Re: [PATCH v8 3/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature
From: H. Nikolaus Schaller
Date: Thu Nov 24 2016 - 13:06:11 EST
> Am 24.11.2016 um 18:38 schrieb Jonathan Cameron <jic23@xxxxxxxxxxxxxxxxxxxxx>:
>
>
>
> On 22 November 2016 14:02:30 GMT+00:00, "H. Nikolaus Schaller" <hns@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx>
>> Reviewed-by: Jonathan Cameron <jic23@xxxxxxxxxx>
>> ---
>> 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@xxxxxxxxxxxxxx>
>> + *
>> + * 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@xxxxxxxxxxxxx>
>> + *
>> + * 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.