[RFC PATCH 9/9] hwmon: lis3: Enhance lis3 selftest with IRQ line test

[Samu Onkalo <samu.p.onkalo-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>]

Configure chip to data ready mode in selftest and count received
interrupts to see that interrupt line(s) are working.

Signed-off-by: Samu Onkalo <samu.p.onkalo-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>
---
 drivers/hwmon/lis3lv02d.c |   87 ++++++++++++++++++++++++++++++++++++++++----
 drivers/hwmon/lis3lv02d.h |    3 +-
 2 files changed, 81 insertions(+), 9 deletions(-)

diff --git a/drivers/hwmon/lis3lv02d.c b/drivers/hwmon/lis3lv02d.c
index 469f251..cf1b4db 100644
--- a/drivers/hwmon/lis3lv02d.c
+++ b/drivers/hwmon/lis3lv02d.c
@@ -47,6 +47,13 @@
 
 #define SYSFS_POWERDOWN_DELAY 5000 /* In milliseconds */
 
+#define SELFTEST_OK	       0
+#define SELFTEST_FAIL	       -1
+#define SELFTEST_IRQ	       -2
+
+#define IRQ_LINE0	       0
+#define IRQ_LINE1	       1
+
 /*
  * The sensor can also generate interrupts (DRDY) but it's pretty pointless
  * because they are generated even if the data do not change. So it's better
@@ -197,6 +204,8 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 	s16 x, y, z;
 	u8 selftest;
 	int ret;
+	u8 ctrl_reg_data;
+	unsigned char irq_cfg;
 
 	mutex_lock(&lis3->mutex);
 	if (lis3_dev.whoami == WAI_12B)
@@ -204,6 +213,20 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 	else
 		selftest = CTRL1_STP;
 
+	irq_cfg = lis3->irq_cfg;
+	if (lis3_dev.whoami == WAI_8B) {
+		lis3->data_ready_count[IRQ_LINE0] = 0;
+		lis3->data_ready_count[IRQ_LINE1] = 0;
+
+		/* Change interrupt cfg to data ready for selftest */
+		atomic_inc(&lis3_dev.wake_thread);
+		lis3->irq_cfg = LIS3_IRQ1_DATA_READY | LIS3_IRQ2_DATA_READY;
+		lis3->read(lis3, CTRL_REG3, &ctrl_reg_data);
+		lis3->write(lis3, CTRL_REG3, (ctrl_reg_data &
+				~(LIS3_IRQ1_MASK | LIS3_IRQ2_MASK)) |
+				(LIS3_IRQ1_DATA_READY | LIS3_IRQ2_DATA_READY));
+	}
+
 	lis3->read(lis3, CTRL_REG1, &reg);
 	lis3->write(lis3, CTRL_REG1, (reg | selftest));
 	msleep(lis3->pwron_delay / lis3lv02d_get_odr());
@@ -222,13 +245,33 @@ static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
 	results[2] = z - lis3->read_data(lis3, OUTZ);
 
 	ret = 0;
+
+	if (lis3_dev.whoami == WAI_8B) {
+		/* Restore original interrupt configuration */
+		atomic_dec(&lis3_dev.wake_thread);
+		lis3->write(lis3, CTRL_REG3, ctrl_reg_data);
+		lis3->irq_cfg = irq_cfg;
+
+		if ((irq_cfg & LIS3_IRQ1_MASK) &&
+			lis3->data_ready_count[IRQ_LINE0] < 2) {
+			ret = SELFTEST_IRQ;
+			goto fail;
+		}
+
+		if ((irq_cfg & LIS3_IRQ2_MASK) &&
+			lis3->data_ready_count[IRQ_LINE1] < 2) {
+			ret = SELFTEST_IRQ;
+			goto fail;
+		}
+	}
+
 	if (lis3->pdata) {
 		int i;
 		for (i = 0; i < 3; i++) {
 			/* Check against selftest acceptance limits */
 			if ((results[i] < lis3->pdata->st_min_limits[i]) ||
 			    (results[i] > lis3->pdata->st_max_limits[i])) {
-				ret = -EIO;
+				ret = SELFTEST_FAIL;
 				goto fail;
 			}
 		}
@@ -391,13 +434,24 @@ static void lis302dl_interrupt_handle_click(struct lis3lv02d *lis3)
 	mutex_unlock(&lis3->mutex);
 }
 
-static irqreturn_t lis302dl_interrupt_thread1_8b(int irq, void *data)
+static inline void lis302dl_data_ready(struct lis3lv02d *lis3, int index)
 {
+	int dummy;
 
+	/* Dummy read to ack interrupt */
+	lis3lv02d_get_xyz(lis3, &dummy, &dummy, &dummy);
+	lis3->data_ready_count[index]++;
+}
+
+static irqreturn_t lis302dl_interrupt_thread1_8b(int irq, void *data)
+{
 	struct lis3lv02d *lis3 = data;
+	u8 irq_cfg = lis3->irq_cfg & LIS3_IRQ1_MASK;
 
-	if ((lis3->irq_cfg & LIS3_IRQ1_MASK) == LIS3_IRQ1_CLICK)
+	if (irq_cfg == LIS3_IRQ1_CLICK)
 		lis302dl_interrupt_handle_click(lis3);
+	else if (unlikely(irq_cfg == LIS3_IRQ1_DATA_READY))
+		lis302dl_data_ready(lis3, IRQ_LINE0);
 	else
 		lis3lv02d_joystick_poll(lis3_dev.idev);
 
@@ -406,11 +460,13 @@ static irqreturn_t lis302dl_interrupt_thread1_8b(int irq, void *data)
 
 static irqreturn_t lis302dl_interrupt_thread2_8b(int irq, void *data)
 {
-
 	struct lis3lv02d *lis3 = data;
+	u8 irq_cfg = lis3->irq_cfg & LIS3_IRQ2_MASK;
 
-	if ((lis3->irq_cfg & LIS3_IRQ2_MASK) == LIS3_IRQ2_CLICK)
+	if (irq_cfg == LIS3_IRQ2_CLICK)
 		lis302dl_interrupt_handle_click(lis3);
+	else if (unlikely(irq_cfg == LIS3_IRQ2_DATA_READY))
+		lis302dl_data_ready(lis3, IRQ_LINE1);
 	else
 		lis3lv02d_joystick_poll(lis3_dev.idev);
 
@@ -613,12 +669,27 @@ static void lis3lv02d_sysfs_poweron(struct lis3lv02d *lis3)
 static ssize_t lis3lv02d_selftest_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
-	int result;
 	s16 values[3];
 
+	static const char ok[] = "OK";
+	static const char fail[] = "FAIL";
+	static const char irq[] = "FAIL_IRQ";
+	const char *res;
+
 	lis3lv02d_sysfs_poweron(&lis3_dev);
-	result = lis3lv02d_selftest(&lis3_dev, values);
-	return sprintf(buf, "%s %d %d %d\n", result == 0 ? "OK" : "FAIL",
+	switch (lis3lv02d_selftest(&lis3_dev, values)) {
+	case SELFTEST_FAIL:
+		res = fail;
+		break;
+	case SELFTEST_IRQ:
+		res = irq;
+		break;
+	case SELFTEST_OK:
+	default:
+		res = ok;
+		break;
+	}
+	return sprintf(buf, "%s %d %d %d\n", res,
 		values[0], values[1], values[2]);
 }
 
diff --git a/drivers/hwmon/lis3lv02d.h b/drivers/hwmon/lis3lv02d.h
index cfff63c..3b739ec 100644
--- a/drivers/hwmon/lis3lv02d.h
+++ b/drivers/hwmon/lis3lv02d.h
@@ -261,7 +261,8 @@ struct lis3lv02d {
 	struct fasync_struct	*async_queue; /* queue for the misc device */
 	wait_queue_head_t	misc_wait; /* Wait queue for the misc device */
 	unsigned long		misc_opened; /* bit0: whether the device is open */
-	atomic_t                wake_thread;
+	int                     data_ready_count[2];
+	atomic_t		wake_thread;
 	unsigned char           irq_cfg;
 
 	struct lis3lv02d_platform_data *pdata;	/* for passing board config */
-- 
1.6.0.4