This adds support for direction to the TI eQEP counter driver. It adds
both a direction attribute to sysfs and a direction change event to
the chrdev. The direction change event type is new public API.
Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---
drivers/counter/ti-eqep.c | 33 +++++++++++++++++++++++++++++++++
include/uapi/linux/counter.h | 2 ++
2 files changed, 35 insertions(+)
diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
index b7c79435e127..9881e5115da6 100644
--- a/drivers/counter/ti-eqep.c
+++ b/drivers/counter/ti-eqep.c
@@ -106,6 +106,15 @@
#define QCLR_PCE BIT(1)
#define QCLR_INT BIT(0)
+#define QEPSTS_UPEVNT BIT(7)
+#define QEPSTS_FDF BIT(6)
+#define QEPSTS_QDF BIT(5)
+#define QEPSTS_QDLF BIT(4)
+#define QEPSTS_COEF BIT(3)
+#define QEPSTS_CDEF BIT(2)
+#define QEPSTS_FIMF BIT(1)
+#define QEPSTS_PCEF BIT(0)
+
/* EQEP Inputs */
enum {
TI_EQEP_SIGNAL_QEPA, /* QEPA/XCLK */
@@ -286,6 +295,9 @@ static int ti_eqep_events_configure(struct counter_device *counter)
case COUNTER_EVENT_UNDERFLOW:
qeint |= QEINT_PCU;
break;
+ case COUNTER_EVENT_DIRECTION_CHANGE:
+ qeint |= QEINT_QDC;
+ break;
}
}
@@ -298,6 +310,7 @@ static int ti_eqep_watch_validate(struct counter_device *counter,
switch (watch->event) {
case COUNTER_EVENT_OVERFLOW:
case COUNTER_EVENT_UNDERFLOW:
+ case COUNTER_EVENT_DIRECTION_CHANGE:
return 0;
default:
return -EINVAL;
@@ -371,11 +384,27 @@ static int ti_eqep_position_enable_write(struct counter_device *counter,
return 0;
}
+static int ti_eqep_direction_read(struct counter_device *counter,
+ struct counter_count *count,
+ enum counter_count_direction *direction)
+{
+ struct ti_eqep_cnt *priv = counter->priv;
+ u32 qepsts;
+
+ regmap_read(priv->regmap16, QEPSTS, &qepsts);
+
+ *direction = (qepsts & QEPSTS_QDF) ? COUNTER_COUNT_DIRECTION_FORWARD
+ : COUNTER_COUNT_DIRECTION_BACKWARD;
+
+ return 0;
+}
+
static struct counter_comp ti_eqep_position_ext[] = {
COUNTER_COMP_CEILING(ti_eqep_position_ceiling_read,
ti_eqep_position_ceiling_write),
COUNTER_COMP_ENABLE(ti_eqep_position_enable_read,
ti_eqep_position_enable_write),
+ COUNTER_COMP_DIRECTION(ti_eqep_direction_read),
};
static struct counter_signal ti_eqep_signals[] = {
@@ -442,6 +471,10 @@ static irqreturn_t ti_eqep_irq_handler(int irq, void *dev_id)
if (qflg & QFLG_PCU)
counter_push_event(counter, COUNTER_EVENT_UNDERFLOW, 0);
+ if (qflg & QFLG_QDC)
+ counter_push_event(counter, COUNTER_EVENT_DIRECTION_CHANGE, 0);
+
+
regmap_set_bits(priv->regmap16, QCLR, ~0);
return IRQ_HANDLED;
diff --git a/include/uapi/linux/counter.h b/include/uapi/linux/counter.h
index d0aa95aeff7b..36dd3b474d09 100644
--- a/include/uapi/linux/counter.h
+++ b/include/uapi/linux/counter.h
@@ -61,6 +61,8 @@ enum counter_event_type {
COUNTER_EVENT_THRESHOLD,
/* Index signal detected */
COUNTER_EVENT_INDEX,
+ /* Direction change detected */
+ COUNTER_EVENT_DIRECTION_CHANGE,
};
/**
--
2.25.1
