* ADS7846 based touchscreen and sensor driver
*
* Copyright (c) 2005 David Brownell
+ * Copyright (c) 2006 Imre Deak <imre.deak@nokia.com>
*
* Using code from:
* - corgi_ts.c
/*
- * This code has been lightly tested on an ads7846.
+ * This code has been heavily tested on a Nokia 770, and lightly
+ * tested on an other ads7846 device.
* Support for ads7843 and ads7845 has only been stubbed in.
*
- * Not yet done: investigate the values reported. Are x/y/pressure
- * event values sane enough for X11? How accurate are the temperature
- * and voltage readings? (System-specific calibration should support
+ * Not yet done: How accurate are the temperature and voltage
+ * readings? (System-specific calibration should support
* accuracy of 0.3 degrees C; otherwise it's 2.0 degrees.)
*
+ * 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 platforms' 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)
struct ts_event tc;
struct spi_transfer xfer[10];
- struct spi_message msg;
+ struct spi_message msg[5];
+ int msg_idx;
+ int read_cnt;
+ int last_read;
+
+ u16 debounce_max;
+ u16 debounce_tol;
spinlock_t lock;
struct timer_list timer; /* P: lock */
unsigned pending:1; /* P: lock */
// FIXME remove "irq_disabled"
unsigned irq_disabled:1; /* P: lock */
+ unsigned disabled:1;
};
/* leave chip selected when we're done, for quicker re-select? */
struct spi_transfer xfer[6];
};
+static void ads7846_enable(struct ads7846 *ts);
+static void ads7846_disable(struct ads7846 *ts);
+
static int ads7846_read12_ser(struct device *dev, unsigned command)
{
struct spi_device *spi = to_spi_device(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);
+ unsigned long flags;
+ char *endp;
+ int i;
+
+ i = simple_strtoul(buf, &endp, 10);
+ spin_lock_irqsave(&ts->lock, flags);
+
+ if (i)
+ ads7846_disable(ts);
+ else
+ ads7846_enable(ts);
+
+ spin_unlock_irqrestore(&ts->lock, flags);
+
+ return count;
+}
+
+static DEVICE_ATTR(disable, 0664, ads7846_disable_show, ads7846_disable_store);
+
/*--------------------------------------------------------------------------*/
/*
spin_unlock_irqrestore(&ts->lock, flags);
}
+static void ads7846_debounce(void *ads)
+{
+ struct ads7846 *ts = ads;
+ struct spi_message *m;
+ struct spi_transfer *t;
+ u16 val;
+ int status;
+
+ m = &ts->msg[ts->msg_idx];
+ t = list_entry(m->transfers.prev, struct spi_transfer, transfer_list);
+ val = (*(u16 *)t->rx_buf) >> 3;
+
+ if (!ts->read_cnt || (abs(ts->last_read - val) > ts->debounce_tol &&
+ ts->read_cnt < ts->debounce_max)) {
+ /* Repeat it, if this was the first read or the read wasn't
+ * consistent enough */
+ ts->read_cnt++;
+ ts->last_read = val;
+ } else {
+ /* Go for the next read */
+ ts->msg_idx++;
+ ts->read_cnt = 0;
+ m++;
+ }
+ 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;
- unsigned long flags;
+
+ ts->msg_idx = 0;
+ status = spi_async(ts->spi, &ts->msg[0]);
+ if (status)
+ dev_err(&ts->spi->dev, "spi_async --> %d\n", status);
+}
+
+static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs)
+{
+ struct ads7846 *ts = handle;
+ unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
- if (!ts->pending) {
- ts->pending = 1;
+ if (likely(!ts->irq_disabled && !ts->disabled)) {
if (!ts->irq_disabled) {
ts->irq_disabled = 1;
+ /* The following has at the moment no effect whatsoever
+ * on OMAP, that's why we maintain the disabled
+ * state ourselves */
disable_irq(ts->spi->irq);
}
- status = spi_async(ts->spi, &ts->msg);
- if (status)
- dev_err(&ts->spi->dev, "spi_async --> %d\n",
- status);
+ if (!ts->pending) {
+ ts->pending = 1;
+ mod_timer(&ts->timer, jiffies);
+ }
}
spin_unlock_irqrestore(&ts->lock, flags);
-}
-static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs)
-{
- ads7846_timer((unsigned long) handle);
return IRQ_HANDLED;
}
/*--------------------------------------------------------------------------*/
-static int
-ads7846_suspend(struct spi_device *spi, pm_message_t message)
+/* Must be called with ts->lock held */
+static void ads7846_disable(struct ads7846 *ts)
{
- struct ads7846 *ts = dev_get_drvdata(&spi->dev);
- unsigned long flags;
-
- spin_lock_irqsave(&ts->lock, flags);
-
- spi->dev.power.power_state = message;
+ if (ts->disabled)
+ return;
/* are we waiting for IRQ, or polling? */
if (!ts->pendown) {
disable_irq(ts->spi->irq);
}
} else {
+ unsigned long flags;
+
/* polling; force a final SPI completion;
* that will clean things up neatly
*/
while (ts->pendown || ts->pending) {
spin_unlock_irqrestore(&ts->lock, flags);
- udelay(10);
+ msleep(1);
spin_lock_irqsave(&ts->lock, flags);
}
}
* leave it that way after every request
*/
+ ts->disabled = 1;
+}
+
+/* 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);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ts->lock, flags);
+
+ spi->dev.power.power_state = message;
+ ads7846_disable(ts);
+
spin_unlock_irqrestore(&ts->lock, flags);
+
return 0;
+
}
static int ads7846_resume(struct spi_device *spi)
{
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
+ unsigned long flags;
+
+ spin_lock_irqsave(&ts->lock, flags);
- ts->irq_disabled = 0;
- enable_irq(ts->spi->irq);
spi->dev.power.power_state = PMSG_ON;
+ ads7846_enable(ts);
+
+ spin_unlock_irqrestore(&ts->lock, flags);
+
return 0;
}
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;
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->debounce_max = pdata->debounce_max ? : 1;
+ ts->debounce_tol = pdata->debounce_tol ? : 10;
snprintf(ts->phys, sizeof(ts->phys), "%s/input0", spi->dev.bus_id);
/* set up the transfers to read touchscreen state; this assumes we
* use formula #2 for pressure, not #3.
*/
- spi_message_init(&ts->msg);
+ 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, &ts->msg);
+ spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.y;
x->len = 2;
- spi_message_add_tail(x, &ts->msg);
+ 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, &ts->msg);
+ spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.z1;
x->len = 2;
- spi_message_add_tail(x, &ts->msg);
+ 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, &ts->msg);
+ spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->tc.z2;
x->len = 2;
- spi_message_add_tail(x, &ts->msg);
- }
-
- /* 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, &ts->msg);
+ spi_message_add_tail(x, m);
- x++;
- x->rx_buf = &ts->tc.x;
- x->len = 2;
- spi_message_add_tail(x, &ts->msg);
+ 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, &ts->msg);
+ spi_message_add_tail(x, m);
x++;
x->rx_buf = &ts->dummy;
x->len = 2;
CS_CHANGE(*x);
- spi_message_add_tail(x, &ts->msg);
+ spi_message_add_tail(x, m);
- ts->msg.complete = ads7846_rx;
- ts->msg.context = ts;
+ m->complete = ads7846_rx;
+ m->context = ts;
if (request_irq(spi->irq, ads7846_irq,
SA_SAMPLE_RANDOM | SA_TRIGGER_FALLING,
device_create_file(&spi->dev, &dev_attr_pen_down);
+ device_create_file(&spi->dev, &dev_attr_disable);
+
err = input_register_device(input_dev);
if (err)
- goto err_free_irq;
+ goto err_remove_attr;
return 0;
- err_free_irq:
+ err_remove_attr:
+ device_remove_file(&spi->dev, &dev_attr_disable);
+ device_remove_file(&spi->dev, &dev_attr_pen_down);
+ if (ts->model == 7846) {
+ device_remove_file(&spi->dev, &dev_attr_temp1);
+ device_remove_file(&spi->dev, &dev_attr_temp0);
+ }
+ if (ts->model != 7845)
+ device_remove_file(&spi->dev, &dev_attr_vbatt);
+ device_remove_file(&spi->dev, &dev_attr_vaux);
+
free_irq(spi->irq, ts);
err_free_mem:
input_free_device(input_dev);
{
struct ads7846 *ts = dev_get_drvdata(&spi->dev);
+ input_unregister_device(ts->input);
+
ads7846_suspend(spi, PMSG_SUSPEND);
- free_irq(ts->spi->irq, ts);
- if (ts->irq_disabled)
- enable_irq(ts->spi->irq);
+ device_remove_file(&spi->dev, &dev_attr_disable);
device_remove_file(&spi->dev, &dev_attr_pen_down);
-
if (ts->model == 7846) {
- device_remove_file(&spi->dev, &dev_attr_temp0);
device_remove_file(&spi->dev, &dev_attr_temp1);
+ device_remove_file(&spi->dev, &dev_attr_temp0);
}
if (ts->model != 7845)
device_remove_file(&spi->dev, &dev_attr_vbatt);
device_remove_file(&spi->dev, &dev_attr_vaux);
- input_unregister_device(ts->input);
+ free_irq(ts->spi->irq, ts);
+ if (ts->irq_disabled)
+ enable_irq(ts->spi->irq);
+
kfree(ts);
dev_dbg(&spi->dev, "unregistered touchscreen\n");
projects / linux-2.6-omap-h63xx.git / blobdiff