lradc, LRADC_CH_ACCUMULATE |
+			  LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1),
+			  LRADC_CH(ch));
+
+	/* from the datasheet:
+	 * "Software must clear this register in preparation for a
+	 * multi-cycle accumulation.
+	 */
+	mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
+
+	/*
+	 * prepare the delay/loop unit according to the oversampling count
+	 *
+	 * from the datasheet:
+	 * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
+	 * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
+	 * the LRADC will not trigger the delay group."
+	 */
+	mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
+			  LRADC_DELAY_TRIGGER_DELAYS(0) |
+			  LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
+			  LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
+			  LRADC_DELAY(3));
+
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch), LRADC_CTRL1);
+
+	/*
+	 * after changing the touchscreen plates setting
+	 * the signals need some initial time to settle. Start the
+	 * SoC's delay unit and start the conversion later
+	 * and automatically.
+	 */
+	mxs_lradc_reg_wrt(
+		lradc,
+		LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
+		LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
+		LRADC_DELAY_KICK |
+		LRADC_DELAY_DELAY(ts->settling_delay),
+		LRADC_DELAY(2));
+}
+
+/*
+ * Pressure detection is special:
+ * We want to do both required measurements for the pressure detection in
+ * one turn. Use the hardware features to chain both conversions and let the
+ * hardware report one interrupt if both conversions are done
+ */
+static void mxs_lradc_setup_ts_pressure(struct mxs_lradc_ts *ts,
+					unsigned int ch1, unsigned int ch2)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+	u32 reg;
+
+	/*
+	 * prepare for oversampling conversion
+	 *
+	 * from the datasheet:
+	 * "The ACCUMULATE bit in the appropriate channel register
+	 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
+	 * otherwise, the IRQs will not fire."
+	 */
+	reg = LRADC_CH_ACCUMULATE |
+		LRADC_CH_NUM_SAMPLES(ts->over_sample_cnt - 1);
+	mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch1));
+	mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch2));
+
+	/* from the datasheet:
+	 * "Software must clear this register in preparation for a
+	 * multi-cycle accumulation.
+	 */
+	mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
+	mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
+
+	/* prepare the delay/loop unit according to the oversampling count */
+	mxs_lradc_reg_wrt(lradc,
+		    LRADC_DELAY_TRIGGER(1 << ch1) |
+		    LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
+		    LRADC_DELAY_TRIGGER_DELAYS(0) |
+		    LRADC_DELAY_LOOP(ts->over_sample_cnt - 1) |
+		    LRADC_DELAY_DELAY(ts->over_sample_delay - 1),
+		    LRADC_DELAY(3));
+
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch2), LRADC_CTRL1);
+
+	/*
+	 * after changing the touchscreen plates setting
+	 * the signals need some initial time to settle. Start the
+	 * SoC's delay unit and start the conversion later
+	 * and automatically.
+	 */
+	mxs_lradc_reg_wrt(lradc,
+		LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
+		LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
+		LRADC_DELAY_KICK |
+		LRADC_DELAY_DELAY(ts->settling_delay), LRADC_DELAY(2));
+}
+
+static unsigned int mxs_lradc_ts_read_raw_channel(struct mxs_lradc_ts *ts,
+						  unsigned int channel)
+{
+	u32 reg;
+	unsigned int num_samples, val;
+	struct mxs_lradc *lradc = ts->lradc;
+
+	reg = readl(lradc->base + LRADC_CH(channel));
+	if (reg & LRADC_CH_ACCUMULATE)
+		num_samples = ts->over_sample_cnt;
+	else
+		num_samples = 1;
+
+	val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
+	return val / num_samples;
+}
+
+static unsigned int mxs_lradc_read_ts_pressure(struct mxs_lradc_ts *ts,
+					unsigned int ch1, unsigned int ch2)
+{
+	u32 reg, mask;
+	unsigned int pressure, m1, m2;
+	struct mxs_lradc *lradc = ts->lradc;
+
+	mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
+	reg = readl(lradc->base + LRADC_CTRL1) & mask;
+
+	while (reg != mask) {
+		reg = readl(lradc->base + LRADC_CTRL1) & mask;
+		dev_dbg(ts->dev, "One channel is still busy: %X\n", reg);
+	}
+
+	m1 = mxs_lradc_ts_read_raw_channel(ts, ch1);
+	m2 = mxs_lradc_ts_read_raw_channel(ts, ch2);
+
+	if (m2 == 0) {
+		dev_warn(ts->dev, "Cannot calculate pressure\n");
+		return 1 << (LRADC_RESOLUTION - 1);
+	}
+
+	/* simply scale the value from 0 ... max ADC resolution */
+	pressure = m1;
+	pressure *= (1 << LRADC_RESOLUTION);
+	pressure /= m2;
+
+	dev_dbg(ts->dev, "Pressure = %u\n", pressure);
+	return pressure;
+}
+
+#define TS_CH_XP 2
+#define TS_CH_YP 3
+#define TS_CH_XM 4
+#define TS_CH_YM 5
+
+/*
+ * YP(open)--+-------------+
+ *	     |		   |--+
+ *	     |		   |  |
+ *    YM(-)--+-------------+  |
+ *	       +--------------+
+ *	       |	      |
+ *	   XP(weak+)	    XM(open)
+ *
+ * "weak+" means 200k Ohm VDDIO
+ * (-) means GND
+ */
+static void mxs_lradc_setup_touch_detection(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	/*
+	 * In order to detect a touch event the 'touch detect enable' bit
+	 * enables:
+	 *  - a weak pullup to the X+ connector
+	 *  - a strong ground at the Y- connector
+	 */
+	mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+	mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
+			  LRADC_CTRL0);
+}
+
+/*
+ * YP(meas)--+-------------+
+ *	     |		   |--+
+ *	     |		   |  |
+ * YM(open)--+-------------+  |
+ *	       +--------------+
+ *	       |	      |
+ *	     XP(+)	    XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_x_pos(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+	mxs_lradc_reg_set(lradc, mxs_lradc_drive_x_plate(lradc), LRADC_CTRL0);
+
+	ts->cur_plate = LRADC_SAMPLE_X;
+	mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
+	mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ *   YP(+)--+-------------+
+ *	    |		  |--+
+ *	    |		  |  |
+ *   YM(-)--+-------------+  |
+ *	      +--------------+
+ *	      |		     |
+ *	   XP(open)	   XM(meas)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_y_pos(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+	mxs_lradc_reg_set(lradc, mxs_lradc_drive_y_plate(lradc), LRADC_CTRL0);
+
+	ts->cur_plate = LRADC_SAMPLE_Y;
+	mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
+	mxs_lradc_setup_ts_channel(ts, TOUCHSCREEN_VCHANNEL1);
+}
+
+/*
+ *    YP(+)--+-------------+
+ *	     |		   |--+
+ *	     |		   |  |
+ * YM(meas)--+-------------+  |
+ *	       +--------------+
+ *	       |	      |
+ *	    XP(meas)	    XM(-)
+ *
+ * (+) means here 1.85 V
+ * (-) means here GND
+ */
+static void mxs_lradc_prepare_pressure(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+	mxs_lradc_reg_set(lradc, mxs_lradc_drive_pressure(lradc), LRADC_CTRL0);
+
+	ts->cur_plate = LRADC_SAMPLE_PRESSURE;
+	mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
+	mxs_lradc_map_ts_channel(lradc, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
+	mxs_lradc_setup_ts_pressure(ts, TOUCHSCREEN_VCHANNEL2,
+				    TOUCHSCREEN_VCHANNEL1);
+}
+
+static void mxs_lradc_enable_touch_detection(struct mxs_lradc_ts *ts)
+{
+	mxs_lradc_setup_touch_detection(ts);
+
+	ts->cur_plate = LRADC_TOUCH;
+	mxs_lradc_reg_clear(ts->lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
+			    LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
+	mxs_lradc_reg_set(ts->lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+			  LRADC_CTRL1);
+}
+
+static void mxs_lradc_start_touch_event(struct mxs_lradc_ts *ts)
+{
+	mxs_lradc_reg_clear(ts->lradc,
+			    LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+			    LRADC_CTRL1);
+	mxs_lradc_reg_set(ts->lradc,
+			  LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1),
+			  LRADC_CTRL1);
+	/*
+	 * start with the Y-pos, because it uses nearly the same plate
+	 * settings like the touch detection
+	 */
+	mxs_lradc_prepare_y_pos(ts);
+}
+
+static void mxs_lradc_report_ts_event(struct mxs_lradc_ts *ts)
+{
+	input_report_abs(ts->ts_input, ABS_X, ts->ts_x_pos);
+	input_report_abs(ts->ts_input, ABS_Y, ts->ts_y_pos);
+	input_report_abs(ts->ts_input, ABS_PRESSURE, ts->ts_pressure);
+	input_report_key(ts->ts_input, BTN_TOUCH, 1);
+	input_sync(ts->ts_input);
+}
+
+static void mxs_lradc_complete_touch_event(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	mxs_lradc_setup_touch_detection(ts);
+	ts->cur_plate = LRADC_SAMPLE_VALID;
+	/*
+	 * start a dummy conversion to burn time to settle the signals
+	 * note: we are not interested in the conversion's value
+	 */
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(TOUCHSCREEN_VCHANNEL1));
+	mxs_lradc_reg_clear(lradc,
+			    LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+			    LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2),
+			    LRADC_CTRL1);
+	mxs_lradc_reg_wrt(lradc,
+		    LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
+		    LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
+		    LRADC_DELAY(2));
+}
+
+/*
+ * in order to avoid false measurements, report only samples where
+ * the surface is still touched after the position measurement
+ */
+static void mxs_lradc_finish_touch_event(struct mxs_lradc_ts *ts, bool valid)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	/* if it is still touched, report the sample */
+	if (valid && mxs_lradc_check_touch_event(lradc)) {
+		ts->ts_valid = true;
+		mxs_lradc_report_ts_event(ts);
+	}
+
+	/* if it is even still touched, continue with the next measurement */
+	if (mxs_lradc_check_touch_event(lradc)) {
+		mxs_lradc_prepare_y_pos(ts);
+		return;
+	}
+
+	if (ts->ts_valid) {
+		/* signal the release */
+		ts->ts_valid = false;
+		input_report_key(ts->ts_input, BTN_TOUCH, 0);
+		input_sync(ts->ts_input);
+	}
+
+	/* if it is released, wait for the next touch via IRQ */
+	ts->cur_plate = LRADC_TOUCH;
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
+	mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
+	mxs_lradc_reg_clear(lradc,
+			    LRADC_CTRL1_TOUCH_DETECT_IRQ |
+			    LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+			    LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1),
+			    LRADC_CTRL1);
+	mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
+}
+
+/* touchscreen's state machine */
+static void mxs_lradc_handle_touch(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	switch (ts->cur_plate) {
+	case LRADC_TOUCH:
+		if (mxs_lradc_check_touch_event(lradc))
+			mxs_lradc_start_touch_event(ts);
+		mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
+				    LRADC_CTRL1);
+		return;
+
+	case LRADC_SAMPLE_Y:
+		ts->ts_y_pos =
+		    mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
+		mxs_lradc_prepare_x_pos(ts);
+		return;
+
+	case LRADC_SAMPLE_X:
+		ts->ts_x_pos =
+		    mxs_lradc_ts_read_raw_channel(ts, TOUCHSCREEN_VCHANNEL1);
+		mxs_lradc_prepare_pressure(ts);
+		return;
+
+	case LRADC_SAMPLE_PRESSURE:
+		ts->ts_pressure =
+		    mxs_lradc_read_ts_pressure(ts,
+					       TOUCHSCREEN_VCHANNEL2,
+					       TOUCHSCREEN_VCHANNEL1);
+		mxs_lradc_complete_touch_event(ts);
+		return;
+
+	case LRADC_SAMPLE_VALID:
+		mxs_lradc_finish_touch_event(ts, 1);
+		break;
+	}
+}
+
+/* IRQ Handling */
+static irqreturn_t mxs_lradc_ts_handle_irq(int irq, void *data)
+{
+	struct mxs_lradc_ts *ts = data;
+	struct mxs_lradc *lradc = ts->lradc;
+	unsigned long reg = readl(lradc->base + LRADC_CTRL1);
+	u32 clr_irq = mxs_lradc_irq_mask(lradc);
+	const u32 ts_irq_mask =
+		LRADC_CTRL1_TOUCH_DETECT_IRQ |
+		LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+		LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
+	unsigned long flags;
+
+	if (!(reg & mxs_lradc_irq_mask(lradc)))
+		return IRQ_NONE;
+
+	if (reg & ts_irq_mask) {
+		spin_lock_irqsave(&ts->lock, flags);
+		mxs_lradc_handle_touch(ts);
+		spin_unlock_irqrestore(&ts->lock, flags);
+		/* Make sure we don't clear the next conversion's interrupt. */
+		clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
+				LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
+		mxs_lradc_reg_clear(lradc, reg & clr_irq, LRADC_CTRL1);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int mxs_lradc_ts_open(struct input_dev *dev)
+{
+	struct mxs_lradc_ts *ts = input_get_drvdata(dev);
+
+	/* Enable the touch-detect circuitry. */
+	mxs_lradc_enable_touch_detection(ts);
+
+	return 0;
+}
+
+static void mxs_lradc_ts_stop(struct mxs_lradc_ts *ts)
+{
+	int i;
+	struct mxs_lradc *lradc = ts->lradc;
+
+	/* stop all interrupts from firing */
+	mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
+		LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
+		LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
+
+	/* Power-down touchscreen touch-detect circuitry. */
+	mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
+
+	mxs_lradc_reg_clear(lradc,
+			lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
+			LRADC_CTRL1);
+
+	for (i = 1; i < LRADC_MAX_DELAY_CHANS; i++)
+		mxs_lradc_reg_wrt(ts->lradc, 0, LRADC_DELAY(i));
+}
+
+static void mxs_lradc_ts_close(struct input_dev *dev)
+{
+	struct mxs_lradc_ts *ts = input_get_drvdata(dev);
+
+	mxs_lradc_ts_stop(ts);
+}
+
+static void mxs_lradc_ts_hw_init(struct mxs_lradc_ts *ts)
+{
+	struct mxs_lradc *lradc = ts->lradc;
+
+	/* Configure the touchscreen type */
+	if (lradc->soc == IMX28_LRADC) {
+		mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+				    LRADC_CTRL0);
+
+		if (lradc->touchscreen_wire == MXS_LRADC_TOUCHSCREEN_5WIRE)
+			mxs_lradc_reg_set(lradc,
+					  LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
+					  LRADC_CTRL0);
+	}
+}
+
+static int mxs_lradc_ts_register(struct mxs_lradc_ts *ts)
+{
+	struct input_dev *input = ts->ts_input;
+	struct device *dev = ts->dev;
+
+	input = devm_input_allocate_device(dev);
+	if (!input)
+		return -ENOMEM;
+
+	input->name = "mxs-lradc-ts";
+	input->id.bustype = BUS_HOST;
+	input->open = mxs_lradc_ts_open;
+	input->close = mxs_lradc_ts_close;
+
+	__set_bit(EV_ABS, input->evbit);
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(BTN_TOUCH, input->keybit);
+	__set_bit(INPUT_PROP_DIRECT, input->propbit);
+	input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
+	input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
+	input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
+			     0, 0);
+
+	ts->ts_input = input;
+	input_set_drvdata(input, ts);
+
+	return input_register_device(input);
+}
+
+static int mxs_lradc_ts_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->parent->of_node;
+	struct mxs_lradc *lradc = dev_get_platdata(dev);
+	struct mxs_lradc_ts *ts;
+	int touch_ret, ret, irq, virq, i;
+	u32 ts_wires = 0, adapt;
+
+	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ts);
+
+	ts->lradc = lradc;
+	ts->dev = dev;
+	spin_lock_init(&ts->lock);
+
+	touch_ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
+					 &ts_wires);
+
+	if (of_property_read_u32(node, "fsl,ave-ctrl", &adapt)) {
+		ts->over_sample_cnt = 4;
+	} else {
+		if (adapt >= 1 || adapt <= 32) {
+			ts->over_sample_cnt = adapt;
+		} else {
+			dev_err(ts->dev, "Invalid sample count (%u)\n",
+				adapt);
+			return -EINVAL;
+		}
+	}
+
+	if (of_property_read_u32(node, "fsl,ave-delay", &adapt)) {
+		ts->over_sample_delay = 2;
+	} else {
+		if (adapt >= 2 || adapt <= LRADC_DELAY_DELAY_MASK + 1) {
+			ts->over_sample_delay = adapt;
+		} else {
+			dev_err(ts->dev, "Invalid sample delay (%u)\n",
+				adapt);
+			return -EINVAL;
+		}
+	}
+
+	if (of_property_read_u32(node, "fsl,settling", &adapt)) {
+		ts->settling_delay = 10;
+	} else {
+		if (adapt >= 1 || adapt <= LRADC_DELAY_DELAY_MASK) {
+			ts->settling_delay = adapt;
+		} else {
+			dev_err(ts->dev, "Invalid settling delay (%u)\n",
+				adapt);
+			return -EINVAL;
+		}
+	}
+
+	mxs_lradc_ts_hw_init(ts);
+
+	for (i = 0; i < 3; i++) {
+		irq = platform_get_irq_byname(pdev, mxs_lradc_ts_irq_names[i]);
+		if (irq < 0)
+			return irq;
+
+		virq = irq_of_parse_and_map(node, irq);
+
+		ret = devm_request_irq(dev, virq,
+				       mxs_lradc_ts_handle_irq,
+				       0, mxs_lradc_ts_irq_names[i], ts);
+		if (ret)
+			return ret;
+	}
+
+	if (!touch_ret) {
+		ret = mxs_lradc_ts_register(ts);
+		if (!ret)
+			goto error;
+	}
+
+	return 0;
+
+error:
+	mxs_lradc_ts_stop(ts);
+
+	return ret;
+}
+
+static struct platform_driver mxs_lradc_ts_driver = {
+	.driver	= {
+		.name = "mxs-lradc-ts",
+	},
+	.probe	= mxs_lradc_ts_probe,
+};
+module_platform_driver(mxs_lradc_ts_driver);
+
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_DESCRIPTION("Freescale MXS LRADC touchscreen driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mxs-lradc-ts");
-- 
1.9.1