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@xxxxxxxxxxx>
> Signed-off-by: Ashish Jangam <ashish.jangam@xxxxxxxxxxxxxxx>
> ---
>  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@xxxxxxxxxxx>
> + *
> + *  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@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:da9052-tsi");
> 
> 

Thanks.

-- 
Dmitry
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