diff options
| -rw-r--r-- | drivers/input/touchscreen/ads7846.c | 144 |
1 files changed, 114 insertions, 30 deletions
diff --git a/drivers/input/touchscreen/ads7846.c b/drivers/input/touchscreen/ads7846.c index bdec112e89c4..fec3b9b22309 100644 --- a/drivers/input/touchscreen/ads7846.c +++ b/drivers/input/touchscreen/ads7846.c @@ -2,6 +2,8 @@ * 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 @@ -34,17 +36,25 @@ /* - * This code has been lightly tested on an ads7846. + * This code has been tested on an ads7846 / N770 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 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) @@ -91,6 +101,7 @@ struct ads7846 { 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? */ @@ -161,6 +172,9 @@ struct ser_req { 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); @@ -257,6 +271,37 @@ static ssize_t ads7846_pen_down_show(struct 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); + 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); + /*--------------------------------------------------------------------------*/ /* @@ -396,12 +441,9 @@ static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs) { struct ads7846 *ts = handle; unsigned long flags; - int r = IRQ_HANDLED; spin_lock_irqsave(&ts->lock, flags); - if (ts->irq_disabled) - r = IRQ_HANDLED; - else { + if (likely(!ts->irq_disabled && !ts->disabled)) { if (!ts->irq_disabled) { /* REVISIT irq logic for many ARM chips has cloned a * bug wherein disabling an irq in its handler won't @@ -419,20 +461,17 @@ static irqreturn_t ads7846_irq(int irq, void *handle, struct pt_regs *regs) } } spin_unlock_irqrestore(&ts->lock, flags); - return r; + + 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) { @@ -448,9 +487,9 @@ ads7846_suspend(struct spi_device *spi, pm_message_t message) mod_timer(&ts->timer, jiffies); while (ts->pendown || ts->pending) { - spin_unlock_irqrestore(&ts->lock, flags); + spin_unlock_irq(&ts->lock); msleep(1); - spin_lock_irqsave(&ts->lock, flags); + spin_lock_irq(&ts->lock); } } @@ -458,17 +497,46 @@ ads7846_suspend(struct spi_device *spi, pm_message_t message) * leave it that way after every request */ - spin_unlock_irqrestore(&ts->lock, flags); + 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); + + 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); - ts->irq_disabled = 0; - enable_irq(ts->spi->irq); + spin_lock_irq(&ts->lock); + spi->dev.power.power_state = PMSG_ON; + ads7846_enable(ts); + + spin_unlock_irq(&ts->lock); + return 0; } @@ -521,6 +589,8 @@ static int __devinit ads7846_probe(struct spi_device *spi) 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; @@ -671,13 +741,25 @@ static int __devinit ads7846_probe(struct spi_device *spi) 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); @@ -689,22 +771,24 @@ 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); - 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"); |