| Message ID | 1526898477-9952-1-git-send-email-eugen.hristev@microchip.com |
|---|---|
| Headers | show |
| Series | Add support for SAMA5D2 touchscreen | expand |
On Mon, May 21, 2018 at 01:27:54PM +0300, Eugen Hristev wrote: > This adds a generic resistive touchscreen (GRTS) driver, which is based > on an IIO device (an ADC). It must be connected to the channels of an ADC > to receive touch data. Then it will feed the data into the input subsystem > where it registers an input device. > It uses an IIO callback buffer to register to the IIO device > > Some parts of this patch are based on initial original work by > Mohamed Jamsheeth Hajanajubudeen and Bandaru Venkateswara Swamy > > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> I assume this will go through IIO tree? Just a couple of comsmetic comments below, feel free to ignore. > --- > Changes in v6: > - changed a dev_err to dev_dbg which was forgotten in v5. > > Changes in v5: > - return error on probe if failed add_action_or_reset > - renamed property touchscreen-threshold-pressure to > touchscreen-min-pressure, changed variables accordingly > > Changes in v4: > - added a small description in file header > - changed MAX_POS_MASK to GRTS_MAX_POS_MASK > - initialized press with 0, as this value means no touch. > press has to be initialized because compiler/checkpatch complains > that can be used uninitialized. > - changed of_property_read_u32 to device_* > - set_abs_params for pressure will have range according to threshold > - changed evbit and keybit with set_capability call > - changed variable names to error instead of ret > - checked errors for add_action_or_reset > - cosmetic cleaning > > Changes in v3: > - pressure now reported naturally growing down-up > - using helpers from touchscreen.h to parse DT properties > - added devm_add_action_or_reset to handle callback buffer clean on exit > - changed compatible and threshold property to adapt to changed bindings > > Changes in v2: > - this is now a generic resistive adc touchscreen driver > > > drivers/input/touchscreen/Kconfig | 13 ++ > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/resistive-adc-touch.c | 201 ++++++++++++++++++++++++ > 3 files changed, 215 insertions(+) > create mode 100644 drivers/input/touchscreen/resistive-adc-touch.c > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index 4f15496..8f85d3a 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -92,6 +92,19 @@ config TOUCHSCREEN_AD7879_SPI > To compile this driver as a module, choose M here: the > module will be called ad7879-spi. > > +config TOUCHSCREEN_ADC > + tristate "Generic ADC based resistive touchscreen" > + depends on IIO > + select IIO_BUFFER_CB > + help > + Say Y here if you want to use the generic ADC > + resistive touchscreen driver. > + > + If unsure, say N (but it's safe to say "Y"). > + > + To compile this driver as a module, choose M here: the > + module will be called resistive-adc-touch.ko. > + > config TOUCHSCREEN_AR1021_I2C > tristate "Microchip AR1020/1021 i2c touchscreen" > depends on I2C && OF > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > index dddae79..843c7f9 100644 > --- a/drivers/input/touchscreen/Makefile > +++ b/drivers/input/touchscreen/Makefile > @@ -13,6 +13,7 @@ obj-$(CONFIG_TOUCHSCREEN_AD7877) += ad7877.o > obj-$(CONFIG_TOUCHSCREEN_AD7879) += ad7879.o > obj-$(CONFIG_TOUCHSCREEN_AD7879_I2C) += ad7879-i2c.o > obj-$(CONFIG_TOUCHSCREEN_AD7879_SPI) += ad7879-spi.o > +obj-$(CONFIG_TOUCHSCREEN_ADC) += resistive-adc-touch.o > obj-$(CONFIG_TOUCHSCREEN_ADS7846) += ads7846.o > obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C) += ar1021_i2c.o > obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT) += atmel_mxt_ts.o > diff --git a/drivers/input/touchscreen/resistive-adc-touch.c b/drivers/input/touchscreen/resistive-adc-touch.c > new file mode 100644 > index 0000000..05d629b > --- /dev/null > +++ b/drivers/input/touchscreen/resistive-adc-touch.c > @@ -0,0 +1,201 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * ADC generic resistive touchscreen (GRTS) > + * This is a generic input driver that connects to an ADC > + * given the channels in device tree, and reports events to the input > + * subsystem. > + * > + * Copyright (C) 2017,2018 Microchip Technology, > + * Author: Eugen Hristev <eugen.hristev@microchip.com> > + * > + */ > +#include <linux/input.h> > +#include <linux/input/touchscreen.h> > +#include <linux/iio/consumer.h> > +#include <linux/iio/iio.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_device.h> > +#include <linux/platform_device.h> > + > +#define DRIVER_NAME "resistive-adc-touch" > +#define GRTS_DEFAULT_PRESSURE_MIN 50000 > +#define GRTS_MAX_POS_MASK GENMASK(11, 0) > + > +/** > + * grts_state - generic resistive touch screen information struct > + * @pressure_min: number representing the minimum for the pressure > + * @pressure: are we getting pressure info or not > + * @iio_chans: list of channels acquired > + * @iio_cb: iio_callback buffer for the data > + * @input: the input device structure that we register > + * @prop: touchscreen properties struct > + */ > +struct grts_state { > + u32 pressure_min; > + bool pressure; > + struct iio_channel *iio_chans; > + struct iio_cb_buffer *iio_cb; > + struct input_dev *input; > + struct touchscreen_properties prop; > +}; > + > +static int grts_cb(const void *data, void *private) > +{ > + const u16 *touch_info = data; > + struct grts_state *st = private; > + unsigned int x, y, press = 0x0; > + > + /* channel data coming in buffer in the order below */ > + x = touch_info[0]; > + y = touch_info[1]; > + if (st->pressure) > + press = touch_info[2]; > + > + if ((!x && !y) || (st->pressure && (press < st->pressure_min))) { > + /* report end of touch */ > + input_report_key(st->input, BTN_TOUCH, 0); > + input_sync(st->input); > + return 0; > + } > + > + /* report proper touch to subsystem*/ > + touchscreen_report_pos(st->input, &st->prop, x, y, false); > + if (st->pressure) > + input_report_abs(st->input, ABS_PRESSURE, press); > + input_report_key(st->input, BTN_TOUCH, 1); > + input_sync(st->input); > + > + return 0; > +} > + > +static int grts_open(struct input_dev *dev) > +{ > + int error; > + struct grts_state *st = input_get_drvdata(dev); > + > + error = iio_channel_start_all_cb(st->iio_cb); > + if (error) { > + dev_err(dev->dev.parent, "failed to start callback buffer.\n"); > + return error; > + } > + return 0; > +} > + > +static void grts_close(struct input_dev *dev) > +{ > + struct grts_state *st = input_get_drvdata(dev); > + > + iio_channel_stop_all_cb(st->iio_cb); > +} > + > +static void grts_disable(void *data) > +{ > + iio_channel_release_all_cb(data); > +} > + > +static int grts_probe(struct platform_device *pdev) > +{ > + struct grts_state *st; > + struct input_dev *input; > + struct device *dev = &pdev->dev; > + struct iio_channel *chan; > + int error; > + > + st = devm_kzalloc(dev, sizeof(struct grts_state), GFP_KERNEL); > + if (!st) > + return -ENOMEM; > + > + error = device_property_read_u32(dev, "touchscreen-min-pressure", > + &st->pressure_min); > + if (error) { > + dev_dbg(dev, "can't get touchscreen-min-pressure property.\n"); > + st->pressure_min = GRTS_DEFAULT_PRESSURE_MIN; > + } I do not think it makes sense to complain about missing property if there is no "pressure" channel. Probably move down? > + > + /* get the channels from IIO device */ > + st->iio_chans = devm_iio_channel_get_all(dev); > + if (IS_ERR(st->iio_chans)) { > + if (PTR_ERR(st->iio_chans) != -EPROBE_DEFER) > + dev_err(dev, "can't get iio channels.\n"); > + return PTR_ERR(st->iio_chans); error = PTR_ERR(st->iio_chans); if (error != -EPROBE_DEFER) dev_err(dev, "can't get iio channels.\n"); return error; > + } > + > + chan = &st->iio_chans[0]; > + st->pressure = false; > + while (chan && chan->indio_dev) { > + if (!strcmp(chan->channel->datasheet_name, "pressure")) > + st->pressure = true; > + chan++; > + } > + > + input = devm_input_allocate_device(dev); > + if (!input) { > + dev_err(dev, "failed to allocate input device.\n"); > + return -ENOMEM; > + } > + > + input->name = DRIVER_NAME; > + input->id.bustype = BUS_HOST; > + input->open = grts_open; > + input->close = grts_close; > + > + input_set_abs_params(input, ABS_X, 0, GRTS_MAX_POS_MASK - 1, 0, 0); > + input_set_abs_params(input, ABS_Y, 0, GRTS_MAX_POS_MASK - 1, 0, 0); > + if (st->pressure) > + input_set_abs_params(input, ABS_PRESSURE, st->pressure_min, > + 0xffff, 0, 0); > + > + input_set_capability(input, EV_KEY, BTN_TOUCH); > + > + /* parse optional device tree properties */ > + touchscreen_parse_properties(input, false, &st->prop); > + > + st->input = input; > + input_set_drvdata(input, st); > + > + error = input_register_device(input); > + if (error) { > + dev_err(dev, "failed to register input device."); > + return error; > + } > + > + st->iio_cb = iio_channel_get_all_cb(dev, grts_cb, st); > + if (IS_ERR(st->iio_cb)) { > + dev_err(dev, "failed to allocate callback buffer.\n"); > + error = PTR_ERR(st->iio_cb); > + return error; Simply: return PTR_ERR(st->iio_cb); since you opted out of printing error codes in error messages. > + } > + > + error = devm_add_action_or_reset(dev, grts_disable, st->iio_cb); > + if (error) { > + dev_err(dev, "failed to add disable action.\n"); > + return error; > + } > + > + return 0; > +} > + > +static const struct of_device_id grts_of_match[] = { > + { > + .compatible = "resistive-adc-touch", > + }, { > + /* sentinel */ > + }, > +}; > + > +MODULE_DEVICE_TABLE(of, grts_of_match); > + > +static struct platform_driver grts_driver = { > + .probe = grts_probe, > + .driver = { > + .name = DRIVER_NAME, > + .of_match_table = of_match_ptr(grts_of_match), > + }, > +}; > + > +module_platform_driver(grts_driver); > + > +MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com>"); > +MODULE_DESCRIPTION("Generic ADC Resistive Touch Driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.7.4 > Thanks.
On 22.05.2018 00:06, Dmitry Torokhov wrote: > On Mon, May 21, 2018 at 01:27:54PM +0300, Eugen Hristev wrote: >> This adds a generic resistive touchscreen (GRTS) driver, which is based >> on an IIO device (an ADC). It must be connected to the channels of an ADC >> to receive touch data. Then it will feed the data into the input subsystem >> where it registers an input device. >> It uses an IIO callback buffer to register to the IIO device >> >> Some parts of this patch are based on initial original work by >> Mohamed Jamsheeth Hajanajubudeen and Bandaru Venkateswara Swamy >> >> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com> > > Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> > > I assume this will go through IIO tree? Just a couple of comsmetic > comments below, feel free to ignore. Thank you, I modified as you suggested and sent out v7. Jonathan said in an earlier e-mail that he will take them through IIO tree. Waiting on his feedback. Eugen > >> --- >> Changes in v6: >> - changed a dev_err to dev_dbg which was forgotten in v5. >> >> Changes in v5: >> - return error on probe if failed add_action_or_reset >> - renamed property touchscreen-threshold-pressure to >> touchscreen-min-pressure, changed variables accordingly >> >> Changes in v4: >> - added a small description in file header >> - changed MAX_POS_MASK to GRTS_MAX_POS_MASK >> - initialized press with 0, as this value means no touch. >> press has to be initialized because compiler/checkpatch complains >> that can be used uninitialized. >> - changed of_property_read_u32 to device_* >> - set_abs_params for pressure will have range according to threshold >> - changed evbit and keybit with set_capability call >> - changed variable names to error instead of ret >> - checked errors for add_action_or_reset >> - cosmetic cleaning >> >> Changes in v3: >> - pressure now reported naturally growing down-up >> - using helpers from touchscreen.h to parse DT properties >> - added devm_add_action_or_reset to handle callback buffer clean on exit >> - changed compatible and threshold property to adapt to changed bindings >> >> Changes in v2: >> - this is now a generic resistive adc touchscreen driver >> >> >> drivers/input/touchscreen/Kconfig | 13 ++ >> drivers/input/touchscreen/Makefile | 1 + >> drivers/input/touchscreen/resistive-adc-touch.c | 201 ++++++++++++++++++++++++ >> 3 files changed, 215 insertions(+) >> create mode 100644 drivers/input/touchscreen/resistive-adc-touch.c >> >> diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig >> index 4f15496..8f85d3a 100644 >> --- a/drivers/input/touchscreen/Kconfig >> +++ b/drivers/input/touchscreen/Kconfig >> @@ -92,6 +92,19 @@ config TOUCHSCREEN_AD7879_SPI >> To compile this driver as a module, choose M here: the >> module will be called ad7879-spi. >> >> +config TOUCHSCREEN_ADC >> + tristate "Generic ADC based resistive touchscreen" >> + depends on IIO >> + select IIO_BUFFER_CB >> + help >> + Say Y here if you want to use the generic ADC >> + resistive touchscreen driver. >> + >> + If unsure, say N (but it's safe to say "Y"). >> + >> + To compile this driver as a module, choose M here: the >> + module will be called resistive-adc-touch.ko. >> + >> config TOUCHSCREEN_AR1021_I2C >> tristate "Microchip AR1020/1021 i2c touchscreen" >> depends on I2C && OF >> diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile >> index dddae79..843c7f9 100644 >> --- a/drivers/input/touchscreen/Makefile >> +++ b/drivers/input/touchscreen/Makefile >> @@ -13,6 +13,7 @@ obj-$(CONFIG_TOUCHSCREEN_AD7877) += ad7877.o >> obj-$(CONFIG_TOUCHSCREEN_AD7879) += ad7879.o >> obj-$(CONFIG_TOUCHSCREEN_AD7879_I2C) += ad7879-i2c.o >> obj-$(CONFIG_TOUCHSCREEN_AD7879_SPI) += ad7879-spi.o >> +obj-$(CONFIG_TOUCHSCREEN_ADC) += resistive-adc-touch.o >> obj-$(CONFIG_TOUCHSCREEN_ADS7846) += ads7846.o >> obj-$(CONFIG_TOUCHSCREEN_AR1021_I2C) += ar1021_i2c.o >> obj-$(CONFIG_TOUCHSCREEN_ATMEL_MXT) += atmel_mxt_ts.o >> diff --git a/drivers/input/touchscreen/resistive-adc-touch.c b/drivers/input/touchscreen/resistive-adc-touch.c >> new file mode 100644 >> index 0000000..05d629b >> --- /dev/null >> +++ b/drivers/input/touchscreen/resistive-adc-touch.c >> @@ -0,0 +1,201 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * ADC generic resistive touchscreen (GRTS) >> + * This is a generic input driver that connects to an ADC >> + * given the channels in device tree, and reports events to the input >> + * subsystem. >> + * >> + * Copyright (C) 2017,2018 Microchip Technology, >> + * Author: Eugen Hristev <eugen.hristev@microchip.com> >> + * >> + */ >> +#include <linux/input.h> >> +#include <linux/input/touchscreen.h> >> +#include <linux/iio/consumer.h> >> +#include <linux/iio/iio.h> >> +#include <linux/module.h> >> +#include <linux/of.h> >> +#include <linux/of_device.h> >> +#include <linux/platform_device.h> >> + >> +#define DRIVER_NAME "resistive-adc-touch" >> +#define GRTS_DEFAULT_PRESSURE_MIN 50000 >> +#define GRTS_MAX_POS_MASK GENMASK(11, 0) >> + >> +/** >> + * grts_state - generic resistive touch screen information struct >> + * @pressure_min: number representing the minimum for the pressure >> + * @pressure: are we getting pressure info or not >> + * @iio_chans: list of channels acquired >> + * @iio_cb: iio_callback buffer for the data >> + * @input: the input device structure that we register >> + * @prop: touchscreen properties struct >> + */ >> +struct grts_state { >> + u32 pressure_min; >> + bool pressure; >> + struct iio_channel *iio_chans; >> + struct iio_cb_buffer *iio_cb; >> + struct input_dev *input; >> + struct touchscreen_properties prop; >> +}; >> + >> +static int grts_cb(const void *data, void *private) >> +{ >> + const u16 *touch_info = data; >> + struct grts_state *st = private; >> + unsigned int x, y, press = 0x0; >> + >> + /* channel data coming in buffer in the order below */ >> + x = touch_info[0]; >> + y = touch_info[1]; >> + if (st->pressure) >> + press = touch_info[2]; >> + >> + if ((!x && !y) || (st->pressure && (press < st->pressure_min))) { >> + /* report end of touch */ >> + input_report_key(st->input, BTN_TOUCH, 0); >> + input_sync(st->input); >> + return 0; >> + } >> + >> + /* report proper touch to subsystem*/ >> + touchscreen_report_pos(st->input, &st->prop, x, y, false); >> + if (st->pressure) >> + input_report_abs(st->input, ABS_PRESSURE, press); >> + input_report_key(st->input, BTN_TOUCH, 1); >> + input_sync(st->input); >> + >> + return 0; >> +} >> + >> +static int grts_open(struct input_dev *dev) >> +{ >> + int error; >> + struct grts_state *st = input_get_drvdata(dev); >> + >> + error = iio_channel_start_all_cb(st->iio_cb); >> + if (error) { >> + dev_err(dev->dev.parent, "failed to start callback buffer.\n"); >> + return error; >> + } >> + return 0; >> +} >> + >> +static void grts_close(struct input_dev *dev) >> +{ >> + struct grts_state *st = input_get_drvdata(dev); >> + >> + iio_channel_stop_all_cb(st->iio_cb); >> +} >> + >> +static void grts_disable(void *data) >> +{ >> + iio_channel_release_all_cb(data); >> +} >> + >> +static int grts_probe(struct platform_device *pdev) >> +{ >> + struct grts_state *st; >> + struct input_dev *input; >> + struct device *dev = &pdev->dev; >> + struct iio_channel *chan; >> + int error; >> + >> + st = devm_kzalloc(dev, sizeof(struct grts_state), GFP_KERNEL); >> + if (!st) >> + return -ENOMEM; >> + >> + error = device_property_read_u32(dev, "touchscreen-min-pressure", >> + &st->pressure_min); >> + if (error) { >> + dev_dbg(dev, "can't get touchscreen-min-pressure property.\n"); >> + st->pressure_min = GRTS_DEFAULT_PRESSURE_MIN; >> + } > > I do not think it makes sense to complain about missing property if > there is no "pressure" channel. Probably move down? > >> + >> + /* get the channels from IIO device */ >> + st->iio_chans = devm_iio_channel_get_all(dev); >> + if (IS_ERR(st->iio_chans)) { >> + if (PTR_ERR(st->iio_chans) != -EPROBE_DEFER) >> + dev_err(dev, "can't get iio channels.\n"); >> + return PTR_ERR(st->iio_chans); > > error = PTR_ERR(st->iio_chans); > if (error != -EPROBE_DEFER) > dev_err(dev, "can't get iio channels.\n"); > return error; > >> + } >> + >> + chan = &st->iio_chans[0]; >> + st->pressure = false; >> + while (chan && chan->indio_dev) { >> + if (!strcmp(chan->channel->datasheet_name, "pressure")) >> + st->pressure = true; >> + chan++; >> + } >> + >> + input = devm_input_allocate_device(dev); >> + if (!input) { >> + dev_err(dev, "failed to allocate input device.\n"); >> + return -ENOMEM; >> + } >> + >> + input->name = DRIVER_NAME; >> + input->id.bustype = BUS_HOST; >> + input->open = grts_open; >> + input->close = grts_close; >> + >> + input_set_abs_params(input, ABS_X, 0, GRTS_MAX_POS_MASK - 1, 0, 0); >> + input_set_abs_params(input, ABS_Y, 0, GRTS_MAX_POS_MASK - 1, 0, 0); >> + if (st->pressure) >> + input_set_abs_params(input, ABS_PRESSURE, st->pressure_min, >> + 0xffff, 0, 0); >> + >> + input_set_capability(input, EV_KEY, BTN_TOUCH); >> + >> + /* parse optional device tree properties */ >> + touchscreen_parse_properties(input, false, &st->prop); >> + >> + st->input = input; >> + input_set_drvdata(input, st); >> + >> + error = input_register_device(input); >> + if (error) { >> + dev_err(dev, "failed to register input device."); >> + return error; >> + } >> + >> + st->iio_cb = iio_channel_get_all_cb(dev, grts_cb, st); >> + if (IS_ERR(st->iio_cb)) { >> + dev_err(dev, "failed to allocate callback buffer.\n"); >> + error = PTR_ERR(st->iio_cb); >> + return error; > > Simply: > > return PTR_ERR(st->iio_cb); > > since you opted out of printing error codes in error messages. > >> + } >> + >> + error = devm_add_action_or_reset(dev, grts_disable, st->iio_cb); >> + if (error) { >> + dev_err(dev, "failed to add disable action.\n"); >> + return error; >> + } >> + >> + return 0; >> +} >> + >> +static const struct of_device_id grts_of_match[] = { >> + { >> + .compatible = "resistive-adc-touch", >> + }, { >> + /* sentinel */ >> + }, >> +}; >> + >> +MODULE_DEVICE_TABLE(of, grts_of_match); >> + >> +static struct platform_driver grts_driver = { >> + .probe = grts_probe, >> + .driver = { >> + .name = DRIVER_NAME, >> + .of_match_table = of_match_ptr(grts_of_match), >> + }, >> +}; >> + >> +module_platform_driver(grts_driver); >> + >> +MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com>"); >> +MODULE_DESCRIPTION("Generic ADC Resistive Touch Driver"); >> +MODULE_LICENSE("GPL v2"); >> -- >> 2.7.4 >> > > Thanks. > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello, This patch series is a rework of my previous series named: [PATCH 00/14] iio: triggers: add consumer support This is the version 6 of the series, and addresses the received feedback on the v2 series named: [PATCH v2 00/10] Add support for SAMA5D2 touchscreen and the v3 series named [PATCH v3 00/11] Add support for SAMA5D2 touchscreen and the v4 series named [PATCH v4 0/9] Add support for SAMA5D2 touchscreen and fixes one bug found in series named [PATCH v5 0/9] Add support for SAMA5D2 touchscreen This series applies on top of fixes-togreg branch of iio.git, specifically on top of commit: "f0c8d1f" : iio: adc: at91-sama5d2_adc: fix channel configuration for differential channels Jonathan, if you need me to rebase this on top of testing, let me know. Changes in v3, v4, v5 and v6 are presented at the end of the cover letter below. Thanks everyone for the feedback. Below is the original v2 cover letter: In few words, this is the implementation of splitting the functionality of the IP block ADC device in SAMA5D2 SoC from ADC with touchscreen support. In order to avoid having a MFD device, two separate drivers that would work on same register base and split the IRQ,etc, as advised on the mailing list, I created a consumer driver for the channels, that will connect to the ADC as described in the device tree. I have collected feedback from everyone and here is the result: I have added a new generic resistive touchscreen driver, which acts as a iio consumer for the given channels and will create an input device and report the events. It uses a callback buffer to register to the IIO device and waits for data to be pushed. Inside the IIO device, I have kept a similar approach with the first version of the series, except that now the driver can take multiple buffers, and will configure the touchscreen part of the hardware device if the specific channels are requested. The SAMA5D2 ADC driver registers three new channels: two for the position on the X and Y axis, and one for the touch pressure. When channels are requested, it will check if the touchscreen channel mask includes the requested channels (it is possible that the consumer driver will not request pressure for example). If it's the case, it will work in touchscreen mode, and will refuse to do usual analog-digital conversion, because we have a single trigger and the touchscreen needs it. When the scan mask will include only old channels, the driver will function in the same way as before. If the scan mask somehow is a mix of the two (the masks intersect), the driver will refuse to work whatsoever (cannot have both in the same time). The driver allows reading raw data for the new channels, if claim direct mode works: no touchscreen driver requested anything. The new channels can act like the old ones. However, when requesting these channels, the usual trigger will not work and will not be enabled. The touchscreen channels require special trigger and irq configuration: pen detect, no pen detect and a periodic trigger to sample the touchscreen position and pressure. If the user attempts to use another trigger while there is a buffer that already requested the touchscreen channels (thus the trigger), the driver will refuse to comply. In order to have defines for the channel numbers, I added a bindings include file that goes on a separate commit : dt-bindings: iio: adc: at91-sama5d2_adc: add channel specific consumer info This should go in the same tree with the following commits : ARM: dts: at91: sama5d2: add channel cells for ADC device ARM: dts: at91: sama5d2: Add resistive touch device as build will break because these commits depend on the binding one which creates the included header file. V5 update: After discussing with Alexandre Belloni on Mailing list, the two DTS patches are to be taken in the next version after bindings reach mainline. Changes in v6: - Fixed a crash in ADC driver , explained in driver patch changelog. - changed a dev_err to dev_dbg in input driver. - added Reviewed-by Rob Herring. Changes in v5: - renamed property touchscreen-threshold-pressure to touchscreen-min-pressure - added one return in touchscreen driver Changes in v4: - removed patch for inkern module get/set kref - addressed feedback on both the ADC and the touchscreen driver. each patch has a history inside the patch file for the specific changes. - patch that fixes the channel fix [PATCH v3 01/11] iio: adc: at91-sama5d2_adc: fix channel configuration for differential channels was accepted in fixes-togreg branch thus removed from this series. - added Reviewed-by for the bindings by Rob Herring Changes in v3: - changed input driver name according to feedback and reworked in commits to adapt to binding changes and new name. - moved channel index fix in at91-sama5d2_adc at the beginning of the series (PATCH 01/11) - created a new optional binding for the touchscreen as a separate commit and added it to the series : [PATCH v3 04/11] dt-bindings: input: touchscreen: add pressure threshold touchscreen property - changed at91-sama5d2_adc driver patch to address the comments. Exact changes are in the patch file for the driver source file. Eugen Hristev (9): MAINTAINERS: add generic resistive touchscreen adc iio: Add channel for Position Relative dt-bindings: input: touchscreen: add minimum pressure touchscreen property dt-bindings: input: touchscreen: resistive-adc-touch: create bindings iio: adc: at91-sama5d2_adc: add support for position and pressure channels input: touchscreen: resistive-adc-touch: add generic resistive ADC touchscreen dt-bindings: iio: adc: at91-sama5d2_adc: add channel specific consumer info ARM: dts: at91: sama5d2: add channel cells for ADC device ARM: dts: at91: sama5d2: Add resistive touch device Documentation/ABI/testing/sysfs-bus-iio | 12 + .../bindings/iio/adc/at91-sama5d2_adc.txt | 9 + .../input/touchscreen/resistive-adc-touch.txt | 30 + .../bindings/input/touchscreen/touchscreen.txt | 3 + MAINTAINERS | 6 + arch/arm/boot/dts/sama5d2.dtsi | 12 + drivers/iio/adc/at91-sama5d2_adc.c | 609 +++++++++++++++++++-- drivers/iio/industrialio-core.c | 1 + drivers/input/touchscreen/Kconfig | 13 + drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/resistive-adc-touch.c | 201 +++++++ include/dt-bindings/iio/adc/at91-sama5d2_adc.h | 16 + include/uapi/linux/iio/types.h | 1 + tools/iio/iio_event_monitor.c | 2 + 14 files changed, 858 insertions(+), 58 deletions(-) create mode 100644 Documentation/devicetree/bindings/input/touchscreen/resistive-adc-touch.txt create mode 100644 drivers/input/touchscreen/resistive-adc-touch.c create mode 100644 include/dt-bindings/iio/adc/at91-sama5d2_adc.h