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-rw-r--r--drivers/input/touchscreen/ad7879.c635
1 files changed, 635 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
new file mode 100644
index 000000000..e85085332
--- /dev/null
+++ b/drivers/input/touchscreen/ad7879.c
@@ -0,0 +1,635 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AD7879/AD7889 based touchscreen and GPIO driver
+ *
+ * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
+ *
+ * History:
+ * Copyright (c) 2005 David Brownell
+ * Copyright (c) 2006 Nokia Corporation
+ * Various changes: Imre Deak <imre.deak@nokia.com>
+ *
+ * Using code from:
+ * - 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
+ * - ad7877.c
+ * Copyright (C) 2006-2008 Analog Devices Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/gpio/driver.h>
+
+#include <linux/input/touchscreen.h>
+#include <linux/module.h>
+#include "ad7879.h"
+
+#define AD7879_REG_ZEROS 0
+#define AD7879_REG_CTRL1 1
+#define AD7879_REG_CTRL2 2
+#define AD7879_REG_CTRL3 3
+#define AD7879_REG_AUX1HIGH 4
+#define AD7879_REG_AUX1LOW 5
+#define AD7879_REG_TEMP1HIGH 6
+#define AD7879_REG_TEMP1LOW 7
+#define AD7879_REG_XPLUS 8
+#define AD7879_REG_YPLUS 9
+#define AD7879_REG_Z1 10
+#define AD7879_REG_Z2 11
+#define AD7879_REG_AUXVBAT 12
+#define AD7879_REG_TEMP 13
+#define AD7879_REG_REVID 14
+
+/* Control REG 1 */
+#define AD7879_TMR(x) ((x & 0xFF) << 0)
+#define AD7879_ACQ(x) ((x & 0x3) << 8)
+#define AD7879_MODE_NOC (0 << 10) /* Do not convert */
+#define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
+#define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
+#define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
+#define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
+
+/* Control REG 2 */
+#define AD7879_FCD(x) ((x & 0x3) << 0)
+#define AD7879_RESET (1 << 4)
+#define AD7879_MFS(x) ((x & 0x3) << 5)
+#define AD7879_AVG(x) ((x & 0x3) << 7)
+#define AD7879_SER (1 << 9) /* non-differential */
+#define AD7879_DFR (0 << 9) /* differential */
+#define AD7879_GPIOPOL (1 << 10)
+#define AD7879_GPIODIR (1 << 11)
+#define AD7879_GPIO_DATA (1 << 12)
+#define AD7879_GPIO_EN (1 << 13)
+#define AD7879_PM(x) ((x & 0x3) << 14)
+#define AD7879_PM_SHUTDOWN (0)
+#define AD7879_PM_DYN (1)
+#define AD7879_PM_FULLON (2)
+
+/* Control REG 3 */
+#define AD7879_TEMPMASK_BIT (1<<15)
+#define AD7879_AUXVBATMASK_BIT (1<<14)
+#define AD7879_INTMODE_BIT (1<<13)
+#define AD7879_GPIOALERTMASK_BIT (1<<12)
+#define AD7879_AUXLOW_BIT (1<<11)
+#define AD7879_AUXHIGH_BIT (1<<10)
+#define AD7879_TEMPLOW_BIT (1<<9)
+#define AD7879_TEMPHIGH_BIT (1<<8)
+#define AD7879_YPLUS_BIT (1<<7)
+#define AD7879_XPLUS_BIT (1<<6)
+#define AD7879_Z1_BIT (1<<5)
+#define AD7879_Z2_BIT (1<<4)
+#define AD7879_AUX_BIT (1<<3)
+#define AD7879_VBAT_BIT (1<<2)
+#define AD7879_TEMP_BIT (1<<1)
+
+enum {
+ AD7879_SEQ_YPOS = 0,
+ AD7879_SEQ_XPOS = 1,
+ AD7879_SEQ_Z1 = 2,
+ AD7879_SEQ_Z2 = 3,
+ AD7879_NR_SENSE = 4,
+};
+
+#define MAX_12BIT ((1<<12)-1)
+#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
+
+struct ad7879 {
+ struct regmap *regmap;
+ struct device *dev;
+ struct input_dev *input;
+ struct timer_list timer;
+#ifdef CONFIG_GPIOLIB
+ struct gpio_chip gc;
+ struct mutex mutex;
+#endif
+ unsigned int irq;
+ bool disabled; /* P: input->mutex */
+ bool suspended; /* P: input->mutex */
+ bool swap_xy;
+ u16 conversion_data[AD7879_NR_SENSE];
+ char phys[32];
+ u8 first_conversion_delay;
+ u8 acquisition_time;
+ u8 averaging;
+ u8 pen_down_acc_interval;
+ u8 median;
+ u16 x_plate_ohms;
+ u16 cmd_crtl1;
+ u16 cmd_crtl2;
+ u16 cmd_crtl3;
+ int x;
+ int y;
+ int Rt;
+};
+
+static int ad7879_read(struct ad7879 *ts, u8 reg)
+{
+ unsigned int val;
+ int error;
+
+ error = regmap_read(ts->regmap, reg, &val);
+ if (error) {
+ dev_err(ts->dev, "failed to read register %#02x: %d\n",
+ reg, error);
+ return error;
+ }
+
+ return val;
+}
+
+static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
+{
+ int error;
+
+ error = regmap_write(ts->regmap, reg, val);
+ if (error) {
+ dev_err(ts->dev,
+ "failed to write %#04x to register %#02x: %d\n",
+ val, reg, error);
+ return error;
+ }
+
+ return 0;
+}
+
+static int ad7879_report(struct ad7879 *ts)
+{
+ struct input_dev *input_dev = ts->input;
+ unsigned Rt;
+ u16 x, y, z1, z2;
+
+ x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
+ y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
+ z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
+ z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
+
+ if (ts->swap_xy)
+ swap(x, y);
+
+ /*
+ * The samples processed here are already preprocessed by the AD7879.
+ * The preprocessing function consists of a median and an averaging
+ * filter. The combination of these two techniques provides a robust
+ * solution, discarding the spurious noise in the signal and keeping
+ * only the data of interest. The size of both filters is
+ * programmable. (dev.platform_data, see linux/platform_data/ad7879.h)
+ * Other user-programmable conversion controls include variable
+ * acquisition time, and first conversion delay. Up to 16 averages can
+ * be taken per conversion.
+ */
+
+ if (likely(x && z1)) {
+ /* compute touch pressure resistance using equation #1 */
+ Rt = (z2 - z1) * x * ts->x_plate_ohms;
+ Rt /= z1;
+ Rt = (Rt + 2047) >> 12;
+
+ /*
+ * Sample found inconsistent, pressure is beyond
+ * the maximum. Don't report it to user space.
+ */
+ if (Rt > input_abs_get_max(input_dev, ABS_PRESSURE))
+ return -EINVAL;
+
+ /*
+ * Note that we delay reporting events by one sample.
+ * This is done to avoid reporting last sample of the
+ * touch sequence, which may be incomplete if finger
+ * leaves the surface before last reading is taken.
+ */
+ if (timer_pending(&ts->timer)) {
+ /* Touch continues */
+ input_report_key(input_dev, BTN_TOUCH, 1);
+ input_report_abs(input_dev, ABS_X, ts->x);
+ input_report_abs(input_dev, ABS_Y, ts->y);
+ input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
+ input_sync(input_dev);
+ }
+
+ ts->x = x;
+ ts->y = y;
+ ts->Rt = Rt;
+
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static void ad7879_ts_event_release(struct ad7879 *ts)
+{
+ struct input_dev *input_dev = ts->input;
+
+ input_report_abs(input_dev, ABS_PRESSURE, 0);
+ input_report_key(input_dev, BTN_TOUCH, 0);
+ input_sync(input_dev);
+}
+
+static void ad7879_timer(struct timer_list *t)
+{
+ struct ad7879 *ts = from_timer(ts, t, timer);
+
+ ad7879_ts_event_release(ts);
+}
+
+static irqreturn_t ad7879_irq(int irq, void *handle)
+{
+ struct ad7879 *ts = handle;
+ int error;
+
+ error = regmap_bulk_read(ts->regmap, AD7879_REG_XPLUS,
+ ts->conversion_data, AD7879_NR_SENSE);
+ if (error)
+ dev_err_ratelimited(ts->dev, "failed to read %#02x: %d\n",
+ AD7879_REG_XPLUS, error);
+ else if (!ad7879_report(ts))
+ mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
+
+ return IRQ_HANDLED;
+}
+
+static void __ad7879_enable(struct ad7879 *ts)
+{
+ ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+ ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
+ ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
+
+ enable_irq(ts->irq);
+}
+
+static void __ad7879_disable(struct ad7879 *ts)
+{
+ u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
+ AD7879_PM(AD7879_PM_SHUTDOWN);
+ disable_irq(ts->irq);
+
+ if (del_timer_sync(&ts->timer))
+ ad7879_ts_event_release(ts);
+
+ ad7879_write(ts, AD7879_REG_CTRL2, reg);
+}
+
+
+static int ad7879_open(struct input_dev *input)
+{
+ struct ad7879 *ts = input_get_drvdata(input);
+
+ /* protected by input->mutex */
+ if (!ts->disabled && !ts->suspended)
+ __ad7879_enable(ts);
+
+ return 0;
+}
+
+static void ad7879_close(struct input_dev *input)
+{
+ struct ad7879 *ts = input_get_drvdata(input);
+
+ /* protected by input->mutex */
+ if (!ts->disabled && !ts->suspended)
+ __ad7879_disable(ts);
+}
+
+static int __maybe_unused ad7879_suspend(struct device *dev)
+{
+ struct ad7879 *ts = dev_get_drvdata(dev);
+
+ mutex_lock(&ts->input->mutex);
+
+ if (!ts->suspended && !ts->disabled && input_device_enabled(ts->input))
+ __ad7879_disable(ts);
+
+ ts->suspended = true;
+
+ mutex_unlock(&ts->input->mutex);
+
+ return 0;
+}
+
+static int __maybe_unused ad7879_resume(struct device *dev)
+{
+ struct ad7879 *ts = dev_get_drvdata(dev);
+
+ mutex_lock(&ts->input->mutex);
+
+ if (ts->suspended && !ts->disabled && input_device_enabled(ts->input))
+ __ad7879_enable(ts);
+
+ ts->suspended = false;
+
+ mutex_unlock(&ts->input->mutex);
+
+ return 0;
+}
+
+SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
+EXPORT_SYMBOL(ad7879_pm_ops);
+
+static void ad7879_toggle(struct ad7879 *ts, bool disable)
+{
+ mutex_lock(&ts->input->mutex);
+
+ if (!ts->suspended && input_device_enabled(ts->input)) {
+
+ if (disable) {
+ if (ts->disabled)
+ __ad7879_enable(ts);
+ } else {
+ if (!ts->disabled)
+ __ad7879_disable(ts);
+ }
+ }
+
+ ts->disabled = disable;
+
+ mutex_unlock(&ts->input->mutex);
+}
+
+static ssize_t ad7879_disable_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ad7879 *ts = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", ts->disabled);
+}
+
+static ssize_t ad7879_disable_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ad7879 *ts = dev_get_drvdata(dev);
+ unsigned int val;
+ int error;
+
+ error = kstrtouint(buf, 10, &val);
+ if (error)
+ return error;
+
+ ad7879_toggle(ts, val);
+
+ return count;
+}
+
+static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
+
+static struct attribute *ad7879_attributes[] = {
+ &dev_attr_disable.attr,
+ NULL
+};
+
+static const struct attribute_group ad7879_attr_group = {
+ .attrs = ad7879_attributes,
+};
+
+#ifdef CONFIG_GPIOLIB
+static int ad7879_gpio_direction_input(struct gpio_chip *chip,
+ unsigned gpio)
+{
+ struct ad7879 *ts = gpiochip_get_data(chip);
+ int err;
+
+ mutex_lock(&ts->mutex);
+ ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
+ err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+ mutex_unlock(&ts->mutex);
+
+ return err;
+}
+
+static int ad7879_gpio_direction_output(struct gpio_chip *chip,
+ unsigned gpio, int level)
+{
+ struct ad7879 *ts = gpiochip_get_data(chip);
+ int err;
+
+ mutex_lock(&ts->mutex);
+ ts->cmd_crtl2 &= ~AD7879_GPIODIR;
+ ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
+ if (level)
+ ts->cmd_crtl2 |= AD7879_GPIO_DATA;
+ else
+ ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
+
+ err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+ mutex_unlock(&ts->mutex);
+
+ return err;
+}
+
+static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+ struct ad7879 *ts = gpiochip_get_data(chip);
+ u16 val;
+
+ mutex_lock(&ts->mutex);
+ val = ad7879_read(ts, AD7879_REG_CTRL2);
+ mutex_unlock(&ts->mutex);
+
+ return !!(val & AD7879_GPIO_DATA);
+}
+
+static void ad7879_gpio_set_value(struct gpio_chip *chip,
+ unsigned gpio, int value)
+{
+ struct ad7879 *ts = gpiochip_get_data(chip);
+
+ mutex_lock(&ts->mutex);
+ if (value)
+ ts->cmd_crtl2 |= AD7879_GPIO_DATA;
+ else
+ ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
+
+ ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
+ mutex_unlock(&ts->mutex);
+}
+
+static int ad7879_gpio_add(struct ad7879 *ts)
+{
+ int ret = 0;
+
+ mutex_init(&ts->mutex);
+
+ /* Do not create a chip unless flagged for it */
+ if (!device_property_read_bool(ts->dev, "gpio-controller"))
+ return 0;
+
+ ts->gc.direction_input = ad7879_gpio_direction_input;
+ ts->gc.direction_output = ad7879_gpio_direction_output;
+ ts->gc.get = ad7879_gpio_get_value;
+ ts->gc.set = ad7879_gpio_set_value;
+ ts->gc.can_sleep = 1;
+ ts->gc.base = -1;
+ ts->gc.ngpio = 1;
+ ts->gc.label = "AD7879-GPIO";
+ ts->gc.owner = THIS_MODULE;
+ ts->gc.parent = ts->dev;
+
+ ret = devm_gpiochip_add_data(ts->dev, &ts->gc, ts);
+ if (ret)
+ dev_err(ts->dev, "failed to register gpio %d\n",
+ ts->gc.base);
+
+ return ret;
+}
+#else
+static int ad7879_gpio_add(struct ad7879 *ts)
+{
+ return 0;
+}
+#endif
+
+static int ad7879_parse_dt(struct device *dev, struct ad7879 *ts)
+{
+ int err;
+ u32 tmp;
+
+ err = device_property_read_u32(dev, "adi,resistance-plate-x", &tmp);
+ if (err) {
+ dev_err(dev, "failed to get resistance-plate-x property\n");
+ return err;
+ }
+ ts->x_plate_ohms = (u16)tmp;
+
+ device_property_read_u8(dev, "adi,first-conversion-delay",
+ &ts->first_conversion_delay);
+ device_property_read_u8(dev, "adi,acquisition-time",
+ &ts->acquisition_time);
+ device_property_read_u8(dev, "adi,median-filter-size", &ts->median);
+ device_property_read_u8(dev, "adi,averaging", &ts->averaging);
+ device_property_read_u8(dev, "adi,conversion-interval",
+ &ts->pen_down_acc_interval);
+
+ ts->swap_xy = device_property_read_bool(dev, "touchscreen-swapped-x-y");
+
+ return 0;
+}
+
+int ad7879_probe(struct device *dev, struct regmap *regmap,
+ int irq, u16 bustype, u8 devid)
+{
+ struct ad7879 *ts;
+ struct input_dev *input_dev;
+ int err;
+ u16 revid;
+
+ if (irq <= 0) {
+ dev_err(dev, "No IRQ specified\n");
+ return -EINVAL;
+ }
+
+ ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ err = ad7879_parse_dt(dev, ts);
+ if (err)
+ return err;
+
+ input_dev = devm_input_allocate_device(dev);
+ if (!input_dev) {
+ dev_err(dev, "Failed to allocate input device\n");
+ return -ENOMEM;
+ }
+
+ ts->dev = dev;
+ ts->input = input_dev;
+ ts->irq = irq;
+ ts->regmap = regmap;
+
+ timer_setup(&ts->timer, ad7879_timer, 0);
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
+
+ input_dev->name = "AD7879 Touchscreen";
+ input_dev->phys = ts->phys;
+ input_dev->dev.parent = dev;
+ input_dev->id.bustype = bustype;
+
+ input_dev->open = ad7879_open;
+ input_dev->close = ad7879_close;
+
+ input_set_drvdata(input_dev, ts);
+
+ input_set_capability(input_dev, EV_KEY, BTN_TOUCH);
+
+ input_set_abs_params(input_dev, ABS_X, 0, MAX_12BIT, 0, 0);
+ input_set_abs_params(input_dev, ABS_Y, 0, MAX_12BIT, 0, 0);
+ input_set_capability(input_dev, EV_ABS, ABS_PRESSURE);
+ touchscreen_parse_properties(input_dev, false, NULL);
+ if (!input_abs_get_max(input_dev, ABS_PRESSURE)) {
+ dev_err(dev, "Touchscreen pressure is not specified\n");
+ return -EINVAL;
+ }
+
+ err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
+ if (err < 0) {
+ dev_err(dev, "Failed to write %s\n", input_dev->name);
+ return err;
+ }
+
+ revid = ad7879_read(ts, AD7879_REG_REVID);
+ input_dev->id.product = (revid & 0xff);
+ input_dev->id.version = revid >> 8;
+ if (input_dev->id.product != devid) {
+ dev_err(dev, "Failed to probe %s (%x vs %x)\n",
+ input_dev->name, devid, revid);
+ return -ENODEV;
+ }
+
+ ts->cmd_crtl3 = AD7879_YPLUS_BIT |
+ AD7879_XPLUS_BIT |
+ AD7879_Z2_BIT |
+ AD7879_Z1_BIT |
+ AD7879_TEMPMASK_BIT |
+ AD7879_AUXVBATMASK_BIT |
+ AD7879_GPIOALERTMASK_BIT;
+
+ ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
+ AD7879_AVG(ts->averaging) |
+ AD7879_MFS(ts->median) |
+ AD7879_FCD(ts->first_conversion_delay);
+
+ ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
+ AD7879_ACQ(ts->acquisition_time) |
+ AD7879_TMR(ts->pen_down_acc_interval);
+
+ err = devm_request_threaded_irq(dev, ts->irq, NULL, ad7879_irq,
+ IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+ dev_name(dev), ts);
+ if (err) {
+ dev_err(dev, "Failed to request IRQ: %d\n", err);
+ return err;
+ }
+
+ __ad7879_disable(ts);
+
+ err = devm_device_add_group(dev, &ad7879_attr_group);
+ if (err)
+ return err;
+
+ err = ad7879_gpio_add(ts);
+ if (err)
+ return err;
+
+ err = input_register_device(input_dev);
+ if (err)
+ return err;
+
+ dev_set_drvdata(dev, ts);
+
+ return 0;
+}
+EXPORT_SYMBOL(ad7879_probe);
+
+MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
+MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
+MODULE_LICENSE("GPL");