[PATCH 2/5] [input] add mc13783 touchscreen driver

[PATCH 2/5] [input] add mc13783 touchscreen driver

[Sascha Hauer]

This driver provides support for the touchscreen interface
integrated into the Freescale MC13783.

changes since v1:

- remove unused functions
- use queue_delayed_work instead of queue_work
- report pen events as BTN_TOUCH instead of ABS_PRESSURE
- handle interrupt registration in open/close functions
- do not call input_free_device() on already registered
  input_device
- use platform_driver_probe instead of platform_driver_register
- add MODULE_ALIAS

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: linux-input@vger.kernel.org
---
 drivers/input/touchscreen/Kconfig      |   12 ++
 drivers/input/touchscreen/Makefile     |    1 +
 drivers/input/touchscreen/mc13783_ts.c |  222 ++++++++++++++++++++++++++++++++
 3 files changed, 235 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/mc13783_ts.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 72e2712..7451cf0 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -413,6 +413,18 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MC13783
+	tristate "Freescale MC13783 touchscreen input driver"
+	depends on MFD_MC13783
+	help
+	  Say Y here if you have an Freescale MC13783 PMIC on your
+	  board and want to use its touchscreen
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mxc_ts.
+
 config TOUCHSCREEN_USB_EGALAX
 	default y
 	bool "eGalax, eTurboTouch CT-410/510/700 device support" if EMBEDDED
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 3e1c5e0..7b79598 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_TOUCHSCREEN_INEXIO)	+= inexio.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
+obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HTCPEN)	+= htcpen.o
diff --git a/drivers/input/touchscreen/mc13783_ts.c b/drivers/input/touchscreen/mc13783_ts.c
new file mode 100644
index 0000000..80163f1
--- /dev/null
+++ b/drivers/input/touchscreen/mc13783_ts.c
@@ -0,0 +1,222 @@
+/*
+ * Driver for the Freescale Semiconductor MC13783 touchscreen.
+ *
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2009 Sascha Hauer, Pengutronix
+ *
+ * Initial development of this code was funded by
+ * Phytec Messtechnik GmbH, http://www.phytec.de
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ */
+
+#include <linux/mfd/mc13783-private.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/mc13783.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+
+#define MC13783_TS_NAME	"mc13783-ts"
+
+struct mc13783_ts_priv {
+	struct input_dev *idev;
+	struct mc13783 *mc13783;
+	struct delayed_work work;
+	struct workqueue_struct *workq;
+	unsigned int sample[4];
+};
+
+#define TS_MIN 1
+#define TS_MAX 1000
+
+static void mc13783_ts_handler(int irq, void *data)
+{
+	struct mc13783_ts_priv *priv = data;
+	unsigned int sts;
+
+	mc13783_reg_read(priv->mc13783, MC13783_REG_INTERRUPT_STATUS_0, &sts);
+	mc13783_reg_write(priv->mc13783, MC13783_REG_INTERRUPT_STATUS_0,
+			sts & MC13783_INT_STAT_TSI);
+
+	if (sts & MC13783_INT_STAT_TSI)
+		queue_delayed_work(priv->workq, &priv->work, 0);
+}
+
+static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
+{
+	int x, y, press = 0;
+
+	x = (priv->sample[2] >> 2) & 0x3ff;
+	y = (priv->sample[3] >> 2) & 0x3ff;
+
+	pr_debug("mc13783_ts: x: %d y: %d\n", x, y);
+
+	if (x > TS_MIN && x < TS_MAX && y > TS_MIN && y < TS_MAX) {
+		press = 1;
+		input_report_abs(priv->idev, ABS_X, x);
+		input_report_abs(priv->idev, ABS_Y, y);
+
+		queue_delayed_work(priv->workq, &priv->work, HZ / 50);
+	}
+
+	input_report_key(priv->idev, BTN_TOUCH, press);
+	input_sync(priv->idev);
+}
+
+static void mc13783_ts_work(struct work_struct *work)
+{
+	struct mc13783_ts_priv *priv =
+		container_of(work, struct mc13783_ts_priv, work.work);
+	unsigned int mode = MC13783_ADC_MODE_TS;
+	unsigned int channel = 12;
+	int ret;
+
+	ret = mc13783_adc_do_conversion
+		(priv->mc13783, mode, channel, priv->sample);
+
+	if (!ret)
+		mc13783_ts_report_sample(priv);
+}
+
+static int mc13783_ts_open(struct input_dev *dev)
+{
+	struct mc13783_ts_priv *priv = input_get_drvdata(dev);
+	int ret;
+
+	ret = mc13783_register_irq(priv->mc13783, MC13783_IRQ_TS,
+		mc13783_ts_handler, priv);
+	if (ret)
+		return ret;
+
+	queue_delayed_work(priv->workq, &priv->work, HZ / 20);
+
+	return 0;
+}
+
+static void mc13783_ts_close(struct input_dev *dev)
+{
+	struct mc13783_ts_priv *priv = input_get_drvdata(dev);
+
+	mc13783_free_irq(priv->mc13783, MC13783_IRQ_TS);
+}
+
+static int __devinit mc13783_ts_probe(struct platform_device *pdev)
+{
+	struct mc13783_ts_priv *priv;
+	struct input_dev *idev;
+	int ret;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
+
+	idev = input_allocate_device();
+	if (!idev) {
+		ret = -ENOMEM;
+		goto err_input_alloc;
+	}
+
+	priv->idev = idev;
+	idev->name = MC13783_TS_NAME;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	idev->absbit[0] = BIT_MASK(ABS_X) | BIT_MASK(ABS_Y);
+	idev->open = mc13783_ts_open;
+	idev->close = mc13783_ts_close;
+	input_set_abs_params(idev, ABS_X, TS_MIN, TS_MAX, 0, 0);
+	input_set_abs_params(idev, ABS_Y, TS_MIN, TS_MAX, 0, 0);
+
+	platform_set_drvdata(pdev, priv);
+
+	INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
+
+	priv->workq = create_singlethread_workqueue("mc13783_ts");
+	if (!priv->workq) {
+		ret = -ENOMEM;
+		goto err_input_alloc;
+	}
+
+	input_set_drvdata(idev, priv);
+
+	ret = input_register_device(priv->idev);
+	if (ret) {
+		dev_err(&pdev->dev,
+				"register input device failed with %d\n", ret);
+		goto err_failed_register;
+	}
+
+	/* unmask the ts wakeup interrupt */
+	mc13783_set_bits(priv->mc13783, MC13783_REG_INTERRUPT_MASK_0,
+			MC13783_INT_MASK_TSM, 0);
+
+	mc13783_adc_set_ts_status(priv->mc13783, 1);
+
+	return 0;
+
+err_failed_register:
+	input_free_device(priv->idev);
+err_input_alloc:
+	kfree(priv);
+
+	return ret;
+}
+
+static int __devexit mc13783_ts_remove(struct platform_device *pdev)
+{
+	struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
+
+	mc13783_adc_set_ts_status(priv->mc13783, 0);
+
+	cancel_delayed_work(&priv->work);
+	destroy_workqueue(priv->workq);
+
+	input_unregister_device(priv->idev);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_driver mc13783_ts_driver = {
+	.remove		= __devexit_p(mc13783_ts_remove),
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= MC13783_TS_NAME,
+	},
+};
+
+static int __init mc13783_ts_init(void)
+{
+	return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe);
+}
+
+static void __exit mc13783_ts_exit(void)
+{
+	platform_driver_unregister(&mc13783_ts_driver);
+}
+
+module_init(mc13783_ts_init);
+module_exit(mc13783_ts_exit);
+
+MODULE_DESCRIPTION("MC13783 input touchscreen driver");
+MODULE_AUTHOR("Sascha Hauer, <s.hauer@pengutronix.de>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:mc13783-touch");
-- 
1.6.3.3

Re: [PATCH 2/5] [input] add mc13783 touchscreen driver

[Dmitry Torokhov]

On Wed, Aug 12, 2009 at 05:05:28PM +0200, Sascha Hauer wrote:
> This driver provides support for the touchscreen interface
> integrated into the Freescale MC13783.
> 
> changes since v1:
> 
> - remove unused functions
> - use queue_delayed_work instead of queue_work
> - report pen events as BTN_TOUCH instead of ABS_PRESSURE
> - handle interrupt registration in open/close functions
> - do not call input_free_device() on already registered
>   input_device
> - use platform_driver_probe instead of platform_driver_register

BTW, if you are using platform_driver_probe() then __init is OK for
.probe() because all probes will only be run once, when driver loads.
IIRC the ability to discard probe() code was the main reason for
introducing platform_driver_probe().

> +
> +	/* unmask the ts wakeup interrupt */
> +	mc13783_set_bits(priv->mc13783, MC13783_REG_INTERRUPT_MASK_0,
> +			MC13783_INT_MASK_TSM, 0);
> +
> +	mc13783_adc_set_ts_status(priv->mc13783, 1);
> +

I actually expected these bits to go into ->open(); not the request IRQ
stuff...

-- 
Dmitry

Re: [PATCH 2/5] [input] add mc13783 touchscreen driver

[Sascha Hauer]

On Wed, Aug 12, 2009 at 09:04:38AM -0700, Dmitry Torokhov wrote:
> On Wed, Aug 12, 2009 at 05:05:28PM +0200, Sascha Hauer wrote:
> > This driver provides support for the touchscreen interface
> > integrated into the Freescale MC13783.
> > 
> > changes since v1:
> > 
> > - remove unused functions
> > - use queue_delayed_work instead of queue_work
> > - report pen events as BTN_TOUCH instead of ABS_PRESSURE
> > - handle interrupt registration in open/close functions
> > - do not call input_free_device() on already registered
> >   input_device
> > - use platform_driver_probe instead of platform_driver_register
> 
> BTW, if you are using platform_driver_probe() then __init is OK for
> .probe() because all probes will only be run once, when driver loads.
> IIRC the ability to discard probe() code was the main reason for
> introducing platform_driver_probe().

But __devinit should be ok also, right?

> 
> > +
> > +	/* unmask the ts wakeup interrupt */
> > +	mc13783_set_bits(priv->mc13783, MC13783_REG_INTERRUPT_MASK_0,
> > +			MC13783_INT_MASK_TSM, 0);
> > +
> > +	mc13783_adc_set_ts_status(priv->mc13783, 1);
> > +
> 
> I actually expected these bits to go into ->open(); not the request IRQ
> stuff...

Yes I know, I just found it convenient to request the interrupts there
so that we do not risk getting interrupts nobody is interested in this
moment.

Sascha

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

Re: [PATCH 2/5] [input] add mc13783 touchscreen driver

[Dmitry Torokhov]

On Thu, Aug 13, 2009 at 02:26:48PM +0200, Sascha Hauer wrote:
> On Wed, Aug 12, 2009 at 09:04:38AM -0700, Dmitry Torokhov wrote:
> > On Wed, Aug 12, 2009 at 05:05:28PM +0200, Sascha Hauer wrote:
> > > This driver provides support for the touchscreen interface
> > > integrated into the Freescale MC13783.
> > > 
> > > changes since v1:
> > > 
> > > - remove unused functions
> > > - use queue_delayed_work instead of queue_work
> > > - report pen events as BTN_TOUCH instead of ABS_PRESSURE
> > > - handle interrupt registration in open/close functions
> > > - do not call input_free_device() on already registered
> > >   input_device
> > > - use platform_driver_probe instead of platform_driver_register
> > 
> > BTW, if you are using platform_driver_probe() then __init is OK for
> > .probe() because all probes will only be run once, when driver loads.
> > IIRC the ability to discard probe() code was the main reason for
> > introducing platform_driver_probe().
> 
> But __devinit should be ok also, right?
> 

It is OK but then what is the point of using platform_driver_probe()
instead of platform_driver_register()? The only reason you'd want to use
platform_driver_probe() if you wanted to discard the probe methods but
it will not happen if the are marked __devinit.

> > 
> > > +
> > > +	/* unmask the ts wakeup interrupt */
> > > +	mc13783_set_bits(priv->mc13783, MC13783_REG_INTERRUPT_MASK_0,
> > > +			MC13783_INT_MASK_TSM, 0);
> > > +
> > > +	mc13783_adc_set_ts_status(priv->mc13783, 1);
> > > +
> > 
> > I actually expected these bits to go into ->open(); not the request IRQ
> > stuff...
> 
> Yes I know, I just found it convenient to request the interrupts there
> so that we do not risk getting interrupts nobody is interested in this
> moment.
> 

OK, but still, the bits above should be moved to open() as well, right?

-- 
Dmitry

[PATCH] [input] add mc13783 touchscreen driver

[Uwe Kleine-König]

From: Sascha Hauer <s.hauer@pengutronix.de>

This driver provides support for the touchscreen interface
integrated into the Freescale MC13783.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Luotao Fu <l.fu@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: linux-input@vger.kernel.org
---
 drivers/input/touchscreen/Kconfig      |   12 ++
 drivers/input/touchscreen/Makefile     |    1 +
 drivers/input/touchscreen/mc13783_ts.c |  259 ++++++++++++++++++++++++++++++++
 3 files changed, 272 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/mc13783_ts.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 8cc453c..cdee9ca 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -425,6 +425,18 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MC13783
+	tristate "Freescale MC13783 touchscreen input driver"
+	depends on MFD_MC13783
+	help
+	  Say Y here if you have an Freescale MC13783 PMIC on your
+	  board and want to use its touchscreen
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mc13783_ts.
+
 config TOUCHSCREEN_USB_EGALAX
 	default y
 	bool "eGalax, eTurboTouch CT-410/510/700 device support" if EMBEDDED
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 15fa62c..ac5ecaf 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
+obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HTCPEN)	+= htcpen.o
diff --git a/drivers/input/touchscreen/mc13783_ts.c b/drivers/input/touchscreen/mc13783_ts.c
new file mode 100644
index 0000000..a36b2ad
--- /dev/null
+++ b/drivers/input/touchscreen/mc13783_ts.c
@@ -0,0 +1,259 @@
+/*
+ * Driver for the Freescale Semiconductor MC13783 touchscreen.
+ *
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2009 Sascha Hauer, Pengutronix
+ *
+ * Initial development of this code was funded by
+ * Phytec Messtechnik GmbH, http://www.phytec.de/
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/platform_device.h>
+#include <linux/mfd/mc13783.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+
+#define MC13783_TS_NAME	"mc13783-ts"
+
+#define DEFAULT_SAMPLE_TOLERANCE 300
+
+static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE;
+module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(sample_tolerance,
+		"If the minimal and maximal value read out for one axis (out "
+		"of three) differ by this value (default: "
+		__stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading "
+		"is supposed to be wrong and is discarded.  Set to 0 to "
+		"disable this check.");
+
+struct mc13783_ts_priv {
+	struct input_dev *idev;
+	struct mc13783 *mc13783;
+	struct delayed_work work;
+	struct workqueue_struct *workq;
+	unsigned int sample[4];
+};
+
+static irqreturn_t mc13783_ts_handler(int irq, void *data)
+{
+	struct mc13783_ts_priv *priv = data;
+
+	mc13783_ackirq(priv->mc13783, irq);
+
+	queue_delayed_work(priv->workq, &priv->work, 0);
+
+	return IRQ_HANDLED;
+}
+
+#define sort3(a0, a1, a2) ({ 						\
+		if (a0 > a1)						\
+			swap(a0, a1);					\
+		if (a1 > a2)						\
+			swap(a1, a2);					\
+		if (a0 > a1)						\
+			swap(a0, a1);					\
+		})
+
+static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
+{
+	int x0, x1, x2, y0, y1, y2;
+	int cr0, cr1;
+
+	/*
+	 * the values are 10-bit wide only, but the two least significant
+	 * bits are for future 12 bit use and reading yields 0
+	 */
+	x0 = priv->sample[0] & 0xfff;
+	x1 = priv->sample[1] & 0xfff;
+	x2 = priv->sample[2] & 0xfff;
+	y0 = priv->sample[3] & 0xfff;
+	y1 = (priv->sample[0] >> 12) & 0xfff;
+	y2 = (priv->sample[1] >> 12) & 0xfff;
+	cr0 = (priv->sample[2] >> 12) & 0xfff;
+	cr1 = (priv->sample[3] >> 12) & 0xfff;
+
+	dev_dbg(&priv->idev->dev, "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) "
+			"cr: (% 4d, % 4d)\n", x0, x1, x2, y0, y1, y2, cr0, cr1);
+
+	sort3(x0, x1, x2);
+	sort3(y0, y1, y2);
+
+	cr0 = (cr0 + cr1) / 2;
+
+	if (!cr0 || !sample_tolerance ||
+			(x2 - x0 < sample_tolerance &&
+			 y2 - y0 < sample_tolerance))
+	{
+		/* report the median coordinate and average pressure */
+		if (cr0) {
+			input_report_abs(priv->idev, ABS_X, x1);
+			input_report_abs(priv->idev, ABS_Y, y1);
+
+			dev_dbg(&priv->idev->dev, "report (%d, %d, %d)\n",
+					x1, y1, 0x1000 - cr0);
+			queue_delayed_work(priv->workq, &priv->work, HZ / 50);
+		} else
+			dev_dbg(&priv->idev->dev, "report release\n");
+
+		input_report_abs(priv->idev, ABS_PRESSURE,
+				cr0 ? 0x1000 - cr0 : cr0);
+		input_report_key(priv->idev, BTN_TOUCH, !!cr0);
+		input_sync(priv->idev);
+	} else
+		dev_dbg(&priv->idev->dev, "discard event\n");
+}
+
+static void mc13783_ts_work(struct work_struct *work)
+{
+	struct mc13783_ts_priv *priv =
+		container_of(work, struct mc13783_ts_priv, work.work);
+	unsigned int mode = MC13783_ADC_MODE_TS;
+	unsigned int channel = 12;
+	int ret;
+
+	ret = mc13783_adc_do_conversion(priv->mc13783, mode, channel,
+			priv->sample);
+
+	if (!ret)
+		mc13783_ts_report_sample(priv);
+}
+
+static int mc13783_ts_open(struct input_dev *dev)
+{
+	struct mc13783_ts_priv *priv = input_get_drvdata(dev);
+	int ret;
+
+	mc13783_lock(priv->mc13783);
+
+	mc13783_ackirq(priv->mc13783, MC13783_IRQ_TS);
+
+	ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_TS,
+		mc13783_ts_handler, MC13783_TS_NAME, priv);
+	if (ret)
+		goto out;
+
+	ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
+			MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0);
+
+out:
+	mc13783_unlock(priv->mc13783);
+
+	return ret;
+}
+
+static void mc13783_ts_close(struct input_dev *dev)
+{
+	struct mc13783_ts_priv *priv = input_get_drvdata(dev);
+
+	mc13783_lock(priv->mc13783);
+	mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
+			MC13783_ADC0_TSMOD_MASK, 0);
+	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
+	mc13783_unlock(priv->mc13783);
+}
+
+static int __init mc13783_ts_probe(struct platform_device *pdev)
+{
+	struct mc13783_ts_priv *priv;
+	struct input_dev *idev;
+	int ret;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
+
+	idev = input_allocate_device();
+	if (!idev) {
+		ret = -ENOMEM;
+		goto err_input_alloc;
+	}
+
+	priv->idev = idev;
+	idev->name = MC13783_TS_NAME;
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	idev->open = mc13783_ts_open;
+	idev->close = mc13783_ts_close;
+	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, 0xfff, 0, 0);
+
+	platform_set_drvdata(pdev, priv);
+
+	INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
+
+	priv->workq = create_singlethread_workqueue("mc13783_ts");
+	if (!priv->workq) {
+		ret = -ENOMEM;
+		goto err_input_alloc;
+	}
+
+	input_set_drvdata(idev, priv);
+
+	ret = input_register_device(priv->idev);
+	if (ret) {
+		dev_err(&pdev->dev,
+				"register input device failed with %d\n", ret);
+		goto err_failed_register;
+	}
+
+	return 0;
+
+err_failed_register:
+	input_free_device(priv->idev);
+
+err_input_alloc:
+	platform_set_drvdata(pdev, NULL);
+	kfree(priv);
+
+	return ret;
+}
+
+static int __devexit mc13783_ts_remove(struct platform_device *pdev)
+{
+	struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	cancel_delayed_work(&priv->work);
+	destroy_workqueue(priv->workq);
+
+	input_unregister_device(priv->idev);
+
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_driver mc13783_ts_driver = {
+	.remove		= __devexit_p(mc13783_ts_remove),
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= MC13783_TS_NAME,
+	},
+};
+
+static int __init mc13783_ts_init(void)
+{
+	return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe);
+}
+module_init(mc13783_ts_init);
+
+static void __exit mc13783_ts_exit(void)
+{
+	platform_driver_unregister(&mc13783_ts_driver);
+}
+module_exit(mc13783_ts_exit);
+
+MODULE_DESCRIPTION("MC13783 input touchscreen driver");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" MC13783_TS_NAME);
-- 
1.6.5.2

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Re: [PATCH] [input] add mc13783 touchscreen driver

[Dmitry Torokhov]

Hi Uwe,

On Fri, Dec 04, 2009 at 08:52:57PM +0100, Uwe Kleine-König wrote:
> From: Sascha Hauer <s.hauer@pengutronix.de>
> 
> This driver provides support for the touchscreen interface
> integrated into the Freescale MC13783.
> 

Unfortunately the driver as presented does not compile because changes
to mc13783 core that are needed by this driver are not in mainline (and
therefore are not in my tree) yet. Do you know when they willbe
submitted to Linus?

At this point we have 2 option - wait till the necessary changes hit
mainline or merge through some other tree. I am OK with merging through
other tree (MFD?) provided that the patch below is applied (just fold it
into original patch). The main changes:

 - we should free IRQ if we fail to activate the device. The old code
   was returning error from mc13783_ts_open() but was leaving IRQ
   registered

 - use cancel_delayed_work_sync() instead of cancel_delayed_work(). You
   want to make sure that work function is not running. It also should
   be called form mc13783_ts_close() and not mc13783_ts_remove()

 - miscellaneous formatting changes.

In this case please feel free add:

	Acked-by: Dmitry Torokhov <dtor@mail.ru>

Thanks.

-- 
Dmitry


diff -u b/drivers/input/touchscreen/mc13783_ts.c b/drivers/input/touchscreen/mc13783_ts.c
--- b/drivers/input/touchscreen/mc13783_ts.c
+++ b/drivers/input/touchscreen/mc13783_ts.c
@@ -46,6 +46,12 @@
 
 	mc13783_ackirq(priv->mc13783, irq);
 
+	/*
+	 * Kick off reading coordinates. Note that if work happens already
+	 * be queued for future execution (it rearms itself) it will not
+	 * be rescheduled for immediate execution here. However the rearm
+	 * delay is HZ / 50 which is acceptable.
+	 */
 	queue_delayed_work(priv->workq, &priv->work, 0);
 
 	return IRQ_HANDLED;
@@ -62,6 +68,7 @@
 
 static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
 {
+	struct input_dev *idev = priv->idev;
 	int x0, x1, x2, y0, y1, y2;
 	int cr0, cr1;
 
@@ -78,8 +85,9 @@
 	cr0 = (priv->sample[2] >> 12) & 0xfff;
 	cr1 = (priv->sample[3] >> 12) & 0xfff;
 
-	dev_dbg(&priv->idev->dev, "x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) "
-			"cr: (% 4d, % 4d)\n", x0, x1, x2, y0, y1, y2, cr0, cr1);
+	dev_dbg(&idev->dev,
+		"x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
+		x0, x1, x2, y0, y1, y2, cr0, cr1);
 
 	sort3(x0, x1, x2);
 	sort3(y0, y1, y2);
@@ -87,26 +95,24 @@
 	cr0 = (cr0 + cr1) / 2;
 
 	if (!cr0 || !sample_tolerance ||
-			(x2 - x0 < sample_tolerance &&
-			 y2 - y0 < sample_tolerance))
-	{
+	    (x2 - x0 < sample_tolerance && y2 - y0 < sample_tolerance)) {
 		/* report the median coordinate and average pressure */
 		if (cr0) {
-			input_report_abs(priv->idev, ABS_X, x1);
-			input_report_abs(priv->idev, ABS_Y, y1);
+			input_report_abs(idev, ABS_X, x1);
+			input_report_abs(idev, ABS_Y, y1);
 
-			dev_dbg(&priv->idev->dev, "report (%d, %d, %d)\n",
-					x1, y1, 0x1000 - cr0);
+			dev_dbg(&idev->dev,
+				"report (%d, %d, %d)\n", x1, y1, 0x1000 - cr0);
 			queue_delayed_work(priv->workq, &priv->work, HZ / 50);
 		} else
-			dev_dbg(&priv->idev->dev, "report release\n");
+			dev_dbg(&idev->dev, "report release\n");
 
-		input_report_abs(priv->idev, ABS_PRESSURE,
-				cr0 ? 0x1000 - cr0 : cr0);
-		input_report_key(priv->idev, BTN_TOUCH, !!cr0);
-		input_sync(priv->idev);
+		input_report_abs(idev, ABS_PRESSURE,
+				 cr0 ? 0x1000 - cr0 : cr0);
+		input_report_key(idev, BTN_TOUCH, cr0);
+		input_sync(idev);
 	} else
-		dev_dbg(&priv->idev->dev, "discard event\n");
+		dev_dbg(&idev->dev, "discard event\n");
 }
 
 static void mc13783_ts_work(struct work_struct *work)
@@ -115,13 +121,11 @@
 		container_of(work, struct mc13783_ts_priv, work.work);
 	unsigned int mode = MC13783_ADC_MODE_TS;
 	unsigned int channel = 12;
-	int ret;
 
-	ret = mc13783_adc_do_conversion(priv->mc13783, mode, channel,
-			priv->sample);
-
-	if (!ret)
+	if (mc13783_adc_do_conversion(priv->mc13783,
+				      mode, channel, priv->sample) == 0) {
 		mc13783_ts_report_sample(priv);
+	}
 }
 
 static int mc13783_ts_open(struct input_dev *dev)
@@ -140,10 +144,10 @@
 
 	ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
 			MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0);
-
+	if (ret)
+		mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
 out:
 	mc13783_unlock(priv->mc13783);
-
 	return ret;
 }
 
@@ -156,65 +160,67 @@
 			MC13783_ADC0_TSMOD_MASK, 0);
 	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
 	mc13783_unlock(priv->mc13783);
+
+	cancel_delayed_work_sync(&priv->work);
 }
 
 static int __init mc13783_ts_probe(struct platform_device *pdev)
 {
 	struct mc13783_ts_priv *priv;
 	struct input_dev *idev;
-	int ret;
+	int error;
 
 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
+	idev = input_allocate_device();
+	if (!priv || !idev) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
 
+	INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
 	priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
+	priv->idev = idev;
 
-	idev = input_allocate_device();
-	if (!idev) {
-		ret = -ENOMEM;
-		goto err_input_alloc;
+	/*
+	 * We need separate workqueue because mc13783_adc_do_conversion
+	 * uses keventd and thus would deadlock.
+	 */
+	priv->workq = create_singlethread_workqueue("mc13783_ts");
+	if (!priv->workq) {
+		error = -ENOMEM;
+		goto err_free_mem;
 	}
 
-	priv->idev = idev;
 	idev->name = MC13783_TS_NAME;
+	idev->dev.parent = &pdev->dev;
+
 	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
-	idev->open = mc13783_ts_open;
-	idev->close = mc13783_ts_close;
 	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, 0xfff, 0, 0);
 
-	platform_set_drvdata(pdev, priv);
-
-	INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
-
-	priv->workq = create_singlethread_workqueue("mc13783_ts");
-	if (!priv->workq) {
-		ret = -ENOMEM;
-		goto err_input_alloc;
-	}
+	idev->open = mc13783_ts_open;
+	idev->close = mc13783_ts_close;
 
 	input_set_drvdata(idev, priv);
 
-	ret = input_register_device(priv->idev);
-	if (ret) {
+	error = input_register_device(priv->idev);
+	if (error) {
 		dev_err(&pdev->dev,
-				"register input device failed with %d\n", ret);
-		goto err_failed_register;
+			"register input device failed with %d\n", error);
+		goto err_destroy_wq;
 	}
 
+	platform_set_drvdata(pdev, priv);
 	return 0;
 
-err_failed_register:
-	input_free_device(priv->idev);
-
-err_input_alloc:
-	platform_set_drvdata(pdev, NULL);
+err_destroy_wq:
+	destroy_workqueue(priv->workq);
+err_free_mem:
+	input_free_device(idev);
 	kfree(priv);
-
-	return ret;
+	return error;
 }
 
 static int __devexit mc13783_ts_remove(struct platform_device *pdev)
@@ -223,11 +229,8 @@
 
 	platform_set_drvdata(pdev, NULL);
 
-	cancel_delayed_work(&priv->work);
 	destroy_workqueue(priv->workq);
-
 	input_unregister_device(priv->idev);
-
 	kfree(priv);
 
 	return 0;
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[PATCH] [input] add mc13783 touchscreen driver

[Uwe Kleine-König]

From: Sascha Hauer <s.hauer@pengutronix.de>

This driver provides support for the touchscreen interface
integrated into the Freescale MC13783.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Luotao Fu <l.fu@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: linux-input@vger.kernel.org
---
Hi Dmitry,

I squashed your changes into this patch, restored my indention style and
simplified error handling in mc13783_ts_probe to assign ret = -ENOMEM 
once at the start of the function instead of each error branch.

In the meantime the changes to mc13783-core are merged in Linus' tree,
so it can go via your's.

Best regards and thanks for your review,
Uwe

 drivers/input/touchscreen/Kconfig      |   12 ++
 drivers/input/touchscreen/Makefile     |    1 +
 drivers/input/touchscreen/mc13783_ts.c |  258 ++++++++++++++++++++++++++++++++
 3 files changed, 271 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/touchscreen/mc13783_ts.c

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 32fc8ba..dfafc76 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -450,6 +450,18 @@ config TOUCHSCREEN_USB_COMPOSITE
 	  To compile this driver as a module, choose M here: the
 	  module will be called usbtouchscreen.
 
+config TOUCHSCREEN_MC13783
+	tristate "Freescale MC13783 touchscreen input driver"
+	depends on MFD_MC13783
+	help
+	  Say Y here if you have an Freescale MC13783 PMIC on your
+	  board and want to use its touchscreen
+
+	  If unsure, say N.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called mc13783_ts.
+
 config TOUCHSCREEN_USB_EGALAX
 	default y
 	bool "eGalax, eTurboTouch CT-410/510/700 device support" if EMBEDDED
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index f1f59c9..7416bab 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_TOUCHSCREEN_MCS5000)	+= mcs5000_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MIGOR)		+= migor_ts.o
 obj-$(CONFIG_TOUCHSCREEN_MTOUCH)	+= mtouch.o
 obj-$(CONFIG_TOUCHSCREEN_MK712)		+= mk712.o
+obj-$(CONFIG_TOUCHSCREEN_MC13783)	+= mc13783_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HP600)		+= hp680_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_HP7XX)		+= jornada720_ts.o
 obj-$(CONFIG_TOUCHSCREEN_HTCPEN)	+= htcpen.o
diff --git a/drivers/input/touchscreen/mc13783_ts.c b/drivers/input/touchscreen/mc13783_ts.c
new file mode 100644
index 0000000..87de17f
--- /dev/null
+++ b/drivers/input/touchscreen/mc13783_ts.c
@@ -0,0 +1,258 @@
+/*
+ * Driver for the Freescale Semiconductor MC13783 touchscreen.
+ *
+ * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright (C) 2009 Sascha Hauer, Pengutronix
+ *
+ * Initial development of this code was funded by
+ * Phytec Messtechnik GmbH, http://www.phytec.de/
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+#include <linux/platform_device.h>
+#include <linux/mfd/mc13783.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+
+#define MC13783_TS_NAME	"mc13783-ts"
+
+#define DEFAULT_SAMPLE_TOLERANCE 300
+
+static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE;
+module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(sample_tolerance,
+		"If the minimal and maximal value read out for one axis (out "
+		"of three) differ by this value (default: "
+		__stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading "
+		"is supposed to be wrong and is discarded.  Set to 0 to "
+		"disable this check.");
+
+struct mc13783_ts_priv {
+	struct input_dev *idev;
+	struct mc13783 *mc13783;
+	struct delayed_work work;
+	struct workqueue_struct *workq;
+	unsigned int sample[4];
+};
+
+static irqreturn_t mc13783_ts_handler(int irq, void *data)
+{
+	struct mc13783_ts_priv *priv = data;
+
+	mc13783_ackirq(priv->mc13783, irq);
+
+	/*
+	 * Kick off reading coordinates. Note that if work happens already
+	 * be queued for future execution (it rearms itself) it will not
+	 * be rescheduled for immediate execution here. However the rearm
+	 * delay is HZ / 50 which is acceptable.
+	 */
+	queue_delayed_work(priv->workq, &priv->work, 0);
+
+	return IRQ_HANDLED;
+}
+
+#define sort3(a0, a1, a2) ({ 						\
+		if (a0 > a1)						\
+			swap(a0, a1);					\
+		if (a1 > a2)						\
+			swap(a1, a2);					\
+		if (a0 > a1)						\
+			swap(a0, a1);					\
+		})
+
+static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
+{
+	struct input_dev *idev = priv->idev;
+	int x0, x1, x2, y0, y1, y2;
+	int cr0, cr1;
+
+	/*
+	 * the values are 10-bit wide only, but the two least significant
+	 * bits are for future 12 bit use and reading yields 0
+	 */
+	x0 = priv->sample[0] & 0xfff;
+	x1 = priv->sample[1] & 0xfff;
+	x2 = priv->sample[2] & 0xfff;
+	y0 = priv->sample[3] & 0xfff;
+	y1 = (priv->sample[0] >> 12) & 0xfff;
+	y2 = (priv->sample[1] >> 12) & 0xfff;
+	cr0 = (priv->sample[2] >> 12) & 0xfff;
+	cr1 = (priv->sample[3] >> 12) & 0xfff;
+
+	dev_dbg(&idev->dev,
+		"x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
+		x0, x1, x2, y0, y1, y2, cr0, cr1);
+
+	sort3(x0, x1, x2);
+	sort3(y0, y1, y2);
+
+	cr0 = (cr0 + cr1) / 2;
+
+	if (!cr0 || !sample_tolerance ||
+			(x2 - x0 < sample_tolerance &&
+			 y2 - y0 < sample_tolerance)) {
+		/* report the median coordinate and average pressure */
+		if (cr0) {
+			input_report_abs(idev, ABS_X, x1);
+			input_report_abs(idev, ABS_Y, y1);
+
+			dev_dbg(&idev->dev, "report (%d, %d, %d)\n",
+					x1, y1, 0x1000 - cr0);
+			queue_delayed_work(priv->workq, &priv->work, HZ / 50);
+		} else
+			dev_dbg(&idev->dev, "report release\n");
+
+		input_report_abs(idev, ABS_PRESSURE,
+				cr0 ? 0x1000 - cr0 : cr0);
+		input_report_key(idev, BTN_TOUCH, cr0);
+		input_sync(idev);
+	} else
+		dev_dbg(&idev->dev, "discard event\n");
+}
+
+static void mc13783_ts_work(struct work_struct *work)
+{
+	struct mc13783_ts_priv *priv =
+		container_of(work, struct mc13783_ts_priv, work.work);
+	unsigned int mode = MC13783_ADC_MODE_TS;
+	unsigned int channel = 12;
+
+	if (mc13783_adc_do_conversion(priv->mc13783,
+				mode, channel, priv->sample) == 0)
+		mc13783_ts_report_sample(priv);
+}
+
+static int mc13783_ts_open(struct input_dev *dev)
+{
+	struct mc13783_ts_priv *priv = input_get_drvdata(dev);
+	int ret;
+
+	mc13783_lock(priv->mc13783);
+
+	mc13783_ackirq(priv->mc13783, MC13783_IRQ_TS);
+
+	ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_TS,
+		mc13783_ts_handler, MC13783_TS_NAME, priv);
+	if (ret)
+		goto out;
+
+	ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
+			MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0);
+	if (ret)
+		mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
+out:
+	mc13783_unlock(priv->mc13783);
+	return ret;
+}
+
+static void mc13783_ts_close(struct input_dev *dev)
+{
+	struct mc13783_ts_priv *priv = input_get_drvdata(dev);
+
+	mc13783_lock(priv->mc13783);
+	mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
+			MC13783_ADC0_TSMOD_MASK, 0);
+	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
+	mc13783_unlock(priv->mc13783);
+
+	cancel_delayed_work_sync(&priv->work);
+}
+
+static int __init mc13783_ts_probe(struct platform_device *pdev)
+{
+	struct mc13783_ts_priv *priv;
+	struct input_dev *idev;
+	int ret = -ENOMEM;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	idev = input_allocate_device();
+	if (!priv || !idev)
+		goto err_free_mem;
+
+	INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
+	priv->mc13783 = dev_get_drvdata(pdev->dev.parent);
+	priv->idev = idev;
+
+	/*
+	 * We need separate workqueue because mc13783_adc_do_conversion
+	 * uses keventd and thus would deadlock.
+	 */
+	priv->workq = create_singlethread_workqueue("mc13783_ts");
+	if (!priv->workq)
+		goto err_free_mem;
+
+	idev->name = MC13783_TS_NAME;
+	idev->dev.parent = &pdev->dev;
+
+	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
+	idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
+	input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
+	input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
+	input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0);
+
+	idev->open = mc13783_ts_open;
+	idev->close = mc13783_ts_close;
+
+	input_set_drvdata(idev, priv);
+
+	ret = input_register_device(priv->idev);
+	if (ret) {
+		dev_err(&pdev->dev,
+			"register input device failed with %d\n", ret);
+		goto err_destroy_wq;
+	}
+
+	platform_set_drvdata(pdev, priv);
+	return 0;
+
+err_destroy_wq:
+	destroy_workqueue(priv->workq);
+err_free_mem:
+	input_free_device(idev);
+	kfree(priv);
+	return ret;
+}
+
+static int __devexit mc13783_ts_remove(struct platform_device *pdev)
+{
+	struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	destroy_workqueue(priv->workq);
+	input_unregister_device(priv->idev);
+	kfree(priv);
+
+	return 0;
+}
+
+static struct platform_driver mc13783_ts_driver = {
+	.remove		= __devexit_p(mc13783_ts_remove),
+	.driver		= {
+		.owner	= THIS_MODULE,
+		.name	= MC13783_TS_NAME,
+	},
+};
+
+static int __init mc13783_ts_init(void)
+{
+	return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe);
+}
+module_init(mc13783_ts_init);
+
+static void __exit mc13783_ts_exit(void)
+{
+	platform_driver_unregister(&mc13783_ts_driver);
+}
+module_exit(mc13783_ts_exit);
+
+MODULE_DESCRIPTION("MC13783 input touchscreen driver");
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" MC13783_TS_NAME);
-- 
1.6.5.2

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Re: [PATCH] [input] add mc13783 touchscreen driver

[Dmitry Torokhov]

Hi Uwe,

On Tue, Dec 15, 2009 at 11:10:28AM +0100, Uwe Kleine-König wrote:
> Hi Dmitry,
> 
> I squashed your changes into this patch, restored my indention style and
> simplified error handling in mc13783_ts_probe to assign ret = -ENOMEM 
> once at the start of the function instead of each error branch.

I prefer to have error defined right before we jump because it allows
reader to see explicitely set error condition instead of having to
verify if earlier code set it properly; it also forces you to set error
conditions on every error branch properly (if you forget while adding a
new one compiler will warn you about uninitialized variable), but I
won't insist.

> 
> In the meantime the changes to mc13783-core are merged in Linus' tree,
> so it can go via your's.
> 

It settled then.

-- 
Dmitry