[Letux-kernel] [PATCH v8 3/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature

H. Nikolaus Schaller hns at goldelico.com
Thu Nov 24 19:05:46 CET 2016


> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23 at jic23.retrosnub.co.uk>:
> 
> 
> 
> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns at goldelico.com> wrote:
>> The tsc2007 chip not only has a resistive touch screen controller but
>> also an external AUX adc imput which can be used for an ambient
>> light sensor, battery voltage monitoring or any general purpose.
>> 
>> Additionally it can measure the chip temperature.
>> 
>> This extension provides an iio interface for these adc channels.
>> 
>> Since it is not wasting much resources and is very straightforward,
>> we simply provide all other adc channels as optional iio interfaces
>> as weel. This can be used for debugging or special applications.
>> 
>> This patch also splits the tsc2007 driver in several source files:
>> tsc2007.h -- constants, structs and stubs
>> tsc2007_core.c -- functional parts of the original driver
>> tsc2007_iio.c -- the optional iio stuff
>> 
>> Makefile magic allows to conditionally link the iio stuff
>> if CONFIG_IIO=y or =m in a way that it works with
>> CONFIG_TOUCHSCREEN_TSC2007=m.
>> 
>> Signed-off-by: H. Nikolaus Schaller <hns at goldelico.com>
>> Reviewed-by: Jonathan Cameron <jic23 at kernel.org>
>> ---
>> drivers/input/touchscreen/Makefile                 |   7 +
>> drivers/input/touchscreen/tsc2007.h                | 116
>> ++++++++++++++++
>> .../touchscreen/{tsc2007.c => tsc2007_core.c}      |  95 +++----------
>> drivers/input/touchscreen/tsc2007_iio.c            | 150
>> +++++++++++++++++++++
>> 4 files changed, 294 insertions(+), 74 deletions(-)
>> create mode 100644 drivers/input/touchscreen/tsc2007.h
>> rename drivers/input/touchscreen/{tsc2007.c => tsc2007_core.c} (86%)
>> create mode 100644 drivers/input/touchscreen/tsc2007_iio.c
>> 
>> diff --git a/drivers/input/touchscreen/Makefile
>> b/drivers/input/touchscreen/Makefile
>> index 81b8645..3be0d19 100644
>> --- a/drivers/input/touchscreen/Makefile
>> +++ b/drivers/input/touchscreen/Makefile
>> @@ -80,6 +80,13 @@ obj-$(CONFIG_TOUCHSCREEN_TSC_SERIO)	+= tsc40.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC200X_CORE)	+= tsc200x-core.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC2004)	+= tsc2004.o
>> obj-$(CONFIG_TOUCHSCREEN_TSC2005)	+= tsc2005.o
>> +tsc2007-y				:= tsc2007_core.o
>> +ifeq ($(CONFIG_IIO),y)
>> +tsc2007-y				+= tsc2007_iio.o
>> +endif
>> +ifeq ($(CONFIG_IIO),m)
>> +tsc2007-y				+= tsc2007_iio.o
> 
> Not tsc2007-m ?
> 
> I don't follow how this works!

I guess tsc2007-y is an internal collector variable name
for multiple .o components. Sort of a "library" object.

While

obj-y += tsc2007.o adds it to the kernel
obj-m += tsc2007.o adds it to the modules

I am not sure if my explanation is correct but it appears
to work that way.

Anyways what shall we do? If CONFIG_TOUCHSCREEN_TSC2007=y
and IIO=m we have a problem that we need dynamic binding.

>> +endif
>> obj-$(CONFIG_TOUCHSCREEN_TSC2007)	+= tsc2007.o
>> obj-$(CONFIG_TOUCHSCREEN_UCB1400)	+= ucb1400_ts.o
>> obj-$(CONFIG_TOUCHSCREEN_WACOM_W8001)	+= wacom_w8001.o
>> diff --git a/drivers/input/touchscreen/tsc2007.h
>> b/drivers/input/touchscreen/tsc2007.h
>> new file mode 100644
>> index 0000000..c25932f
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/tsc2007.h
>> @@ -0,0 +1,116 @@
>> +/*
>> + * Copyright (c) 2008 MtekVision Co., Ltd.
>> + *	Kwangwoo Lee <kwlee at mtekvision.com>
>> + *
>> + * Using code from:
>> + *  - ads7846.c
>> + *	Copyright (c) 2005 David Brownell
>> + *	Copyright (c) 2006 Nokia Corporation
>> + *  - corgi_ts.c
>> + *	Copyright (C) 2004-2005 Richard Purdie
>> + *  - omap_ts.[hc], ads7846.h, ts_osk.c
>> + *	Copyright (C) 2002 MontaVista Software
>> + *	Copyright (C) 2004 Texas Instruments
>> + *	Copyright (C) 2005 Dirk Behme
>> + *
>> + *  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/input/touchscreen.h>
>> +
>> +#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>> +#define TSC2007_MEASURE_AUX		(0x2 << 4)
>> +#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>> +#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>> +#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>> +#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>> +#define TSC2007_SETUP			(0xb << 4)
>> +#define TSC2007_MEASURE_X		(0xc << 4)
>> +#define TSC2007_MEASURE_Y		(0xd << 4)
>> +#define TSC2007_MEASURE_Z1		(0xe << 4)
>> +#define TSC2007_MEASURE_Z2		(0xf << 4)
>> +
>> +#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>> +#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>> +#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>> +#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>> +
>> +#define TSC2007_12BIT			(0x0 << 1)
>> +#define TSC2007_8BIT			(0x1 << 1)
>> +
>> +#define	MAX_12BIT			((1 << 12) - 1)
>> +
>> +#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>> +
>> +#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>> +#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>> +#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>> +#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>> +#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>> +
>> +struct ts_event {
>> +	u16	x;
>> +	u16	y;
>> +	u16	z1, z2;
>> +};
>> +
>> +struct tsc2007 {
>> +	struct input_dev	*input;
>> +	char			phys[32];
>> +
>> +	struct i2c_client	*client;
>> +
>> +	u16			model;
>> +	u16			x_plate_ohms;
>> +
>> +	struct touchscreen_properties prop;
>> +
>> +	bool			report_resistance;
>> +	u16			min_x;
>> +	u16			min_y;
>> +	u16			max_x;
>> +	u16			max_y;
>> +	u16			max_rt;
>> +	unsigned long		poll_period; /* in jiffies */
>> +	int			fuzzx;
>> +	int			fuzzy;
>> +	int			fuzzz;
>> +
>> +	unsigned int		gpio;
>> +	int			irq;
>> +
>> +	wait_queue_head_t	wait;
>> +	bool			stopped;
>> +	bool			pendown;
>> +
>> +	int			(*get_pendown_state)(struct device *);
>> +	void			(*clear_penirq)(void);
>> +
>> +	struct mutex		mlock;
>> +	struct iio_dev		*iio_dev;	/* optional */
>> +};
>> +
>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd);
>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>> +					struct ts_event *tc);
>> +bool tsc2007_is_pen_down(struct tsc2007 *ts);
>> +
>> +#if IS_ENABLED(CONFIG_IIO)
>> +
>> +/* defined in tsc2007_iio.c */
>> +int tsc2007_iio_configure(struct tsc2007 *ts);
>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts);
>> +
>> +#else /* CONFIG_IIO */
>> +
>> +static inline int tsc2007_iio_configure(struct tsc2007 *ts)
>> +{
>> +	return 0;
>> +}
>> +static inline void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>> +{
>> +}
>> +
>> +#endif /* CONFIG_IIO */
>> diff --git a/drivers/input/touchscreen/tsc2007.c
>> b/drivers/input/touchscreen/tsc2007_core.c
>> similarity index 86%
>> rename from drivers/input/touchscreen/tsc2007.c
>> rename to drivers/input/touchscreen/tsc2007_core.c
>> index 76b462b..812ded8 100644
>> --- a/drivers/input/touchscreen/tsc2007.c
>> +++ b/drivers/input/touchscreen/tsc2007_core.c
>> @@ -27,79 +27,11 @@
>> #include <linux/i2c.h>
>> #include <linux/i2c/tsc2007.h>
>> #include <linux/of_device.h>
>> -#include <linux/of.h>
>> #include <linux/of_gpio.h>
>> -#include <linux/input/touchscreen.h>
>> -
>> -#define TSC2007_MEASURE_TEMP0		(0x0 << 4)
>> -#define TSC2007_MEASURE_AUX		(0x2 << 4)
>> -#define TSC2007_MEASURE_TEMP1		(0x4 << 4)
>> -#define TSC2007_ACTIVATE_XN		(0x8 << 4)
>> -#define TSC2007_ACTIVATE_YN		(0x9 << 4)
>> -#define TSC2007_ACTIVATE_YP_XN		(0xa << 4)
>> -#define TSC2007_SETUP			(0xb << 4)
>> -#define TSC2007_MEASURE_X		(0xc << 4)
>> -#define TSC2007_MEASURE_Y		(0xd << 4)
>> -#define TSC2007_MEASURE_Z1		(0xe << 4)
>> -#define TSC2007_MEASURE_Z2		(0xf << 4)
>> -
>> -#define TSC2007_POWER_OFF_IRQ_EN	(0x0 << 2)
>> -#define TSC2007_ADC_ON_IRQ_DIS0		(0x1 << 2)
>> -#define TSC2007_ADC_OFF_IRQ_EN		(0x2 << 2)
>> -#define TSC2007_ADC_ON_IRQ_DIS1		(0x3 << 2)
>> -
>> -#define TSC2007_12BIT			(0x0 << 1)
>> -#define TSC2007_8BIT			(0x1 << 1)
>> -
>> -#define	MAX_12BIT			((1 << 12) - 1)
>> -
>> -#define ADC_ON_12BIT	(TSC2007_12BIT | TSC2007_ADC_ON_IRQ_DIS0)
>> -
>> -#define READ_Y		(ADC_ON_12BIT | TSC2007_MEASURE_Y)
>> -#define READ_Z1		(ADC_ON_12BIT | TSC2007_MEASURE_Z1)
>> -#define READ_Z2		(ADC_ON_12BIT | TSC2007_MEASURE_Z2)
>> -#define READ_X		(ADC_ON_12BIT | TSC2007_MEASURE_X)
>> -#define PWRDOWN		(TSC2007_12BIT | TSC2007_POWER_OFF_IRQ_EN)
>> -
>> -struct ts_event {
>> -	u16	x;
>> -	u16	y;
>> -	u16	z1, z2;
>> -};
>> -
>> -struct tsc2007 {
>> -	struct input_dev	*input;
>> -	char			phys[32];
>> -
>> -	struct i2c_client	*client;
>> -
>> -	u16			model;
>> -	u16			x_plate_ohms;
>> -
>> -	struct touchscreen_properties prop;
>> -
>> -	bool			report_resistance;
>> -	u16			min_x;
>> -	u16			min_y;
>> -	u16			max_x;
>> -	u16			max_y;
>> -	u16			max_rt;
>> -	unsigned long		poll_period; /* in jiffies */
>> -	int			fuzzx;
>> -	int			fuzzy;
>> -	int			fuzzz;
>> -
>> -	unsigned		gpio;
>> -	int			irq;
>> -
>> -	wait_queue_head_t	wait;
>> -	bool			stopped;
>> +#include "tsc2007.h"
>> 
>> -	int			(*get_pendown_state)(struct device *);
>> -	void			(*clear_penirq)(void);
>> -};
>> 
>> -static inline int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>> +int tsc2007_xfer(struct tsc2007 *tsc, u8 cmd)
>> {
>> 	s32 data;
>> 	u16 val;
>> @@ -137,7 +69,7 @@ static void tsc2007_read_values(struct tsc2007 *tsc,
>> struct ts_event *tc)
>> 	tsc2007_xfer(tsc, PWRDOWN);
>> }
>> 
>> -static u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>> +u32 tsc2007_calculate_resistance(struct tsc2007 *tsc,
>> 					struct ts_event *tc)
>> {
>> 	u32 rt = 0;
>> @@ -158,7 +90,7 @@ static u32 tsc2007_calculate_resistance(struct
>> tsc2007 *tsc,
>> 	return rt;
>> }
>> 
>> -static bool tsc2007_is_pen_down(struct tsc2007 *ts)
>> +bool tsc2007_is_pen_down(struct tsc2007 *ts)
>> {
>> 	/*
>> 	 * NOTE: We can't rely on the pressure to determine the pen down
>> @@ -191,7 +123,10 @@ static irqreturn_t tsc2007_soft_irq(int irq, void
>> *handle)
>> 	while (!ts->stopped && tsc2007_is_pen_down(ts)) {
>> 
>> 		/* pen is down, continue with the measurement */
>> +
>> +		mutex_lock(&ts->mlock);
>> 		tsc2007_read_values(ts, &tc);
>> +		mutex_unlock(&ts->mlock);
>> 
>> 		rt = tsc2007_calculate_resistance(ts, &tc);
>> 
>> @@ -441,7 +376,8 @@ static void tsc2007_call_exit_platform_hw(void
>> *data)
>> static int tsc2007_probe(struct i2c_client *client,
>> 			 const struct i2c_device_id *id)
>> {
>> -	const struct tsc2007_platform_data *pdata =
>> dev_get_platdata(&client->dev);
>> +	const struct tsc2007_platform_data *pdata =
>> +		dev_get_platdata(&client->dev);
>> 	struct tsc2007 *ts;
>> 	struct input_dev *input_dev;
>> 	int err;
>> @@ -463,7 +399,9 @@ static int tsc2007_probe(struct i2c_client *client,
>> 	ts->client = client;
>> 	ts->irq = client->irq;
>> 	ts->input = input_dev;
>> +
>> 	init_waitqueue_head(&ts->wait);
>> +	mutex_init(&ts->mlock);
>> 
>> 	snprintf(ts->phys, sizeof(ts->phys),
>> 		 "%s/input0", dev_name(&client->dev));
>> @@ -534,7 +472,7 @@ static int tsc2007_probe(struct i2c_client *client,
>> 	if (err < 0) {
>> 		dev_err(&client->dev,
>> 			"Failed to setup chip: %d\n", err);
>> -		return err;	/* usually, chip does not respond */
>> +		return err;	/* chip does not respond */
>> 	}
>> 
>> 	err = input_register_device(input_dev);
>> @@ -544,6 +482,14 @@ static int tsc2007_probe(struct i2c_client
>> *client,
>> 		return err;
>> 	}
>> 
>> +	return tsc2007_iio_configure(ts);
>> +}
>> +
>> +static int tsc2007_remove(struct i2c_client *client)
>> +{
>> +	struct tsc2007 *ts = i2c_get_clientdata(client);
>> +
>> +	tsc2007_iio_unconfigure(ts);
>> 	return 0;
>> }
>> 
>> @@ -569,6 +515,7 @@ static struct i2c_driver tsc2007_driver = {
>> 	},
>> 	.id_table	= tsc2007_idtable,
>> 	.probe		= tsc2007_probe,
>> +	.remove		= tsc2007_remove,
>> };
>> 
>> module_i2c_driver(tsc2007_driver);
>> diff --git a/drivers/input/touchscreen/tsc2007_iio.c
>> b/drivers/input/touchscreen/tsc2007_iio.c
>> new file mode 100644
>> index 0000000..ed79944
>> --- /dev/null
>> +++ b/drivers/input/touchscreen/tsc2007_iio.c
>> @@ -0,0 +1,150 @@
>> +/*
>> + * Copyright (c) 2016 Golden Delicious Comp. GmbH&Co. KG
>> + *	Nikolaus Schaller <hns at goldelico.com>
>> + *
>> + *  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/i2c.h>
>> +#include <linux/iio/iio.h>
>> +#include "tsc2007.h"
>> +
>> +struct tsc2007_iio {
>> +	struct tsc2007 *ts;
>> +};
>> +
>> +#define TSC2007_CHAN_IIO(_chan, _name, _type, _chan_info) \
>> +{ \
>> +	.datasheet_name = _name, \
>> +	.type = _type, \
>> +	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
>> +			BIT(_chan_info), \
>> +	.indexed = 1, \
>> +	.channel = _chan, \
>> +}
>> +
>> +static const struct iio_chan_spec tsc2007_iio_channel[] = {
>> +	TSC2007_CHAN_IIO(0, "x", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(1, "y", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(2, "z1", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(3, "z2", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(4, "adc", IIO_VOLTAGE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(5, "rt", IIO_VOLTAGE, IIO_CHAN_INFO_RAW), /* Ohms?
>> */
>> +	TSC2007_CHAN_IIO(6, "pen", IIO_PRESSURE, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(7, "temp0", IIO_TEMP, IIO_CHAN_INFO_RAW),
>> +	TSC2007_CHAN_IIO(8, "temp1", IIO_TEMP, IIO_CHAN_INFO_RAW),
>> +};
>> +
>> +static int tsc2007_read_raw(struct iio_dev *indio_dev,
>> +	struct iio_chan_spec const *chan, int *val, int *val2, long mask)
>> +{
>> +	struct tsc2007_iio *iio = iio_priv(indio_dev);
>> +	struct tsc2007 *tsc = iio->ts;
>> +	int adc_chan = chan->channel;
>> +	int ret = 0;
>> +
>> +	if (adc_chan >= ARRAY_SIZE(tsc2007_iio_channel))
>> +		return -EINVAL;
>> +
>> +	if (mask != IIO_CHAN_INFO_RAW)
>> +		return -EINVAL;
>> +
>> +	mutex_lock(&tsc->mlock);
>> +
>> +	switch (chan->channel) {
>> +	case 0:
>> +		*val = tsc2007_xfer(tsc, READ_X);
>> +		break;
>> +	case 1:
>> +		*val = tsc2007_xfer(tsc, READ_Y);
>> +		break;
>> +	case 2:
>> +		*val = tsc2007_xfer(tsc, READ_Z1);
>> +		break;
>> +	case 3:
>> +		*val = tsc2007_xfer(tsc, READ_Z2);
>> +		break;
>> +	case 4:
>> +		*val = tsc2007_xfer(tsc, (ADC_ON_12BIT | TSC2007_MEASURE_AUX));
>> +		break;
>> +	case 5: {
>> +		struct ts_event tc;
>> +
>> +		tc.x = tsc2007_xfer(tsc, READ_X);
>> +		tc.z1 = tsc2007_xfer(tsc, READ_Z1);
>> +		tc.z2 = tsc2007_xfer(tsc, READ_Z2);
>> +		*val = tsc2007_calculate_resistance(tsc, &tc);
>> +		break;
>> +	}
>> +	case 6:
>> +		*val = tsc2007_is_pen_down(tsc);
>> +		break;
>> +	case 7:
>> +		*val = tsc2007_xfer(tsc,
>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP0));
>> +		break;
>> +	case 8:
>> +		*val = tsc2007_xfer(tsc,
>> +				    (ADC_ON_12BIT | TSC2007_MEASURE_TEMP1));
>> +		break;
>> +	}
>> +
>> +	/* Prepare for next touch reading - power down ADC, enable PENIRQ */
>> +	tsc2007_xfer(tsc, PWRDOWN);
>> +
>> +	mutex_unlock(&tsc->mlock);
>> +
>> +	ret = IIO_VAL_INT;
>> +
>> +	return ret;
>> +}
>> +
>> +static const struct iio_info tsc2007_iio_info = {
>> +	.read_raw = tsc2007_read_raw,
>> +	.driver_module = THIS_MODULE,
>> +};
>> +
>> +int tsc2007_iio_configure(struct tsc2007 *ts)
>> +{
>> +	int err;
>> +	struct iio_dev *indio_dev;
>> +	struct tsc2007_iio *iio;
>> +
>> +	indio_dev = devm_iio_device_alloc(&ts->client->dev,
>> +		sizeof(struct tsc2007_iio));
>> +	if (!indio_dev) {
>> +		dev_err(&ts->client->dev, "iio_device_alloc failed\n");
>> +		return -ENOMEM;
>> +	}
>> +
>> +	iio = iio_priv(indio_dev);
>> +	iio->ts = ts;
>> +	ts->iio_dev = (void *) indio_dev;
>> +
>> +	indio_dev->name = "tsc2007";
>> +	indio_dev->dev.parent = &ts->client->dev;
>> +	indio_dev->info = &tsc2007_iio_info;
>> +	indio_dev->modes = INDIO_DIRECT_MODE;
>> +	indio_dev->channels = tsc2007_iio_channel;
>> +	indio_dev->num_channels = ARRAY_SIZE(tsc2007_iio_channel);
>> +
>> +	err = iio_device_register(indio_dev);
>> +	if (err < 0) {
>> +		dev_err(&ts->client->dev, "iio_device_register() failed: %d\n",
>> +			err);
>> +		return err;
>> +	}
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(tsc2007_iio_configure);
>> +
>> +void tsc2007_iio_unconfigure(struct tsc2007 *ts)
>> +{
>> +	struct iio_dev *indio_dev = ts->iio_dev;
>> +
>> +	iio_device_unregister(indio_dev);
>> +}
>> +EXPORT_SYMBOL(tsc2007_iio_unconfigure);
> 
> -- 
> Sent from my Android device with K-9 Mail. Please excuse my brevity.



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