blob: c6164b6f476a3ecb5fde27af07ddd05c38557d01 [file] [log] [blame]
/*
* ADS7846 based touchscreen and sensor driver
*
* 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
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#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/ads7846.h>
#include <asm/irq.h>
#ifdef CONFIG_ARM
#include <asm/mach-types.h>
#ifdef CONFIG_ARCH_OMAP
#include <asm/arch/gpio.h>
#endif
#endif
/*
* This code has been heavily tested on a Nokia 770, and lightly
* tested on other ads7846 devices (OSK/Mistral, Lubbock).
* Support for ads7843 and ads7845 has only been stubbed in.
*
* IRQ handling needs a workaround because of a shortcoming in handling
* edge triggered IRQs on some platforms like the OMAP1/2. These
* platforms don't handle the ARM lazy IRQ disabling properly, thus we
* have to maintain our own SW IRQ disabled status. This should be
* removed as soon as the affected platform's IRQ handling is fixed.
*
* app note sbaa036 talks in more detail about accurate sampling...
* that ought to help in situations like LCDs inducing noise (which
* can also be helped by using synch signals) and more generally.
* This driver tries to utilize the measures described in the app
* note. The strength of filtering can be set in the board-* specific
* files.
*/
#define TS_POLL_PERIOD msecs_to_jiffies(10)
/* this driver doesn't aim at the peak continuous sample rate */
#define SAMPLE_BITS (8 /*cmd*/ + 16 /*sample*/ + 2 /* before, after */)
struct ts_event {
/* For portability, we can't read 12 bit values using SPI (which
* would make the controller deliver them as native byteorder u16
* with msbs zeroed). Instead, we read them as two 8-bit values,
* which need byteswapping then range adjustment.
*/
__be16 x;
__be16 y;
__be16 z1, z2;
int ignore;
};
struct ads7846 {
struct input_dev *input;
char phys[32];
struct spi_device *spi;
struct attribute_group *attr_group;
u16 model;
u16 vref_delay_usecs;
u16 x_plate_ohms;
u16 pressure_max;
u8 read_x, read_y, read_z1, read_z2, pwrdown;
u16 dummy; /* for the pwrdown read */
struct ts_event tc;
struct spi_transfer xfer[10];
struct spi_message msg[5];
struct spi_message *last_msg;
int msg_idx;
int read_cnt;
int read_rep;
int last_read;
u16 debounce_max;
u16 debounce_tol;
u16 debounce_rep;
spinlock_t lock;
struct timer_list timer; /* P: lock */
unsigned pendown:1; /* P: lock */
unsigned pending:1; /* P: lock */
// FIXME remove "irq_disabled"
unsigned irq_disabled:1; /* P: lock */
unsigned disabled:1;
int (*get_pendown_state)(void);
};
/* leave chip selected when we're done, for quicker re-select? */
#if 0
#define CS_CHANGE(xfer) ((xfer).cs_change = 1)
#else
#define CS_CHANGE(xfer) ((xfer).cs_change = 0)
#endif
/*--------------------------------------------------------------------------*/
/* The ADS7846 has touchscreen and other sensors.
* Earlier ads784x chips are somewhat compatible.
*/
#define ADS_START (1 << 7)
#define ADS_A2A1A0_d_y (1 << 4) /* differential */
#define ADS_A2A1A0_d_z1 (3 << 4) /* differential */
#define ADS_A2A1A0_d_z2 (4 << 4) /* differential */
#define ADS_A2A1A0_d_x (5 << 4) /* differential */
#define ADS_A2A1A0_temp0 (0 << 4) /* non-differential */
#define ADS_A2A1A0_vbatt (2 << 4) /* non-differential */
#define ADS_A2A1A0_vaux (6 << 4) /* non-differential */
#define ADS_A2A1A0_temp1 (7 << 4) /* non-differential */
#define ADS_8_BIT (1 << 3)
#define ADS_12_BIT (0 << 3)
#define ADS_SER (1 << 2) /* non-differential */
#define ADS_DFR (0 << 2) /* differential */
#define ADS_PD10_PDOWN (0 << 0) /* lowpower mode + penirq */
#define ADS_PD10_ADC_ON (1 << 0) /* ADC on */
#define ADS_PD10_REF_ON (2 << 0) /* vREF on + penirq */
#define ADS_PD10_ALL_ON (3 << 0) /* ADC + vREF on */
#define MAX_12BIT ((1<<12)-1)
/* leave ADC powered up (disables penirq) between differential samples */
#define READ_12BIT_DFR(x) (ADS_START | ADS_A2A1A0_d_ ## x \
| ADS_12_BIT | ADS_DFR)
#define READ_Y (READ_12BIT_DFR(y) | ADS_PD10_ADC_ON)
#define READ_Z1 (READ_12BIT_DFR(z1) | ADS_PD10_ADC_ON)
#define READ_Z2 (READ_12BIT_DFR(z2) | ADS_PD10_ADC_ON)
#define READ_X (READ_12BIT_DFR(x) | ADS_PD10_ADC_ON)
#define PWRDOWN (READ_12BIT_DFR(y) | ADS_PD10_PDOWN) /* LAST */
/* single-ended samples need to first power up reference voltage;
* we leave both ADC and VREF powered
*/
#define READ_12BIT_SER(x) (ADS_START | ADS_A2A1A0_ ## x \
| ADS_12_BIT | ADS_SER)
#define REF_ON (READ_12BIT_DFR(x) | ADS_PD10_ALL_ON)
#define REF_OFF (READ_12BIT_DFR(y) | ADS_PD10_PDOWN)
/*--------------------------------------------------------------------------*/
/*
* Non-touchscreen sensors only use single-ended conversions.
*/
struct ser_req {
u8 ref_on;
u8 command;
u8 ref_off;
u16 scratch;
__be16 sample;
struct spi_message msg;
struct spi_transfer xfer[6];
};
static void ads7846_enable(struct ads7846 *ts);
static void ads7846_disable(struct ads7846 *ts);
static int device_suspended(struct device *dev)
{
struct ads7846 *ts = dev_get_drvdata(dev);
return dev->power.power_state.event != PM_EVENT_ON || ts->disabled;
}
static int ads7846_read12_ser(struct device *dev, unsigned command)
{
struct spi_device *spi = to_spi_device(dev);
struct ads7846 *ts = dev_get_drvdata(dev);
struct ser_req *req = kzalloc(sizeof *req, GFP_KERNEL);
int status;
int sample;
int i;
if (!req)
return -ENOMEM;
spi_message_init(&req->msg);
/* activate reference, so it has time to settle; */
req->ref_on = REF_ON;
req->xfer[0].tx_buf = &req->ref_on;
req->xfer[0].len = 1;
req->xfer[1].rx_buf = &req->scratch;
req->xfer[1].len = 2;
/*
* for external VREF, 0 usec (and assume it's always on);
* for 1uF, use 800 usec;
* no cap, 100 usec.
*/
req->xfer[1].delay_usecs = ts->vref_delay_usecs;
/* take sample */
req->command = (u8) command;
req->xfer[2].tx_buf = &req->command;
req->xfer[2].len = 1;
req->xfer[3].rx_buf = &req->sample;
req->xfer[3].len = 2;
/* REVISIT: take a few more samples, and compare ... */
/* turn off reference */
req->ref_off = REF_OFF;
req->xfer[4].tx_buf = &req->ref_off;
req->xfer[4].len = 1;
req->xfer[5].rx_buf = &req->scratch;
req->xfer[5].len = 2;
CS_CHANGE(req->xfer[5]);
/* 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);
ts->irq_disabled = 1;
disable_irq(spi->irq);
status = spi_sync(spi, &req->msg);
ts->irq_disabled = 0;
enable_irq(spi->irq);
if (req->msg.status)
status = req->msg.status;
/* on-wire is a must-ignore bit, a BE12 value, then padding */
sample = be16_to_cpu(req->sample);
sample = sample >> 3;
sample &= 0x0fff;
kfree(req);
return status ? status : sample;
}
#define SHOW(name) static ssize_t \
name ## _show(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
ssize_t v = ads7846_read12_ser(dev, \
READ_12BIT_SER(name) | ADS_PD10_ALL_ON); \
if (v < 0) \
return v; \
return sprintf(buf, "%u\n", (unsigned) v); \
} \
static DEVICE_ATTR(name, S_IRUGO, name ## _show, NULL);
SHOW(temp0)
SHOW(temp1)
SHOW(vaux)
SHOW(vbatt)
static int is_pen_down(struct device *dev)
{
struct ads7846 *ts = dev_get_drvdata(dev);
return ts->pendown;
}
static ssize_t ads7846_pen_down_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "%u\n", is_pen_down(dev));
}
static DEVICE_ATTR(pen_down, S_IRUGO, ads7846_pen_down_show, NULL);
static ssize_t ads7846_disable_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ads7846 *ts = dev_get_drvdata(dev);
return sprintf(buf, "%u\n", ts->disabled);
}
static ssize_t ads7846_disable_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ads7846 *ts = dev_get_drvdata(dev);
char *endp;
int i;
i = simple_strtoul(buf, &endp, 10);
spin_lock_irq(&ts->lock);
if (i)
ads7846_disable(ts);
else
ads7846_enable(ts);
spin_unlock_irq(&ts->lock);
return count;
}
static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
static struct attribute *ads7846_attributes[] = {
&dev_attr_temp0.attr,
&dev_attr_temp1.attr,
&dev_attr_vbatt.attr,
&dev_attr_vaux.attr,
&dev_attr_pen_down.attr,
&dev_attr_disable.attr,
NULL,
};
static struct attribute_group ads7846_attr_group = {
.attrs = ads7846_attributes,
};
/*
* ads7843/7845 don't have temperature sensors, and
* use the other sensors a bit differently too
*/
static struct attribute *ads7843_attributes[] = {
&dev_attr_vbatt.attr,
&dev_attr_vaux.attr,
&dev_attr_pen_down.attr,
&dev_attr_disable.attr,
NULL,
};
static struct attribute_group ads7843_attr_group = {
.attrs = ads7843_attributes,
};
static struct attribute *ads7845_attributes[] = {
&dev_attr_vaux.attr,
&dev_attr_pen_down.attr,
&dev_attr_disable.attr,
NULL,
};
static struct attribute_group ads7845_attr_group = {
.attrs = ads7845_attributes,
};
/*--------------------------------------------------------------------------*/
/*
* PENIRQ only kicks the timer. The timer only reissues the SPI transfer,
* to retrieve touchscreen status.
*
* The SPI transfer completion callback does the real work. It reports
* touchscreen events and reactivates the timer (or IRQ) as appropriate.
*/
static void ads7846_rx(void *ads)
{
struct ads7846 *ts = ads;
struct input_dev *input_dev = ts->input;
unsigned Rt;
unsigned sync = 0;
u16 x, y, z1, z2;
unsigned long flags;
/* adjust: on-wire is a must-ignore bit, a BE12 value, then padding;
* built from two 8 bit values written msb-first.
*/
x = (be16_to_cpu(ts->tc.x) >> 3) & 0x0fff;
y = (be16_to_cpu(ts->tc.y) >> 3) & 0x0fff;
z1 = (be16_to_cpu(ts->tc.z1) >> 3) & 0x0fff;
z2 = (be16_to_cpu(ts->tc.z2) >> 3) & 0x0fff;
/* range filtering */
if (x == MAX_12BIT)
x = 0;
if (likely(x && z1 && !device_suspended(&ts->spi->dev))) {
/* compute touch pressure resistance using equation #2 */
Rt = z2;
Rt -= z1;
Rt *= x;
Rt *= ts->x_plate_ohms;
Rt /= z1;
Rt = (Rt + 2047) >> 12;
} else
Rt = 0;
/* Sample found inconsistent by debouncing or pressure is beyond
* the maximum. Don't report it to user space, repeat at least
* once more the measurement */
if (ts->tc.ignore || Rt > ts->pressure_max) {
mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
return;
}
/* NOTE: "pendown" is inferred from pressure; we don't rely on
* being able to check nPENIRQ status, or "friendly" trigger modes
* (both-edges is much better than just-falling or low-level).
*
* REVISIT: some boards may require reading nPENIRQ; it's
* needed on 7843. and 7845 reads pressure differently...
*
* REVISIT: the touchscreen might not be connected; this code
* won't notice that, even if nPENIRQ never fires ...
*/
if (!ts->pendown && Rt != 0) {
input_report_key(input_dev, BTN_TOUCH, 1);
sync = 1;
} else if (ts->pendown && Rt == 0) {
input_report_key(input_dev, BTN_TOUCH, 0);
sync = 1;
}
if (Rt) {
input_report_abs(input_dev, ABS_X, x);
input_report_abs(input_dev, ABS_Y, y);
sync = 1;
}
if (sync) {
input_report_abs(input_dev, ABS_PRESSURE, Rt);
input_sync(input_dev);
}
#ifdef VERBOSE
if (Rt || ts->pendown)
pr_debug("%s: %d/%d/%d%s\n", ts->spi->dev.bus_id,
x, y, Rt, Rt ? "" : " UP");
#endif
spin_lock_irqsave(&ts->lock, flags);
ts->pendown = (Rt != 0);
mod_timer(&ts->timer, jiffies + TS_POLL_PERIOD);
spin_unlock_irqrestore(&ts->lock, flags);
}
static void ads7846_debounce(void *ads)
{
struct ads7846 *ts = ads;
struct spi_message *m;
struct spi_transfer *t;
int val;
int status;
m = &ts->msg[ts->msg_idx];
t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
val = (be16_to_cpu(*(__be16 *)t->rx_buf) >> 3) & 0x0fff;
if (!ts->read_cnt || (abs(ts->last_read - val) > ts->debounce_tol)) {
/* Repeat it, if this was the first read or the read
* wasn't consistent enough. */
if (ts->read_cnt < ts->debounce_max) {
ts->last_read = val;
ts->read_cnt++;
} else {
/* Maximum number of debouncing reached and still
* not enough number of consistent readings. Abort
* the whole sample, repeat it in the next sampling
* period.
*/
ts->tc.ignore = 1;
ts->read_cnt = 0;
/* Last message will contain ads7846_rx() as the
* completion function.
*/
m = ts->last_msg;
}
/* Start over collecting consistent readings. */
ts->read_rep = 0;
} else {
if (++ts->read_rep > ts->debounce_rep) {
/* Got a good reading for this coordinate,
* go for the next one. */
ts->tc.ignore = 0;
ts->msg_idx++;
ts->read_cnt = 0;
ts->read_rep = 0;
m++;
} else
/* Read more values that are consistent. */
ts->read_cnt++;
}
status = spi_async(ts->spi, m);
if (status)
dev_err(&ts->spi->dev, "spi_async --> %d\n",
status);
}
static void ads7846_timer(unsigned long handle)
{
struct ads7846 *ts = (void *)handle;
int status = 0;
spin_lock_irq(&ts->lock);
if (unlikely(ts->msg_idx && !ts->pendown)) {
/* measurement cycle ended */
if (!device_suspended(&ts->spi->dev)) {
ts->irq_disabled = 0;
enable_irq(ts->spi->irq);
}
ts->pending = 0;
ts->msg_idx = 0;
} else {
/* pen is still down, continue with the measurement */
ts->msg_idx = 0;
status = spi_async(ts->spi, &ts->msg[0]);
if (status)
dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
}
spin_unlock_irq(&ts->lock);
}
static irqreturn_t ads7846_irq(int irq, void *handle)
{
struct ads7846 *ts = handle;
unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
if (likely(ts->get_pendown_state())) {
if (!ts->irq_disabled) {
/* The ARM do_simple_IRQ() dispatcher doesn't act
* like the other dispatchers: it will report IRQs
* even after they've been disabled. We work around
* that here. (The "generic irq" framework may help...)
*/
ts->irq_disabled = 1;
disable_irq(ts->spi->irq);
ts->pending = 1;
mod_timer(&ts->timer, jiffies);
}
}
spin_unlock_irqrestore(&ts->lock, flags);
return IRQ_HANDLED;
}
/*--------------------------------------------------------------------------*/
/* Must be called with ts->lock held */
static void ads7846_disable(struct ads7846 *ts)
{
if (ts->disabled)
return;
ts->disabled = 1;
/* are we waiting for IRQ, or polling? */
if (!ts->pending) {
ts->irq_disabled = 1;
disable_irq(ts->spi->irq);
} else {
/* the timer will run at least once more, and
* leave everything in a clean state, IRQ disabled
*/
while (ts->pending) {
spin_unlock_irq(&ts->lock);
msleep(1);
spin_lock_irq(&ts->lock);
}
}
/* we know the chip's in lowpower mode since we always
* leave it that way after every request
*/
}
/* Must be called with ts->lock held */
static void ads7846_enable(struct ads7846 *ts)
{
if (!ts->disabled)
return;
ts->disabled = 0;
ts->irq_disabled = 0;
enable_irq(ts->spi->irq);
}
static int ads7846_suspend(struct spi_device *spi, pm_message_t message)
{
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
spin_lock_irq(&ts->lock);
spi->dev.power.power_state = message;
ads7846_disable(ts);
spin_unlock_irq(&ts->lock);
return 0;
}
static int ads7846_resume(struct spi_device *spi)
{
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
spin_lock_irq(&ts->lock);
spi->dev.power.power_state = PMSG_ON;
ads7846_enable(ts);
spin_unlock_irq(&ts->lock);
return 0;
}
static int __devinit ads7846_probe(struct spi_device *spi)
{
struct ads7846 *ts;
struct input_dev *input_dev;
struct ads7846_platform_data *pdata = spi->dev.platform_data;
struct spi_message *m;
struct spi_transfer *x;
int err;
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 sample rate */
if (spi->max_speed_hz > (125000 * SAMPLE_BITS)) {
dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
(spi->max_speed_hz/SAMPLE_BITS)/1000);
return -EINVAL;
}
/* REVISIT when the irq can be triggered active-low, or if for some
* reason the touchscreen isn't hooked up, we don't need to access
* the pendown state.
*/
if (pdata->get_pendown_state == NULL) {
dev_dbg(&spi->dev, "no get_pendown_state function?\n");
return -EINVAL;
}
/* We'd set TX wordsize 8 bits and RX wordsize to 13 bits ... except
* that even if the hardware can do that, the SPI controller driver
* may not. So we stick to very-portable 8 bit words, both RX and TX.
*/
spi->bits_per_word = 8;
ts = kzalloc(sizeof(struct ads7846), GFP_KERNEL);
input_dev = input_allocate_device();
if (!ts || !input_dev) {
err = -ENOMEM;
goto err_free_mem;
}
dev_set_drvdata(&spi->dev, ts);
spi->dev.power.power_state = PMSG_ON;
ts->spi = spi;
ts->input = input_dev;
init_timer(&ts->timer);
ts->timer.data = (unsigned long) ts;
ts->timer.function = ads7846_timer;
spin_lock_init(&ts->lock);
ts->model = pdata->model ? : 7846;
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;
if (pdata->debounce_max) {
ts->debounce_max = pdata->debounce_max;
ts->debounce_tol = pdata->debounce_tol;
ts->debounce_rep = pdata->debounce_rep;
if (ts->debounce_rep > ts->debounce_max + 1)
ts->debounce_rep = ts->debounce_max - 1;
} else
ts->debounce_tol = ~0;
ts->get_pendown_state = pdata->get_pendown_state;
snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
input_dev->name = "ADS784x Touchscreen";
input_dev->phys = ts->phys;
input_dev->cdev.dev = &spi->dev;
input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
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);
/* set up the transfers to read touchscreen state; this assumes we
* use formula #2 for pressure, not #3.
*/
m = &ts->msg[0];
x = ts->xfer;
spi_message_init(m);
/* y- still on; turn on only y+ (and ADC) */
ts->read_y = READ_Y;
x->tx_buf = &ts->read_y;
x->len = 1;
spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.y;
x->len = 2;
spi_message_add_tail(x, m);
m->complete = ads7846_debounce;
m->context = ts;
m++;
spi_message_init(m);
/* turn y- off, x+ on, then leave in lowpower */
x++;
ts->read_x = READ_X;
x->tx_buf = &ts->read_x;
x->len = 1;
spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.x;
x->len = 2;
spi_message_add_tail(x, m);
m->complete = ads7846_debounce;
m->context = ts;
/* turn y+ off, x- on; we'll use formula #2 */
if (ts->model == 7846) {
m++;
spi_message_init(m);
x++;
ts->read_z1 = READ_Z1;
x->tx_buf = &ts->read_z1;
x->len = 1;
spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.z1;
x->len = 2;
spi_message_add_tail(x, m);
m->complete = ads7846_debounce;
m->context = ts;
m++;
spi_message_init(m);
x++;
ts->read_z2 = READ_Z2;
x->tx_buf = &ts->read_z2;
x->len = 1;
spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.z2;
x->len = 2;
spi_message_add_tail(x, m);
m->complete = ads7846_debounce;
m->context = ts;
}
/* power down */
m++;
spi_message_init(m);
x++;
ts->pwrdown = PWRDOWN;
x->tx_buf = &ts->pwrdown;
x->len = 1;
spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->dummy;
x->len = 2;
CS_CHANGE(*x);
spi_message_add_tail(x, m);
m->complete = ads7846_rx;
m->context = ts;
ts->last_msg = m;
if (request_irq(spi->irq, ads7846_irq, IRQF_TRIGGER_FALLING,
spi->dev.driver->name, ts)) {
dev_dbg(&spi->dev, "irq %d busy?\n", spi->irq);
err = -EBUSY;
goto err_free_mem;
}
dev_info(&spi->dev, "touchscreen, irq %d\n", spi->irq);
/* take a first sample, leaving nPENIRQ active; avoid
* the touchscreen, in case it's not connected.
*/
(void) ads7846_read12_ser(&spi->dev,
READ_12BIT_SER(vaux) | ADS_PD10_ALL_ON);
switch (ts->model) {
case 7846:
ts->attr_group = &ads7846_attr_group;
break;
case 7845:
ts->attr_group = &ads7845_attr_group;
break;
default:
ts->attr_group = &ads7843_attr_group;
break;
}
err = sysfs_create_group(&spi->dev.kobj, ts->attr_group);
if (err)
goto err_free_irq;
err = input_register_device(input_dev);
if (err)
goto err_remove_attr_group;
return 0;
err_remove_attr_group:
sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
err_free_irq:
free_irq(spi->irq, ts);
err_free_mem:
input_free_device(input_dev);
kfree(ts);
return err;
}
static int __devexit ads7846_remove(struct spi_device *spi)
{
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
input_unregister_device(ts->input);
ads7846_suspend(spi, PMSG_SUSPEND);
sysfs_remove_group(&spi->dev.kobj, ts->attr_group);
free_irq(ts->spi->irq, ts);
/* suspend left the IRQ disabled */
enable_irq(ts->spi->irq);
kfree(ts);
dev_dbg(&spi->dev, "unregistered touchscreen\n");
return 0;
}
static struct spi_driver ads7846_driver = {
.driver = {
.name = "ads7846",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = ads7846_probe,
.remove = __devexit_p(ads7846_remove),
.suspend = ads7846_suspend,
.resume = ads7846_resume,
};
static int __init ads7846_init(void)
{
/* grr, board-specific init should stay out of drivers!! */
#ifdef CONFIG_ARCH_OMAP
if (machine_is_omap_osk()) {
/* GPIO4 = PENIRQ; GPIO6 = BUSY */
omap_request_gpio(4);
omap_set_gpio_direction(4, 1);
omap_request_gpio(6);
omap_set_gpio_direction(6, 1);
}
// also TI 1510 Innovator, bitbanging through FPGA
// also Nokia 770
// also Palm Tungsten T2
#endif
// PXA:
// also Dell Axim X50
// also HP iPaq H191x/H192x/H415x/H435x
// also Intel Lubbock (additional to UCB1400; as temperature sensor)
// also Sharp Zaurus C7xx, C8xx (corgi/sheperd/husky)
// Atmel at91sam9261-EK uses ads7843
// also various AMD Au1x00 devel boards
return spi_register_driver(&ads7846_driver);
}
module_init(ads7846_init);
static void __exit ads7846_exit(void)
{
spi_unregister_driver(&ads7846_driver);
#ifdef CONFIG_ARCH_OMAP
if (machine_is_omap_osk()) {
omap_free_gpio(4);
omap_free_gpio(6);
}
#endif
}
module_exit(ads7846_exit);
MODULE_DESCRIPTION("ADS7846 TouchScreen Driver");
MODULE_LICENSE("GPL");