[PATCH 1/1] input: AD7879 Touchscreen driver
From: Bryan Wu
Date: Thu Oct 16 2008 - 13:57:09 EST
From: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
---
drivers/input/touchscreen/Kconfig | 27 ++
drivers/input/touchscreen/Makefile | 1 +
drivers/input/touchscreen/ad7879.c | 794 ++++++++++++++++++++++++++++++++++++
include/linux/spi/ad7879.h | 35 ++
4 files changed, 857 insertions(+), 0 deletions(-)
create mode 100644 drivers/input/touchscreen/ad7879.c
create mode 100644 include/linux/spi/ad7879.h
diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 2fc51d0..83403b8 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -42,6 +42,33 @@ config TOUCHSCREEN_AD7877
To compile this driver as a module, choose M here: the
module will be called ad7877.
+config TOUCHSCREEN_AD7879
+ tristate "AD7879 based touchscreens"
+ depends on SPI_MASTER || I2C
+ help
+ Say Y here if you have a touchscreen interface using the
+ AD7879(-1) controller, and your board-specific initialization
+ code includes that in its table of SPI/I2C devices.
+
+ 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 ad7879.
+
+choice
+ prompt "Interface Selection"
+ depends on TOUCHSCREEN_AD7879
+
+config TOUCHSCREEN_AD7879_I2C
+ bool "AD7879-1 I2C"
+ depends on I2C
+
+config TOUCHSCREEN_AD7879_SPI
+ bool "AD7879 SPI"
+ depends on SPI_MASTER
+endchoice
+
+
config TOUCHSCREEN_BITSY
tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
depends on SA1100_BITSY
diff --git a/drivers/input/touchscreen/Makefile b/drivers/input/touchscreen/Makefile
index 89a3660..de249f7 100644
--- a/drivers/input/touchscreen/Makefile
+++ b/drivers/input/touchscreen/Makefile
@@ -7,6 +7,7 @@
wm97xx-ts-y := wm97xx-core.o
obj-$(CONFIG_TOUCHSCREEN_AD7877) += ad7877.o
+obj-$(CONFIG_TOUCHSCREEN_AD7879) += ad7879.o
obj-$(CONFIG_TOUCHSCREEN_ADS7846) += ads7846.o
obj-$(CONFIG_TOUCHSCREEN_ATMEL_TSADCC) += atmel_tsadcc.o
obj-$(CONFIG_TOUCHSCREEN_BITSY) += h3600_ts_input.o
diff --git a/drivers/input/touchscreen/ad7879.c b/drivers/input/touchscreen/ad7879.c
new file mode 100644
index 0000000..6865974
--- /dev/null
+++ b/drivers/input/touchscreen/ad7879.c
@@ -0,0 +1,794 @@
+/*
+ * File: drivers/input/touchscreen/ad7879.c
+ *
+ * Copyright (C) 2008 Michael Hennerich, Analog Devices Inc.
+ *
+ * Description: AD7879 based touchscreen, and GPIO driver (I2C/SPI Interface)
+ *
+ * Bugs: Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * History:
+ * Copyright (c) 2005 David Brownell
+ * Copyright (c) 2006 Nokia Corporation
+ * Various changes: Imre Deak <imre.deak@xxxxxxxxx>
+ *
+ * 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/init.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/spi/spi.h>
+#include <linux/i2c.h>
+
+#include <linux/spi/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_XPOS = 0,
+ AD7879_SEQ_YPOS = 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)
+
+#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI)
+#define AD7879_DEVID 0x7A
+typedef struct spi_device bus_device;
+#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C)
+#define AD7879_DEVID 0x79
+typedef struct i2c_client bus_device;
+#endif
+
+struct ad7879 {
+ bus_device *bus;
+ struct input_dev *input;
+ struct work_struct work;
+ struct timer_list timer;
+ spinlock_t lock;
+
+#ifdef CONFIG_TOUCHSCREEN_AD7879_SPI
+ struct spi_message msg;
+ struct spi_transfer xfer[AD7879_NR_SENSE + 1];
+ u16 cmd;
+#endif
+ 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 pressure_max;
+ u16 gpio_init;
+ u16 cmd_crtl1;
+ u16 cmd_crtl2;
+ u16 cmd_crtl3;
+ unsigned disabled:1; /* P: lock */
+ unsigned gpio:1;
+};
+
+static int ad7879_read(bus_device *, u8);
+static int ad7879_write(bus_device *, u8, u16);
+static void ad7879_collect(struct ad7879 *);
+
+static void 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;
+
+ /*
+ * 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/spi/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;
+ } else
+ Rt = 0;
+
+ if (Rt) {
+ input_report_abs(input_dev, ABS_X, x);
+ input_report_abs(input_dev, ABS_Y, y);
+ input_report_abs(input_dev, ABS_PRESSURE, Rt);
+ input_sync(input_dev);
+ }
+}
+
+static void ad7879_work(struct work_struct *work)
+{
+ struct ad7879 *ts = container_of(work, struct ad7879, work);
+
+ /* use keventd context to read the result registers */
+ ad7879_collect(ts);
+ ad7879_report(ts);
+ mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
+}
+
+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_sync(input_dev);
+}
+
+static void ad7879_timer(unsigned long handle)
+{
+ struct ad7879 *ts = (void *)handle;
+
+ ad7879_ts_event_release(ts);
+}
+
+static irqreturn_t ad7879_irq(int irq, void *handle)
+{
+ struct ad7879 *ts = handle;
+
+ /* The repeated conversion sequencer controlled by TMR kicked off too fast.
+ * We ignore the last and process the sample sequence currently in the queue.
+ * It can't be older than 9.4ms
+ */
+
+ if (!work_pending(&ts->work))
+ schedule_work(&ts->work);
+
+ return IRQ_HANDLED;
+}
+
+static void ad7879_disable(struct ad7879 *ts)
+{
+ unsigned long flags;
+
+ if (ts->disabled)
+ return;
+
+ spin_lock_irqsave(&ts->lock, flags);
+ ts->disabled = 1;
+ disable_irq(ts->bus->irq);
+ spin_unlock_irqrestore(&ts->lock, flags);
+
+ cancel_work_sync(&ts->work);
+
+ if (del_timer_sync(&ts->timer))
+ ad7879_ts_event_release(ts);
+
+ /* we know the chip's in lowpower mode since we always
+ * leave it that way after every request
+ */
+}
+
+static void ad7879_enable(struct ad7879 *ts)
+{
+ unsigned long flags;
+
+ if (!ts->disabled)
+ return;
+
+ spin_lock_irqsave(&ts->lock, flags);
+ ts->disabled = 0;
+ enable_irq(ts->bus->irq);
+ spin_unlock_irqrestore(&ts->lock, flags);
+}
+
+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 long val;
+ int ret;
+
+ ret = strict_strtoul(buf, 10, &val);
+
+ if (ret)
+ return ret;
+
+ if (val)
+ ad7879_disable(ts);
+ else
+ ad7879_enable(ts);
+
+ return count;
+}
+
+static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
+
+static ssize_t ad7879_gpio_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ad7879 *ts = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", ts->gpio);
+}
+
+static ssize_t ad7879_gpio_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ad7879 *ts = dev_get_drvdata(dev);
+ unsigned long val;
+ int ret;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ ts->gpio = !!val;
+
+ ret = ad7879_write(ts->bus, AD7879_REG_CTRL2,
+ ts->gpio ? ts->cmd_crtl2 & ~AD7879_GPIO_DATA
+ : ts->cmd_crtl2 | AD7879_GPIO_DATA);
+
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store);
+
+static struct attribute *ad7879_attributes[] = {
+ &dev_attr_disable.attr,
+ &dev_attr_gpio.attr,
+ NULL
+};
+
+static const struct attribute_group ad7879_attr_group = {
+ .attrs = ad7879_attributes,
+};
+
+static void ad7879_setup(bus_device *bus, struct ad7879 *ts)
+{
+ 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->gpio_init;
+
+ ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
+ AD7879_ACQ(ts->acquisition_time) |
+ AD7879_TMR(ts->pen_down_acc_interval);
+
+ ad7879_write(bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
+ ad7879_write(bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
+ ad7879_write(bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
+}
+
+static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
+{
+ struct input_dev *input_dev;
+ struct ad7879_platform_data *pdata = bus->dev.platform_data;
+ int err;
+ u16 revid;
+
+ if (!bus->irq) {
+ dev_err(&bus->dev, "no IRQ?\n");
+ return -ENODEV;
+ }
+
+ if (!pdata) {
+ dev_err(&bus->dev, "no platform data?\n");
+ return -ENODEV;
+ }
+
+ input_dev = input_allocate_device();
+ if (!input_dev)
+ return -ENOMEM;
+
+ ts->input = input_dev;
+
+ setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
+ INIT_WORK(&ts->work, ad7879_work);
+ spin_lock_init(&ts->lock);
+
+ ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
+ ts->pressure_max = pdata->pressure_max ? : ~0;
+
+ ts->first_conversion_delay = pdata->first_conversion_delay;
+ ts->acquisition_time = pdata->acquisition_time;
+ ts->averaging = pdata->averaging;
+ ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
+ ts->median = pdata->median;
+
+ if (pdata->gpio_output)
+ ts->gpio_init = AD7879_GPIO_EN |
+ (pdata->gpio_default ? 0 : AD7879_GPIO_DATA);
+ else
+ ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR;
+
+ snprintf(ts->phys, sizeof(ts->phys), "%s/inputX", bus->dev.bus_id);
+
+ input_dev->name = "AD7879 Touchscreen";
+ input_dev->phys = ts->phys;
+ input_dev->dev.parent = &bus->dev;
+
+ __set_bit(EV_ABS, input_dev->evbit);
+ __set_bit(ABS_X, input_dev->absbit);
+ __set_bit(ABS_Y, input_dev->absbit);
+ __set_bit(ABS_PRESSURE, input_dev->absbit);
+
+ input_set_abs_params(input_dev, ABS_X,
+ pdata->x_min ? : 0,
+ pdata->x_max ? : MAX_12BIT,
+ 0, 0);
+ input_set_abs_params(input_dev, ABS_Y,
+ pdata->y_min ? : 0,
+ pdata->y_max ? : MAX_12BIT,
+ 0, 0);
+ input_set_abs_params(input_dev, ABS_PRESSURE,
+ pdata->pressure_min, pdata->pressure_max, 0, 0);
+
+ err = ad7879_write(bus, AD7879_REG_CTRL2, AD7879_RESET);
+
+ if (err < 0) {
+ dev_err(&bus->dev, "Failed to write %s\n", input_dev->name);
+ goto err_free_mem;
+ }
+
+ revid = ad7879_read(bus, AD7879_REG_REVID);
+
+ if ((revid & 0xFF) != AD7879_DEVID) {
+ dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name);
+ err = -ENODEV;
+ goto err_free_mem;
+ }
+
+ ad7879_setup(bus, ts);
+
+ err = request_irq(bus->irq, ad7879_irq, IRQF_TRIGGER_FALLING |
+ IRQF_SAMPLE_RANDOM, bus->dev.driver->name, ts);
+
+ if (err) {
+ dev_err(&bus->dev, "irq %d busy?\n", bus->irq);
+ goto err_free_mem;
+ }
+
+ err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group);
+ if (err)
+ goto err_free_irq;
+
+ err = input_register_device(input_dev);
+ if (err)
+ goto err_remove_attr;
+
+ dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
+ revid >> 8, bus->irq);
+
+ return 0;
+
+err_remove_attr:
+ sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
+err_free_irq:
+ free_irq(bus->irq, ts);
+err_free_mem:
+ input_free_device(input_dev);
+
+ return err;
+}
+
+static int __devexit ad7879_destruct(bus_device *bus, struct ad7879 *ts)
+{
+ ad7879_disable(ts);
+ ad7879_write(ts->bus, AD7879_REG_CTRL2,
+ AD7879_PM(AD7879_PM_SHUTDOWN));
+ sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
+ free_irq(ts->bus->irq, ts);
+ input_unregister_device(ts->input);
+ dev_dbg(&bus->dev, "unregistered touchscreen\n");
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int ad7879_suspend(bus_device *bus, pm_message_t message)
+{
+ struct ad7879 *ts = dev_get_drvdata(&bus->dev);
+
+ ad7879_disable(ts);
+ ad7879_write(bus, AD7879_REG_CTRL2,
+ AD7879_PM(AD7879_PM_SHUTDOWN));
+
+ return 0;
+}
+
+static int ad7879_resume(bus_device *bus)
+{
+ struct ad7879 *ts = dev_get_drvdata(&bus->dev);
+
+ ad7879_setup(bus, ts);
+ ad7879_enable(ts);
+
+ return 0;
+}
+#else
+#define ad7879_suspend NULL
+#define ad7879_resume NULL
+#endif
+
+#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI)
+#define MAX_SPI_FREQ_HZ 5000000
+#define AD7879_CMD_MAGIC 0xE000
+#define AD7879_CMD_READ (1 << 10)
+#define AD7879_WRITECMD(reg) (AD7879_CMD_MAGIC | (reg & 0xF))
+#define AD7879_READCMD(reg) (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF))
+
+struct ser_req {
+ u16 command;
+ u16 data;
+ struct spi_message msg;
+ struct spi_transfer xfer[2];
+};
+
+/*
+ * ad7879_read/write are only used for initial setup and for sysfs controls.
+ * The main traffic is done in ad7879_collect().
+ */
+
+static int ad7879_read(struct spi_device *spi, u8 reg)
+{
+ struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
+ int status, ret;
+
+ if (!req)
+ return -ENOMEM;
+
+ spi_message_init(&req->msg);
+
+ req->command = (u16) AD7879_READCMD(reg);
+ req->xfer[0].tx_buf = &req->command;
+ req->xfer[0].len = 2;
+
+ req->xfer[1].rx_buf = &req->data;
+ req->xfer[1].len = 2;
+
+ spi_message_add_tail(&req->xfer[0], &req->msg);
+ spi_message_add_tail(&req->xfer[1], &req->msg);
+
+ status = spi_sync(spi, &req->msg);
+
+ if (status == 0)
+ status = req->msg.status;
+
+ ret = status ? status : req->data;
+ kfree(req);
+
+ return ret;
+}
+
+static int ad7879_write(struct spi_device *spi, u8 reg, u16 val)
+{
+ struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
+ int status;
+
+ if (!req)
+ return -ENOMEM;
+
+ spi_message_init(&req->msg);
+
+ req->command = (u16) AD7879_WRITECMD(reg);
+ req->xfer[0].tx_buf = &req->command;
+ req->xfer[0].len = 2;
+
+ req->data = val;
+ req->xfer[1].tx_buf = &req->data;
+ req->xfer[1].len = 2;
+
+ spi_message_add_tail(&req->xfer[0], &req->msg);
+ spi_message_add_tail(&req->xfer[1], &req->msg);
+
+ status = spi_sync(spi, &req->msg);
+
+ if (status == 0)
+ status = req->msg.status;
+
+ kfree(req);
+
+ return status;
+}
+
+static void ad7879_collect(struct ad7879 *ts)
+{
+ int status = spi_sync(ts->bus, &ts->msg);
+ if (status)
+ dev_err(&ts->bus->dev, "spi_sync --> %d\n", status);
+}
+
+static void ad7879_setup_ts_def_msg(struct ad7879 *ts)
+{
+ struct spi_message *m;
+ int i;
+
+ ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS);
+
+ m = &ts->msg;
+ spi_message_init(m);
+ ts->xfer[0].tx_buf = &ts->cmd;
+ ts->xfer[0].len = 2;
+
+ spi_message_add_tail(&ts->xfer[0], m);
+
+ for (i = 0; i < AD7879_NR_SENSE; i++) {
+ ts->xfer[i + 1].rx_buf = &ts->conversion_data[i];
+ ts->xfer[i + 1].len = 2;
+ spi_message_add_tail(&ts->xfer[i + 1], m);
+ }
+}
+
+static int __devinit ad7879_probe(struct spi_device *spi)
+{
+ struct ad7879 *ts;
+ int ret;
+
+ /* don't exceed max specified SPI CLK frequency */
+ if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
+ dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
+ return -EINVAL;
+ }
+
+ ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ dev_set_drvdata(&spi->dev, ts);
+ ts->bus = spi;
+
+ ad7879_setup_ts_def_msg(ts);
+
+ ret = ad7879_construct(spi, ts);
+ if (!ret)
+ return ret;
+
+ dev_set_drvdata(&spi->dev, NULL);
+ kfree(ts);
+
+ return ret;
+}
+
+static int __devexit ad7879_remove(struct spi_device *spi)
+{
+ struct ad7879 *ts = dev_get_drvdata(&spi->dev);
+
+ ad7879_destruct(spi, ts);
+ dev_set_drvdata(&spi->dev, NULL);
+ kfree(ts);
+ return 0;
+}
+
+static struct spi_driver ad7879_driver = {
+ .driver = {
+ .name = "ad7879",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7879_probe,
+ .remove = __devexit_p(ad7879_remove),
+ .suspend = ad7879_suspend,
+ .resume = ad7879_resume,
+};
+
+static int __init ad7879_init(void)
+{
+ return spi_register_driver(&ad7879_driver);
+}
+module_init(ad7879_init);
+
+static void __exit ad7879_exit(void)
+{
+ spi_unregister_driver(&ad7879_driver);
+}
+module_exit(ad7879_exit);
+
+#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C)
+
+/* All registers are word-sized.
+ * AD7879 uses a high-byte first convention.
+ */
+static int ad7879_read(struct i2c_client *client, u8 reg)
+{
+ return swab16(i2c_smbus_read_word_data(client, reg));
+}
+
+static int ad7879_write(struct i2c_client *client, u8 reg, u16 val)
+{
+ return i2c_smbus_write_word_data(client, reg, swab16(val));
+}
+
+static void ad7879_collect(struct ad7879 *ts)
+{
+ int i;
+ for (i = 0; i < AD7879_NR_SENSE; i++)
+ ts->conversion_data[i] =
+ ad7879_read(ts->bus, AD7879_REG_XPLUS + i);
+}
+
+static int __devinit ad7879_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct ad7879 *ts;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA)) {
+ dev_err(&client->dev, "SMBUS Word Data not Supported\n");
+ return -EIO;
+ }
+
+ ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
+ if (!ts)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ts);
+ ts->bus = client;
+
+ ret = ad7879_construct(client, ts);
+ if (!ret)
+ return ret;
+
+ i2c_set_clientdata(client, NULL);
+ kfree(ts);
+
+ return ret;
+}
+
+static int __devexit ad7879_remove(struct i2c_client *client)
+{
+ struct ad7879 *ts = dev_get_drvdata(&client->dev);
+
+ ad7879_destruct(client, ts);
+ i2c_set_clientdata(client, NULL);
+ kfree(ts);
+ return 0;
+}
+static const struct i2c_device_id ad7979_id[] = {
+ { "ad7879", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ad7979_id);
+
+static struct i2c_driver ad7879_driver = {
+ .driver = {
+ .name = "ad7879",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7879_probe,
+ .remove = __devexit_p(ad7879_remove),
+ .suspend = ad7879_suspend,
+ .resume = ad7879_resume,
+ .id_table = ad7979_id,
+};
+
+static int __init ad7879_init(void)
+{
+ return i2c_add_driver(&ad7879_driver);
+}
+module_init(ad7879_init);
+
+static void __exit ad7879_exit(void)
+{
+ i2c_del_driver(&ad7879_driver);
+}
+module_exit(ad7879_exit);
+#endif
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@xxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/spi/ad7879.h b/include/linux/spi/ad7879.h
new file mode 100644
index 0000000..4231104
--- /dev/null
+++ b/include/linux/spi/ad7879.h
@@ -0,0 +1,35 @@
+/* linux/spi/ad7879.h */
+
+/* Touchscreen characteristics vary between boards and models. The
+ * platform_data for the device's "struct device" holds this information.
+ *
+ * It's OK if the min/max values are zero.
+ */
+struct ad7879_platform_data {
+ u16 model; /* 7879 */
+ u16 x_plate_ohms;
+ u16 x_min, x_max;
+ u16 y_min, y_max;
+ u16 pressure_min, pressure_max;
+
+ /* [0..255] 0=OFF Starts at 1=550us and goes
+ * all the way to 9.440ms in steps of 35us.
+ */
+ u8 pen_down_acc_interval;
+ /* [0..15] Starts at 0=128us and goes all the
+ * way to 4.096ms in steps of 128us.
+ */
+ u8 first_conversion_delay;
+ /* [0..3] 0 = 2us, 1 = 4us, 2 = 8us, 3 = 16us */
+ u8 acquisition_time;
+ /* [0..3] Average X middle samples 0 = 2, 1 = 4, 2 = 8, 3 = 16 */
+ u8 averaging;
+ /* [0..3] Perform X measurements 0 = OFF,
+ * 1 = 4, 2 = 8, 3 = 16 (median > averaging)
+ */
+ u8 median;
+ /* 1 = AUX/VBAT/GPIO set to GPIO Output */
+ u8 gpio_output;
+ /* Initial GPIO pin state (valid if gpio_output = 1) */
+ u8 gpio_default;
+};
--
1.5.6
--
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