[Patch v1 08/11] Touch: DA9052 touchscreen driver

[Patch v1 08/11] Touch: DA9052 touchscreen driver

[ashishj3]

This driver add support for DA9052 4-wire resistive ADC interfaced touchscreen
controller.

DA9052 is a MFD therefore this driver depends on DA9052 core driver for core
functionalities.

Signed-off-by: David Dajun Chen <dchen@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
---
 drivers/input/touchscreen/Kconfig      |    7 +
 drivers/input/touchscreen/Makefile     |    1 +
 drivers/input/touchscreen/da9052_tsi.c |  489 ++++++++++++++++++++++++++++++++
 3 files changed, 497 insertions(+), 0 deletions(-)
 create mode 100755 drivers/input/touchscreen/da9052_tsi.c
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index cabd9e5..a5d2e7b 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -144,6 +144,13 @@ config TOUCHSCREEN_DA9034
 	  Say Y here to enable the support for the touchscreen found
 	  on Dialog Semiconductor DA9034 PMIC.
 
+config TOUCHSCREEN_DA9052
+	tristate "Dialog DA9052 TSI"
+	depends on PMIC_DA9052
+	help
+	  Say y here to support the touchscreen found on
+	  Dialog Semiconductor DA9052 PMIC
+
 config TOUCHSCREEN_DYNAPRO
 	tristate "Dynapro serial touchscreen"
 	select SERIO
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 282d6f7..a4aeb25 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_TOUCHSCREEN_BITSY)		+= h3600_ts_input.o
 obj-$(CONFIG_TOUCHSCREEN_BU21013)       += bu21013_ts.o
 obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110)	+= cy8ctmg110_ts.o
 obj-$(CONFIG_TOUCHSCREEN_DA9034)	+= da9034-ts.o
+obj-$(CONFIG_TOUCHSCREEN_DA9052)	+= da9052_tsi.o
 obj-$(CONFIG_TOUCHSCREEN_DYNAPRO)	+= dynapro.o
 obj-$(CONFIG_TOUCHSCREEN_HAMPSHIRE)	+= hampshire.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)		+= gunze.o
diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
new file mode 100755
index 0000000..dade0a9
--- /dev/null
+++ b/drivers/input/touchscreen/da9052_tsi.c
@@ -0,0 +1,489 @@
+/*
+ * TSI driver for Dialog DA9052
+ *
+ * Copyright(c) 2011 Dialog Semiconductor Ltd.
+ *
+ * Author: David Dajun Chen <dchen@diasemi.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.
+ *
+ */
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
+#include <linux/kfifo.h>
+
+#include <linux/mfd/da9052/reg.h>
+#include <linux/mfd/da9052/da9052.h>
+
+#define DA9052_ACTIVE			1
+#define DA9052_INACTIVE		0
+
+#define DA9052_TSI_FIFOSIZE		640
+
+enum {
+	DA9052_PEN_IDLE,
+	DA9052_PEN_DOWN,
+	DA9052_PEN_UP
+};
+
+struct da9052_tsi_reg {
+	u16	x;
+	u16	y;
+};
+
+struct tsi_thread_type {
+	u8		pid;
+	u8		state;
+	struct completion	notifier;
+	struct task_struct	*thread_task;
+};
+
+struct da9052_tsi {
+	struct da9052	*da9052;
+	struct input_dev *dev;
+	struct tsi_thread_type	tsi_pen_state_thread;
+	struct tsi_thread_type  tsi_filter_thread;
+	struct kfifo fifo;
+	struct kfifo fifo_buf;
+	u8 pen_up_detect_interval;
+	u32 zero_data_cnt;
+	u32 valid_penup_count;
+	u8 pen_state;
+	int irq_pendwn;
+	int irq_datardy;
+};
+
+static inline int da9052_ts_start(struct da9052_tsi *tsi)
+{
+	return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
+				 1 << 0, 1 << 0);
+}
+
+static inline int da9052_ts_stop(struct da9052_tsi *tsi)
+{
+	return da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
+}
+
+static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
+{
+	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
+	struct da9052 *da9052 = tsi->da9052;
+	int ret;
+
+	da9052->events_mask |= DA9052_E_PEN_DOWN;
+	da9052->events_mask &= ~DA9052_E_TSI_READY;
+
+	/* Mask PEN_DOWN event and unmask TSI_READY event*/
+	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x80, 0x40);
+	if (ret < 0)
+		return IRQ_NONE;
+
+	da9052_ts_start(tsi);
+	tsi->pen_state = DA9052_PEN_DOWN;
+
+	return IRQ_HANDLED;
+}
+
+static int da9052_ts_read(struct da9052_tsi *tsi)
+{
+	struct da9052_tsi_reg co_ord = {0, 0};
+	int ret;
+	uint8_t _x, _y, _v;
+
+	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
+	if (ret < 0)
+		return ret;
+
+	_x = (uint8_t) ret;
+
+	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
+	if (ret < 0)
+		return ret;
+
+	_y = (uint8_t) ret;
+
+	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
+	if (ret < 0)
+		return ret;
+
+	_v = (uint8_t) ret;
+
+	co_ord.x = ((_x << 2) & 0x3fc) | (_v & 0x3);
+	co_ord.y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
+
+	ret = kfifo_in(&tsi->fifo, &co_ord, sizeof(struct da9052_tsi_reg));
+
+	return 0;
+}
+
+static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
+{
+	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
+	int ret;
+
+	ret = da9052_ts_read(tsi);
+	if (ret) {
+		dev_err(tsi->da9052->dev,
+			"Failed to read TSI co-ordinate, %d\n", ret);
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*
+* Two FIFO are been used. FIFO1 is used for detecting pen up and
+* FIFO2 for reporting pen down co-ordinate.
+*/
+void da9052_ts_process_reg_data(struct da9052_tsi *tsi)
+{
+	struct da9052_tsi_reg tmp_raw_data;
+	u32 reg_data_cnt;
+	int ret;
+
+	reg_data_cnt = kfifo_len(&tsi->fifo);
+
+	while (reg_data_cnt-- > 0) {
+		ret = kfifo_out(&tsi->fifo, &tmp_raw_data,
+				sizeof(struct da9052_tsi_reg));
+		if (ret < 0)
+			continue;
+		kfifo_in(&tsi->fifo_buf, &tmp_raw_data,
+			 sizeof(struct da9052_tsi_reg));
+	}
+	return;
+}
+
+static void da9052_ts_report_penup(struct da9052_tsi *tsi)
+{
+	struct input_dev *ip_dev = tsi->dev;
+	struct da9052 *da9052 = tsi->da9052;
+	ssize_t ret;
+
+	ret = da9052_ts_stop(tsi);
+	if (ret < 0)
+		return;
+
+	da9052->events_mask |= DA9052_E_TSI_READY;
+	da9052->events_mask &= ~DA9052_E_PEN_DOWN;
+
+	/* Mask TSI_READY event and unmask PEN_DOWN event*/
+	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
+	if (ret < 0)
+		return;
+
+	input_report_abs(ip_dev, BTN_TOUCH, 0);
+	input_sync(ip_dev);
+
+	tsi->zero_data_cnt = 0;
+}
+
+/*
+* This function detects the pen up state using the kfifo len.
+* If kfifo len is zero for some interval then pen up is reported.
+* Else pen co-ordinate are reported.
+*/
+static int da9052_ts_monitor_pen_state(void *data)
+{
+	struct da9052_tsi *tsi = (struct da9052_tsi *) data;
+	u32 data_cnt;
+
+	set_freezable();
+
+	while (tsi->tsi_pen_state_thread.state == DA9052_ACTIVE) {
+		try_to_freeze();
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(msecs_to_jiffies(10));
+
+		if (tsi->pen_state != DA9052_PEN_DOWN)
+			continue;
+
+		data_cnt = kfifo_len(&tsi->fifo);
+		if (data_cnt < 0)
+			continue;
+
+		da9052_ts_process_reg_data(tsi);
+
+		if (data_cnt)
+			tsi->zero_data_cnt = 0;
+		else {
+			if ((++(tsi->zero_data_cnt)) >
+				tsi->valid_penup_count) {
+				tsi->pen_state = DA9052_PEN_UP;
+				da9052_ts_report_penup(tsi);
+			}
+		}
+	}
+
+	complete_and_exit(&tsi->tsi_pen_state_thread.notifier, 0);
+	return 0;
+}
+
+static int da9052_ts_process_thread(void *ptr)
+{
+	struct da9052_tsi_reg co_ord;
+	int cnt = 0, ret;
+	struct da9052_tsi *tsi = (struct da9052_tsi *)ptr;
+
+	set_freezable();
+
+	while (tsi->tsi_filter_thread.state == DA9052_ACTIVE) {
+
+		try_to_freeze();
+
+		set_current_state(TASK_INTERRUPTIBLE);
+		schedule_timeout(msecs_to_jiffies(10));
+		cnt = kfifo_len(&tsi->fifo_buf);
+		if (cnt <= 0)
+			continue;
+
+		ret = kfifo_out(&tsi->fifo_buf, &co_ord,
+				sizeof(struct da9052_tsi_reg));
+		if (ret < 0)
+			continue;
+
+		input_report_abs(tsi->dev, BTN_TOUCH, 1);
+		input_report_abs(tsi->dev, ABS_X, co_ord.x);
+		input_report_abs(tsi->dev, ABS_Y, co_ord.y);
+		input_sync(tsi->dev);
+	}
+
+	tsi->tsi_filter_thread.thread_task = NULL;
+	complete_and_exit(&tsi->tsi_filter_thread.notifier, 0);
+
+	return 0;
+}
+
+static int da9052_ts_configure_gpio(struct da9052 *da9052)
+{
+	int ret;
+
+	ret = da9052_clear_bits(da9052, DA9052_GPIO_2_3_REG, 0x30);
+	if (ret < 0)
+		return -EIO;
+
+	ret = da9052_clear_bits(da9052, DA9052_GPIO_4_5_REG, 0x33);
+	if (ret < 0)
+		return -EIO;
+
+	ret = da9052_clear_bits(da9052, DA9052_GPIO_6_7_REG, 0x33);
+	if (ret < 0)
+		return -EIO;
+
+	return ret;
+}
+
+static int __init da9052_ts_enable_device(struct da9052_tsi *tsi)
+{
+	ssize_t ret;
+	struct da9052 *da9052 = tsi->da9052;
+
+	ret = da9052_ts_configure_gpio(tsi->da9052);
+	if (ret < 0)
+		return ret;
+
+	ret = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
+	if (ret < 0)
+		return ret;
+
+	tsi->valid_penup_count = 5;
+
+	init_completion(&tsi->tsi_pen_state_thread.notifier);
+	tsi->tsi_pen_state_thread.state = DA9052_ACTIVE;
+	tsi->tsi_pen_state_thread.pid = kernel_thread(da9052_ts_monitor_pen_state, tsi,
+						      CLONE_KERNEL | SIGCHLD);
+
+	init_completion(&tsi->tsi_filter_thread.notifier);
+	tsi->tsi_filter_thread.state = DA9052_ACTIVE;
+	tsi->tsi_filter_thread.pid = kernel_thread(da9052_ts_process_thread, tsi,
+						   CLONE_KERNEL | SIGCHLD);
+
+	tsi->zero_data_cnt = 0;
+
+	/* Measure TSI sample every 1ms */
+	ret = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
+				1 << 6, 1 << 6);
+	if (ret < 0)
+		return ret;
+
+	/* TSI_DELAY: 4 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
+	ret = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
+				1 << 1, 1 << 1);
+	if (ret < 0)
+		return ret;
+
+	da9052->events_mask |= DA9052_E_TSI_READY;
+
+	/* Mask TSI_READY event*/
+	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0, 0x80);
+	if (ret < 0)
+		return ret;
+
+	/*Supply TSIRef thru LD09 */
+	ret = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
+
+	return ret;
+}
+
+static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
+{
+	struct da9052_tsi *tsi;
+	struct input_dev *input_dev;
+	struct da9052 *da9052;
+	int ret;
+
+	da9052 = dev_get_drvdata(pdev->dev.parent);
+
+	tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
+	if (!tsi)
+		return -ENOMEM;
+
+	input_dev = input_allocate_device();
+	if (!input_dev) {
+		dev_err(tsi->da9052->dev,
+			"failed to allocate input device\n");
+		ret = -ENOMEM;
+		goto err_mem;
+	}
+
+	ret = kfifo_alloc(&tsi->fifo, DA9052_TSI_FIFOSIZE, GFP_KERNEL);
+	if (ret < 0)
+		goto err_input;
+
+	ret = kfifo_alloc(&tsi->fifo_buf, DA9052_TSI_FIFOSIZE, GFP_KERNEL);
+	if (ret < 0)
+		goto err_fifo;
+
+	tsi->da9052 = da9052;
+	tsi->pen_up_detect_interval = 5;
+	platform_set_drvdata(pdev, tsi);
+
+	input_dev->id.version = 0x0101;
+	input_dev->id.vendor = 0x15B6;
+	input_dev->id.product = 0x9052;
+	input_dev->id.bustype = BUS_RS232;
+	input_dev->name = "Dialog DA9052 TouchScreen Driver";
+	input_dev->dev.parent	= &pdev->dev;
+	__set_bit(EV_ABS, input_dev->evbit);
+	__set_bit(EV_KEY, input_dev->evbit);
+	__set_bit(BTN_TOUCH, input_dev->keybit);
+	__set_bit(ABS_X, input_dev->absbit);
+	__set_bit(ABS_Y, input_dev->absbit);
+
+	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
+	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
+	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
+
+	tsi->dev = input_dev;
+	input_set_drvdata(input_dev, tsi);
+	ret = input_register_device(tsi->dev);
+	if (ret)
+		goto err_mem;
+
+	tsi->irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
+	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_pendwn,
+				NULL, da9052_ts_pendwn_irq,
+				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				"PENDWN", tsi);
+	if (ret < 0) {
+		dev_err(tsi->da9052->dev,
+			"Failed to register %s IRQ %d, error = %d\n", "PENDWN",
+			tsi->da9052->irq_base + tsi->irq_pendwn, ret);
+		goto err_fifo_buf;
+	}
+
+	tsi->irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
+	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_datardy,
+				NULL, da9052_ts_datardy_irq,
+				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				"TSIRDY", tsi);
+	if (ret < 0) {
+		dev_err(tsi->da9052->dev,
+			"Failed to register %s IRQ %d, error = %d\n", "TSIRDY",
+			tsi->da9052->irq_base + tsi->irq_datardy, ret);
+		goto err_fifo_buf;
+	}
+
+	ret = da9052_ts_enable_device(tsi);
+	if (ret < 0)
+		goto err_fifo_buf;
+
+	return 0;
+
+err_fifo_buf:
+	kfifo_free(&tsi->fifo_buf);
+err_fifo:
+	kfifo_free(&tsi->fifo);
+err_input:
+	input_free_device(input_dev);
+err_mem:
+	kfree(tsi);
+	return ret;
+}
+
+static int __devexit da9052_ts_remove(struct platform_device *pdev)
+{
+	struct da9052_tsi *tsi = platform_get_drvdata(pdev);
+	s32 ret;
+
+	ret = da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
+	if (ret < 0)
+		return ret;
+
+	ret = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
+	if (ret < 0)
+		return ret;
+
+	free_irq(tsi->da9052->irq_base + tsi->irq_pendwn, NULL);
+	free_irq(tsi->da9052->irq_base + tsi->irq_datardy, NULL);
+
+	tsi->tsi_pen_state_thread.state = DA9052_INACTIVE;
+	wait_for_completion(&tsi->tsi_pen_state_thread.notifier);
+
+	tsi->tsi_filter_thread.state = DA9052_INACTIVE;
+	wait_for_completion(&tsi->tsi_filter_thread.notifier);
+
+	input_unregister_device(tsi->dev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	kfifo_free(&tsi->fifo);
+	kfifo_free(&tsi->fifo_buf);
+	kfree(tsi);
+
+	return 0;
+}
+
+static struct platform_driver da9052_tsi_driver = {
+	.probe = da9052_ts_probe,
+	.remove = __devexit_p(da9052_ts_remove),
+	.driver = {
+		.name = "da9052-tsi",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init da9052_ts_init(void)
+{
+	return platform_driver_register(&da9052_tsi_driver);
+}
+module_init(da9052_ts_init);
+
+static void __exit da9052_ts_exit(void)
+{
+	platform_driver_unregister(&da9052_tsi_driver);
+}
+module_exit(da9052_ts_exit);
+
+MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
+MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9052-tsi");

Re: [Patch v1 08/11] Touch: DA9052 touchscreen driver

[ashishj3]

On Thu, 2011-07-14 at 14:28 +0530, ashishj3 wrote: 
> This driver add support for DA9052 4-wire resistive ADC interfaced touchscreen
> controller.
> 
> DA9052 is a MFD therefore this driver depends on DA9052 core driver for core
> functionalities.
> 
> Signed-off-by: David Dajun Chen <dchen@diasemi.com>
> Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
> ---
If there are no comments then can this patch get ACK?

Re: [Patch v1 08/11] Touch: DA9052 touchscreen driver

[ashishj3]

On Thu, 2011-07-14 at 14:28 +0530, ashishj3 wrote: 
> This driver add support for DA9052 4-wire resistive ADC interfaced touchscreen
> controller.
> 
> DA9052 is a MFD therefore this driver depends on DA9052 core driver for core
> functionalities.
> 
> Signed-off-by: David Dajun Chen <dchen@diasemi.com>
> Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
> ---
If there are no comments then can this patch get ACK?

Re: [Patch v1 08/11] Touch: DA9052 touchscreen driver

[Dmitry Torokhov]

Hi Ashish,

On Thu, Jul 14, 2011 at 02:28:10PM +0530, ashishj3 wrote:
> This driver add support for DA9052 4-wire resistive ADC interfaced touchscreen
> controller.
> 
> DA9052 is a MFD therefore this driver depends on DA9052 core driver for core
> functionalities.
> 
> Signed-off-by: David Dajun Chen <dchen@diasemi.com>
> Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
> ---
>  drivers/input/touchscreen/Kconfig      |    7 +
>  drivers/input/touchscreen/Makefile     |    1 +
>  drivers/input/touchscreen/da9052_tsi.c |  489 ++++++++++++++++++++++++++++++++
>  3 files changed, 497 insertions(+), 0 deletions(-)
>  create mode 100755 drivers/input/touchscreen/da9052_tsi.c
> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
> index cabd9e5..a5d2e7b 100644
> --- a/drivers/input/touchscreen/Kconfig
> +++ b/drivers/input/touchscreen/Kconfig
> @@ -144,6 +144,13 @@ config TOUCHSCREEN_DA9034
>  	  Say Y here to enable the support for the touchscreen found
>  	  on Dialog Semiconductor DA9034 PMIC.
>  
> +config TOUCHSCREEN_DA9052
> +	tristate "Dialog DA9052 TSI"
> +	depends on PMIC_DA9052
> +	help
> +	  Say y here to support the touchscreen found on
> +	  Dialog Semiconductor DA9052 PMIC
> +

To compile this driver as a module...

>  config TOUCHSCREEN_DYNAPRO
>  	tristate "Dynapro serial touchscreen"
>  	select SERIO
> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
> index 282d6f7..a4aeb25 100644
> --- a/drivers/input/touchscreen/Makefile
> +++ b/drivers/input/touchscreen/Makefile
> @@ -18,6 +18,7 @@ obj-$(CONFIG_TOUCHSCREEN_BITSY)		+= h3600_ts_input.o
>  obj-$(CONFIG_TOUCHSCREEN_BU21013)       += bu21013_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_CY8CTMG110)	+= cy8ctmg110_ts.o
>  obj-$(CONFIG_TOUCHSCREEN_DA9034)	+= da9034-ts.o
> +obj-$(CONFIG_TOUCHSCREEN_DA9052)	+= da9052_tsi.o
>  obj-$(CONFIG_TOUCHSCREEN_DYNAPRO)	+= dynapro.o
>  obj-$(CONFIG_TOUCHSCREEN_HAMPSHIRE)	+= hampshire.o
>  obj-$(CONFIG_TOUCHSCREEN_GUNZE)		+= gunze.o
> diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
> new file mode 100755
> index 0000000..dade0a9
> --- /dev/null
> +++ b/drivers/input/touchscreen/da9052_tsi.c
> @@ -0,0 +1,489 @@
> +/*
> + * TSI driver for Dialog DA9052
> + *
> + * Copyright(c) 2011 Dialog Semiconductor Ltd.
> + *
> + * Author: David Dajun Chen <dchen@diasemi.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.
> + *
> + */
> +#include <linux/module.h>
> +#include <linux/input.h>
> +#include <linux/delay.h>
> +#include <linux/platform_device.h>
> +#include <linux/freezer.h>
> +#include <linux/kthread.h>
> +#include <linux/kfifo.h>
> +
> +#include <linux/mfd/da9052/reg.h>
> +#include <linux/mfd/da9052/da9052.h>
> +
> +#define DA9052_ACTIVE			1
> +#define DA9052_INACTIVE		0
> +
> +#define DA9052_TSI_FIFOSIZE		640
> +
> +enum {
> +	DA9052_PEN_IDLE,
> +	DA9052_PEN_DOWN,
> +	DA9052_PEN_UP
> +};
> +
> +struct da9052_tsi_reg {
> +	u16	x;
> +	u16	y;
> +};
> +
> +struct tsi_thread_type {
> +	u8		pid;
> +	u8		state;
> +	struct completion	notifier;
> +	struct task_struct	*thread_task;
> +};

What is the reason for rolling out your own kernel thread
implementation? From what I understand you just need periodically to
check for "pen up" and that's it, so simply use standard workqueue to
schedule checks.

> +
> +struct da9052_tsi {
> +	struct da9052	*da9052;
> +	struct input_dev *dev;
> +	struct tsi_thread_type	tsi_pen_state_thread;
> +	struct tsi_thread_type  tsi_filter_thread;
> +	struct kfifo fifo;
> +	struct kfifo fifo_buf;
> +	u8 pen_up_detect_interval;
> +	u32 zero_data_cnt;
> +	u32 valid_penup_count;
> +	u8 pen_state;
> +	int irq_pendwn;
> +	int irq_datardy;
> +};
> +
> +static inline int da9052_ts_start(struct da9052_tsi *tsi)

Drop inline, let compiler figure out if the function needs to be
inlined.

Normally only fucntions in header files should be marked as static
inline.

> +{
> +	return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
> +				 1 << 0, 1 << 0);
> +}
> +
> +static inline int da9052_ts_stop(struct da9052_tsi *tsi)
> +{
> +	return da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
> +}
> +
> +static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
> +{
> +	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
> +	struct da9052 *da9052 = tsi->da9052;
> +	int ret;
> +
> +	da9052->events_mask |= DA9052_E_PEN_DOWN;
> +	da9052->events_mask &= ~DA9052_E_TSI_READY;
> +
> +	/* Mask PEN_DOWN event and unmask TSI_READY event*/
> +	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x80, 0x40);
> +	if (ret < 0)
> +		return IRQ_NONE;
> +
> +	da9052_ts_start(tsi);
> +	tsi->pen_state = DA9052_PEN_DOWN;
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int da9052_ts_read(struct da9052_tsi *tsi)
> +{
> +	struct da9052_tsi_reg co_ord = {0, 0};
> +	int ret;
> +	uint8_t _x, _y, _v;
> +
> +	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_X_MSB_REG);
> +	if (ret < 0)
> +		return ret;
> +
> +	_x = (uint8_t) ret;
> +
> +	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_Y_MSB_REG);
> +	if (ret < 0)
> +		return ret;
> +
> +	_y = (uint8_t) ret;
> +
> +	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
> +	if (ret < 0)
> +		return ret;
> +
> +	_v = (uint8_t) ret;
> +
> +	co_ord.x = ((_x << 2) & 0x3fc) | (_v & 0x3);
> +	co_ord.y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
> +
> +	ret = kfifo_in(&tsi->fifo, &co_ord, sizeof(struct da9052_tsi_reg));


You have data, you know the pen state, why mess with 2! kfifos? Just
report the events right here.

> +
> +	return 0;
> +}
> +
> +static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
> +{
> +	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
> +	int ret;
> +
> +	ret = da9052_ts_read(tsi);
> +	if (ret) {
> +		dev_err(tsi->da9052->dev,
> +			"Failed to read TSI co-ordinate, %d\n", ret);
> +		return IRQ_NONE;
> +	}
> +
> +	return IRQ_HANDLED;
> +}
> +
> +/*
> +* Two FIFO are been used. FIFO1 is used for detecting pen up and
> +* FIFO2 for reporting pen down co-ordinate.
> +*/
> +void da9052_ts_process_reg_data(struct da9052_tsi *tsi)
> +{
> +	struct da9052_tsi_reg tmp_raw_data;
> +	u32 reg_data_cnt;
> +	int ret;
> +
> +	reg_data_cnt = kfifo_len(&tsi->fifo);
> +
> +	while (reg_data_cnt-- > 0) {
> +		ret = kfifo_out(&tsi->fifo, &tmp_raw_data,
> +				sizeof(struct da9052_tsi_reg));
> +		if (ret < 0)
> +			continue;
> +		kfifo_in(&tsi->fifo_buf, &tmp_raw_data,
> +			 sizeof(struct da9052_tsi_reg));
> +	}
> +	return;
> +}
> +
> +static void da9052_ts_report_penup(struct da9052_tsi *tsi)
> +{
> +	struct input_dev *ip_dev = tsi->dev;
> +	struct da9052 *da9052 = tsi->da9052;
> +	ssize_t ret;
> +
> +	ret = da9052_ts_stop(tsi);
> +	if (ret < 0)
> +		return;
> +
> +	da9052->events_mask |= DA9052_E_TSI_READY;
> +	da9052->events_mask &= ~DA9052_E_PEN_DOWN;
> +
> +	/* Mask TSI_READY event and unmask PEN_DOWN event*/
> +	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
> +	if (ret < 0)
> +		return;
> +
> +	input_report_abs(ip_dev, BTN_TOUCH, 0);
> +	input_sync(ip_dev);
> +
> +	tsi->zero_data_cnt = 0;
> +}
> +
> +/*
> +* This function detects the pen up state using the kfifo len.
> +* If kfifo len is zero for some interval then pen up is reported.
> +* Else pen co-ordinate are reported.
> +*/
> +static int da9052_ts_monitor_pen_state(void *data)
> +{
> +	struct da9052_tsi *tsi = (struct da9052_tsi *) data;
> +	u32 data_cnt;
> +
> +	set_freezable();
> +
> +	while (tsi->tsi_pen_state_thread.state == DA9052_ACTIVE) {
> +		try_to_freeze();
> +
> +		set_current_state(TASK_INTERRUPTIBLE);
> +		schedule_timeout(msecs_to_jiffies(10));
> +
> +		if (tsi->pen_state != DA9052_PEN_DOWN)
> +			continue;
> +
> +		data_cnt = kfifo_len(&tsi->fifo);
> +		if (data_cnt < 0)
> +			continue;
> +
> +		da9052_ts_process_reg_data(tsi);
> +
> +		if (data_cnt)
> +			tsi->zero_data_cnt = 0;
> +		else {
> +			if ((++(tsi->zero_data_cnt)) >
> +				tsi->valid_penup_count) {
> +				tsi->pen_state = DA9052_PEN_UP;
> +				da9052_ts_report_penup(tsi);
> +			}
> +		}
> +	}
> +
> +	complete_and_exit(&tsi->tsi_pen_state_thread.notifier, 0);
> +	return 0;
> +}
> +
> +static int da9052_ts_process_thread(void *ptr)
> +{
> +	struct da9052_tsi_reg co_ord;
> +	int cnt = 0, ret;
> +	struct da9052_tsi *tsi = (struct da9052_tsi *)ptr;
> +
> +	set_freezable();
> +
> +	while (tsi->tsi_filter_thread.state == DA9052_ACTIVE) {
> +
> +		try_to_freeze();
> +
> +		set_current_state(TASK_INTERRUPTIBLE);
> +		schedule_timeout(msecs_to_jiffies(10));
> +		cnt = kfifo_len(&tsi->fifo_buf);
> +		if (cnt <= 0)
> +			continue;
> +
> +		ret = kfifo_out(&tsi->fifo_buf, &co_ord,
> +				sizeof(struct da9052_tsi_reg));
> +		if (ret < 0)
> +			continue;
> +
> +		input_report_abs(tsi->dev, BTN_TOUCH, 1);
> +		input_report_abs(tsi->dev, ABS_X, co_ord.x);
> +		input_report_abs(tsi->dev, ABS_Y, co_ord.y);
> +		input_sync(tsi->dev);
> +	}
> +
> +	tsi->tsi_filter_thread.thread_task = NULL;
> +	complete_and_exit(&tsi->tsi_filter_thread.notifier, 0);
> +
> +	return 0;
> +}
> +
> +static int da9052_ts_configure_gpio(struct da9052 *da9052)
> +{
> +	int ret;
> +
> +	ret = da9052_clear_bits(da9052, DA9052_GPIO_2_3_REG, 0x30);
> +	if (ret < 0)
> +		return -EIO;
> +
> +	ret = da9052_clear_bits(da9052, DA9052_GPIO_4_5_REG, 0x33);
> +	if (ret < 0)
> +		return -EIO;
> +
> +	ret = da9052_clear_bits(da9052, DA9052_GPIO_6_7_REG, 0x33);
> +	if (ret < 0)
> +		return -EIO;
> +
> +	return ret;
> +}
> +
> +static int __init da9052_ts_enable_device(struct da9052_tsi *tsi)
> +{
> +	ssize_t ret;
> +	struct da9052 *da9052 = tsi->da9052;
> +
> +	ret = da9052_ts_configure_gpio(tsi->da9052);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
> +	if (ret < 0)
> +		return ret;
> +
> +	tsi->valid_penup_count = 5;
> +
> +	init_completion(&tsi->tsi_pen_state_thread.notifier);
> +	tsi->tsi_pen_state_thread.state = DA9052_ACTIVE;
> +	tsi->tsi_pen_state_thread.pid = kernel_thread(da9052_ts_monitor_pen_state, tsi,
> +						      CLONE_KERNEL | SIGCHLD);
> +
> +	init_completion(&tsi->tsi_filter_thread.notifier);
> +	tsi->tsi_filter_thread.state = DA9052_ACTIVE;
> +	tsi->tsi_filter_thread.pid = kernel_thread(da9052_ts_process_thread, tsi,
> +						   CLONE_KERNEL | SIGCHLD);
> +
> +	tsi->zero_data_cnt = 0;
> +
> +	/* Measure TSI sample every 1ms */
> +	ret = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
> +				1 << 6, 1 << 6);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* TSI_DELAY: 4 slots, TSI_SKIP: 0 slots, TSI_MODE: XYZP */
> +	ret = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
> +				1 << 1, 1 << 1);
> +	if (ret < 0)
> +		return ret;
> +
> +	da9052->events_mask |= DA9052_E_TSI_READY;
> +
> +	/* Mask TSI_READY event*/
> +	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0, 0x80);
> +	if (ret < 0)
> +		return ret;
> +
> +	/*Supply TSIRef thru LD09 */
> +	ret = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
> +
> +	return ret;
> +}
> +
> +static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
> +{
> +	struct da9052_tsi *tsi;
> +	struct input_dev *input_dev;
> +	struct da9052 *da9052;
> +	int ret;
> +
> +	da9052 = dev_get_drvdata(pdev->dev.parent);

Check for NULL?

> +
> +	tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
> +	if (!tsi)
> +		return -ENOMEM;
> +
> +	input_dev = input_allocate_device();
> +	if (!input_dev) {
> +		dev_err(tsi->da9052->dev,
> +			"failed to allocate input device\n");
> +		ret = -ENOMEM;
> +		goto err_mem;
> +	}
> +
> +	ret = kfifo_alloc(&tsi->fifo, DA9052_TSI_FIFOSIZE, GFP_KERNEL);
> +	if (ret < 0)
> +		goto err_input;
> +
> +	ret = kfifo_alloc(&tsi->fifo_buf, DA9052_TSI_FIFOSIZE, GFP_KERNEL);
> +	if (ret < 0)
> +		goto err_fifo;
> +
> +	tsi->da9052 = da9052;
> +	tsi->pen_up_detect_interval = 5;
> +	platform_set_drvdata(pdev, tsi);

Can probably be moved right before "return 0;" statement.

> +
> +	input_dev->id.version = 0x0101;
> +	input_dev->id.vendor = 0x15B6;
> +	input_dev->id.product = 0x9052;
> +	input_dev->id.bustype = BUS_RS232;

Is it really RS232? BUS_HOST or leave it 0.

> +	input_dev->name = "Dialog DA9052 TouchScreen Driver";
> +	input_dev->dev.parent	= &pdev->dev;
> +	__set_bit(EV_ABS, input_dev->evbit);
> +	__set_bit(EV_KEY, input_dev->evbit);
> +	__set_bit(BTN_TOUCH, input_dev->keybit);
> +	__set_bit(ABS_X, input_dev->absbit);
> +	__set_bit(ABS_Y, input_dev->absbit);
> +
> +	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
> +	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
> +	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
> +
> +	tsi->dev = input_dev;
> +	input_set_drvdata(input_dev, tsi);

I do not think you are using input_get_drvdata() enywhere...

> +	ret = input_register_device(tsi->dev);
> +	if (ret)
> +		goto err_mem;
> +
> +	tsi->irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");

What if call fails?

> +	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_pendwn,
> +				NULL, da9052_ts_pendwn_irq,
> +				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +				"PENDWN", tsi);
> +	if (ret < 0) {
> +		dev_err(tsi->da9052->dev,
> +			"Failed to register %s IRQ %d, error = %d\n", "PENDWN",
> +			tsi->da9052->irq_base + tsi->irq_pendwn, ret);
> +		goto err_fifo_buf;
> +	}
> +
> +	tsi->irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
> +	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_datardy,
> +				NULL, da9052_ts_datardy_irq,
> +				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +				"TSIRDY", tsi);
> +	if (ret < 0) {
> +		dev_err(tsi->da9052->dev,
> +			"Failed to register %s IRQ %d, error = %d\n", "TSIRDY",
> +			tsi->da9052->irq_base + tsi->irq_datardy, ret);
> +		goto err_fifo_buf;
> +	}
> +
> +	ret = da9052_ts_enable_device(tsi);
> +	if (ret < 0)
> +		goto err_fifo_buf;
> +
> +	return 0;
> +
> +err_fifo_buf:

Error handling is busted, you forgetting to free IRQs.

> +	kfifo_free(&tsi->fifo_buf);
> +err_fifo:
> +	kfifo_free(&tsi->fifo);
> +err_input:

Sometimes device is already registered here, you need to call
input_unregister_device() in such cases. The easiest way to handle this
case it to register input device as the very last action.

> +	input_free_device(input_dev);
> +err_mem:
> +	kfree(tsi);
> +	return ret;
> +}
> +
> +static int __devexit da9052_ts_remove(struct platform_device *pdev)
> +{
> +	struct da9052_tsi *tsi = platform_get_drvdata(pdev);
> +	s32 ret;
> +
> +	ret = da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
> +	if (ret < 0)
> +		return ret;
> +
> +	free_irq(tsi->da9052->irq_base + tsi->irq_pendwn, NULL);
> +	free_irq(tsi->da9052->irq_base + tsi->irq_datardy, NULL);

You passed 'tsi' to request_irq(), here you are passing NULL thus
leaking IRQs.

> +
> +	tsi->tsi_pen_state_thread.state = DA9052_INACTIVE;
> +	wait_for_completion(&tsi->tsi_pen_state_thread.notifier);
> +
> +	tsi->tsi_filter_thread.state = DA9052_INACTIVE;
> +	wait_for_completion(&tsi->tsi_filter_thread.notifier);
> +
> +	input_unregister_device(tsi->dev);
> +
> +	platform_set_drvdata(pdev, NULL);
> +
> +	kfifo_free(&tsi->fifo);
> +	kfifo_free(&tsi->fifo_buf);
> +	kfree(tsi);
> +
> +	return 0;
> +}
> +
> +static struct platform_driver da9052_tsi_driver = {
> +	.probe = da9052_ts_probe,
> +	.remove = __devexit_p(da9052_ts_remove),
> +	.driver = {
> +		.name = "da9052-tsi",
> +		.owner = THIS_MODULE,
> +	},
> +};
> +
> +static int __init da9052_ts_init(void)
> +{
> +	return platform_driver_register(&da9052_tsi_driver);
> +}
> +module_init(da9052_ts_init);
> +
> +static void __exit da9052_ts_exit(void)
> +{
> +	platform_driver_unregister(&da9052_tsi_driver);
> +}
> +module_exit(da9052_ts_exit);
> +
> +MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9052");
> +MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:da9052-tsi");
> 
> 

Thanks.

-- 
Dmitry

Re: [Patch v1 08/11] Touch: DA9052 touchscreen driver

[Michael Grzeschik]

Hi Ashish,

On Thu, Jul 14, 2011 at 02:28:10PM +0530, ashishj3 wrote:
> This driver add support for DA9052 4-wire resistive ADC interfaced touchscreen
> controller.
> 
> DA9052 is a MFD therefore this driver depends on DA9052 core driver for core
> functionalities.
> 
> Signed-off-by: David Dajun Chen <dchen@diasemi.com>
> Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
> ---
>  drivers/input/touchscreen/Kconfig      |    7 +
>  drivers/input/touchscreen/Makefile     |    1 +
>  drivers/input/touchscreen/da9052_tsi.c |  489 ++++++++++++++++++++++++++++++++
>  3 files changed, 497 insertions(+), 0 deletions(-)
>  create mode 100755 drivers/input/touchscreen/da9052_tsi.c
[snip]
> +	ret = da9052_clear_bits(da9052, DA9052_GPIO_4_5_REG, 0x33);
> +	if (ret < 0)
> +		return -EIO;
> +
> +	ret = da9052_clear_bits(da9052, DA9052_GPIO_6_7_REG, 0x33);

Those two register defines are missing in your posted MFD driver headerfile "reg.h".

Regards,
Michael

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
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[RFC PATCH] da9052_tsi: remove fifo and use delayed work

[Michael Grzeschik]

Remove the coordinate fifo and check for penup with a delayed work,
instead of a watching kernel thread.

Issues:
Sometimes there are well defined jitter values on the x-axys this must
be more investigated. Hint: DA9052_TSI_CONT_A_REG holds some time Adjust
values for TSI_SKIP and TSI_DELAY, which might have to be properly
aligned to the touch events.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
 drivers/input/touchscreen/da9052_tsi.c |  245 ++++++++------------------------
 1 files changed, 61 insertions(+), 184 deletions(-)

diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
index 91e051a..91d489f 100755
--- a/drivers/input/touchscreen/da9052_tsi.c
+++ b/drivers/input/touchscreen/da9052_tsi.c
@@ -15,47 +15,24 @@
 #include <linux/input.h>
 #include <linux/delay.h>
 #include <linux/platform_device.h>
-#include <linux/freezer.h>
+#include <linux/sched.h>
 #include <linux/kthread.h>
-#include <linux/kfifo.h>
 
 #include <linux/mfd/da9052/reg.h>
 #include <linux/mfd/da9052/da9052.h>
 
-#define DA9052_ACTIVE			1
-#define DA9052_INACTIVE		0
-
-#define DA9052_TSI_FIFOSIZE		640
-
-enum {
-	DA9052_PEN_IDLE,
-	DA9052_PEN_DOWN,
-	DA9052_PEN_UP
-};
-
 struct da9052_tsi_reg {
 	u16	x;
 	u16	y;
 };
 
-struct tsi_thread_type {
-	u8		pid;
-	u8		state;
-	struct completion	notifier;
-	struct task_struct	*thread_task;
-};
-
 struct da9052_tsi {
 	struct da9052	*da9052;
 	struct input_dev *dev;
-	struct tsi_thread_type	tsi_pen_state_thread;
-	struct tsi_thread_type  tsi_filter_thread;
-	struct kfifo fifo;
-	struct kfifo fifo_buf;
 	u8 pen_up_detect_interval;
 	u32 zero_data_cnt;
 	u32 valid_penup_count;
-	u8 pen_state;
+	struct delayed_work work;
 	int irq_pendwn;
 	int irq_datardy;
 };
@@ -71,6 +48,48 @@ static inline int da9052_ts_stop(struct da9052_tsi *tsi)
 	return da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
 }
 
+static void da9052_work(struct work_struct *work)
+{
+	struct da9052_tsi *tsi = container_of(work, struct da9052_tsi, work.work);
+	struct da9052 *da9052 = tsi->da9052;
+	int ret;
+	uint8_t _v;
+	u16 down;
+
+	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
+	if (ret < 0)
+		return;
+
+	_v = (uint8_t) ret;
+	down = ((_v & 0x40) >> 6);
+
+	if (!down) {
+		tsi->da9052->events_mask |= DA9052_E_TSI_READY;
+		tsi->da9052->events_mask &= ~DA9052_E_PEN_DOWN;
+
+		/* Mask TSI_READY event and unmask PEN_DOWN event*/
+		ret = da9052_reg_update(tsi->da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
+		if (ret < 0)
+			return;
+
+		input_report_abs(tsi->dev, ABS_PRESSURE, 0);
+		input_report_key(tsi->dev, BTN_TOUCH, 1);
+		input_sync(tsi->dev);
+	} else {
+		da9052->events_mask |= DA9052_E_PEN_DOWN;
+		da9052->events_mask &= ~DA9052_E_TSI_READY;
+
+		/* Mask PEN_DOWN event and unmask TSI_READY event*/
+		ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x80, 0x40);
+		if (ret < 0)
+			return;
+
+		/* start polling for touch_det to detect release */
+		schedule_delayed_work(&tsi->work, HZ / 50);
+	}
+
+}
+
 static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
 {
 	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
@@ -86,7 +105,10 @@ static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
 		return IRQ_NONE;
 
 	da9052_ts_start(tsi);
-	tsi->pen_state = DA9052_PEN_DOWN;
+
+	input_report_abs(tsi->dev, ABS_PRESSURE, 1023);
+	input_report_key(tsi->dev, BTN_TOUCH, 0);
+	input_sync(tsi->dev);
 
 	return IRQ_HANDLED;
 }
@@ -118,7 +140,10 @@ static int da9052_ts_read(struct da9052_tsi *tsi)
 	co_ord.x = ((_x << 2) & 0x3fc) | (_v & 0x3);
 	co_ord.y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
 
-	ret = kfifo_in(&tsi->fifo, &co_ord, sizeof(struct da9052_tsi_reg));
+	input_report_abs(tsi->dev, ABS_X, co_ord.x);
+	input_report_abs(tsi->dev, ABS_Y, co_ord.y);
+	input_report_abs(tsi->dev, ABS_PRESSURE, 1023);
+	input_sync(tsi->dev);
 
 	return 0;
 }
@@ -135,131 +160,10 @@ static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
 		return IRQ_NONE;
 	}
 
-	return IRQ_HANDLED;
-}
-
-/*
-* Two FIFO are been used. FIFO1 is used for detecting pen up and
-* FIFO2 for reporting pen down co-ordinate.
-*/
-void da9052_ts_process_reg_data(struct da9052_tsi *tsi)
-{
-	struct da9052_tsi_reg tmp_raw_data;
-	u32 reg_data_cnt;
-	int ret;
-
-	reg_data_cnt = kfifo_len(&tsi->fifo);
-
-	while (reg_data_cnt-- > 0) {
-		ret = kfifo_out(&tsi->fifo, &tmp_raw_data,
-				sizeof(struct da9052_tsi_reg));
-		if (ret < 0)
-			continue;
-		kfifo_in(&tsi->fifo_buf, &tmp_raw_data,
-			 sizeof(struct da9052_tsi_reg));
-	}
-	return;
-}
-
-static void da9052_ts_report_penup(struct da9052_tsi *tsi)
-{
-	struct input_dev *ip_dev = tsi->dev;
-	struct da9052 *da9052 = tsi->da9052;
-	ssize_t ret;
-
-	ret = da9052_ts_stop(tsi);
-	if (ret < 0)
-		return;
-
-	da9052->events_mask |= DA9052_E_TSI_READY;
-	da9052->events_mask &= ~DA9052_E_PEN_DOWN;
-
-	/* Mask TSI_READY event and unmask PEN_DOWN event*/
-	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
-	if (ret < 0)
-		return;
-
-	input_report_abs(ip_dev, BTN_TOUCH, 0);
-	input_sync(ip_dev);
-
-	tsi->zero_data_cnt = 0;
-}
-
-/*
-* This function detects the pen up state using the kfifo len.
-* If kfifo len is zero for some interval then pen up is reported.
-* Else pen co-ordinate are reported.
-*/
-static int da9052_ts_monitor_pen_state(void *data)
-{
-	struct da9052_tsi *tsi = (struct da9052_tsi *) data;
-	u32 data_cnt;
-
-	set_freezable();
-
-	while (tsi->tsi_pen_state_thread.state == DA9052_ACTIVE) {
-		try_to_freeze();
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(msecs_to_jiffies(10));
-
-		if (tsi->pen_state != DA9052_PEN_DOWN)
-			continue;
-
-		data_cnt = kfifo_len(&tsi->fifo);
-		if (data_cnt < 0)
-			continue;
-
-		da9052_ts_process_reg_data(tsi);
-
-		if (data_cnt)
-			tsi->zero_data_cnt = 0;
-		else {
-			if ((++(tsi->zero_data_cnt)) >
-				tsi->valid_penup_count) {
-				tsi->pen_state = DA9052_PEN_UP;
-				da9052_ts_report_penup(tsi);
-			}
-		}
-	}
-
-	complete_and_exit(&tsi->tsi_pen_state_thread.notifier, 0);
-	return 0;
-}
-
-static int da9052_ts_process_thread(void *ptr)
-{
-	struct da9052_tsi_reg co_ord;
-	int cnt = 0, ret;
-	struct da9052_tsi *tsi = (struct da9052_tsi *)ptr;
-
-	set_freezable();
-
-	while (tsi->tsi_filter_thread.state == DA9052_ACTIVE) {
-
-		try_to_freeze();
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(msecs_to_jiffies(10));
-		cnt = kfifo_len(&tsi->fifo_buf);
-		if (cnt <= 0)
-			continue;
-
-		ret = kfifo_out(&tsi->fifo_buf, &co_ord,
-				sizeof(struct da9052_tsi_reg));
-		if (ret < 0)
-			continue;
-
-		input_report_abs(tsi->dev, BTN_TOUCH, 1);
-		input_report_abs(tsi->dev, ABS_X, co_ord.x);
-		input_report_abs(tsi->dev, ABS_Y, co_ord.y);
-		input_sync(tsi->dev);
-	}
-
-	tsi->tsi_filter_thread.thread_task = NULL;
-	complete_and_exit(&tsi->tsi_filter_thread.notifier, 0);
+	/* start polling for touch_det to detect release */
+	schedule_delayed_work(&tsi->work, HZ / 50);
 
-	return 0;
+	return IRQ_HANDLED;
 }
 
 static int da9052_ts_configure_gpio(struct da9052 *da9052)
@@ -296,16 +200,6 @@ static int __init da9052_ts_enable_device(struct da9052_tsi *tsi)
 
 	tsi->valid_penup_count = 5;
 
-	init_completion(&tsi->tsi_pen_state_thread.notifier);
-	tsi->tsi_pen_state_thread.state = DA9052_ACTIVE;
-	tsi->tsi_pen_state_thread.pid = kernel_thread(da9052_ts_monitor_pen_state, tsi,
-						      CLONE_KERNEL | SIGCHLD);
-
-	init_completion(&tsi->tsi_filter_thread.notifier);
-	tsi->tsi_filter_thread.state = DA9052_ACTIVE;
-	tsi->tsi_filter_thread.pid = kernel_thread(da9052_ts_process_thread, tsi,
-						   CLONE_KERNEL | SIGCHLD);
-
 	tsi->zero_data_cnt = 0;
 
 	/* Measure TSI sample every 1ms */
@@ -354,14 +248,6 @@ static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
 		goto err_mem;
 	}
 
-	ret = kfifo_alloc(&tsi->fifo, DA9052_TSI_FIFOSIZE, GFP_KERNEL);
-	if (ret < 0)
-		goto err_input;
-
-	ret = kfifo_alloc(&tsi->fifo_buf, DA9052_TSI_FIFOSIZE, GFP_KERNEL);
-	if (ret < 0)
-		goto err_fifo;
-
 	tsi->da9052 = da9052;
 	tsi->pen_up_detect_interval = 5;
 	platform_set_drvdata(pdev, tsi);
@@ -388,6 +274,8 @@ static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_mem;
 
+	INIT_DELAYED_WORK(&tsi->work, da9052_work);
+
 	tsi->irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
 	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_pendwn,
 				NULL, da9052_ts_pendwn_irq,
@@ -397,7 +285,7 @@ static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
 		dev_err(tsi->da9052->dev,
 			"Failed to register %s IRQ %d, error = %d\n", "PENDWN",
 			tsi->da9052->irq_base + tsi->irq_pendwn, ret);
-		goto err_fifo_buf;
+		goto err_input;
 	}
 
 	tsi->irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
@@ -409,19 +297,15 @@ static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
 		dev_err(tsi->da9052->dev,
 			"Failed to register %s IRQ %d, error = %d\n", "TSIRDY",
 			tsi->da9052->irq_base + tsi->irq_datardy, ret);
-		goto err_fifo_buf;
+		goto err_input;
 	}
 
 	ret = da9052_ts_enable_device(tsi);
 	if (ret < 0)
-		goto err_fifo_buf;
+		goto err_input;
 
 	return 0;
 
-err_fifo_buf:
-	kfifo_free(&tsi->fifo_buf);
-err_fifo:
-	kfifo_free(&tsi->fifo);
 err_input:
 	input_free_device(input_dev);
 err_mem:
@@ -445,18 +329,11 @@ static int __devexit da9052_ts_remove(struct platform_device *pdev)
 	free_irq(tsi->da9052->irq_base + tsi->irq_pendwn, NULL);
 	free_irq(tsi->da9052->irq_base + tsi->irq_datardy, NULL);
 
-	tsi->tsi_pen_state_thread.state = DA9052_INACTIVE;
-	wait_for_completion(&tsi->tsi_pen_state_thread.notifier);
-
-	tsi->tsi_filter_thread.state = DA9052_INACTIVE;
-	wait_for_completion(&tsi->tsi_filter_thread.notifier);
-
+	cancel_delayed_work(&tsi->work);
 	input_unregister_device(tsi->dev);
 
 	platform_set_drvdata(pdev, NULL);
 
-	kfifo_free(&tsi->fifo);
-	kfifo_free(&tsi->fifo_buf);
 	kfree(tsi);
 
 	return 0;
-- 
1.7.5.4

Re: [RFC PATCH] da9052_tsi: remove fifo and use delayed work

[Dmitry Torokhov]

Hi Michael,

On Tue, Aug 09, 2011 at 03:59:32PM +0200, Michael Grzeschik wrote:
> Remove the coordinate fifo and check for penup with a delayed work,
> instead of a watching kernel thread.
> 

Yes, this looks much better. A few comments below.

> Issues:
> Sometimes there are well defined jitter values on the x-axys this must
> be more investigated. Hint: DA9052_TSI_CONT_A_REG holds some time Adjust
> values for TSI_SKIP and TSI_DELAY, which might have to be properly
> aligned to the touch events.
> 
> Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
> ---
>  drivers/input/touchscreen/da9052_tsi.c |  245 ++++++++------------------------
>  1 files changed, 61 insertions(+), 184 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
> index 91e051a..91d489f 100755
> --- a/drivers/input/touchscreen/da9052_tsi.c
> +++ b/drivers/input/touchscreen/da9052_tsi.c
> @@ -15,47 +15,24 @@
>  #include <linux/input.h>
>  #include <linux/delay.h>
>  #include <linux/platform_device.h>
> -#include <linux/freezer.h>
> +#include <linux/sched.h>
>  #include <linux/kthread.h>

That can be dropped too I think.

> -#include <linux/kfifo.h>
>  
>  #include <linux/mfd/da9052/reg.h>
>  #include <linux/mfd/da9052/da9052.h>
>  
> -#define DA9052_ACTIVE			1
> -#define DA9052_INACTIVE		0
> -
> -#define DA9052_TSI_FIFOSIZE		640
> -
> -enum {
> -	DA9052_PEN_IDLE,
> -	DA9052_PEN_DOWN,
> -	DA9052_PEN_UP
> -};
> -
>  struct da9052_tsi_reg {
>  	u16	x;
>  	u16	y;
>  };
>  
> -struct tsi_thread_type {
> -	u8		pid;
> -	u8		state;
> -	struct completion	notifier;
> -	struct task_struct	*thread_task;
> -};
> -
>  struct da9052_tsi {
>  	struct da9052	*da9052;
>  	struct input_dev *dev;
> -	struct tsi_thread_type	tsi_pen_state_thread;
> -	struct tsi_thread_type  tsi_filter_thread;
> -	struct kfifo fifo;
> -	struct kfifo fifo_buf;
>  	u8 pen_up_detect_interval;
>  	u32 zero_data_cnt;
>  	u32 valid_penup_count;

Above 2 are not used.

> -	u8 pen_state;
> +	struct delayed_work work;
>  	int irq_pendwn;
>  	int irq_datardy;
>  };
> @@ -71,6 +48,48 @@ static inline int da9052_ts_stop(struct da9052_tsi *tsi)
>  	return da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
>  }
>  
> +static void da9052_work(struct work_struct *work)
> +{
> +	struct da9052_tsi *tsi = container_of(work, struct da9052_tsi, work.work);
> +	struct da9052 *da9052 = tsi->da9052;
> +	int ret;
> +	uint8_t _v;
> +	u16 down;
> +
> +	ret = da9052_reg_read(tsi->da9052, DA9052_TSI_LSB_REG);
> +	if (ret < 0)
> +		return;
> +
> +	_v = (uint8_t) ret;
> +	down = ((_v & 0x40) >> 6);
> +
> +	if (!down) {
> +		tsi->da9052->events_mask |= DA9052_E_TSI_READY;
> +		tsi->da9052->events_mask &= ~DA9052_E_PEN_DOWN;
> +
> +		/* Mask TSI_READY event and unmask PEN_DOWN event*/
> +		ret = da9052_reg_update(tsi->da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
> +		if (ret < 0)
> +			return;

There is no good way to handle da9052_reg_update() failure so don't.

> +
> +		input_report_abs(tsi->dev, ABS_PRESSURE, 0);

No fake pressure events please.

> +		input_report_key(tsi->dev, BTN_TOUCH, 1);
> +		input_sync(tsi->dev);
> +	} else {
> +		da9052->events_mask |= DA9052_E_PEN_DOWN;
> +		da9052->events_mask &= ~DA9052_E_TSI_READY;
> +
> +		/* Mask PEN_DOWN event and unmask TSI_READY event*/
> +		ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x80, 0x40);
> +		if (ret < 0)
> +			return;

Why do we need to do the masking again? Just re-schedule the work.

> +
> +		/* start polling for touch_det to detect release */
> +		schedule_delayed_work(&tsi->work, HZ / 50);
> +	}
> +
> +}
> +
>  static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
>  {
>  	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
> @@ -86,7 +105,10 @@ static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
>  		return IRQ_NONE;
>  
>  	da9052_ts_start(tsi);
> -	tsi->pen_state = DA9052_PEN_DOWN;
> +
> +	input_report_abs(tsi->dev, ABS_PRESSURE, 1023);
> +	input_report_key(tsi->dev, BTN_TOUCH, 0);
> +	input_sync(tsi->dev);
>  
>  	return IRQ_HANDLED;
>  }
> @@ -118,7 +140,10 @@ static int da9052_ts_read(struct da9052_tsi *tsi)
>  	co_ord.x = ((_x << 2) & 0x3fc) | (_v & 0x3);
>  	co_ord.y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
>  
> -	ret = kfifo_in(&tsi->fifo, &co_ord, sizeof(struct da9052_tsi_reg));
> +	input_report_abs(tsi->dev, ABS_X, co_ord.x);
> +	input_report_abs(tsi->dev, ABS_Y, co_ord.y);
> +	input_report_abs(tsi->dev, ABS_PRESSURE, 1023);
> +	input_sync(tsi->dev);
>  
>  	return 0;
>  }
> @@ -135,131 +160,10 @@ static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
>  		return IRQ_NONE;
>  	}
>  

[skip[

> +	/* start polling for touch_det to detect release */
> +	schedule_delayed_work(&tsi->work, HZ / 50);
>  

What if da9052_ts_datardy_irq() never comes? You should schedule from
pendown IRQ handler.

> -	return 0;
> +	return IRQ_HANDLED;
>  }
>  

...

> -
> +	cancel_delayed_work(&tsi->work);

cancel_delayed_work_sync()

There are a few other changes in the patch below, however I can't
compile it since the rest of the MFD code is not in mainline nor in
linux-next.

Thanks.

-- 
Dmitry


Input: da9052 - misc fixes

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

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

 drivers/input/touchscreen/da9052_tsi.c |  210 +++++++++++++++-----------------
 1 files changed, 96 insertions(+), 114 deletions(-)


diff --git a/drivers/input/touchscreen/da9052_tsi.c b/drivers/input/touchscreen/da9052_tsi.c
index 0445d88..095999e 100644
--- a/drivers/input/touchscreen/da9052_tsi.c
+++ b/drivers/input/touchscreen/da9052_tsi.c
@@ -15,7 +15,6 @@
 #include <linux/delay.h>
 #include <linux/platform_device.h>
 #include <linux/sched.h>
-#include <linux/kthread.h>
 
 #include <linux/mfd/da9052/reg.h>
 #include <linux/mfd/da9052/da9052.h>
@@ -26,23 +25,20 @@ struct da9052_tsi_reg {
 };
 
 struct da9052_tsi {
-	struct da9052	*da9052;
+	struct da9052 *da9052;
 	struct input_dev *dev;
-	u8 pen_up_detect_interval;
-	u32 zero_data_cnt;
-	u32 valid_penup_count;
 	struct delayed_work work;
 	int irq_pendwn;
 	int irq_datardy;
 };
 
-static inline int da9052_ts_start(struct da9052_tsi *tsi)
+static int da9052_ts_start(struct da9052_tsi *tsi)
 {
 	return da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG,
 				 1 << 0, 1 << 0);
 }
 
-static inline int da9052_ts_stop(struct da9052_tsi *tsi)
+static int da9052_ts_stop(struct da9052_tsi *tsi)
 {
 	return da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
 }
@@ -63,51 +59,43 @@ static void da9052_work(struct work_struct *work)
 	down = ((_v & 0x40) >> 6);
 
 	if (!down) {
+		input_report_key(tsi->dev, BTN_TOUCH, 0);
+		input_sync(tsi->dev);
+
+		da9052_ts_stop(tsi);
+
 		tsi->da9052->events_mask |= DA9052_E_TSI_READY;
 		tsi->da9052->events_mask &= ~DA9052_E_PEN_DOWN;
 
 		/* Mask TSI_READY event and unmask PEN_DOWN event*/
-		ret = da9052_reg_update(tsi->da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
-		if (ret < 0)
-			return;
-
-		input_report_abs(tsi->dev, ABS_PRESSURE, 0);
-		input_report_key(tsi->dev, BTN_TOUCH, 1);
-		input_sync(tsi->dev);
+		da9052_reg_update(tsi->da9052, DA9052_IRQ_MASK_B_REG, 0x40, 0x80);
 	} else {
-		da9052->events_mask |= DA9052_E_PEN_DOWN;
-		da9052->events_mask &= ~DA9052_E_TSI_READY;
-
-		/* Mask PEN_DOWN event and unmask TSI_READY event*/
-		ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x80, 0x40);
-		if (ret < 0)
-			return;
-
-		/* start polling for touch_det to detect release */
+		/* keep polling to detect release */
 		schedule_delayed_work(&tsi->work, HZ / 50);
 	}
-
 }
 
 static irqreturn_t da9052_ts_pendwn_irq(int irq, void *data)
 {
-	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
+	struct da9052_tsi *tsi = data;
 	struct da9052 *da9052 = tsi->da9052;
 	int ret;
 
+	input_report_key(tsi->dev, BTN_TOUCH, 1);
+	input_sync(tsi->dev);
+
 	da9052->events_mask |= DA9052_E_PEN_DOWN;
 	da9052->events_mask &= ~DA9052_E_TSI_READY;
 
-	/* Mask PEN_DOWN event and unmask TSI_READY event*/
+	/* Mask PEN_DOWN event and unmask TSI_READY event */
 	ret = da9052_reg_update(da9052, DA9052_IRQ_MASK_B_REG, 0x80, 0x40);
 	if (ret < 0)
 		return IRQ_NONE;
 
 	da9052_ts_start(tsi);
 
-	input_report_abs(tsi->dev, ABS_PRESSURE, 1023);
-	input_report_key(tsi->dev, BTN_TOUCH, 0);
-	input_sync(tsi->dev);
+	/* start polling for touch_det to detect release */
+	schedule_delayed_work(&tsi->work, HZ / 50);
 
 	return IRQ_HANDLED;
 }
@@ -141,7 +129,6 @@ static int da9052_ts_read(struct da9052_tsi *tsi)
 
 	input_report_abs(tsi->dev, ABS_X, co_ord.x);
 	input_report_abs(tsi->dev, ABS_Y, co_ord.y);
-	input_report_abs(tsi->dev, ABS_PRESSURE, 1023);
 	input_sync(tsi->dev);
 
 	return 0;
@@ -149,23 +136,20 @@ static int da9052_ts_read(struct da9052_tsi *tsi)
 
 static irqreturn_t da9052_ts_datardy_irq(int irq, void *data)
 {
-	struct da9052_tsi *tsi = (struct da9052_tsi *)data;
-	int ret;
+	struct da9052_tsi *tsi = data;
+	int error;
 
-	ret = da9052_ts_read(tsi);
-	if (ret) {
+	error = da9052_ts_read(tsi);
+	if (error) {
 		dev_err(tsi->da9052->dev,
-			"Failed to read TSI co-ordinate, %d\n", ret);
+			"Failed to read TSI co-ordinate, error: %d\n", error);
 		return IRQ_NONE;
 	}
 
-	/* start polling for touch_det to detect release */
-	schedule_delayed_work(&tsi->work, HZ / 50);
-
 	return IRQ_HANDLED;
 }
 
-static int da9052_ts_configure_gpio(struct da9052 *da9052)
+static int __devinit da9052_ts_configure_gpio(struct da9052 *da9052)
 {
 	int ret;
 
@@ -181,26 +165,22 @@ static int da9052_ts_configure_gpio(struct da9052 *da9052)
 	if (ret < 0)
 		return -EIO;
 
-	return ret;
+	return 0;
 }
 
-static int __init da9052_ts_enable_device(struct da9052_tsi *tsi)
+static int __devinit da9052_ts_enable_device(struct da9052_tsi *tsi)
 {
-	ssize_t ret;
 	struct da9052 *da9052 = tsi->da9052;
+	int error;
 
-	ret = da9052_ts_configure_gpio(tsi->da9052);
-	if (ret < 0)
-		return ret;
+	error = da9052_ts_configure_gpio(tsi->da9052);
+	if (error)
+		return error;
 
 	ret = da9052_reg_update(tsi->da9052, DA9052_TSI_CONT_A_REG, 0xFC, 0xC0);
 	if (ret < 0)
 		return ret;
 
-	tsi->valid_penup_count = 5;
-
-	tsi->zero_data_cnt = 0;
-
 	/* Measure TSI sample every 1ms */
 	ret = da9052_reg_update(tsi->da9052, DA9052_ADC_CONT_REG,
 				1 << 6, 1 << 6);
@@ -220,43 +200,49 @@ static int __init da9052_ts_enable_device(struct da9052_tsi *tsi)
 	if (ret < 0)
 		return ret;
 
-	/*Supply TSIRef thru LD09 */
+	/* Supply TSIRef thru LD09 */
 	ret = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x59);
+	if (ret < 0)
+		return ret;
 
-	return ret;
+	return 0;
 }
 
-static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
+static int __devinit da9052_ts_probe(struct platform_device *pdev)
 {
+	struct da9052 *da9052 = platform_get_drvdata(pdev->dev.parent);
 	struct da9052_tsi *tsi;
 	struct input_dev *input_dev;
-	struct da9052 *da9052;
-	int ret;
-
-	da9052 = dev_get_drvdata(pdev->dev.parent);
+	int irq_pendown, irq_datardy;
+	int error;
+
+	irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
+	irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
+	if (irq_pendown < 0 || irq_datardy < 0) {
+		dev_err(da9052->dev, "Unable to determine device interrupts\n");
+		return -ENXIO;
+	}
 
 	tsi = kzalloc(sizeof(struct da9052_tsi), GFP_KERNEL);
-	if (!tsi)
-		return -ENOMEM;
-
 	input_dev = input_allocate_device();
-	if (!input_dev) {
-		dev_err(tsi->da9052->dev,
-			"failed to allocate input device\n");
+	if (!tsi || !input_dev) {
+		dev_err(da9052->dev, "failed to allocate memory\n");
 		ret = -ENOMEM;
-		goto err_mem;
+		goto err_free_mem;
 	}
 
 	tsi->da9052 = da9052;
-	tsi->pen_up_detect_interval = 5;
-	platform_set_drvdata(pdev, tsi);
+	tsi->dev = input_dev;
+	tsi->irq_pendown = irq_pendwn;
+	tsi->irq_datadry = irq_datardy;
+	INIT_DELAYED_WORK(&tsi->work, da9052_work);
 
+	input_dev->name = "Dialog DA9052 TouchScreen Driver";
 	input_dev->id.version = 0x0101;
 	input_dev->id.vendor = 0x15B6;
 	input_dev->id.product = 0x9052;
 	input_dev->id.bustype = BUS_RS232;
-	input_dev->name = "Dialog DA9052 TouchScreen Driver";
-	input_dev->dev.parent	= &pdev->dev;
+	input_dev->dev.parent = &pdev->dev;
 	__set_bit(EV_ABS, input_dev->evbit);
 	__set_bit(EV_KEY, input_dev->evbit);
 	__set_bit(BTN_TOUCH, input_dev->keybit);
@@ -265,85 +251,81 @@ static s32 __devinit da9052_ts_probe(struct platform_device *pdev)
 
 	input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
 	input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
-	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 1023, 0, 0);
 
-	tsi->dev = input_dev;
 	input_set_drvdata(input_dev, tsi);
-	ret = input_register_device(tsi->dev);
-	if (ret)
-		goto err_mem;
 
-	INIT_DELAYED_WORK(&tsi->work, da9052_work);
-
-	tsi->irq_pendwn = platform_get_irq_byname(pdev, "PENDWN");
-	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_pendwn,
-				NULL, da9052_ts_pendwn_irq,
-				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
-				"PENDWN", tsi);
-	if (ret < 0) {
-		dev_err(tsi->da9052->dev,
+	error = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_pendwn,
+				     NULL, da9052_ts_pendwn_irq,
+				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				     "PENDWN", tsi);
+	if (error) {
+		dev_err(da9052->dev,
 			"Failed to register %s IRQ %d, error = %d\n", "PENDWN",
-			tsi->da9052->irq_base + tsi->irq_pendwn, ret);
+			tsi->da9052->irq_base + tsi->irq_pendwn, error);
 		goto err_input;
 	}
 
-	tsi->irq_datardy = platform_get_irq_byname(pdev, "TSIRDY");
-	ret = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_datardy,
-				NULL, da9052_ts_datardy_irq,
-				IRQF_TRIGGER_LOW | IRQF_ONESHOT,
-				"TSIRDY", tsi);
-	if (ret < 0) {
-		dev_err(tsi->da9052->dev,
+	error = request_threaded_irq(tsi->da9052->irq_base + tsi->irq_datardy,
+				     NULL, da9052_ts_datardy_irq,
+				     IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+				     "TSIRDY", tsi);
+	if (error) {
+		dev_err(da9052->dev,
 			"Failed to register %s IRQ %d, error = %d\n", "TSIRDY",
-			tsi->da9052->irq_base + tsi->irq_datardy, ret);
-		goto err_input;
+			tsi->da9052->irq_base + tsi->irq_datardy, error);
+		goto err_free_pendown;
 	}
 
-	ret = da9052_ts_enable_device(tsi);
-	if (ret < 0)
-		goto err_input;
+	error = da9052_ts_enable_device(tsi);
+	if (error) {
+		dev_err(da9052->dev,
+			"Failed to enable device, error: %d\n", error);
+		goto err_free_datardy;
+	}
 
+	error = input_register_device(tsi->dev);
+	if (error)
+		goto err_free_datardy;
+
+	platform_set_drvdata(pdev, tsi);
 	return 0;
 
-err_input:
+err_free_pendown:
+	free_irq(tsi->da9052->irq_base + tsi->irq_pendwn, tsi);
+err_free_datardy:
+	free_irq(tsi->da9052->irq_base + tsi->irq_datardy, tsi);
+err_free_mem:
 	input_free_device(input_dev);
-err_mem:
 	kfree(tsi);
-	return ret;
+	return error;
 }
 
 static int __devexit da9052_ts_remove(struct platform_device *pdev)
 {
 	struct da9052_tsi *tsi = platform_get_drvdata(pdev);
-	s32 ret;
 
-	ret = da9052_clear_bits(tsi->da9052, DA9052_TSI_CONT_A_REG, 1 << 0);
-	if (ret < 0)
-		return ret;
+	da9052_ts_stop(tsi);
+	da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
 
-	ret = da9052_reg_write(tsi->da9052, DA9052_LDO9_REG, 0x19);
-	if (ret < 0)
-		return ret;
+	free_irq(tsi->da9052->irq_base + tsi->irq_pendwn, tsi);
+	free_irq(tsi->da9052->irq_base + tsi->irq_datardy, tsi);
 
-	free_irq(tsi->da9052->irq_base + tsi->irq_pendwn, NULL);
-	free_irq(tsi->da9052->irq_base + tsi->irq_datardy, NULL);
+	cancel_delayed_work_sync(&tsi->work);
 
-	cancel_delayed_work(&tsi->work);
 	input_unregister_device(tsi->dev);
+	kfree(tsi);
 
 	platform_set_drvdata(pdev, NULL);
 
-	kfree(tsi);
-
 	return 0;
 }
 
 static struct platform_driver da9052_tsi_driver = {
-	.probe = da9052_ts_probe,
-	.remove = __devexit_p(da9052_ts_remove),
-	.driver = {
-		.name = "da9052-tsi",
-		.owner = THIS_MODULE,
+	.probe	= da9052_ts_probe,
+	.remove	= __devexit_p(da9052_ts_remove),
+	.driver	= {
+		.name	= "da9052-tsi",
+		.owner	= THIS_MODULE,
 	},
 };