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authorDavid S. Miller <davem@davemloft.net>2009-04-16 17:35:26 -0700
committerDavid S. Miller <davem@davemloft.net>2009-04-16 17:35:26 -0700
commita54bfa40fd16aeb90bc556189221576f746f8567 (patch)
tree176bb7a99ffab5f42f0dd4e9671f335be3f3efa0 /drivers/input/touchscreen/ad7877.c
parentfe957c40ec5e2763b9977c565beab3bde3aaf85b (diff)
parent134ffb4cad92a6aa534e55a9be145bca780a32c1 (diff)
downloadblackbird-op-linux-a54bfa40fd16aeb90bc556189221576f746f8567.tar.gz
blackbird-op-linux-a54bfa40fd16aeb90bc556189221576f746f8567.zip
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Diffstat (limited to 'drivers/input/touchscreen/ad7877.c')
-rw-r--r--drivers/input/touchscreen/ad7877.c844
1 files changed, 844 insertions, 0 deletions
diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c
new file mode 100644
index 000000000000..e4728a28f492
--- /dev/null
+++ b/drivers/input/touchscreen/ad7877.c
@@ -0,0 +1,844 @@
+/*
+ * Copyright (C) 2006-2008 Michael Hennerich, Analog Devices Inc.
+ *
+ * Description: AD7877 based touchscreen, sensor (ADCs), DAC and GPIO driver
+ * Based on: ads7846.c
+ *
+ * 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@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
+ */
+
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/ad7877.h>
+#include <asm/irq.h>
+
+#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
+
+#define MAX_SPI_FREQ_HZ 20000000
+#define MAX_12BIT ((1<<12)-1)
+
+#define AD7877_REG_ZEROS 0
+#define AD7877_REG_CTRL1 1
+#define AD7877_REG_CTRL2 2
+#define AD7877_REG_ALERT 3
+#define AD7877_REG_AUX1HIGH 4
+#define AD7877_REG_AUX1LOW 5
+#define AD7877_REG_BAT1HIGH 6
+#define AD7877_REG_BAT1LOW 7
+#define AD7877_REG_BAT2HIGH 8
+#define AD7877_REG_BAT2LOW 9
+#define AD7877_REG_TEMP1HIGH 10
+#define AD7877_REG_TEMP1LOW 11
+#define AD7877_REG_SEQ0 12
+#define AD7877_REG_SEQ1 13
+#define AD7877_REG_DAC 14
+#define AD7877_REG_NONE1 15
+#define AD7877_REG_EXTWRITE 15
+#define AD7877_REG_XPLUS 16
+#define AD7877_REG_YPLUS 17
+#define AD7877_REG_Z2 18
+#define AD7877_REG_aux1 19
+#define AD7877_REG_aux2 20
+#define AD7877_REG_aux3 21
+#define AD7877_REG_bat1 22
+#define AD7877_REG_bat2 23
+#define AD7877_REG_temp1 24
+#define AD7877_REG_temp2 25
+#define AD7877_REG_Z1 26
+#define AD7877_REG_GPIOCTRL1 27
+#define AD7877_REG_GPIOCTRL2 28
+#define AD7877_REG_GPIODATA 29
+#define AD7877_REG_NONE2 30
+#define AD7877_REG_NONE3 31
+
+#define AD7877_SEQ_YPLUS_BIT (1<<11)
+#define AD7877_SEQ_XPLUS_BIT (1<<10)
+#define AD7877_SEQ_Z2_BIT (1<<9)
+#define AD7877_SEQ_AUX1_BIT (1<<8)
+#define AD7877_SEQ_AUX2_BIT (1<<7)
+#define AD7877_SEQ_AUX3_BIT (1<<6)
+#define AD7877_SEQ_BAT1_BIT (1<<5)
+#define AD7877_SEQ_BAT2_BIT (1<<4)
+#define AD7877_SEQ_TEMP1_BIT (1<<3)
+#define AD7877_SEQ_TEMP2_BIT (1<<2)
+#define AD7877_SEQ_Z1_BIT (1<<1)
+
+enum {
+ AD7877_SEQ_YPOS = 0,
+ AD7877_SEQ_XPOS = 1,
+ AD7877_SEQ_Z2 = 2,
+ AD7877_SEQ_AUX1 = 3,
+ AD7877_SEQ_AUX2 = 4,
+ AD7877_SEQ_AUX3 = 5,
+ AD7877_SEQ_BAT1 = 6,
+ AD7877_SEQ_BAT2 = 7,
+ AD7877_SEQ_TEMP1 = 8,
+ AD7877_SEQ_TEMP2 = 9,
+ AD7877_SEQ_Z1 = 10,
+ AD7877_NR_SENSE = 11,
+};
+
+/* DAC Register Default RANGE 0 to Vcc, Volatge Mode, DAC On */
+#define AD7877_DAC_CONF 0x1
+
+/* If gpio3 is set AUX3/GPIO3 acts as GPIO Output */
+#define AD7877_EXTW_GPIO_3_CONF 0x1C4
+#define AD7877_EXTW_GPIO_DATA 0x200
+
+/* Control REG 2 */
+#define AD7877_TMR(x) ((x & 0x3) << 0)
+#define AD7877_REF(x) ((x & 0x1) << 2)
+#define AD7877_POL(x) ((x & 0x1) << 3)
+#define AD7877_FCD(x) ((x & 0x3) << 4)
+#define AD7877_PM(x) ((x & 0x3) << 6)
+#define AD7877_ACQ(x) ((x & 0x3) << 8)
+#define AD7877_AVG(x) ((x & 0x3) << 10)
+
+/* Control REG 1 */
+#define AD7877_SER (1 << 11) /* non-differential */
+#define AD7877_DFR (0 << 11) /* differential */
+
+#define AD7877_MODE_NOC (0) /* Do not convert */
+#define AD7877_MODE_SCC (1) /* Single channel conversion */
+#define AD7877_MODE_SEQ0 (2) /* Sequence 0 in Slave Mode */
+#define AD7877_MODE_SEQ1 (3) /* Sequence 1 in Master Mode */
+
+#define AD7877_CHANADD(x) ((x&0xF)<<7)
+#define AD7877_READADD(x) ((x)<<2)
+#define AD7877_WRITEADD(x) ((x)<<12)
+
+#define AD7877_READ_CHAN(x) (AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_SER | \
+ AD7877_MODE_SCC | AD7877_CHANADD(AD7877_REG_ ## x) | \
+ AD7877_READADD(AD7877_REG_ ## x))
+
+#define AD7877_MM_SEQUENCE (AD7877_SEQ_YPLUS_BIT | AD7877_SEQ_XPLUS_BIT | \
+ AD7877_SEQ_Z2_BIT | AD7877_SEQ_Z1_BIT)
+
+/*
+ * Non-touchscreen sensors only use single-ended conversions.
+ */
+
+struct ser_req {
+ u16 reset;
+ u16 ref_on;
+ u16 command;
+ u16 sample;
+ struct spi_message msg;
+ struct spi_transfer xfer[6];
+};
+
+struct ad7877 {
+ struct input_dev *input;
+ char phys[32];
+
+ struct spi_device *spi;
+ u16 model;
+ u16 vref_delay_usecs;
+ u16 x_plate_ohms;
+ u16 pressure_max;
+
+ u16 cmd_crtl1;
+ u16 cmd_crtl2;
+ u16 cmd_dummy;
+ u16 dac;
+
+ u8 stopacq_polarity;
+ u8 first_conversion_delay;
+ u8 acquisition_time;
+ u8 averaging;
+ u8 pen_down_acc_interval;
+
+ u16 conversion_data[AD7877_NR_SENSE];
+
+ struct spi_transfer xfer[AD7877_NR_SENSE + 2];
+ struct spi_message msg;
+
+ struct mutex mutex;
+ unsigned disabled:1; /* P: mutex */
+ unsigned gpio3:1; /* P: mutex */
+ unsigned gpio4:1; /* P: mutex */
+
+ spinlock_t lock;
+ struct timer_list timer; /* P: lock */
+ unsigned pending:1; /* P: lock */
+};
+
+static int gpio3;
+module_param(gpio3, int, 0);
+MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3");
+
+/*
+ * ad7877_read/write are only used for initial setup and for sysfs controls.
+ * The main traffic is done using spi_async() in the interrupt handler.
+ */
+
+static int ad7877_read(struct spi_device *spi, u16 reg)
+{
+ struct ser_req *req;
+ int status, ret;
+
+ req = kzalloc(sizeof *req, GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ spi_message_init(&req->msg);
+
+ req->command = (u16) (AD7877_WRITEADD(AD7877_REG_CTRL1) |
+ AD7877_READADD(reg));
+ req->xfer[0].tx_buf = &req->command;
+ req->xfer[0].len = 2;
+
+ req->xfer[1].rx_buf = &req->sample;
+ 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);
+ ret = status ? : req->sample;
+
+ kfree(req);
+
+ return ret;
+}
+
+static int ad7877_write(struct spi_device *spi, u16 reg, u16 val)
+{
+ struct ser_req *req;
+ int status;
+
+ req = kzalloc(sizeof *req, GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ spi_message_init(&req->msg);
+
+ req->command = (u16) (AD7877_WRITEADD(reg) | (val & MAX_12BIT));
+ req->xfer[0].tx_buf = &req->command;
+ req->xfer[0].len = 2;
+
+ spi_message_add_tail(&req->xfer[0], &req->msg);
+
+ status = spi_sync(spi, &req->msg);
+
+ kfree(req);
+
+ return status;
+}
+
+static int ad7877_read_adc(struct spi_device *spi, unsigned command)
+{
+ struct ad7877 *ts = dev_get_drvdata(&spi->dev);
+ struct ser_req *req;
+ int status;
+ int sample;
+ int i;
+
+ req = kzalloc(sizeof *req, GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ spi_message_init(&req->msg);
+
+ /* activate reference, so it has time to settle; */
+ req->ref_on = AD7877_WRITEADD(AD7877_REG_CTRL2) |
+ AD7877_POL(ts->stopacq_polarity) |
+ AD7877_AVG(0) | AD7877_PM(2) | AD7877_TMR(0) |
+ AD7877_ACQ(ts->acquisition_time) | AD7877_FCD(0);
+
+ req->reset = AD7877_WRITEADD(AD7877_REG_CTRL1) | AD7877_MODE_NOC;
+
+ req->command = (u16) command;
+
+ req->xfer[0].tx_buf = &req->reset;
+ req->xfer[0].len = 2;
+
+ req->xfer[1].tx_buf = &req->ref_on;
+ req->xfer[1].len = 2;
+ req->xfer[1].delay_usecs = ts->vref_delay_usecs;
+
+ req->xfer[2].tx_buf = &req->command;
+ req->xfer[2].len = 2;
+ req->xfer[2].delay_usecs = ts->vref_delay_usecs;
+
+ req->xfer[3].rx_buf = &req->sample;
+ req->xfer[3].len = 2;
+
+ req->xfer[4].tx_buf = &ts->cmd_crtl2; /*REF OFF*/
+ req->xfer[4].len = 2;
+
+ req->xfer[5].tx_buf = &ts->cmd_crtl1; /*DEFAULT*/
+ req->xfer[5].len = 2;
+
+ /* group all the transfers together, so we can't interfere with
+ * reading touchscreen state; disable penirq while sampling
+ */
+ for (i = 0; i < 6; i++)
+ spi_message_add_tail(&req->xfer[i], &req->msg);
+
+ status = spi_sync(spi, &req->msg);
+ sample = req->sample;
+
+ kfree(req);
+
+ return status ? : sample;
+}
+
+static void ad7877_rx(struct ad7877 *ts)
+{
+ struct input_dev *input_dev = ts->input;
+ unsigned Rt;
+ u16 x, y, z1, z2;
+
+ x = ts->conversion_data[AD7877_SEQ_XPOS] & MAX_12BIT;
+ y = ts->conversion_data[AD7877_SEQ_YPOS] & MAX_12BIT;
+ z1 = ts->conversion_data[AD7877_SEQ_Z1] & MAX_12BIT;
+ z2 = ts->conversion_data[AD7877_SEQ_Z2] & MAX_12BIT;
+
+ /*
+ * The samples processed here are already preprocessed by the AD7877.
+ * The preprocessing function consists of an averaging filter.
+ * The combination of 'first conversion delay' and averaging provides a robust solution,
+ * discarding the spurious noise in the signal and keeping only the data of interest.
+ * The size of the averaging filter is programmable. (dev.platform_data, see linux/spi/ad7877.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;
+
+ 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 inline void ad7877_ts_event_release(struct ad7877 *ts)
+{
+ struct input_dev *input_dev = ts->input;
+
+ input_report_abs(input_dev, ABS_PRESSURE, 0);
+ input_sync(input_dev);
+}
+
+static void ad7877_timer(unsigned long handle)
+{
+ struct ad7877 *ts = (void *)handle;
+
+ ad7877_ts_event_release(ts);
+}
+
+static irqreturn_t ad7877_irq(int irq, void *handle)
+{
+ struct ad7877 *ts = handle;
+ unsigned long flags;
+ int status;
+
+ /*
+ * 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, and we
+ * need to avoid that ts->msg doesn't get issued twice while in work.
+ */
+
+ spin_lock_irqsave(&ts->lock, flags);
+ if (!ts->pending) {
+ ts->pending = 1;
+
+ status = spi_async(ts->spi, &ts->msg);
+ if (status)
+ dev_err(&ts->spi->dev, "spi_sync --> %d\n", status);
+ }
+ spin_unlock_irqrestore(&ts->lock, flags);
+
+ return IRQ_HANDLED;
+}
+
+static void ad7877_callback(void *_ts)
+{
+ struct ad7877 *ts = _ts;
+
+ spin_lock_irq(&ts->lock);
+
+ ad7877_rx(ts);
+ ts->pending = 0;
+ mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
+
+ spin_unlock_irq(&ts->lock);
+}
+
+static void ad7877_disable(struct ad7877 *ts)
+{
+ mutex_lock(&ts->mutex);
+
+ if (!ts->disabled) {
+ ts->disabled = 1;
+ disable_irq(ts->spi->irq);
+
+ /* Wait for spi_async callback */
+ while (ts->pending)
+ msleep(1);
+
+ if (del_timer_sync(&ts->timer))
+ ad7877_ts_event_release(ts);
+ }
+
+ /* we know the chip's in lowpower mode since we always
+ * leave it that way after every request
+ */
+
+ mutex_unlock(&ts->mutex);
+}
+
+static void ad7877_enable(struct ad7877 *ts)
+{
+ mutex_lock(&ts->mutex);
+
+ if (ts->disabled) {
+ ts->disabled = 0;
+ enable_irq(ts->spi->irq);
+ }
+
+ mutex_unlock(&ts->mutex);
+}
+
+#define SHOW(name) static ssize_t \
+name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
+{ \
+ struct ad7877 *ts = dev_get_drvdata(dev); \
+ ssize_t v = ad7877_read_adc(ts->spi, \
+ AD7877_READ_CHAN(name)); \
+ if (v < 0) \
+ return v; \
+ return sprintf(buf, "%u\n", (unsigned) v); \
+} \
+static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
+
+SHOW(aux1)
+SHOW(aux2)
+SHOW(aux3)
+SHOW(bat1)
+SHOW(bat2)
+SHOW(temp1)
+SHOW(temp2)
+
+static ssize_t ad7877_disable_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", ts->disabled);
+}
+
+static ssize_t ad7877_disable_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+ unsigned long val;
+ int error;
+
+ error = strict_strtoul(buf, 10, &val);
+ if (error)
+ return error;
+
+ if (val)
+ ad7877_disable(ts);
+ else
+ ad7877_enable(ts);
+
+ return count;
+}
+
+static DEVICE_ATTR(disable, 0664, ad7877_disable_show, ad7877_disable_store);
+
+static ssize_t ad7877_dac_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", ts->dac);
+}
+
+static ssize_t ad7877_dac_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+ unsigned long val;
+ int error;
+
+ error = strict_strtoul(buf, 10, &val);
+ if (error)
+ return error;
+
+ mutex_lock(&ts->mutex);
+ ts->dac = val & 0xFF;
+ ad7877_write(ts->spi, AD7877_REG_DAC, (ts->dac << 4) | AD7877_DAC_CONF);
+ mutex_unlock(&ts->mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR(dac, 0664, ad7877_dac_show, ad7877_dac_store);
+
+static ssize_t ad7877_gpio3_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", ts->gpio3);
+}
+
+static ssize_t ad7877_gpio3_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+ unsigned long val;
+ int error;
+
+ error = strict_strtoul(buf, 10, &val);
+ if (error)
+ return error;
+
+ mutex_lock(&ts->mutex);
+ ts->gpio3 = !!val;
+ ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
+ (ts->gpio4 << 4) | (ts->gpio3 << 5));
+ mutex_unlock(&ts->mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR(gpio3, 0664, ad7877_gpio3_show, ad7877_gpio3_store);
+
+static ssize_t ad7877_gpio4_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+
+ return sprintf(buf, "%u\n", ts->gpio4);
+}
+
+static ssize_t ad7877_gpio4_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ad7877 *ts = dev_get_drvdata(dev);
+ unsigned long val;
+ int error;
+
+ error = strict_strtoul(buf, 10, &val);
+ if (error)
+ return error;
+
+ mutex_lock(&ts->mutex);
+ ts->gpio4 = !!val;
+ ad7877_write(ts->spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_DATA |
+ (ts->gpio4 << 4) | (ts->gpio3 << 5));
+ mutex_unlock(&ts->mutex);
+
+ return count;
+}
+
+static DEVICE_ATTR(gpio4, 0664, ad7877_gpio4_show, ad7877_gpio4_store);
+
+static struct attribute *ad7877_attributes[] = {
+ &dev_attr_temp1.attr,
+ &dev_attr_temp2.attr,
+ &dev_attr_aux1.attr,
+ &dev_attr_aux2.attr,
+ &dev_attr_bat1.attr,
+ &dev_attr_bat2.attr,
+ &dev_attr_disable.attr,
+ &dev_attr_dac.attr,
+ &dev_attr_gpio4.attr,
+ NULL
+};
+
+static const struct attribute_group ad7877_attr_group = {
+ .attrs = ad7877_attributes,
+};
+
+static void ad7877_setup_ts_def_msg(struct spi_device *spi, struct ad7877 *ts)
+{
+ struct spi_message *m;
+ int i;
+
+ ts->cmd_crtl2 = AD7877_WRITEADD(AD7877_REG_CTRL2) |
+ AD7877_POL(ts->stopacq_polarity) |
+ AD7877_AVG(ts->averaging) | AD7877_PM(1) |
+ AD7877_TMR(ts->pen_down_acc_interval) |
+ AD7877_ACQ(ts->acquisition_time) |
+ AD7877_FCD(ts->first_conversion_delay);
+
+ ad7877_write(spi, AD7877_REG_CTRL2, ts->cmd_crtl2);
+
+ ts->cmd_crtl1 = AD7877_WRITEADD(AD7877_REG_CTRL1) |
+ AD7877_READADD(AD7877_REG_XPLUS-1) |
+ AD7877_MODE_SEQ1 | AD7877_DFR;
+
+ ad7877_write(spi, AD7877_REG_CTRL1, ts->cmd_crtl1);
+
+ ts->cmd_dummy = 0;
+
+ m = &ts->msg;
+
+ spi_message_init(m);
+
+ m->complete = ad7877_callback;
+ m->context = ts;
+
+ ts->xfer[0].tx_buf = &ts->cmd_crtl1;
+ ts->xfer[0].len = 2;
+
+ spi_message_add_tail(&ts->xfer[0], m);
+
+ ts->xfer[1].tx_buf = &ts->cmd_dummy; /* Send ZERO */
+ ts->xfer[1].len = 2;
+
+ spi_message_add_tail(&ts->xfer[1], m);
+
+ for (i = 0; i < 11; i++) {
+ ts->xfer[i + 2].rx_buf = &ts->conversion_data[AD7877_SEQ_YPOS + i];
+ ts->xfer[i + 2].len = 2;
+ spi_message_add_tail(&ts->xfer[i + 2], m);
+ }
+}
+
+static int __devinit ad7877_probe(struct spi_device *spi)
+{
+ struct ad7877 *ts;
+ struct input_dev *input_dev;
+ struct ad7877_platform_data *pdata = spi->dev.platform_data;
+ int err;
+ u16 verify;
+
+ if (!spi->irq) {
+ dev_dbg(&spi->dev, "no IRQ?\n");
+ return -ENODEV;
+ }
+
+ if (!pdata) {
+ dev_dbg(&spi->dev, "no platform data?\n");
+ return -ENODEV;
+ }
+
+ /* don't exceed max specified SPI CLK frequency */
+ if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
+ dev_dbg(&spi->dev, "SPI CLK %d Hz?\n",spi->max_speed_hz);
+ return -EINVAL;
+ }
+
+ ts = kzalloc(sizeof(struct ad7877), GFP_KERNEL);
+ input_dev = input_allocate_device();
+ if (!ts || !input_dev) {
+ err = -ENOMEM;
+ goto err_free_mem;
+ }
+
+ dev_set_drvdata(&spi->dev, ts);
+ ts->spi = spi;
+ ts->input = input_dev;
+
+ setup_timer(&ts->timer, ad7877_timer, (unsigned long) ts);
+ mutex_init(&ts->mutex);
+ spin_lock_init(&ts->lock);
+
+ ts->model = pdata->model ? : 7877;
+ ts->vref_delay_usecs = pdata->vref_delay_usecs ? : 100;
+ ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
+ ts->pressure_max = pdata->pressure_max ? : ~0;
+
+ ts->stopacq_polarity = pdata->stopacq_polarity;
+ 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;
+
+ snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&spi->dev));
+
+ input_dev->name = "AD7877 Touchscreen";
+ input_dev->phys = ts->phys;
+ input_dev->dev.parent = &spi->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);
+
+ ad7877_write(spi, AD7877_REG_SEQ1, AD7877_MM_SEQUENCE);
+
+ verify = ad7877_read(spi, AD7877_REG_SEQ1);
+
+ if (verify != AD7877_MM_SEQUENCE){
+ dev_err(&spi->dev, "%s: Failed to probe %s\n",
+ dev_name(&spi->dev), input_dev->name);
+ err = -ENODEV;
+ goto err_free_mem;
+ }
+
+ if (gpio3)
+ ad7877_write(spi, AD7877_REG_EXTWRITE, AD7877_EXTW_GPIO_3_CONF);
+
+ ad7877_setup_ts_def_msg(spi, ts);
+
+ /* Request AD7877 /DAV GPIO interrupt */
+
+ err = request_irq(spi->irq, ad7877_irq, IRQF_TRIGGER_FALLING |
+ IRQF_SAMPLE_RANDOM, spi->dev.driver->name, ts);
+ if (err) {
+ dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
+ goto err_free_mem;
+ }
+
+ err = sysfs_create_group(&spi->dev.kobj, &ad7877_attr_group);
+ if (err)
+ goto err_free_irq;
+
+ err = device_create_file(&spi->dev,
+ gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
+ if (err)
+ goto err_remove_attr_group;
+
+ err = input_register_device(input_dev);
+ if (err)
+ goto err_remove_attr;
+
+ return 0;
+
+err_remove_attr:
+ device_remove_file(&spi->dev,
+ gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
+err_remove_attr_group:
+ sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
+err_free_irq:
+ free_irq(spi->irq, ts);
+err_free_mem:
+ input_free_device(input_dev);
+ kfree(ts);
+ dev_set_drvdata(&spi->dev, NULL);
+ return err;
+}
+
+static int __devexit ad7877_remove(struct spi_device *spi)
+{
+ struct ad7877 *ts = dev_get_drvdata(&spi->dev);
+
+ sysfs_remove_group(&spi->dev.kobj, &ad7877_attr_group);
+ device_remove_file(&spi->dev,
+ gpio3 ? &dev_attr_gpio3 : &dev_attr_aux3);
+
+ ad7877_disable(ts);
+ free_irq(ts->spi->irq, ts);
+
+ input_unregister_device(ts->input);
+ kfree(ts);
+
+ dev_dbg(&spi->dev, "unregistered touchscreen\n");
+ dev_set_drvdata(&spi->dev, NULL);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int ad7877_suspend(struct spi_device *spi, pm_message_t message)
+{
+ struct ad7877 *ts = dev_get_drvdata(&spi->dev);
+
+ ad7877_disable(ts);
+
+ return 0;
+}
+
+static int ad7877_resume(struct spi_device *spi)
+{
+ struct ad7877 *ts = dev_get_drvdata(&spi->dev);
+
+ ad7877_enable(ts);
+
+ return 0;
+}
+#else
+#define ad7877_suspend NULL
+#define ad7877_resume NULL
+#endif
+
+static struct spi_driver ad7877_driver = {
+ .driver = {
+ .name = "ad7877",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7877_probe,
+ .remove = __devexit_p(ad7877_remove),
+ .suspend = ad7877_suspend,
+ .resume = ad7877_resume,
+};
+
+static int __init ad7877_init(void)
+{
+ return spi_register_driver(&ad7877_driver);
+}
+module_init(ad7877_init);
+
+static void __exit ad7877_exit(void)
+{
+ spi_unregister_driver(&ad7877_driver);
+}
+module_exit(ad7877_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("AD7877 touchscreen Driver");
+MODULE_LICENSE("GPL");
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