| Message ID | bb234514d6921c3d184930d78e7822381c481b79.1438763030.git.maitysanchayan@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Sanchayan, On Wed, Aug 05, 2015 at 02:25:51PM +0530, Sanchayan Maity wrote: > The Colibri Vybrid VF50 module supports 4-wire touchscreens using > FETs and ADC inputs. This driver uses the IIO consumer interface > and relies on the vf610_adc driver based on the IIO framework. > > Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com> > --- > drivers/input/touchscreen/Kconfig | 12 + > drivers/input/touchscreen/Makefile | 1 + > drivers/input/touchscreen/colibri-vf50-ts.c | 404 ++++++++++++++++++++++++++++ > 3 files changed, 417 insertions(+) > create mode 100644 drivers/input/touchscreen/colibri-vf50-ts.c > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > index 80f6386..28948ca 100644 > --- a/drivers/input/touchscreen/Kconfig > +++ b/drivers/input/touchscreen/Kconfig > @@ -1027,4 +1027,16 @@ config TOUCHSCREEN_ZFORCE > To compile this driver as a module, choose M here: the > module will be called zforce_ts. > > +config TOUCHSCREEN_COLIBRI_VF50 > + tristate "Toradex Colibri on board touchscreen driver" > + depends on GPIOLIB && IIO && VF610_ADC > + help > + Say Y here if you have a Colibri VF50 and plan to use > + the on-board provided 4-wire touchscreen driver. > + > + If unsure, say N. > + > + To compile this driver as a module, choose M here: the > + module will be called colibri_vf50_ts. > + > endif > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > index 44deea7..93746a0 100644 > --- a/drivers/input/touchscreen/Makefile > +++ b/drivers/input/touchscreen/Makefile > @@ -84,3 +84,4 @@ obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o > obj-$(CONFIG_TOUCHSCREEN_SX8654) += sx8654.o > obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o > obj-$(CONFIG_TOUCHSCREEN_ZFORCE) += zforce_ts.o > +obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o > diff --git a/drivers/input/touchscreen/colibri-vf50-ts.c b/drivers/input/touchscreen/colibri-vf50-ts.c > new file mode 100644 > index 0000000..d7bc91a > --- /dev/null > +++ b/drivers/input/touchscreen/colibri-vf50-ts.c > @@ -0,0 +1,404 @@ > +/* Copyright 2015 Toradex AG > + * > + * Toradex Colibri VF50 Touchscreen driver > + * > + * Originally authored by Stefan Agner for 3.0 kernel > + * > + * 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/delay.h> > +#include <linux/err.h> > +#include <linux/gpio.h> > +#include <linux/iio/consumer.h> > +#include <linux/iio/types.h> > +#include <linux/input.h> > +#include <linux/interrupt.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/pinctrl/consumer.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > +#include <linux/types.h> > + > +#define DRIVER_NAME "colibri-vf50-ts" > +#define DRV_VERSION "1.0" > + > +#define VF_ADC_MAX ((1 << 12) - 1) > + > +#define COLI_TOUCH_MIN_DELAY_US 1000 > +#define COLI_TOUCH_MAX_DELAY_US 2000 > + > +static int min_pressure = 200; > + > +struct vf50_touch_device { > + struct platform_device *pdev; > + struct input_dev *ts_input; > + struct iio_channel *channels; > + struct gpio_desc *gpio_xp; > + struct gpio_desc *gpio_xm; > + struct gpio_desc *gpio_yp; > + struct gpio_desc *gpio_ym; > + struct gpio_desc *gpio_pen_detect; > + int pen_irq; > + bool stop_touchscreen; > +}; > + > +/* > + * Enables given plates and measures touch parameters using ADC > + */ > +static int adc_ts_measure(struct iio_channel *channel, > + struct gpio_desc *plate_p, struct gpio_desc *plate_m) > +{ > + int i, value = 0, val = 0; > + int ret; > + > + gpiod_set_value(plate_p, 1); > + gpiod_set_value(plate_m, 1); > + > + usleep_range(COLI_TOUCH_MIN_DELAY_US, COLI_TOUCH_MAX_DELAY_US); > + > + for (i = 0; i < 5; i++) { Can we have a #define for 5? > + ret = iio_read_channel_raw(channel, &val); > + if (ret < 0) { > + value = ret; > + goto error_iio_read; > + } > + > + value += val; > + } > + > + value /= 5; > + > +error_iio_read: > + gpiod_set_value(plate_p, 0); > + gpiod_set_value(plate_m, 0); > + > + return value; > +} > + > +/* > + * Enable touch detection using falling edge detection on XM > + */ > +static void vf50_ts_enable_touch_detection(struct vf50_touch_device *vf50_ts) > +{ > + /* Enable plate YM (needs to be strong GND, high active) */ > + gpiod_set_value(vf50_ts->gpio_ym, 1); > + > + /* > + * Let the platform mux to idle state in order to enable > + * Pull-Up on GPIO > + */ > + pinctrl_pm_select_idle_state(&vf50_ts->pdev->dev); > +} > + > +/* > + * ADC touch screen sampling bottom half irq handler > + */ > +static irqreturn_t vf50_ts_irq_bh(int irq, void *private) > +{ > + struct vf50_touch_device *vf50_ts = (struct vf50_touch_device *)private; > + struct device *dev = &vf50_ts->pdev->dev; > + int val_x, val_y, val_z1, val_z2, val_p = 0; > + bool discard_val_on_start = true; > + > + /* Disable the touch detection plates */ > + gpiod_set_value(vf50_ts->gpio_ym, 0); > + > + /* Let the platform mux to default state in order to mux as ADC */ > + pinctrl_pm_select_default_state(dev); > + > + while (!vf50_ts->stop_touchscreen) { > + /* X-Direction */ > + val_x = adc_ts_measure(&vf50_ts->channels[0], > + vf50_ts->gpio_xp, vf50_ts->gpio_xm); > + if (val_x < 0) > + break; > + > + /* Y-Direction */ > + val_y = adc_ts_measure(&vf50_ts->channels[1], > + vf50_ts->gpio_yp, vf50_ts->gpio_ym); > + if (val_y < 0) > + break; > + > + /* > + * Touch pressure > + * Measure on XP/YM > + */ > + val_z1 = adc_ts_measure(&vf50_ts->channels[2], > + vf50_ts->gpio_yp, vf50_ts->gpio_xm); > + if (val_z1 < 0) > + break; > + val_z2 = adc_ts_measure(&vf50_ts->channels[3], > + vf50_ts->gpio_yp, vf50_ts->gpio_xm); > + if (val_z2 < 0) > + break; > + > + /* Validate signal (avoid calculation using noise) */ > + if (val_z1 > 64 && val_x > 64) { > + /* > + * Calculate resistance between the plates > + * lower resistance means higher pressure > + */ > + int r_x = (1000 * val_x) / VF_ADC_MAX; > + > + val_p = (r_x * val_z2) / val_z1 - r_x; > + > + } else { > + val_p = 2000; > + } > + > + val_p = 2000 - val_p; > + dev_dbg(dev, "Measured values: x: %d, y: %d, z1: %d, z2: %d, " > + "p: %d\n", val_x, val_y, val_z1, val_z2, val_p); > + > + /* > + * If touch pressure is too low, stop measuring and reenable > + * touch detection > + */ > + if (val_p < min_pressure || val_p > 2000) > + break; > + > + /* > + * The pressure may not be enough for the first x and the > + * second y measurement, but, the pressure is ok when the > + * driver is doing the third and fourth measurement. To > + * take care of this, we drop the first measurement always. > + */ > + if (discard_val_on_start) { > + discard_val_on_start = false; > + } else { > + /* > + * Report touch position and sleep for > + * next measurement > + */ > + input_report_abs(vf50_ts->ts_input, > + ABS_X, VF_ADC_MAX - val_x); > + input_report_abs(vf50_ts->ts_input, > + ABS_Y, VF_ADC_MAX - val_y); > + input_report_abs(vf50_ts->ts_input, > + ABS_PRESSURE, val_p); > + input_report_key(vf50_ts->ts_input, BTN_TOUCH, 1); > + input_sync(vf50_ts->ts_input); > + } > + > + msleep(10); > + } > + > + /* Report no more touch, reenable touch detection */ > + input_report_abs(vf50_ts->ts_input, ABS_PRESSURE, 0); > + input_report_key(vf50_ts->ts_input, BTN_TOUCH, 0); > + input_sync(vf50_ts->ts_input); > + > + vf50_ts_enable_touch_detection(vf50_ts); > + > + /* Wait for the pull-up to be stable on high */ > + msleep(10); > + > + return IRQ_HANDLED; > +} > + > +static int vf50_ts_open(struct input_dev *dev_input) > +{ > + int ret; > + struct vf50_touch_device *touchdev = input_get_drvdata(dev_input); > + struct device *dev = &touchdev->pdev->dev; > + > + dev_dbg(dev, "Input device %s opened, starting touch detection\n", > + dev_input->name); > + > + touchdev->stop_touchscreen = false; > + > + ret = gpiod_direction_output(touchdev->gpio_xp, 0); > + if (ret) { > + dev_err(dev, "Could not set gpio xp as output %d\n", ret); > + return ret; > + } > + > + ret = gpiod_direction_output(touchdev->gpio_xm, 0); > + if (ret) { > + dev_err(dev, "Could not set gpio xm as output %d\n", ret); > + return ret; > + } > + > + ret = gpiod_direction_output(touchdev->gpio_yp, 0); > + if (ret) { > + dev_err(dev, "Could not set gpio yp as output %d\n", ret); > + return ret; > + } > + > + ret = gpiod_direction_output(touchdev->gpio_ym, 0); > + if (ret) { > + dev_err(dev, "Could not set gpio ym as output %d\n", ret); > + return ret; > + } > + > + ret = gpiod_direction_input(touchdev->gpio_pen_detect); > + if (ret) { > + dev_err(dev, > + "Could not set gpio pen detect as input %d\n", ret); > + return ret; > + } Why do we do this on every open? You can configure gpios as you request them. > + > + /* Mux detection before request IRQ, wait for pull-up to settle */ > + vf50_ts_enable_touch_detection(touchdev); > + msleep(10); > + > + return 0; > +} > + > +static void vf50_ts_close(struct input_dev *dev_input) > +{ > + struct vf50_touch_device *touchdev = input_get_drvdata(dev_input); > + struct device *dev = &touchdev->pdev->dev; > + > + touchdev->stop_touchscreen = true; I think you also need: mb(); synchronize_irq(touchdev->irq); to make sure interrupt routine is not running past close. > + > + dev_dbg(dev, "Input device %s closed, disable touch detection\n", > + dev_input->name); > +} > + > +static inline int vf50_ts_get_gpiod(struct device *dev, Drop inline, let compiler decide whether it should be inlined or not. > + struct gpio_desc **gpio_d, const char *con_id) > +{ > + int ret; Personal preference: call this variable "error". > + > + *gpio_d = devm_gpiod_get(dev, con_id); I think you need use GPIOD_OUT_LOW (assuming you do not use the function for pen detect gpio, see below). > + if (IS_ERR(*gpio_d)) { > + ret = PTR_ERR(*gpio_d); > + dev_err(dev, "Could not get gpio_%s %d\n", con_id, ret); > + return ret; > + } > + > + return 0; > +} > + > +static int vf50_ts_probe(struct platform_device *pdev) > +{ > + struct input_dev *input; > + struct iio_channel *channels; > + struct device *dev = &pdev->dev; > + struct vf50_touch_device *touchdev; > + int ret; Personal preference: call this variable "error". > + > + channels = iio_channel_get_all(dev); > + if (IS_ERR(channels)) > + return PTR_ERR(channels); Please either introduce devm_iio_channel_get_all() or install iio_channel_release_all as a custom devm action (devm_add_action). > + > + touchdev = devm_kzalloc(dev, sizeof(*touchdev), GFP_KERNEL); > + if (touchdev == NULL) { if (!touchdev) please. > + ret = -ENOMEM; > + goto error_release_channels; > + } > + > + input = devm_input_allocate_device(dev); > + if (!input) { > + dev_err(dev, "Failed to allocate TS input device\n"); > + ret = -ENOMEM; > + goto error_release_channels; > + } > + > + platform_set_drvdata(pdev, touchdev); > + > + touchdev->pdev = pdev; > + touchdev->channels = channels; > + > + input->name = DRIVER_NAME; > + input->id.bustype = BUS_HOST; > + input->dev.parent = dev; > + input->open = vf50_ts_open; > + input->close = vf50_ts_close; > + > + _set_bit(EV_ABS, input->evbit); > + _set_bit(EV_KEY, input->evbit); > + _set_bit(BTN_TOUCH, input->keybit); input_set_capability(dev, EV_KEY, BTN_TOUCH); and kill _set_bit()s above. > + input_set_abs_params(input, ABS_X, 0, VF_ADC_MAX, 0, 0); > + input_set_abs_params(input, ABS_Y, 0, VF_ADC_MAX, 0, 0); > + input_set_abs_params(input, ABS_PRESSURE, 0, VF_ADC_MAX, 0, 0); > + > + touchdev->ts_input = input; > + input_set_drvdata(input, touchdev); > + ret = input_register_device(input); > + if (ret) { > + dev_err(dev, "Failed to register input device\n"); > + goto error_release_channels; > + } > + > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_xp, "xp"); > + if (ret) > + goto error_release_channels; > + > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_xm, "xm"); > + if (ret) > + goto error_release_channels; > + > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_yp, "yp"); > + if (ret) > + goto error_release_channels; > + > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_ym, "ym"); > + if (ret) > + goto error_release_channels; > + > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_pen_detect, > + "pen-detect"); > + if (ret) > + goto error_release_channels; > + > + touchdev->pen_irq = gpiod_to_irq(touchdev->gpio_pen_detect); > + if (touchdev->pen_irq < 0) { > + ret = touchdev->pen_irq; > + dev_err(dev, "Unable to get IRQ for GPIO\n"); > + goto error_release_channels; > + } I do not think you need to specify this as gpio, since you are not reading it's state. Map it using "interrupts" property instead and do touchdev->pen_irq = platform_get_irq(pdev, 0); > + > + ret = devm_request_threaded_irq(dev, touchdev->pen_irq, NULL, > + vf50_ts_irq_bh, IRQF_TRIGGER_LOW | IRQF_ONESHOT, Just use IRQF_ONESHOT here, rely on the platform/OF to read and set up the trigger properly (via "interrupts" property). > + "vf50 touch", touchdev); > + if (ret < 0) { > + dev_err(dev, "Unable to request IRQ %d\n", touchdev->pen_irq); > + goto error_release_channels; > + } > + > + return 0; > + > +error_release_channels: > + iio_channel_release_all(channels); > + return ret; > +} > + > +static int vf50_ts_remove(struct platform_device *pdev) > +{ > + struct vf50_touch_device *touchdev = platform_get_drvdata(pdev); > + > + iio_channel_release_all(touchdev->channels); This is wrong order, I do not think you want to release channels while your interrupt routine still running. With custom devm action you can avoid this and also remove whole vf50_ts_remove. > + > + return 0; > +} > + > +static const struct of_device_id vf50_touch_of_match[] = { > + { .compatible = "toradex,vf50-touchscreen", }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, vf50_touch_of_match); > + > +static struct platform_driver vf50_touch_driver = { > + .driver = { > + .name = "toradex,vf50_touchctrl", > + .of_match_table = vf50_touch_of_match, > + }, > + .probe = vf50_ts_probe, > + .remove = vf50_ts_remove, > +}; > + > +module_platform_driver(vf50_touch_driver); > + > +module_param(min_pressure, int, 0600); > +MODULE_PARM_DESC(min_pressure, "Minimum pressure for touch detection"); Since it is my understanding this is not user preference but rather property of device, I'd rather this been part of DT binding. > +MODULE_AUTHOR("Sanchayan Maity"); > +MODULE_DESCRIPTION("Colibri VF50 Touchscreen driver"); > +MODULE_LICENSE("GPL v2"); > +MODULE_VERSION(DRV_VERSION); > -- > 2.5.0 > Thanks.
Hello Dmitry, Will take care of all points with the next revision. Thank you for the feedback. - Sanchayan. On 15-08-14 15:53:46, Dmitry Torokhov wrote: > Hi Sanchayan, > > On Wed, Aug 05, 2015 at 02:25:51PM +0530, Sanchayan Maity wrote: > > The Colibri Vybrid VF50 module supports 4-wire touchscreens using > > FETs and ADC inputs. This driver uses the IIO consumer interface > > and relies on the vf610_adc driver based on the IIO framework. > > > > Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com> > > --- > > drivers/input/touchscreen/Kconfig | 12 + > > drivers/input/touchscreen/Makefile | 1 + > > drivers/input/touchscreen/colibri-vf50-ts.c | 404 ++++++++++++++++++++++++++++ > > 3 files changed, 417 insertions(+) > > create mode 100644 drivers/input/touchscreen/colibri-vf50-ts.c > > > > diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig > > index 80f6386..28948ca 100644 > > --- a/drivers/input/touchscreen/Kconfig > > +++ b/drivers/input/touchscreen/Kconfig > > @@ -1027,4 +1027,16 @@ config TOUCHSCREEN_ZFORCE > > To compile this driver as a module, choose M here: the > > module will be called zforce_ts. > > > > +config TOUCHSCREEN_COLIBRI_VF50 > > + tristate "Toradex Colibri on board touchscreen driver" > > + depends on GPIOLIB && IIO && VF610_ADC > > + help > > + Say Y here if you have a Colibri VF50 and plan to use > > + the on-board provided 4-wire touchscreen driver. > > + > > + If unsure, say N. > > + > > + To compile this driver as a module, choose M here: the > > + module will be called colibri_vf50_ts. > > + > > endif > > diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile > > index 44deea7..93746a0 100644 > > --- a/drivers/input/touchscreen/Makefile > > +++ b/drivers/input/touchscreen/Makefile > > @@ -84,3 +84,4 @@ obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o > > obj-$(CONFIG_TOUCHSCREEN_SX8654) += sx8654.o > > obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o > > obj-$(CONFIG_TOUCHSCREEN_ZFORCE) += zforce_ts.o > > +obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o > > diff --git a/drivers/input/touchscreen/colibri-vf50-ts.c b/drivers/input/touchscreen/colibri-vf50-ts.c > > new file mode 100644 > > index 0000000..d7bc91a > > --- /dev/null > > +++ b/drivers/input/touchscreen/colibri-vf50-ts.c > > @@ -0,0 +1,404 @@ > > +/* Copyright 2015 Toradex AG > > + * > > + * Toradex Colibri VF50 Touchscreen driver > > + * > > + * Originally authored by Stefan Agner for 3.0 kernel > > + * > > + * 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/delay.h> > > +#include <linux/err.h> > > +#include <linux/gpio.h> > > +#include <linux/iio/consumer.h> > > +#include <linux/iio/types.h> > > +#include <linux/input.h> > > +#include <linux/interrupt.h> > > +#include <linux/kernel.h> > > +#include <linux/module.h> > > +#include <linux/pinctrl/consumer.h> > > +#include <linux/platform_device.h> > > +#include <linux/slab.h> > > +#include <linux/types.h> > > + > > +#define DRIVER_NAME "colibri-vf50-ts" > > +#define DRV_VERSION "1.0" > > + > > +#define VF_ADC_MAX ((1 << 12) - 1) > > + > > +#define COLI_TOUCH_MIN_DELAY_US 1000 > > +#define COLI_TOUCH_MAX_DELAY_US 2000 > > + > > +static int min_pressure = 200; > > + > > +struct vf50_touch_device { > > + struct platform_device *pdev; > > + struct input_dev *ts_input; > > + struct iio_channel *channels; > > + struct gpio_desc *gpio_xp; > > + struct gpio_desc *gpio_xm; > > + struct gpio_desc *gpio_yp; > > + struct gpio_desc *gpio_ym; > > + struct gpio_desc *gpio_pen_detect; > > + int pen_irq; > > + bool stop_touchscreen; > > +}; > > + > > +/* > > + * Enables given plates and measures touch parameters using ADC > > + */ > > +static int adc_ts_measure(struct iio_channel *channel, > > + struct gpio_desc *plate_p, struct gpio_desc *plate_m) > > +{ > > + int i, value = 0, val = 0; > > + int ret; > > + > > + gpiod_set_value(plate_p, 1); > > + gpiod_set_value(plate_m, 1); > > + > > + usleep_range(COLI_TOUCH_MIN_DELAY_US, COLI_TOUCH_MAX_DELAY_US); > > + > > + for (i = 0; i < 5; i++) { > > Can we have a #define for 5? > > > + ret = iio_read_channel_raw(channel, &val); > > + if (ret < 0) { > > + value = ret; > > + goto error_iio_read; > > + } > > + > > + value += val; > > + } > > + > > + value /= 5; > > + > > +error_iio_read: > > + gpiod_set_value(plate_p, 0); > > + gpiod_set_value(plate_m, 0); > > + > > + return value; > > +} > > + > > +/* > > + * Enable touch detection using falling edge detection on XM > > + */ > > +static void vf50_ts_enable_touch_detection(struct vf50_touch_device *vf50_ts) > > +{ > > + /* Enable plate YM (needs to be strong GND, high active) */ > > + gpiod_set_value(vf50_ts->gpio_ym, 1); > > + > > + /* > > + * Let the platform mux to idle state in order to enable > > + * Pull-Up on GPIO > > + */ > > + pinctrl_pm_select_idle_state(&vf50_ts->pdev->dev); > > +} > > + > > +/* > > + * ADC touch screen sampling bottom half irq handler > > + */ > > +static irqreturn_t vf50_ts_irq_bh(int irq, void *private) > > +{ > > + struct vf50_touch_device *vf50_ts = (struct vf50_touch_device *)private; > > + struct device *dev = &vf50_ts->pdev->dev; > > + int val_x, val_y, val_z1, val_z2, val_p = 0; > > + bool discard_val_on_start = true; > > + > > + /* Disable the touch detection plates */ > > + gpiod_set_value(vf50_ts->gpio_ym, 0); > > + > > + /* Let the platform mux to default state in order to mux as ADC */ > > + pinctrl_pm_select_default_state(dev); > > + > > + while (!vf50_ts->stop_touchscreen) { > > + /* X-Direction */ > > + val_x = adc_ts_measure(&vf50_ts->channels[0], > > + vf50_ts->gpio_xp, vf50_ts->gpio_xm); > > + if (val_x < 0) > > + break; > > + > > + /* Y-Direction */ > > + val_y = adc_ts_measure(&vf50_ts->channels[1], > > + vf50_ts->gpio_yp, vf50_ts->gpio_ym); > > + if (val_y < 0) > > + break; > > + > > + /* > > + * Touch pressure > > + * Measure on XP/YM > > + */ > > + val_z1 = adc_ts_measure(&vf50_ts->channels[2], > > + vf50_ts->gpio_yp, vf50_ts->gpio_xm); > > + if (val_z1 < 0) > > + break; > > + val_z2 = adc_ts_measure(&vf50_ts->channels[3], > > + vf50_ts->gpio_yp, vf50_ts->gpio_xm); > > + if (val_z2 < 0) > > + break; > > + > > + /* Validate signal (avoid calculation using noise) */ > > + if (val_z1 > 64 && val_x > 64) { > > + /* > > + * Calculate resistance between the plates > > + * lower resistance means higher pressure > > + */ > > + int r_x = (1000 * val_x) / VF_ADC_MAX; > > + > > + val_p = (r_x * val_z2) / val_z1 - r_x; > > + > > + } else { > > + val_p = 2000; > > + } > > + > > + val_p = 2000 - val_p; > > + dev_dbg(dev, "Measured values: x: %d, y: %d, z1: %d, z2: %d, " > > + "p: %d\n", val_x, val_y, val_z1, val_z2, val_p); > > + > > + /* > > + * If touch pressure is too low, stop measuring and reenable > > + * touch detection > > + */ > > + if (val_p < min_pressure || val_p > 2000) > > + break; > > + > > + /* > > + * The pressure may not be enough for the first x and the > > + * second y measurement, but, the pressure is ok when the > > + * driver is doing the third and fourth measurement. To > > + * take care of this, we drop the first measurement always. > > + */ > > + if (discard_val_on_start) { > > + discard_val_on_start = false; > > + } else { > > + /* > > + * Report touch position and sleep for > > + * next measurement > > + */ > > + input_report_abs(vf50_ts->ts_input, > > + ABS_X, VF_ADC_MAX - val_x); > > + input_report_abs(vf50_ts->ts_input, > > + ABS_Y, VF_ADC_MAX - val_y); > > + input_report_abs(vf50_ts->ts_input, > > + ABS_PRESSURE, val_p); > > + input_report_key(vf50_ts->ts_input, BTN_TOUCH, 1); > > + input_sync(vf50_ts->ts_input); > > + } > > + > > + msleep(10); > > + } > > + > > + /* Report no more touch, reenable touch detection */ > > + input_report_abs(vf50_ts->ts_input, ABS_PRESSURE, 0); > > + input_report_key(vf50_ts->ts_input, BTN_TOUCH, 0); > > + input_sync(vf50_ts->ts_input); > > + > > + vf50_ts_enable_touch_detection(vf50_ts); > > + > > + /* Wait for the pull-up to be stable on high */ > > + msleep(10); > > + > > + return IRQ_HANDLED; > > +} > > + > > +static int vf50_ts_open(struct input_dev *dev_input) > > +{ > > + int ret; > > + struct vf50_touch_device *touchdev = input_get_drvdata(dev_input); > > + struct device *dev = &touchdev->pdev->dev; > > + > > + dev_dbg(dev, "Input device %s opened, starting touch detection\n", > > + dev_input->name); > > + > > + touchdev->stop_touchscreen = false; > > + > > + ret = gpiod_direction_output(touchdev->gpio_xp, 0); > > + if (ret) { > > + dev_err(dev, "Could not set gpio xp as output %d\n", ret); > > + return ret; > > + } > > + > > + ret = gpiod_direction_output(touchdev->gpio_xm, 0); > > + if (ret) { > > + dev_err(dev, "Could not set gpio xm as output %d\n", ret); > > + return ret; > > + } > > + > > + ret = gpiod_direction_output(touchdev->gpio_yp, 0); > > + if (ret) { > > + dev_err(dev, "Could not set gpio yp as output %d\n", ret); > > + return ret; > > + } > > + > > + ret = gpiod_direction_output(touchdev->gpio_ym, 0); > > + if (ret) { > > + dev_err(dev, "Could not set gpio ym as output %d\n", ret); > > + return ret; > > + } > > + > > + ret = gpiod_direction_input(touchdev->gpio_pen_detect); > > + if (ret) { > > + dev_err(dev, > > + "Could not set gpio pen detect as input %d\n", ret); > > + return ret; > > + } > > Why do we do this on every open? You can configure gpios as you request > them. > > > + > > + /* Mux detection before request IRQ, wait for pull-up to settle */ > > + vf50_ts_enable_touch_detection(touchdev); > > + msleep(10); > > + > > + return 0; > > +} > > + > > +static void vf50_ts_close(struct input_dev *dev_input) > > +{ > > + struct vf50_touch_device *touchdev = input_get_drvdata(dev_input); > > + struct device *dev = &touchdev->pdev->dev; > > + > > + touchdev->stop_touchscreen = true; > > I think you also need: > > mb(); > synchronize_irq(touchdev->irq); > > to make sure interrupt routine is not running past close. > > > + > > + dev_dbg(dev, "Input device %s closed, disable touch detection\n", > > + dev_input->name); > > +} > > + > > +static inline int vf50_ts_get_gpiod(struct device *dev, > > Drop inline, let compiler decide whether it should be inlined or not. > > > + struct gpio_desc **gpio_d, const char *con_id) > > +{ > > + int ret; > > Personal preference: call this variable "error". > > > + > > + *gpio_d = devm_gpiod_get(dev, con_id); > > I think you need use GPIOD_OUT_LOW (assuming you do not use the function > for pen detect gpio, see below). > > > + if (IS_ERR(*gpio_d)) { > > + ret = PTR_ERR(*gpio_d); > > + dev_err(dev, "Could not get gpio_%s %d\n", con_id, ret); > > + return ret; > > + } > > + > > + return 0; > > +} > > + > > +static int vf50_ts_probe(struct platform_device *pdev) > > +{ > > + struct input_dev *input; > > + struct iio_channel *channels; > > + struct device *dev = &pdev->dev; > > + struct vf50_touch_device *touchdev; > > + int ret; > > Personal preference: call this variable "error". > > > > + > > + channels = iio_channel_get_all(dev); > > + if (IS_ERR(channels)) > > + return PTR_ERR(channels); > > > Please either introduce devm_iio_channel_get_all() or install > iio_channel_release_all as a custom devm action (devm_add_action). > > > + > > + touchdev = devm_kzalloc(dev, sizeof(*touchdev), GFP_KERNEL); > > + if (touchdev == NULL) { > > if (!touchdev) > > please. > > > + ret = -ENOMEM; > > + goto error_release_channels; > > + } > > + > > + input = devm_input_allocate_device(dev); > > + if (!input) { > > + dev_err(dev, "Failed to allocate TS input device\n"); > > + ret = -ENOMEM; > > + goto error_release_channels; > > + } > > + > > + platform_set_drvdata(pdev, touchdev); > > + > > + touchdev->pdev = pdev; > > + touchdev->channels = channels; > > + > > + input->name = DRIVER_NAME; > > + input->id.bustype = BUS_HOST; > > + input->dev.parent = dev; > > + input->open = vf50_ts_open; > > + input->close = vf50_ts_close; > > + > > + _set_bit(EV_ABS, input->evbit); > > + _set_bit(EV_KEY, input->evbit); > > + _set_bit(BTN_TOUCH, input->keybit); > > input_set_capability(dev, EV_KEY, BTN_TOUCH); > > and kill _set_bit()s above. > > > + input_set_abs_params(input, ABS_X, 0, VF_ADC_MAX, 0, 0); > > + input_set_abs_params(input, ABS_Y, 0, VF_ADC_MAX, 0, 0); > > + input_set_abs_params(input, ABS_PRESSURE, 0, VF_ADC_MAX, 0, 0); > > + > > + touchdev->ts_input = input; > > + input_set_drvdata(input, touchdev); > > + ret = input_register_device(input); > > + if (ret) { > > + dev_err(dev, "Failed to register input device\n"); > > + goto error_release_channels; > > + } > > + > > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_xp, "xp"); > > + if (ret) > > + goto error_release_channels; > > + > > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_xm, "xm"); > > + if (ret) > > + goto error_release_channels; > > + > > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_yp, "yp"); > > + if (ret) > > + goto error_release_channels; > > + > > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_ym, "ym"); > > + if (ret) > > + goto error_release_channels; > > + > > + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_pen_detect, > > + "pen-detect"); > > + if (ret) > > + goto error_release_channels; > > + > > + touchdev->pen_irq = gpiod_to_irq(touchdev->gpio_pen_detect); > > + if (touchdev->pen_irq < 0) { > > + ret = touchdev->pen_irq; > > + dev_err(dev, "Unable to get IRQ for GPIO\n"); > > + goto error_release_channels; > > + } > > I do not think you need to specify this as gpio, since you are not > reading it's state. Map it using "interrupts" property instead and do > > touchdev->pen_irq = platform_get_irq(pdev, 0); > > > + > > + ret = devm_request_threaded_irq(dev, touchdev->pen_irq, NULL, > > + vf50_ts_irq_bh, IRQF_TRIGGER_LOW | IRQF_ONESHOT, > > Just use IRQF_ONESHOT here, rely on the platform/OF to read and set up > the trigger properly (via "interrupts" property). > > > + "vf50 touch", touchdev); > > + if (ret < 0) { > > + dev_err(dev, "Unable to request IRQ %d\n", touchdev->pen_irq); > > + goto error_release_channels; > > + } > > + > > + return 0; > > + > > +error_release_channels: > > + iio_channel_release_all(channels); > > + return ret; > > +} > > + > > +static int vf50_ts_remove(struct platform_device *pdev) > > +{ > > + struct vf50_touch_device *touchdev = platform_get_drvdata(pdev); > > + > > + iio_channel_release_all(touchdev->channels); > > This is wrong order, I do not think you want to release channels while > your interrupt routine still running. With custom devm action you can > avoid this and also remove whole vf50_ts_remove. > > > + > > + return 0; > > +} > > + > > +static const struct of_device_id vf50_touch_of_match[] = { > > + { .compatible = "toradex,vf50-touchscreen", }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, vf50_touch_of_match); > > + > > +static struct platform_driver vf50_touch_driver = { > > + .driver = { > > + .name = "toradex,vf50_touchctrl", > > + .of_match_table = vf50_touch_of_match, > > + }, > > + .probe = vf50_ts_probe, > > + .remove = vf50_ts_remove, > > +}; > > + > > +module_platform_driver(vf50_touch_driver); > > + > > +module_param(min_pressure, int, 0600); > > +MODULE_PARM_DESC(min_pressure, "Minimum pressure for touch detection"); > > Since it is my understanding this is not user preference but rather > property of device, I'd rather this been part of DT binding. > > > +MODULE_AUTHOR("Sanchayan Maity"); > > +MODULE_DESCRIPTION("Colibri VF50 Touchscreen driver"); > > +MODULE_LICENSE("GPL v2"); > > +MODULE_VERSION(DRV_VERSION); > > -- > > 2.5.0 > > > > Thanks. > > -- > Dmitry
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig index 80f6386..28948ca 100644 --- a/drivers/input/touchscreen/Kconfig +++ b/drivers/input/touchscreen/Kconfig @@ -1027,4 +1027,16 @@ config TOUCHSCREEN_ZFORCE To compile this driver as a module, choose M here: the module will be called zforce_ts. +config TOUCHSCREEN_COLIBRI_VF50 + tristate "Toradex Colibri on board touchscreen driver" + depends on GPIOLIB && IIO && VF610_ADC + help + Say Y here if you have a Colibri VF50 and plan to use + the on-board provided 4-wire touchscreen driver. + + If unsure, say N. + + To compile this driver as a module, choose M here: the + module will be called colibri_vf50_ts. + endif diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile index 44deea7..93746a0 100644 --- a/drivers/input/touchscreen/Makefile +++ b/drivers/input/touchscreen/Makefile @@ -84,3 +84,4 @@ obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o obj-$(CONFIG_TOUCHSCREEN_SX8654) += sx8654.o obj-$(CONFIG_TOUCHSCREEN_TPS6507X) += tps6507x-ts.o obj-$(CONFIG_TOUCHSCREEN_ZFORCE) += zforce_ts.o +obj-$(CONFIG_TOUCHSCREEN_COLIBRI_VF50) += colibri-vf50-ts.o diff --git a/drivers/input/touchscreen/colibri-vf50-ts.c b/drivers/input/touchscreen/colibri-vf50-ts.c new file mode 100644 index 0000000..d7bc91a --- /dev/null +++ b/drivers/input/touchscreen/colibri-vf50-ts.c @@ -0,0 +1,404 @@ +/* Copyright 2015 Toradex AG + * + * Toradex Colibri VF50 Touchscreen driver + * + * Originally authored by Stefan Agner for 3.0 kernel + * + * 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/delay.h> +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/iio/consumer.h> +#include <linux/iio/types.h> +#include <linux/input.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/pinctrl/consumer.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/types.h> + +#define DRIVER_NAME "colibri-vf50-ts" +#define DRV_VERSION "1.0" + +#define VF_ADC_MAX ((1 << 12) - 1) + +#define COLI_TOUCH_MIN_DELAY_US 1000 +#define COLI_TOUCH_MAX_DELAY_US 2000 + +static int min_pressure = 200; + +struct vf50_touch_device { + struct platform_device *pdev; + struct input_dev *ts_input; + struct iio_channel *channels; + struct gpio_desc *gpio_xp; + struct gpio_desc *gpio_xm; + struct gpio_desc *gpio_yp; + struct gpio_desc *gpio_ym; + struct gpio_desc *gpio_pen_detect; + int pen_irq; + bool stop_touchscreen; +}; + +/* + * Enables given plates and measures touch parameters using ADC + */ +static int adc_ts_measure(struct iio_channel *channel, + struct gpio_desc *plate_p, struct gpio_desc *plate_m) +{ + int i, value = 0, val = 0; + int ret; + + gpiod_set_value(plate_p, 1); + gpiod_set_value(plate_m, 1); + + usleep_range(COLI_TOUCH_MIN_DELAY_US, COLI_TOUCH_MAX_DELAY_US); + + for (i = 0; i < 5; i++) { + ret = iio_read_channel_raw(channel, &val); + if (ret < 0) { + value = ret; + goto error_iio_read; + } + + value += val; + } + + value /= 5; + +error_iio_read: + gpiod_set_value(plate_p, 0); + gpiod_set_value(plate_m, 0); + + return value; +} + +/* + * Enable touch detection using falling edge detection on XM + */ +static void vf50_ts_enable_touch_detection(struct vf50_touch_device *vf50_ts) +{ + /* Enable plate YM (needs to be strong GND, high active) */ + gpiod_set_value(vf50_ts->gpio_ym, 1); + + /* + * Let the platform mux to idle state in order to enable + * Pull-Up on GPIO + */ + pinctrl_pm_select_idle_state(&vf50_ts->pdev->dev); +} + +/* + * ADC touch screen sampling bottom half irq handler + */ +static irqreturn_t vf50_ts_irq_bh(int irq, void *private) +{ + struct vf50_touch_device *vf50_ts = (struct vf50_touch_device *)private; + struct device *dev = &vf50_ts->pdev->dev; + int val_x, val_y, val_z1, val_z2, val_p = 0; + bool discard_val_on_start = true; + + /* Disable the touch detection plates */ + gpiod_set_value(vf50_ts->gpio_ym, 0); + + /* Let the platform mux to default state in order to mux as ADC */ + pinctrl_pm_select_default_state(dev); + + while (!vf50_ts->stop_touchscreen) { + /* X-Direction */ + val_x = adc_ts_measure(&vf50_ts->channels[0], + vf50_ts->gpio_xp, vf50_ts->gpio_xm); + if (val_x < 0) + break; + + /* Y-Direction */ + val_y = adc_ts_measure(&vf50_ts->channels[1], + vf50_ts->gpio_yp, vf50_ts->gpio_ym); + if (val_y < 0) + break; + + /* + * Touch pressure + * Measure on XP/YM + */ + val_z1 = adc_ts_measure(&vf50_ts->channels[2], + vf50_ts->gpio_yp, vf50_ts->gpio_xm); + if (val_z1 < 0) + break; + val_z2 = adc_ts_measure(&vf50_ts->channels[3], + vf50_ts->gpio_yp, vf50_ts->gpio_xm); + if (val_z2 < 0) + break; + + /* Validate signal (avoid calculation using noise) */ + if (val_z1 > 64 && val_x > 64) { + /* + * Calculate resistance between the plates + * lower resistance means higher pressure + */ + int r_x = (1000 * val_x) / VF_ADC_MAX; + + val_p = (r_x * val_z2) / val_z1 - r_x; + + } else { + val_p = 2000; + } + + val_p = 2000 - val_p; + dev_dbg(dev, "Measured values: x: %d, y: %d, z1: %d, z2: %d, " + "p: %d\n", val_x, val_y, val_z1, val_z2, val_p); + + /* + * If touch pressure is too low, stop measuring and reenable + * touch detection + */ + if (val_p < min_pressure || val_p > 2000) + break; + + /* + * The pressure may not be enough for the first x and the + * second y measurement, but, the pressure is ok when the + * driver is doing the third and fourth measurement. To + * take care of this, we drop the first measurement always. + */ + if (discard_val_on_start) { + discard_val_on_start = false; + } else { + /* + * Report touch position and sleep for + * next measurement + */ + input_report_abs(vf50_ts->ts_input, + ABS_X, VF_ADC_MAX - val_x); + input_report_abs(vf50_ts->ts_input, + ABS_Y, VF_ADC_MAX - val_y); + input_report_abs(vf50_ts->ts_input, + ABS_PRESSURE, val_p); + input_report_key(vf50_ts->ts_input, BTN_TOUCH, 1); + input_sync(vf50_ts->ts_input); + } + + msleep(10); + } + + /* Report no more touch, reenable touch detection */ + input_report_abs(vf50_ts->ts_input, ABS_PRESSURE, 0); + input_report_key(vf50_ts->ts_input, BTN_TOUCH, 0); + input_sync(vf50_ts->ts_input); + + vf50_ts_enable_touch_detection(vf50_ts); + + /* Wait for the pull-up to be stable on high */ + msleep(10); + + return IRQ_HANDLED; +} + +static int vf50_ts_open(struct input_dev *dev_input) +{ + int ret; + struct vf50_touch_device *touchdev = input_get_drvdata(dev_input); + struct device *dev = &touchdev->pdev->dev; + + dev_dbg(dev, "Input device %s opened, starting touch detection\n", + dev_input->name); + + touchdev->stop_touchscreen = false; + + ret = gpiod_direction_output(touchdev->gpio_xp, 0); + if (ret) { + dev_err(dev, "Could not set gpio xp as output %d\n", ret); + return ret; + } + + ret = gpiod_direction_output(touchdev->gpio_xm, 0); + if (ret) { + dev_err(dev, "Could not set gpio xm as output %d\n", ret); + return ret; + } + + ret = gpiod_direction_output(touchdev->gpio_yp, 0); + if (ret) { + dev_err(dev, "Could not set gpio yp as output %d\n", ret); + return ret; + } + + ret = gpiod_direction_output(touchdev->gpio_ym, 0); + if (ret) { + dev_err(dev, "Could not set gpio ym as output %d\n", ret); + return ret; + } + + ret = gpiod_direction_input(touchdev->gpio_pen_detect); + if (ret) { + dev_err(dev, + "Could not set gpio pen detect as input %d\n", ret); + return ret; + } + + /* Mux detection before request IRQ, wait for pull-up to settle */ + vf50_ts_enable_touch_detection(touchdev); + msleep(10); + + return 0; +} + +static void vf50_ts_close(struct input_dev *dev_input) +{ + struct vf50_touch_device *touchdev = input_get_drvdata(dev_input); + struct device *dev = &touchdev->pdev->dev; + + touchdev->stop_touchscreen = true; + + dev_dbg(dev, "Input device %s closed, disable touch detection\n", + dev_input->name); +} + +static inline int vf50_ts_get_gpiod(struct device *dev, + struct gpio_desc **gpio_d, const char *con_id) +{ + int ret; + + *gpio_d = devm_gpiod_get(dev, con_id); + if (IS_ERR(*gpio_d)) { + ret = PTR_ERR(*gpio_d); + dev_err(dev, "Could not get gpio_%s %d\n", con_id, ret); + return ret; + } + + return 0; +} + +static int vf50_ts_probe(struct platform_device *pdev) +{ + struct input_dev *input; + struct iio_channel *channels; + struct device *dev = &pdev->dev; + struct vf50_touch_device *touchdev; + int ret; + + channels = iio_channel_get_all(dev); + if (IS_ERR(channels)) + return PTR_ERR(channels); + + touchdev = devm_kzalloc(dev, sizeof(*touchdev), GFP_KERNEL); + if (touchdev == NULL) { + ret = -ENOMEM; + goto error_release_channels; + } + + input = devm_input_allocate_device(dev); + if (!input) { + dev_err(dev, "Failed to allocate TS input device\n"); + ret = -ENOMEM; + goto error_release_channels; + } + + platform_set_drvdata(pdev, touchdev); + + touchdev->pdev = pdev; + touchdev->channels = channels; + + input->name = DRIVER_NAME; + input->id.bustype = BUS_HOST; + input->dev.parent = dev; + input->open = vf50_ts_open; + input->close = vf50_ts_close; + + _set_bit(EV_ABS, input->evbit); + _set_bit(EV_KEY, input->evbit); + _set_bit(BTN_TOUCH, input->keybit); + input_set_abs_params(input, ABS_X, 0, VF_ADC_MAX, 0, 0); + input_set_abs_params(input, ABS_Y, 0, VF_ADC_MAX, 0, 0); + input_set_abs_params(input, ABS_PRESSURE, 0, VF_ADC_MAX, 0, 0); + + touchdev->ts_input = input; + input_set_drvdata(input, touchdev); + ret = input_register_device(input); + if (ret) { + dev_err(dev, "Failed to register input device\n"); + goto error_release_channels; + } + + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_xp, "xp"); + if (ret) + goto error_release_channels; + + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_xm, "xm"); + if (ret) + goto error_release_channels; + + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_yp, "yp"); + if (ret) + goto error_release_channels; + + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_ym, "ym"); + if (ret) + goto error_release_channels; + + ret = vf50_ts_get_gpiod(dev, &touchdev->gpio_pen_detect, + "pen-detect"); + if (ret) + goto error_release_channels; + + touchdev->pen_irq = gpiod_to_irq(touchdev->gpio_pen_detect); + if (touchdev->pen_irq < 0) { + ret = touchdev->pen_irq; + dev_err(dev, "Unable to get IRQ for GPIO\n"); + goto error_release_channels; + } + + ret = devm_request_threaded_irq(dev, touchdev->pen_irq, NULL, + vf50_ts_irq_bh, IRQF_TRIGGER_LOW | IRQF_ONESHOT, + "vf50 touch", touchdev); + if (ret < 0) { + dev_err(dev, "Unable to request IRQ %d\n", touchdev->pen_irq); + goto error_release_channels; + } + + return 0; + +error_release_channels: + iio_channel_release_all(channels); + return ret; +} + +static int vf50_ts_remove(struct platform_device *pdev) +{ + struct vf50_touch_device *touchdev = platform_get_drvdata(pdev); + + iio_channel_release_all(touchdev->channels); + + return 0; +} + +static const struct of_device_id vf50_touch_of_match[] = { + { .compatible = "toradex,vf50-touchscreen", }, + { } +}; +MODULE_DEVICE_TABLE(of, vf50_touch_of_match); + +static struct platform_driver vf50_touch_driver = { + .driver = { + .name = "toradex,vf50_touchctrl", + .of_match_table = vf50_touch_of_match, + }, + .probe = vf50_ts_probe, + .remove = vf50_ts_remove, +}; + +module_platform_driver(vf50_touch_driver); + +module_param(min_pressure, int, 0600); +MODULE_PARM_DESC(min_pressure, "Minimum pressure for touch detection"); +MODULE_AUTHOR("Sanchayan Maity"); +MODULE_DESCRIPTION("Colibri VF50 Touchscreen driver"); +MODULE_LICENSE("GPL v2"); +MODULE_VERSION(DRV_VERSION);
The Colibri Vybrid VF50 module supports 4-wire touchscreens using FETs and ADC inputs. This driver uses the IIO consumer interface and relies on the vf610_adc driver based on the IIO framework. Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com> --- drivers/input/touchscreen/Kconfig | 12 + drivers/input/touchscreen/Makefile | 1 + drivers/input/touchscreen/colibri-vf50-ts.c | 404 ++++++++++++++++++++++++++++ 3 files changed, 417 insertions(+) create mode 100644 drivers/input/touchscreen/colibri-vf50-ts.c