interface for configuring freefall/wakeup interrupts for the accelerometers

Hi!

First: Unfortunately, the freerunner currently wakes up immediately on
suspend when the accelerometer IRQ is selected as a wakeup source. I'm
posting this for comments and if someone else wants to have a look at
this problem.

The patch should be safe to apply even though the sleep portion doesn't
work - as long as it's configured it will not disturb anything.

// Simon
--
lis302dl-configure-wakeup-interrupts.patch

From: simon.kagstrom <simon.kagstrom@gmail.com>

First: Unfortunately, the freerunner currently wakes up immediately on
suspend when the accelerometer IRQ is selected as a wakeup source.


Add configuration of wakeup/freefall interrupts through a sysfs
interface. Configuration is done through echoing a value of the
form

   X Y Z THRESHOLD DURATION SPEC

to freefall_wakeup_1/2. X, Y and Z are threshold values, given as a
value > 0, < 0 or 0 to specify if an interrupt should be generated for
high or low thresholds or neither (off). THRESHOLD specifies the
threshold that must be exceeded. DURATION specifies the time in
milliseconds for which the acceleration should be measured. SPEC is
either '1' or '0' and specifies if the thresholds should be taken all
together or one at a time ('and' or 'or' mode).

Echoing '0' to the file turns off the interrupts.

Example:

  echo "1 1 1 60 60 0" > freefall_wakeup_1   # Turn on x,y,z, 60ms/60 threshold, or-mode
  echo "0" > freefall_wakeup_1 # Turn off interrupt

The hardware supports two simulataneous wakeup sources to be configured,
but the freerunner only connects one of the interrupt outputs. The patch
exports both. Similarly, only the "top" accelerometer can be used as a
wake-up source, and it's not possible to generate DATA_READY interrupts
while the wakeup interrupts are active.

Signed-off-by: Simon Kagstrom <simon.kagstrom@gmail.com>

1 files changed, 221 insertions, 11 deletions

diff --git a/drivers/input/misc/lis302dl.c b/drivers/input/misc/lis302dl.c
index 944e5ebcccf..59fc4141263 100644
--- a/drivers/input/misc/lis302dl.c
+++ b/drivers/input/misc/lis302dl.c
@@ -248,10 +248,212 @@ static ssize_t lis302dl_dump(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR(dump, S_IRUGO, lis302dl_dump, NULL);
 
+static int freefall_ms_to_duration(struct lis302dl_info *lis, int ms)
+{
+	u_int8_t r = reg_read(lis, LIS302DL_REG_CTRL1);
+
+	/* If we have 400 ms sampling rate, the stepping is 2.5 ms,
+	 * on 100 ms the stepping is 10ms */
+	if ( r & LIS302DL_CTRL1_DR ) {
+		/* Too large */
+		if (ms > 637)
+			return -1;
+
+		return (ms * 10) / 25;
+	}
+
+	/* Too large value */
+	if (ms > 2550)
+			return -1;
+	return ms / 10;
+}
+
+static int freefall_duration_to_ms(struct lis302dl_info *lis, int duration)
+{
+	u_int8_t r = reg_read(lis, LIS302DL_REG_CTRL1);
+
+	if ( r & LIS302DL_CTRL1_DR )
+		return (duration * 25) / 10;
+
+	return duration * 10;
+}
+
+/* Configure freefall/wakeup interrupts */
+static ssize_t set_freefall_common(int which, struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	struct lis302dl_info *lis = dev_get_drvdata(dev);
+	u_int8_t x_lo, y_lo, z_lo;
+	u_int8_t x_hi, y_hi, z_hi;
+	int duration;
+	int threshold;
+	int and_events;
+	int r_ths = LIS302DL_REG_FF_WU_THS_1; /* registers, assume first pin */
+	int r_duration = LIS302DL_REG_FF_WU_DURATION_1;
+	int r_cfg = LIS302DL_REG_FF_WU_CFG_1;
+	int flag_mask = LIS302DL_F_WUP_FF_1;
+	int intmode = LIS302DL_INTMODE_FF_WU_1;
+	int x, y, z;
+	int ms;
+	unsigned long flags;
+
+	/* Configure for second freefall/wakeup pin */
+	if (which == 2) {
+		r_ths = LIS302DL_REG_FF_WU_THS_2;
+		r_duration = LIS302DL_REG_FF_WU_DURATION_2;
+		r_cfg = LIS302DL_REG_FF_WU_CFG_2;
+		flag_mask = LIS302DL_F_WUP_FF_2;
+		intmode = LIS302DL_INTMODE_FF_WU_2;
+
+		printk(KERN_WARNING "Configuring second freefall / wakeup interrupt\n");
+	}
+
+	/* Parse the input */
+	if (strcmp(buf, "0\n") == 0)
+	{
+		/* Turn off the interrupt */
+		local_save_flags(flags);
+		if ( (lis->flags & LIS302DL_F_IRQ_WAKE) != 0 )
+			disable_irq_wake(lis->spi_dev->irq);
+		lis302dl_int_mode(lis->spi_dev, which, LIS302DL_INTMODE_DATA_READY);
+		lis->flags &= ~(flag_mask | LIS302DL_F_IRQ_WAKE);
+
+		reg_write(lis, r_cfg, 0);
+		reg_write(lis, r_ths, 0);
+		reg_write(lis, r_duration, 0);
+
+		/* Power off unless the input subsystem is using the device */
+		if ( (lis->flags & LIS302DL_F_INPUT_OPEN) == 0 )
+			reg_set_bit_mask(lis, LIS302DL_REG_CTRL1, LIS302DL_CTRL1_PD, 0);
+
+		local_irq_restore(flags);
+
+		return count;
+	}
+
+	if (sscanf(buf, "%d %d %d %d %d %d", &x, &y, &z, &threshold, &ms, &and_events) != 6)
+		return -EINVAL;
+
+	duration = freefall_ms_to_duration(lis, ms);
+	if (duration < 0)
+		return -ERANGE;
+
+	/* 7 bits */
+	if (threshold < 0 || threshold > 127)
+		return -ERANGE;
+
+	/* Interrupt flags */
+	x_lo = x < 0 ? LIS302DL_FFWUCFG_XLIE : 0;
+	y_lo = y < 0 ? LIS302DL_FFWUCFG_YLIE : 0;
+	z_lo = z < 0 ? LIS302DL_FFWUCFG_ZLIE : 0;
+	x_hi = x > 0 ? LIS302DL_FFWUCFG_XHIE : 0;
+	y_hi = y > 0 ? LIS302DL_FFWUCFG_YHIE : 0;
+	z_hi = z > 0 ? LIS302DL_FFWUCFG_ZHIE : 0;
+
+	/* Setup the configuration registers */
+	local_save_flags(flags);
+	reg_write(lis, r_cfg, 0); /* First zero to get to a known state */
+	reg_write(lis, r_cfg,
+		(and_events ? LIS302DL_FFWUCFG_AOI : 0) |
+		x_lo | x_hi | y_lo | y_hi | z_lo | z_hi);
+	reg_write(lis, r_ths, threshold & ~LIS302DL_FFWUTHS_DCRM);
+	reg_write(lis, r_duration, duration);
+
+	/* Route the interrupt for wakeup */
+	lis302dl_int_mode(lis->spi_dev, which, intmode);
+
+	/* Power up the device and note that we want to wake up from
+	 * this interrupt */
+	if ( (lis->flags & LIS302DL_F_IRQ_WAKE) == 0 )
+		enable_irq_wake(lis->spi_dev->irq);
+
+	lis->flags |= flag_mask | LIS302DL_F_IRQ_WAKE;
+	reg_set_bit_mask(lis, LIS302DL_REG_CTRL1, LIS302DL_CTRL1_PD,
+			LIS302DL_CTRL1_PD);
+	local_irq_restore(flags);
+
+	return count;
+}
+
+static ssize_t set_freefall_1(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	return set_freefall_common(1, dev, attr, buf, count);
+}
+static ssize_t set_freefall_2(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	return set_freefall_common(2, dev, attr, buf, count);
+}
+
+
+static ssize_t show_freefall_common(int which, struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct lis302dl_info *lis = dev_get_drvdata(dev);
+	u_int8_t duration;
+	u_int8_t threshold;
+	u_int8_t config;
+	u_int8_t r4;
+	u_int8_t r5;
+	int r_ths = LIS302DL_REG_FF_WU_THS_1; /* registers, assume first pin */
+	int r_duration = LIS302DL_REG_FF_WU_DURATION_1;
+	int r_cfg = LIS302DL_REG_FF_WU_CFG_1;
+	int r_src = LIS302DL_REG_FF_WU_SRC_1;
+
+	/* Configure second freefall/wakeup pin */
+	if (which == 2) {
+		r_ths = LIS302DL_REG_FF_WU_THS_2;
+		r_duration = LIS302DL_REG_FF_WU_DURATION_2;
+		r_cfg = LIS302DL_REG_FF_WU_CFG_2;
+		r_src = LIS302DL_REG_FF_WU_SRC_2;
+	}
+	config = reg_read(lis, r_cfg);
+	threshold = reg_read(lis, r_ths);
+	duration = reg_read(lis, r_duration);
+	r4 = reg_read(lis, r_src);
+	r5 = reg_read(lis, LIS302DL_REG_CTRL3);
+
+	/* All events off? */
+	if ((config & (LIS302DL_FFWUCFG_XLIE | LIS302DL_FFWUCFG_XHIE |
+			LIS302DL_FFWUCFG_YLIE | LIS302DL_FFWUCFG_YHIE |
+			LIS302DL_FFWUCFG_ZLIE | LIS302DL_FFWUCFG_ZHIE)) == 0)
+		return sprintf(buf, "off\n");
+
+	return sprintf(buf,"%s events, %s interrupt, duration %d, threshold %d, "
+			"enabled: %s %s %s %s %s %s\n",
+			(config & LIS302DL_FFWUCFG_AOI) == 0 ? "or" : "and",
+			(config & LIS302DL_FFWUCFG_LIR) == 0 ? "don't latch" : "latch",
+			freefall_duration_to_ms(lis, duration), threshold,
+			(config & LIS302DL_FFWUCFG_XLIE) == 0 ? "---" : "xlo",
+			(config & LIS302DL_FFWUCFG_XHIE) == 0 ? "---" : "xhi",
+			(config & LIS302DL_FFWUCFG_YLIE) == 0 ? "---" : "ylo",
+			(config & LIS302DL_FFWUCFG_YHIE) == 0 ? "---" : "yhi",
+			(config & LIS302DL_FFWUCFG_ZLIE) == 0 ? "---" : "zlo",
+			(config & LIS302DL_FFWUCFG_ZHIE) == 0 ? "---" : "zhi");
+}
+
+static ssize_t show_freefall_1(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return show_freefall_common(1, dev, attr, buf);
+}
+
+static ssize_t show_freefall_2(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return show_freefall_common(2, dev, attr, buf);
+}
+
+static DEVICE_ATTR(freefall_wakeup_1, S_IRUGO | S_IWUSR, show_freefall_1, set_freefall_1);
+static DEVICE_ATTR(freefall_wakeup_2, S_IRUGO | S_IWUSR, show_freefall_2, set_freefall_2);
+
 static struct attribute *lis302dl_sysfs_entries[] = {
 	&dev_attr_sample_rate.attr,
 	&dev_attr_full_scale.attr,
 	&dev_attr_dump.attr,
+	&dev_attr_freefall_wakeup_1.attr,
+	&dev_attr_freefall_wakeup_2.attr,
 	NULL
 };
 
@@ -274,6 +476,8 @@ static int lis302dl_input_open(struct input_dev *inp)
 	reg_set_bit_mask(lis, LIS302DL_REG_CTRL1, ctrl1, ctrl1);
 	local_irq_restore(flags);
 
+	lis->flags |= LIS302DL_F_INPUT_OPEN;
+
 	/* kick it off -- since we are edge triggered, if we missed the edge
 	 * permanent low interrupt is death for us */
 	(lis->pdata->lis302dl_bitbang_read)(lis);
@@ -294,6 +498,7 @@ static void lis302dl_input_close(struct input_dev *inp)
 	 * only see close() for the close of the last user, we can safely
 	 * disable the data ready events */
 	reg_set_bit_mask(lis, LIS302DL_REG_CTRL1, ctrl1, 0x00);
+	lis->flags &= ~LIS302DL_F_INPUT_OPEN;
 
 	/* however, don't power down the whole device if still needed */
 	if (!(lis->flags & LIS302DL_F_WUP_FF ||
@@ -406,9 +611,9 @@ static int __devinit lis302dl_probe(struct spi_device *spi)
 	reg_write(lis, LIS302DL_REG_CTRL2, 0);
 	reg_write(lis, LIS302DL_REG_CTRL3, LIS302DL_CTRL3_PP_OD |
 							    LIS302DL_CTRL3_IHL);
-	reg_write(lis, LIS302DL_REG_FF_WU_THS_1, 0x14);
+	reg_write(lis, LIS302DL_REG_FF_WU_THS_1, 0x0);
 	reg_write(lis, LIS302DL_REG_FF_WU_DURATION_1, 0x00);
-	reg_write(lis, LIS302DL_REG_FF_WU_CFG_1, 0x95);
+	reg_write(lis, LIS302DL_REG_FF_WU_CFG_1, 0x0);
 
 	/* start off in powered down mode; we power up when someone opens us */
 	reg_write(lis, LIS302DL_REG_CTRL1, LIS302DL_CTRL1_Xen |
@@ -486,6 +691,12 @@ static int lis302dl_suspend(struct spi_device *spi, pm_message_t state)
 {
 	struct lis302dl_info *lis = dev_get_drvdata(&spi->dev);
 	unsigned long flags;
+	u_int8_t tmp;
+
+	/* determine if we want to wake up from the accel. */
+	if (lis->flags & LIS302DL_F_WUP_FF ||
+		lis->flags & LIS302DL_F_WUP_CLICK)
+		return 0;
 
 	disable_irq(lis->spi_dev->irq);
 	local_save_flags(flags);
@@ -528,15 +739,10 @@ static int lis302dl_suspend(struct spi_device *spi, pm_message_t state)
 	lis->regs[LIS302DL_REG_CLICK_WINDOW] =
 				reg_read(lis, LIS302DL_REG_CLICK_WINDOW);
 
-	/* determine if we want to wake up from the accel. */
-	if (!(lis->flags & LIS302DL_F_WUP_FF ||
-	      lis->flags & LIS302DL_F_WUP_CLICK)) {
-		/* power down */
-		u_int8_t tmp;
-		tmp = reg_read(lis, LIS302DL_REG_CTRL1);
-		tmp &= ~LIS302DL_CTRL1_PD;
-		reg_write(lis, LIS302DL_REG_CTRL1, tmp);
-	}
+	/* power down */
+	tmp = reg_read(lis, LIS302DL_REG_CTRL1);
+	tmp &= ~LIS302DL_CTRL1_PD;
+	reg_write(lis, LIS302DL_REG_CTRL1, tmp);
 
 	/* place our IO to the device in sleep-compatible states */
 	(lis->pdata->lis302dl_suspend_io)(lis, 0);
@@ -551,6 +757,10 @@ static int lis302dl_resume(struct spi_device *spi)
 	struct lis302dl_info *lis = dev_get_drvdata(&spi->dev);
 	unsigned long flags;
 
+	if (lis->flags & LIS302DL_F_WUP_FF ||
+		lis->flags & LIS302DL_F_WUP_CLICK)
+		return 0;
+
 	local_save_flags(flags);
 
 	/* get our IO to the device back in operational states */