mx28: added LRADC and touchscreen support

This patch is based on the Freescale SDK 2010.08. It supports the on-chip Low Resolution ADC and a capacitive touchscreen connected to it.

Tested on Ka-Ro TX28 module

Signed-off-by Peter Rusko <[email protected]>

---
 arch/arm/mach-mxs/devices-mx28.h                |    6 +
 arch/arm/mach-mxs/devices/Kconfig               |    3 +
 arch/arm/mach-mxs/devices/Makefile              |    1 +
 arch/arm/mach-mxs/devices/platform-mxs-lradc.c  |   25 +
 arch/arm/mach-mxs/devices/platform-mxs-ts.c     |   34 +
 arch/arm/mach-mxs/include/mach/devices-common.h |   22 +
 arch/arm/mach-mxs/include/mach/lradc.h          |   61 ++
 arch/arm/mach-mxs/include/mach/mx28.h           |    4 +-
 arch/arm/mach-mxs/include/mach/regs-lradc.h     |  772 +++++++++++++++++++++++
 drivers/input/touchscreen/Kconfig               |   11 +
 drivers/input/touchscreen/Makefile              |    1 +
 drivers/input/touchscreen/mxs_ts.c              |  470 ++++++++++++++
 drivers/misc/Kconfig                            |    3 +
 drivers/misc/Makefile                           |    1 +

 drivers/misc/mxs_lradc.c                        |  381 +++++++++++
 15 files changed, 1793 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm/mach-mxs/devices/platform-mxs-lradc.c
 create mode 100644 arch/arm/mach-mxs/devices/platform-mxs-ts.c
 create mode 100644 arch/arm/mach-mxs/include/mach/lradc.h
 create mode 100644 arch/arm/mach-mxs/include/mach/regs-lradc.h
 create mode 100644 drivers/input/touchscreen/mxs_ts.c
 create mode 100644 drivers/misc/mxs_lradc.c

I think this patch should probably be split into 4.

* lradc drivers/staging/iio/adc/ (rather than drivers/misc/) part
* lradc arch/arm/mach-mxs part
* touchscreen drivers/input/touchscreen part
* touchscreen arch/arm/mach-mxs part

And you need to look into MAINTAINERS for the mailing list and people that the 'drivers' part should be sent to.

Quoted 10 lines

I think this patch should probably be split into 4.

* lradc drivers/staging/iio/adc/ (rather than drivers/misc/) part
* lradc arch/arm/mach-mxs part
* touchscreen drivers/input/touchscreen part
* touchscreen arch/arm/mach-mxs part

And you need to look into MAINTAINERS for the mailing list and people that the 'drivers' part should be sent to.

You're right, I'm working on it.

Shall I split the arch/arm/mach-mxs parts? In this patch I use HAVE_MXS_LRADC to compile both of them. I think they come together, the ADC supports the touchscreen, so there is no need to split them.

This patch is based on the Freescale SDK 2010.08. It supports the on-chip Low Resolution ADC and a capacitive touchscreen connected to it.

Tested on Ka-Ro TX28 module

Signed-off-by Peter Rusko <[email protected]>

---
 arch/arm/mach-mxs/devices-mx28.h                |    6 +
 arch/arm/mach-mxs/devices/Kconfig               |    3 +
 arch/arm/mach-mxs/devices/Makefile              |    1 +
 arch/arm/mach-mxs/devices/platform-mxs-lradc.c  |   25 +
 arch/arm/mach-mxs/devices/platform-mxs-ts.c     |   34 +
 arch/arm/mach-mxs/include/mach/devices-common.h |   22 +
 arch/arm/mach-mxs/include/mach/lradc.h          |   61 ++
 arch/arm/mach-mxs/include/mach/mx28.h           |    4 +-
 arch/arm/mach-mxs/include/mach/regs-lradc.h     |  772 +++++++++++++++++++++++
 drivers/input/touchscreen/Kconfig               |   11 +
 drivers/input/touchscreen/Makefile              |    1 +
 drivers/input/touchscreen/mxs_ts.c              |  470 ++++++++++++++
 drivers/misc/Kconfig                            |    3 +
 drivers/misc/Makefile                           |    1 +
 drivers/misc/mxs_lradc.c                        |  381 +++++++++++
 15 files changed, 1793 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm/mach-mxs/devices/platform-mxs-lradc.c
 create mode 100644 arch/arm/mach-mxs/devices/platform-mxs-ts.c
 create mode 100644 arch/arm/mach-mxs/include/mach/lradc.h
 create mode 100644 arch/arm/mach-mxs/include/mach/regs-lradc.h
 create mode 100644 drivers/input/touchscreen/mxs_ts.c
 create mode 100644 drivers/misc/mxs_lradc.c

arch/arm/mach-mxs/devices-mx28.h +6 -0

index c888710..b0efa25 100644
@@ -46,6 +46,12 @@ extern const struct mxs_mxs_mmc_data mx28_mxs_mmc_data[] __initconst;
 struct platform_device *__init mx28_add_mxsfb(
 		const struct mxsfb_platform_data *pdata);
 
+struct platform_device * __init mx28_add_lradc(
+		const struct mxs_lradc_plat_data *pdata);
+
+struct platform_device *__init mx28_add_ts(
+		const struct mxs_touchscreen_plat_data *pdata);
+
 extern const struct mxs_saif_data mx28_saif_data[] __initconst;
 #define mx28_add_saif(id)              mxs_add_saif(&mx28_saif_data[id])
 

arch/arm/mach-mxs/devices/Kconfig +3 -0

index 18b6bf5..58d1c1e 100644
@@ -15,6 +15,9 @@ config MXS_HAVE_PLATFORM_FLEXCAN
 config MXS_HAVE_PLATFORM_MXS_I2C
 	bool
 
+config MXS_HAVE_PLATFORM_MXS_LRADC
+	bool
+
 config MXS_HAVE_PLATFORM_MXS_MMC
 	bool
 

arch/arm/mach-mxs/devices/Makefile +1 -0

index f52e3e5..9ba66ed 100644
@@ -4,6 +4,7 @@ obj-y += platform-dma.o
 obj-$(CONFIG_MXS_HAVE_PLATFORM_FEC) += platform-fec.o
 obj-$(CONFIG_MXS_HAVE_PLATFORM_FLEXCAN) += platform-flexcan.o
 obj-$(CONFIG_MXS_HAVE_PLATFORM_MXS_I2C) += platform-mxs-i2c.o
+obj-$(CONFIG_MXS_HAVE_PLATFORM_MXS_LRADC) += platform-mxs-lradc.o platform-mxs-ts.o
 obj-$(CONFIG_MXS_HAVE_PLATFORM_MXS_MMC) += platform-mxs-mmc.o
 obj-$(CONFIG_MXS_HAVE_PLATFORM_MXS_PWM) += platform-mxs-pwm.o
 obj-y += platform-gpio-mxs.o

arch/arm/mach-mxs/devices/platform-mxs-lradc.c new file +25 -0

new file mode 100644
index 0000000..d1af2ec
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+
+#include <mach/devices-common.h>
+#include <mach/mx28.h>
+
+struct platform_device * __init mx28_add_lradc(
+		const struct mxs_lradc_plat_data *pdata)
+{
+	struct resource res[] = {
+		{
+			.start = MX28_LRADC_BASE_ADDR,
+			.end = MX28_LRADC_BASE_ADDR + SZ_16K - 1,
+			.flags = IORESOURCE_MEM,
+		},
+	};
+
+	return mxs_add_platform_device("mxs-lradc", 0,
+			res, ARRAY_SIZE(res), pdata, sizeof(*pdata));
+}

arch/arm/mach-mxs/devices/platform-mxs-ts.c new file +9 -0

new file mode 100644
index 0000000..05343af
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+
+#include <mach/devices-common.h>

arch/arm/mach-mxs/devices/platform-mxs-ts.c new file +5 -0

+
+	return mxs_add_platform_device("mxs-ts", 0,
+			res, ARRAY_SIZE(res), pdata, sizeof(*pdata));
+
+}

arch/arm/mach-mxs/include/mach/devices-common.h +22 -0

index a8080f4..e86b193 100644
@@ -76,6 +76,12 @@ struct mxs_mxs_i2c_data {
 struct platform_device * __init mxs_add_mxs_i2c(
 		const struct mxs_mxs_i2c_data *data);
 
+/* lradc */
+struct mxs_lradc_plat_data {
+	unsigned int vddio_voltage;
+	unsigned int battery_voltage;
+};
+
 /* mmc */
 #include <mach/mmc.h>
 struct mxs_mxs_mmc_data {

@@ -104,3 +110,19 @@ struct mxs_saif_data {
 
 struct platform_device *__init mxs_add_saif(
 		const struct mxs_saif_data *data);
+
+/* touchscreen */
+struct mxs_touchscreen_plat_data {
+	u8 x_plus_chan;
+	u8 x_minus_chan;
+	u8 y_plus_chan;
+	u8 y_minus_chan;
+	unsigned int x_plus_val;
+	unsigned int x_minus_val;
+	unsigned int y_plus_val;
+	unsigned int y_minus_val;
+	unsigned int x_plus_mask;
+	unsigned int x_minus_mask;
+	unsigned int y_plus_mask;
+	unsigned int y_minus_mask;
+};

arch/arm/mach-mxs/include/mach/lradc.h new file +61 -0

new file mode 100644
index 0000000..c2c0a7d
@@ -0,0 +1,61 @@
+/*
+ * Freescale STMP37XX/STMP378X LRADC helper interface
+ *
+ * Embedded Alley Solutions, Inc <[email protected]>
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#ifndef __ASM_PLAT_LRADC_H
+#define __ASM_PLAT_LRADC_H
+
+int hw_lradc_use_channel(int);
+int hw_lradc_unuse_channel(int);
+extern u32 hw_lradc_vddio(void);
+void hw_lradc_set_delay_trigger_kick(int trigger, int value);
+void hw_lradc_configure_channel(int channel, int enable_div2,
+		int enable_acc, int samples);
+int hw_lradc_present(int channel);
+int hw_lradc_init_ladder(int channel, int trigger, unsigned sampling);
+int hw_lradc_stop_ladder(int channel, int trigger);
+void hw_lradc_set_delay_trigger(int trigger, u32 trigger_lradc,
+		u32 delay_triggers, u32 loops, u32 delays);
+void hw_lradc_clear_delay_trigger(int trigger, u32 trigger_lradc,
+		u32 delay_triggers);
+
+
+#define LRADC_CH0		0
+#define LRADC_CH1		1
+#define LRADC_CH2		2
+#define LRADC_CH3		3
+#define LRADC_CH4		4
+#define LRADC_CH5		5
+#define LRADC_CH6		6
+#define LRADC_CH7		7
+#define LRADC_TOUCH_X_PLUS	LRADC_CH2
+#define LRADC_TOUCH_Y_PLUS	LRADC_CH3
+#define LRADC_TOUCH_X_MINUS	LRADC_CH4
+#define LRADC_TOUCH_Y_MINUS	LRADC_CH5
+#define VDDIO_VOLTAGE_CH	LRADC_CH6
+#define BATTERY_VOLTAGE_CH	LRADC_CH7
+
+#define LRADC_CLOCK_6MHZ	0
+#define LRADC_CLOCK_4MHZ	1
+#define LRADC_CLOCK_3MHZ	2
+#define LRADC_CLOCK_2MHZ	3
+
+#define LRADC_DELAY_TRIGGER_BUTTON	0
+#define LRADC_DELAY_TRIGGER_BATTERY	1
+#define LRADC_DELAY_TRIGGER_TOUCHSCREEN	2
+#define LRADC_DELAY_TRIGGER_DIE		3
+
+#endif /* __ASM_PLAT_LRADC_H */

arch/arm/mach-mxs/include/mach/mx28.h +2 -2

index 75d8611..30c7990 100644
@@ -104,8 +104,8 @@
 #define MX28_INT_CAN1			9
 #define MX28_INT_LRADC_TOUCH		10
 #define MX28_INT_HSADC			13
-#define MX28_INT_IRADC_THRESH0		14
-#define MX28_INT_IRADC_THRESH1		15
+#define MX28_INT_LRADC_THRESH0		14
+#define MX28_INT_LRADC_THRESH1		15
 #define MX28_INT_LRADC_CH0		16
 #define MX28_INT_LRADC_CH1		17
 #define MX28_INT_LRADC_CH2		18

arch/arm/mach-mxs/include/mach/regs-lradc.h new file +24 -0

new file mode 100644
index 0000000..d7906b9
@@ -0,0 +1,772 @@
+/*
+ * Freescale LRADC Register Definitions
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ *
+ * This file is created by xml file. Don't Edit it.
+ *
+ * Xml Revision: 1.50
+ * Template revision: 26195
+ */

drivers/input/touchscreen/Kconfig +11 -0

index 3488ffe..36bd3cf 100644
@@ -339,6 +339,17 @@ config TOUCHSCREEN_HP7XX
 	  To compile this driver as a module, choose M here: the
 	  module will be called jornada720_ts.
 
+config TOUCHSCREEN_MXS
+	tristate "MXS LRADC-based touchscreen"
+	depends on MXS_LRADC
+	select SERIO
+	help
+	  Say Y here if you want to enable touchscreen, connected to MXS
+	  Low-Resoulion ADC.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mxs_ts.
+
 config TOUCHSCREEN_HTCPEN
 	tristate "HTC Shift X9500 touchscreen"
 	depends on ISA

drivers/input/touchscreen/Makefile +1 -0

index f957676..6c3728c 100644
@@ -35,6 +35,7 @@ obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
+obj-$(CONFIG_TOUCHSCREEN_MXS)		+= mxs_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HTCPEN)	+= htcpen.o
 obj-$(CONFIG_TOUCHSCREEN_USB_COMPOSITE)	+= usbtouchscreen.o
 obj-$(CONFIG_TOUCHSCREEN_PCAP)		+= pcap_ts.o

drivers/input/touchscreen/mxs_ts.c new file +31 -0

new file mode 100644
index 0000000..ad05c3f
@@ -0,0 +1,470 @@
+/*
+ * Freesclae MXS Touchscreen driver
+ *
+ * Author: Vitaly Wool <[email protected]>
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/fsl_devices.h>
+#include <linux/module.h>
+#include <linux/io.h>
+
+#include <mach/hardware.h>
+#include <mach/lradc.h>

drivers/input/touchscreen/mxs_ts.c new file +27 -0

+	u8 x_plus_chan;
+	u8 x_minus_chan;
+	u8 y_plus_chan;
+	u8 y_minus_chan;
+
+	unsigned int x_plus_val;
+	unsigned int x_minus_val;
+	unsigned int y_plus_val;
+	unsigned int y_minus_val;
+	unsigned int x_plus_mask;
+	unsigned int x_minus_mask;
+	unsigned int y_plus_mask;
+	unsigned int y_minus_mask;
+
+	struct input_dev *idev;
+	enum {
+		TS_STATE_DISABLED,
+		TS_STATE_TOUCH_DETECT,
+		TS_STATE_TOUCH_VERIFY,
+		TS_STATE_X_PLANE,
+		TS_STATE_Y_PLANE,
+	} state;
+	u16 x;
+	u16 y;
+	int sample_count;
+};
+

drivers/input/touchscreen/mxs_ts.c new file +181 -0

+
+	__raw_writel(BM_LRADC_CTRL1_LRADC0_IRQ << info->y_minus_chan,
+		     info->base + HW_LRADC_CTRL1_CLR);
+	__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ,
+		     info->base + HW_LRADC_CTRL1_CLR);
+	/*
+	 * turn off the yplus and yminus pullup and pulldown, and turn off touch
+	 * detect (enables yminus, and xplus through a resistor.On a press,
+	 * xplus is pulled down)
+	 */
+	__raw_writel(info->y_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->y_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_SET);
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 0);
+	info->state = TS_STATE_TOUCH_DETECT;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_disabled(struct mxs_ts_info *info)
+{
+	__raw_writel(info->y_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->y_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_CLR);
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 0);
+	info->state = TS_STATE_DISABLED;
+	info->sample_count = 0;
+}
+
+
+static inline void enter_state_x_plane(struct mxs_ts_info *info)
+{
+	__raw_writel(info->y_plus_val, info->base + HW_LRADC_CTRL0_SET);
+	__raw_writel(info->y_minus_val, info->base + HW_LRADC_CTRL0_SET);
+	__raw_writel(info->x_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_CLR);
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+
+	info->state = TS_STATE_X_PLANE;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_y_plane(struct mxs_ts_info *info)
+{
+	__raw_writel(info->y_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->y_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_plus_val, info->base + HW_LRADC_CTRL0_SET);
+	__raw_writel(info->x_minus_val, info->base + HW_LRADC_CTRL0_SET);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_CLR);
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+	info->state = TS_STATE_Y_PLANE;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_touch_verify(struct mxs_ts_info *info)
+{
+	__raw_writel(info->y_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->y_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_SET);
+	info->state = TS_STATE_TOUCH_VERIFY;
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+	info->sample_count = 0;
+}
+
+static void process_lradc(struct mxs_ts_info *info, u16 x, u16 y,
+			int pressure)
+{
+	switch (info->state) {
+	case TS_STATE_X_PLANE:
+		pr_debug("%s: x plane state, sample_count %d\n", __func__,
+				info->sample_count);
+		if (info->sample_count < 2) {
+			info->x = x;
+			info->sample_count++;
+		} else {
+			if (abs(info->x - x) > TOUCH_DEBOUNCE_TOLERANCE)
+				info->sample_count = 1;
+			else {
+				u16 x_c = info->x * (info->sample_count - 1);
+				info->x = (x_c + x) / info->sample_count;
+				info->sample_count++;
+			}
+		}
+		if (info->sample_count > 4)
+			enter_state_y_plane(info);
+		else
+			hw_lradc_set_delay_trigger_kick(
+					LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+		break;
+
+	case TS_STATE_Y_PLANE:
+		pr_debug("%s: y plane state, sample_count %d\n", __func__,
+				info->sample_count);
+		if (info->sample_count < 2) {
+			info->y = y;
+			info->sample_count++;
+		} else {
+			if (abs(info->y - y) > TOUCH_DEBOUNCE_TOLERANCE)
+				info->sample_count = 1;
+			else {
+				u16 y_c = info->y * (info->sample_count - 1);
+				info->y = (y_c + y) / info->sample_count;
+				info->sample_count++;
+			}
+		}
+		if (info->sample_count > 4)
+			enter_state_touch_verify(info);
+		else
+			hw_lradc_set_delay_trigger_kick(
+					LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+		break;
+
+	case TS_STATE_TOUCH_VERIFY:
+		pr_debug("%s: touch verify state, sample_count %d\n", __func__,
+				info->sample_count);
+		pr_debug("%s: x %d, y %d\n", __func__, info->x, info->y);
+		input_report_abs(info->idev, ABS_X, info->x);
+		input_report_abs(info->idev, ABS_Y, info->y);
+		input_report_abs(info->idev, ABS_PRESSURE, pressure);
+		input_sync(info->idev);
+		/* fall through */
+	case TS_STATE_TOUCH_DETECT:
+		pr_debug("%s: touch detect state, sample_count %d\n", __func__,
+				info->sample_count);
+		if (pressure) {
+			input_report_abs(info->idev, ABS_PRESSURE, pressure);
+			enter_state_x_plane(info);
+			hw_lradc_set_delay_trigger_kick(
+					LRADC_DELAY_TRIGGER_TOUCHSCREEN, 1);
+		} else
+			enter_state_touch_detect(info);
+		break;
+
+	default:
+		printk(KERN_ERR "%s: unknown touchscreen state %d\n", __func__,
+				info->state);
+	}
+}
+
+static irqreturn_t ts_handler(int irq, void *dev_id)
+{
+	struct mxs_ts_info *info = dev_id;
+	u16 x_plus, y_plus;
+	int pressure = 0;
+
+	if (irq == info->touch_irq)
+		__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ,
+			     info->base + HW_LRADC_CTRL1_CLR);
+	else if (irq == info->device_irq)
+		__raw_writel(BM_LRADC_CTRL1_LRADC0_IRQ << info->y_minus_chan,
+			     info->base + HW_LRADC_CTRL1_CLR);
+
+	/* get x, y values */
+	x_plus = __raw_readl(info->base + HW_LRADC_CHn(info->x_plus_chan)) &
+		BM_LRADC_CHn_VALUE;
+	y_plus = __raw_readl(info->base + HW_LRADC_CHn(info->y_plus_chan)) &
+		BM_LRADC_CHn_VALUE;
+
+	/* pressed? */
+	if (__raw_readl(info->base + HW_LRADC_STATUS) &
+	    BM_LRADC_STATUS_TOUCH_DETECT_RAW)
+		pressure = 1;
+
+	pr_debug("%s: irq %d, x_plus %d, y_plus %d, pressure %d\n",
+			__func__, irq, x_plus, y_plus, pressure);
+
+	process_lradc(info, x_plus, y_plus, pressure);
+
+	return IRQ_HANDLED;
+}

drivers/input/touchscreen/mxs_ts.c new file +34 -0

+	if (plat_data == NULL)
+		return -ENODEV;
+
+	idev = input_allocate_device();
+	if (idev == NULL)
+		return -ENOMEM;
+
+	info = kzalloc(sizeof(struct mxs_ts_info), GFP_KERNEL);
+	if (info == NULL) {
+		ret = -ENOMEM;
+		goto out_nomem_info;
+	}
+
+	idev->name = "MXS touchscreen";
+	idev->evbit[0] = BIT(EV_ABS);
+	input_set_abs_params(idev, ABS_X, 0, 0xFFF, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xFFF, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0, 1, 0, 0);
+
+	ret = input_register_device(idev);
+	if (ret)
+		goto out_nomem;
+
+	info->idev = idev;
+	info->x_plus_chan = plat_data->x_plus_chan;
+	info->x_minus_chan = plat_data->x_minus_chan;
+	info->y_plus_chan = plat_data->y_plus_chan;
+	info->y_minus_chan = plat_data->y_minus_chan;
+	info->x_plus_val = plat_data->x_plus_val;
+	info->x_minus_val = plat_data->x_minus_val;
+	info->y_plus_val = plat_data->y_plus_val;
+	info->y_minus_val = plat_data->y_minus_val;
+	info->x_plus_mask = plat_data->x_plus_mask;
+	info->x_minus_mask = plat_data->x_minus_mask;

drivers/input/touchscreen/mxs_ts.c new file +82 -0

+static int __devexit mxs_ts_remove(struct platform_device *pdev)
+{
+	struct mxs_ts_info *info = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	hw_lradc_unuse_channel(info->x_plus_chan);
+	hw_lradc_unuse_channel(info->x_minus_chan);
+	hw_lradc_unuse_channel(info->y_plus_chan);
+	hw_lradc_unuse_channel(info->y_minus_chan);
+
+	__raw_writel(BM_LRADC_CTRL1_LRADC0_IRQ_EN << info->y_minus_chan,
+		     info->base + HW_LRADC_CTRL1_CLR);
+	__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
+		     info->base + HW_LRADC_CTRL1_CLR);
+
+	free_irq(info->device_irq, info);
+	free_irq(info->touch_irq, info);
+	input_free_device(info->idev);
+
+	enter_state_disabled(info);
+	kfree(info->idev);
+	kfree(info);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int mxs_ts_suspend(struct platform_device *pdev,
+				pm_message_t state)
+{
+	struct mxs_ts_info *info = platform_get_drvdata(pdev);
+
+	if (!device_may_wakeup(&pdev->dev)) {
+		hw_lradc_unuse_channel(info->x_plus_chan);
+		hw_lradc_unuse_channel(info->x_minus_chan);
+		hw_lradc_unuse_channel(info->y_plus_chan);
+		hw_lradc_unuse_channel(info->y_minus_chan);
+	}
+	return 0;
+}
+
+static int mxs_ts_resume(struct platform_device *pdev)
+{
+	struct mxs_ts_info *info = platform_get_drvdata(pdev);
+
+	if (!device_may_wakeup(&pdev->dev)) {
+		hw_lradc_use_channel(info->x_plus_chan);
+		hw_lradc_use_channel(info->x_minus_chan);
+		hw_lradc_use_channel(info->y_plus_chan);
+		hw_lradc_use_channel(info->y_minus_chan);
+	}
+	return 0;
+}
+#endif
+
+static struct platform_driver mxs_ts_driver = {
+	.probe		= mxs_ts_probe,
+	.remove		= __devexit_p(mxs_ts_remove),
+#ifdef CONFIG_PM
+	.suspend	= mxs_ts_suspend,
+	.resume		= mxs_ts_resume,
+#endif
+	.driver		= {
+		.name	= "mxs-ts",
+	},
+};
+
+static int __init mxs_ts_init(void)
+{
+	return platform_driver_register(&mxs_ts_driver);
+}
+
+static void __exit mxs_ts_exit(void)
+{
+	platform_driver_unregister(&mxs_ts_driver);
+}
+
+module_init(mxs_ts_init);
+module_exit(mxs_ts_exit);
+
+MODULE_DESCRIPTION("MXS touchscreen driver");
+MODULE_LICENSE("GPL");

drivers/misc/Kconfig +3 -0

index d593878..ab89b1b 100644
@@ -499,6 +499,9 @@ config USB_SWITCH_FSA9480
 	  stereo and mono audio, video, microphone and UART data to use
 	  a common connector port.
 
+config MXS_LRADC
+	tristate "ARM MXS LRADC Support"
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"

drivers/misc/Makefile +1 -0

index b26495a..0ce0017 100644
@@ -47,4 +47,5 @@ obj-$(CONFIG_AB8500_PWM)	+= ab8500-pwm.o
 obj-y				+= lis3lv02d/
 obj-y				+= carma/
 obj-$(CONFIG_USB_SWITCH_FSA9480) += fsa9480.o
+obj-$(CONFIG_MXS_LRADC)		+= mxs_lradc.o
 obj-$(CONFIG_ALTERA_STAPL)	+=altera-stapl/

drivers/misc/mxs_lradc.c new file +27 -0

new file mode 100644
index 0000000..cc32fac
@@ -0,0 +1,381 @@
+/*
+ * Freescale STMP37XX/STMP378X LRADC helper routines
+ *
+ * Embedded Alley Solutions, Inc <[email protected]>
+ *
+ * Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+
+/*
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sysdev.h>
+#include <linux/platform_device.h>
+#include <linux/bitops.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/delay.h>

drivers/misc/mxs_lradc.c new file +3 -0

+	unsigned int vddio_voltage;
+	unsigned int battery_voltage;
+};

drivers/misc/mxs_lradc.c new file +40 -0

+void hw_lradc_reinit(int enable_ground_ref, unsigned freq)
+{
+	__raw_writel(BM_LRADC_CTRL0_SFTRST,
+		     mxs_lradc.base + HW_LRADC_CTRL0_SET);
+	udelay(1);
+	__raw_writel(BM_LRADC_CTRL0_SFTRST,
+		     mxs_lradc.base + HW_LRADC_CTRL0_CLR);
+
+	/* Clear the Clock Gate for normal operation */
+	__raw_writel(BM_LRADC_CTRL0_CLKGATE,
+		     mxs_lradc.base + HW_LRADC_CTRL0_CLR);
+
+	if (enable_ground_ref)
+		__raw_writel(BM_LRADC_CTRL0_ONCHIP_GROUNDREF,
+			     mxs_lradc.base + HW_LRADC_CTRL0_SET);
+	else
+		__raw_writel(BM_LRADC_CTRL0_ONCHIP_GROUNDREF,
+			    mxs_lradc.base + HW_LRADC_CTRL0_CLR);
+
+	__raw_writel(BM_LRADC_CTRL3_CYCLE_TIME,
+		     mxs_lradc.base + HW_LRADC_CTRL3_CLR);
+	__raw_writel(BF_LRADC_CTRL3_CYCLE_TIME(freq),
+		     mxs_lradc.base + HW_LRADC_CTRL3_SET);
+
+	__raw_writel(BM_LRADC_CTRL4_LRADC6SELECT | BM_LRADC_CTRL4_LRADC7SELECT,
+		     mxs_lradc.base + HW_LRADC_CTRL4_CLR);
+	__raw_writel(BF_LRADC_CTRL4_LRADC6SELECT(mxs_lradc.vddio_voltage),
+		     mxs_lradc.base + HW_LRADC_CTRL4_SET);
+	__raw_writel(BF_LRADC_CTRL4_LRADC7SELECT(mxs_lradc.battery_voltage),
+		     mxs_lradc.base + HW_LRADC_CTRL4_SET);
+}
+
+int hw_lradc_init_ladder(int channel, int trigger, unsigned sampling)
+{
+	/*
+	 * check if the lradc channel is present in this product
+	 */
+	if (!hw_lradc_present(channel))
+		return -ENODEV;
+

drivers/misc/mxs_lradc.c new file +22 -0

+	return 0;
+}
+EXPORT_SYMBOL(hw_lradc_init_ladder);
+
+int hw_lradc_stop_ladder(int channel, int trigger)
+{
+	/*
+	 * check if the lradc channel is present in this product
+	 */
+	if (!hw_lradc_present(channel))
+		return -ENODEV;
+	hw_lradc_clear_delay_trigger(trigger, 1 << channel, 1 << trigger);
+	return 0;
+}
+EXPORT_SYMBOL(hw_lradc_stop_ladder);
+
+int hw_lradc_present(int channel)
+{
+	if (channel < 0 || channel > 7)
+		return 0;
+	return __raw_readl(mxs_lradc.base + HW_LRADC_STATUS)
+	    & (1 << (16 + channel));

From my point it is more readable to have the operator at the end of

drivers/misc/mxs_lradc.c new file +4 -0

+EXPORT_SYMBOL(hw_lradc_present);
+
+void hw_lradc_configure_channel(int channel, int enable_div2,
+				int enable_acc, int samples)

drivers/misc/mxs_lradc.c new file +60 -0

+	/* Sets NUM_SAMPLES bitfield of HW_LRADC_CHn register. */
+	__raw_writel(BM_LRADC_CHn_NUM_SAMPLES,
+		     mxs_lradc.base + HW_LRADC_CHn_CLR(channel));
+	__raw_writel(BF_LRADC_CHn_NUM_SAMPLES(samples),
+		     mxs_lradc.base + HW_LRADC_CHn_SET(channel));
+
+	if (enable_acc)
+		__raw_writel(BM_LRADC_CHn_ACCUMULATE,
+			     mxs_lradc.base + HW_LRADC_CHn_SET(channel));
+	else
+		__raw_writel(BM_LRADC_CHn_ACCUMULATE,
+			     mxs_lradc.base + HW_LRADC_CHn_CLR(channel));
+}
+EXPORT_SYMBOL(hw_lradc_configure_channel);
+
+void hw_lradc_set_delay_trigger(int trigger, u32 trigger_lradc,
+				u32 delay_triggers, u32 loops, u32 delays)
+{
+	/* set TRIGGER_LRADCS in HW_LRADC_DELAYn */
+	__raw_writel(BF_LRADC_DELAYn_TRIGGER_LRADCS(trigger_lradc),
+		     mxs_lradc.base + HW_LRADC_DELAYn_SET(trigger));
+	__raw_writel(BF_LRADC_DELAYn_TRIGGER_DELAYS(delay_triggers),
+		     mxs_lradc.base + HW_LRADC_DELAYn_SET(trigger));
+
+	__raw_writel(BM_LRADC_DELAYn_LOOP_COUNT | BM_LRADC_DELAYn_DELAY,
+		     mxs_lradc.base + HW_LRADC_DELAYn_CLR(trigger));
+	__raw_writel(BF_LRADC_DELAYn_LOOP_COUNT(loops),
+		     mxs_lradc.base  + HW_LRADC_DELAYn_SET(trigger));
+	__raw_writel(BF_LRADC_DELAYn_DELAY(delays),
+		     mxs_lradc.base + HW_LRADC_DELAYn_SET(trigger));
+}
+EXPORT_SYMBOL(hw_lradc_set_delay_trigger);
+
+void hw_lradc_clear_delay_trigger(int trigger, u32 trigger_lradc,
+				  u32 delay_triggers)
+{
+	__raw_writel(BF_LRADC_DELAYn_TRIGGER_LRADCS(trigger_lradc),
+		     mxs_lradc.base + HW_LRADC_DELAYn_CLR(trigger));
+	__raw_writel(BF_LRADC_DELAYn_TRIGGER_DELAYS(delay_triggers),
+		     mxs_lradc.base + HW_LRADC_DELAYn_CLR(trigger));
+}
+EXPORT_SYMBOL(hw_lradc_clear_delay_trigger);
+
+void hw_lradc_set_delay_trigger_kick(int trigger, int value)
+{
+	if (value)
+		__raw_writel(BM_LRADC_DELAYn_KICK,
+			     mxs_lradc.base + HW_LRADC_DELAYn_SET(trigger));
+	else
+		__raw_writel(BM_LRADC_DELAYn_KICK,
+			     mxs_lradc.base + HW_LRADC_DELAYn_CLR(trigger));
+}
+EXPORT_SYMBOL(hw_lradc_set_delay_trigger_kick);
+
+u32 hw_lradc_vddio(void)
+{
+	/* Clear the Soft Reset and Clock Gate for normal operation */
+	__raw_writel(BM_LRADC_CTRL0_SFTRST | BM_LRADC_CTRL0_CLKGATE,
+		     mxs_lradc.base + HW_LRADC_CTRL0_CLR);
+

drivers/misc/mxs_lradc.c new file +7 -0

+
+	/* Clear the interrupt flag */
+	__raw_writel(BM_LRADC_CTRL1_LRADC6_IRQ,
+		     mxs_lradc.base + HW_LRADC_CTRL1_CLR);
+
+	/*
+	 * Get VddIO; this is the max scale value for the button resistor

drivers/misc/mxs_lradc.c new file +60 -0

+static int do_gate;
+
+static int hw_lradc_suspend(struct device *dev, pm_message_t state)
+{
+	int i;
+
+	do_gate = 1;
+	for (i = 0; i < ARRAY_SIZE(channels); i++)
+		if (channels[i] > 0) {
+			do_gate = 0;
+			break;
+		}
+
+	for (i = 0; i < ARRAY_SIZE(lradc_registers); i++)
+		lradc_registers[i] = __raw_readl(mxs_lradc.base + (i << 4));
+
+	if (do_gate)
+		__raw_writel(BM_LRADC_CTRL0_CLKGATE,
+			     mxs_lradc.base + HW_LRADC_CTRL0_SET);
+	return 0;
+}
+
+static int hw_lradc_resume(struct device *dev)
+{
+	int i;
+
+	if (do_gate) {
+		__raw_writel(BM_LRADC_CTRL0_SFTRST,
+			     mxs_lradc.base + HW_LRADC_CTRL0_SET);
+		udelay(10);
+		__raw_writel(BM_LRADC_CTRL0_SFTRST |
+			     BM_LRADC_CTRL0_CLKGATE,
+			     mxs_lradc.base + HW_LRADC_CTRL0_CLR);
+	}
+	for (i = 0; i < ARRAY_SIZE(lradc_registers); i++)
+		__raw_writel(lradc_registers[i], mxs_lradc.base + (i << 4));
+	return 0;
+}
+
+#endif
+
+static struct sysdev_class mxs_lradc_sysclass = {
+	.name = "mxs-lradc",
+};
+
+static int lradc_freq = LRADC_CLOCK_6MHZ;
+
+static int __init lradc_freq_setup(char *str)
+{
+	long freq;
+
+	if (kstrtol(str, 0, &freq) < 0)
+		return 0;
+
+	if (freq < 0)
+		return 0;
+	if (freq >= 6)
+		lradc_freq = LRADC_CLOCK_6MHZ;
+	else if (freq >= 4)
+		lradc_freq = LRADC_CLOCK_4MHZ;

drivers/misc/mxs_lradc.c new file +20 -0

+	mxs_lradc.sys.id = -1;
+	mxs_lradc.sys.cls = &mxs_lradc_sysclass;
+	mxs_lradc.vddio_voltage = plat_data->vddio_voltage;
+	mxs_lradc.battery_voltage = plat_data->battery_voltage;
+	hw_lradc_reinit(0, lradc_freq);
+	return sysdev_register(&mxs_lradc.sys);
+}
+
+static int __devexit mxs_lradc_remove(struct platform_device *pdev)
+{
+	sysdev_unregister(&mxs_lradc.sys);
+	return 0;
+}
+
+static __refdata struct platform_driver mxs_lradc_drv = {
+	.probe = mxs_lradc_probe,
+	.remove = __devexit_p(mxs_lradc_remove),
+	.driver = {
+		.name = "mxs-lradc",
+		.owner = THIS_MODULE,

Quoted 21 lines

(quoted diff) +21 -0

+static int lradc_freq = LRADC_CLOCK_6MHZ;
+
+static int __init lradc_freq_setup(char *str)
+{
+ ? ? long freq;
+
+ ? ? if (kstrtol(str, 0, &freq) < 0)
+ ? ? ? ? ? ? return 0;
+
+ ? ? if (freq < 0)
+ ? ? ? ? ? ? return 0;
+ ? ? if (freq >= 6)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_6MHZ;
+ ? ? else if (freq >= 4)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_4MHZ;
+ ? ? else if (freq >= 3)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_3MHZ;
+ ? ? else if (freq >= 2)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_2MHZ;
+ ? ? else
+ ? ? ? ? ? ? return 0;

drivers/misc/mxs_lradc.c line 321

Quoted 5 lines

+ ? ? return 1;

drivers/misc/mxs_lradc.c new file +3 -0

+}
+
+__setup("lradc_freq=", lradc_freq_setup);

How do you set lradc_freq when the driver is compiled as a module? module_param() would work for the driver compiled as a module as well as built-in

Quoted 21 lines · Lothar Wa?mann

Quoted 21 lines

(quoted diff) +21 -0

+static int lradc_freq = LRADC_CLOCK_6MHZ;
+
+static int __init lradc_freq_setup(char *str)
+{
+ ? ? long freq;
+
+ ? ? if (kstrtol(str, 0, &freq) < 0)
+ ? ? ? ? ? ? return 0;
+
+ ? ? if (freq < 0)
+ ? ? ? ? ? ? return 0;
+ ? ? if (freq >= 6)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_6MHZ;
+ ? ? else if (freq >= 4)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_4MHZ;
+ ? ? else if (freq >= 3)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_3MHZ;
+ ? ? else if (freq >= 2)
+ ? ? ? ? ? ? lradc_freq = LRADC_CLOCK_2MHZ;
+ ? ? else
+ ? ? ? ? ? ? return 0;

Quoted 8 lines

drivers/misc/mxs_lradc.c line 321

Quoted 5 lines

+ ? ? return 1;

drivers/misc/mxs_lradc.c new file +3 -0

+}
+
+__setup("lradc_freq=", lradc_freq_setup);

How do you set lradc_freq when the driver is compiled as a module? module_param() would work for the driver compiled as a module as well as built-in

What about passing lradc_freq as platform data?

This patch is based on the Freescale SDK 2010.08. It supports the on-chip Low Resolution ADC and a capacitive touchscreen connected to it.

Tested on Ka-Ro TX28 module

Signed-off-by Peter Rusko <[email protected]>

---
 arch/arm/mach-mxs/devices-mx28.h                |    6 +
 arch/arm/mach-mxs/devices/Kconfig               |    3 +
 arch/arm/mach-mxs/devices/Makefile              |    1 +
 arch/arm/mach-mxs/devices/platform-mxs-lradc.c  |   25 +
 arch/arm/mach-mxs/devices/platform-mxs-ts.c     |   34 +
 arch/arm/mach-mxs/include/mach/devices-common.h |   22 +
 arch/arm/mach-mxs/include/mach/lradc.h          |   61 ++
 arch/arm/mach-mxs/include/mach/mx28.h           |    4 +-
 arch/arm/mach-mxs/include/mach/regs-lradc.h     |  772 +++++++++++++++++++++++
 drivers/input/touchscreen/Kconfig               |   11 +
 drivers/input/touchscreen/Makefile              |    1 +
 drivers/input/touchscreen/mxs_ts.c              |  470 ++++++++++++++
 drivers/misc/Kconfig                            |    3 +
 drivers/misc/Makefile                           |    1 +

 drivers/misc/mxs_lradc.c                        |  381 +++++++++++
 15 files changed, 1793 insertions(+), 2 deletions(-)
 create mode 100644 arch/arm/mach-mxs/devices/platform-mxs-lradc.c
 create mode 100644 arch/arm/mach-mxs/devices/platform-mxs-ts.c
 create mode 100644 arch/arm/mach-mxs/include/mach/lradc.h
 create mode 100644 arch/arm/mach-mxs/include/mach/regs-lradc.h
 create mode 100644 drivers/input/touchscreen/mxs_ts.c
 create mode 100644 drivers/misc/mxs_lradc.c

arch/arm/mach-mxs/include/mach/devices-common.h +12 -0

index a8080f4..e86b193 100644
@@ -76,6 +76,12 @@ struct mxs_mxs_i2c_data {
 struct platform_device * __init mxs_add_mxs_i2c(
 		const struct mxs_mxs_i2c_data *data);
 
+/* lradc */
+struct mxs_lradc_plat_data {
+	unsigned int vddio_voltage;
+	unsigned int battery_voltage;
+};
+
 /* mmc */
 #include <mach/mmc.h>
 struct mxs_mxs_mmc_data {

@@ -104,3 +110,19 @@ struct mxs_saif_data {
 
 struct platform_device *__init mxs_add_saif(
 		const struct mxs_saif_data *data);
+
+/* touchscreen */
+struct mxs_touchscreen_plat_data {
+	u8 x_plus_chan;
+	u8 x_minus_chan;
+	u8 y_plus_chan;

arch/arm/mach-mxs/include/mach/lradc.h new file +4 -0

new file mode 100644
index 0000000..c2c0a7d
 
+
+int hw_lradc_use_channel(int);
+int hw_lradc_unuse_channel(int);
+extern u32 hw_lradc_vddio(void);

arch/arm/mach-mxs/include/mach/mx28.h +0 -0

index 75d8611..30c7990 100644

arch/arm/mach-mxs/include/mach/regs-lradc.h new file +6 -0

+#define BP_LRADC_CTRL0_RSRVD2	27
+#define BM_LRADC_CTRL0_RSRVD2	0x38000000
+#define BF_LRADC_CTRL0_RSRVD2(v)  \
+		(((v) << 27) & BM_LRADC_CTRL0_RSRVD2)
+#define BM_LRADC_CTRL0_ONCHIP_GROUNDREF	0x04000000
+#define BV_LRADC_CTRL0_ONCHIP_GROUNDREF__OFF 0x0

arch/arm/mach-mxs/include/mach/regs-lradc.h new file +6 -0

+
+static inline void enter_state_touch_detect(struct mxs_ts_info *info)
+{
+	__raw_writel(0xFFFFFFFF,
+		     info->base + HW_LRADC_CHn_CLR(info->x_plus_chan));
+	__raw_writel(0xFFFFFFFF,

arch/arm/mach-mxs/include/mach/regs-lradc.h new file +32 -0

+	/*
+	 * turn off the yplus and yminus pullup and pulldown, and turn off touch
+	 * detect (enables yminus, and xplus through a resistor.On a press,
+	 * xplus is pulled down)
+	 */
+	__raw_writel(info->y_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->y_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_SET);
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 0);
+	info->state = TS_STATE_TOUCH_DETECT;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_disabled(struct mxs_ts_info *info)
+{
+	__raw_writel(info->y_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->y_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_plus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(info->x_minus_mask, info->base + HW_LRADC_CTRL0_CLR);
+	__raw_writel(BM_LRADC_CTRL0_TOUCH_DETECT_ENABLE,
+		     info->base + HW_LRADC_CTRL0_CLR);
+	hw_lradc_set_delay_trigger_kick(LRADC_DELAY_TRIGGER_TOUCHSCREEN, 0);
+	info->state = TS_STATE_DISABLED;
+	info->sample_count = 0;
+}
+
+static inline void enter_state_x_plane(struct mxs_ts_info *info)
+{
...
+}

arch/arm/mach-mxs/include/mach/regs-lradc.h new file +21 -0

+static irqreturn_t ts_handler(int irq, void *dev_id)
+{
+	struct mxs_ts_info *info = dev_id;
+	u16 x_plus, y_plus;
+	int pressure = 0;
+
+	if (irq == info->touch_irq)
+		__raw_writel(BM_LRADC_CTRL1_TOUCH_DETECT_IRQ,
+			     info->base + HW_LRADC_CTRL1_CLR);
+	else if (irq == info->device_irq)
+		__raw_writel(BM_LRADC_CTRL1_LRADC0_IRQ << info->y_minus_chan,
+			     info->base + HW_LRADC_CTRL1_CLR);
+
+	/* get x, y values */
+	x_plus = __raw_readl(info->base + HW_LRADC_CHn(info->x_plus_chan)) &
+		BM_LRADC_CHn_VALUE;
+	y_plus = __raw_readl(info->base + HW_LRADC_CHn(info->y_plus_chan)) &
+		BM_LRADC_CHn_VALUE;
+
+	/* pressed? */
+	if (__raw_readl(info->base + HW_LRADC_STATUS) &

drivers/misc/mxs_lradc.c new file +19 -0

@@ -0,0 +1,381 @@
 
+
+struct lradc_device {
+	struct sys_device sys;
+	unsigned int base;
+	unsigned int vddio_voltage;
+	unsigned int battery_voltage;
+};
+
+static int channels[8];
+
+static __refdata struct lradc_device mxs_lradc;
+
+int hw_lradc_use_channel(int channel)
+{
+	if (channel < 0 || channel > 7)
+		return -EINVAL;
+	channels[channel]++;
+	return 0;
+}

drivers/misc/mxs_lradc.c new file +13 -0

+static int __init lradc_freq_setup(char *str)
+{
+	long freq;
+
+	if (kstrtol(str, 0, &freq) < 0)
+		return 0;
+
+	if (freq < 0)
+		return 0;
+	if (freq >= 6)
+		lradc_freq = LRADC_CLOCK_6MHZ;
+	else if (freq >= 4)
+		lradc_freq = LRADC_CLOCK_4MHZ;

Quoted 8 lines

arch/arm/mach-mxs/include/mach/lradc.h new file +4 -0

new file mode 100644
index 0000000..c2c0a7d
 
+
+int hw_lradc_use_channel(int);
+int hw_lradc_unuse_channel(int);
+extern u32 hw_lradc_vddio(void);

arch/arm/mach-mxs/include/mach/lradc.h line 33

Quoted 10 lines

arch/arm/mach-mxs/include/mach/lradc.h new file +10 -0

+void hw_lradc_set_delay_trigger_kick(int trigger, int value);
+void hw_lradc_configure_channel(int channel, int enable_div2,
+		int enable_acc, int samples);
+int hw_lradc_present(int channel);
+int hw_lradc_init_ladder(int channel, int trigger, unsigned sampling);
+int hw_lradc_stop_ladder(int channel, int trigger);
+void hw_lradc_set_delay_trigger(int trigger, u32 trigger_lradc,
+		u32 delay_triggers, u32 loops, u32 delays);
+void hw_lradc_clear_delay_trigger(int trigger, u32 trigger_lradc,
+		u32 delay_triggers);

As indicated by Shawn, adding a new driver specific kernel-level ADC interface is not a good idea. IIRC, the result of the last discussion was that all ADC drivers should be part of IIO and you should use the IIO in-kernel interfaces. Not sure what the state of that code is, but if it's not in mainline yet, you should work with Jonathan to make sure it gets there. Having more users for that code can only speed up the process, and I'm going to refuse another ADC driver in drivers/misc or arch/arm/mach-*/.

Quoted 8 lines

As indicated by Shawn, adding a new driver specific kernel-level ADC interface is not a good idea. IIRC, the result of the last discussion was that all ADC drivers should be part of IIO and you should use the IIO in-kernel interfaces. Not sure what the state of that code is, but if it's not in mainline yet, you should work with Jonathan to make sure it gets there. Having more users for that code can only speed up the process, and I'm going to refuse another ADC driver in drivers/misc or arch/arm/mach-*/.

Quick summary of IIO status. Nothing is in mainline yet. Intent is to get the first set of core code (including in kernel pull interfaces) into linux-next fairly shortly (these have had enough postive feedback now I think). Doing push interfaces (as I think we would need here) is possible with existing patches on top of the stuff in the iio staging tree but there are some 'interesting' cases where both push and pull interfaces exist that still need addressing.

Also, note the push interface stuff (e.g. interrupt driven) requires a lot more of the IIO infrastructure to be in place (buffered support and the demux unit) so may still be some time. Personally my time is currently very restricted so all the help anyone can offer is most welcome!

Quoted 17 lines · Jonathan Cameron

Quoted 8 lines

As indicated by Shawn, adding a new driver specific kernel-level ADC interface is not a good idea. IIRC, the result of the last discussion was that all ADC drivers should be part of IIO and you should use the IIO in-kernel interfaces. Not sure what the state of that code is, but if it's not in mainline yet, you should work with Jonathan to make sure it gets there. Having more users for that code can only speed up the process, and I'm going to refuse another ADC driver in drivers/misc or arch/arm/mach-*/.

Quick summary of IIO status. Nothing is in mainline yet. Intent is to get the first set of core code (including in kernel pull interfaces) into linux-next fairly shortly (these have had enough postive feedback now I think). Doing push interfaces (as I think we would need here) is possible with existing patches on top of the stuff in the iio staging tree but there are some 'interesting' cases where both push and pull interfaces exist that still need addressing.

Quoted 4 lines

Also, note the push interface stuff (e.g. interrupt driven) requires a lot more of the IIO infrastructure to be in place (buffered support and the demux unit) so may still be some time. Personally my time is currently very restricted so all the help anyone can offer is most welcome!

Ok, thanks for the summary!

Peter, I guess what this means for you is that it's best to first get your code working with the IIO/ADC stuff that is in staging, and get the touchscreen driver ready for merging, on top of that.

Ideally, you would also help out a bit on getting the IIO parts you need graduated from staging. Given Jonathan's explanation, I think my initial reaction was valid: we shouldn't take the ADC driver outside of IIO, because that ends up being more painful than getting the driver ready for inclusion now, and then rewriting it shortly after.

Arnd

Quoted 37 lines · Jonathan Cameron

Quoted 17 lines

Quoted 8 lines

As indicated by Shawn, adding a new driver specific kernel-level ADC interface is not a good idea. IIRC, the result of the last discussion was that all ADC drivers should be part of IIO and you should use the IIO in-kernel interfaces. Not sure what the state of that code is, but if it's not in mainline yet, you should work with Jonathan to make sure it gets there. Having more users for that code can only speed up the process, and I'm going to refuse another ADC driver in drivers/misc or arch/arm/mach-*/.

Quick summary of IIO status. Nothing is in mainline yet. Intent is to get the first set of core code (including in kernel pull interfaces) into linux-next fairly shortly (these have had enough postive feedback now I think). Doing push interfaces (as I think we would need here) is possible with existing patches on top of the stuff in the iio staging tree but there are some 'interesting' cases where both push and pull interfaces exist that still need addressing.

Quoted 5 lines

Also, note the push interface stuff (e.g. interrupt driven) requires a lot more of the IIO infrastructure to be in place (buffered support and the demux unit) so may still be some time. Personally my time is currently very restricted so all the help anyone can offer is most welcome!

Ok, thanks for the summary!

Peter, I guess what this means for you is that it's best to first get your code working with the IIO/ADC stuff that is in staging, and get the touchscreen driver ready for merging, on top of that.

Ideally, you would also help out a bit on getting the IIO parts you need graduated from staging. Given Jonathan's explanation, I think my initial reaction was valid: we shouldn't take the ADC driver outside of IIO, because that ends up being more painful than getting the driver ready for inclusion now, and then rewriting it shortly after.

Quoted 1 line

Arnd

Thank you all for your comments. I'm now working on the interface change to iio, it may take some time...
I've also applied most of the suggestions, they'll be in the next patches.