Change in coreboot[master]: libpayload/i8042: Add API to peek on keyboard input queue

[Nico Huber (Code Review)]

Nico Huber has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/47592 )

Change subject: libpayload/i8042: Add API to peek on keyboard input queue
......................................................................

libpayload/i8042: Add API to peek on keyboard input queue

Change-Id: I60699e044b5bacd3f5292fed7edbf529ae133284
Signed-off-by: Nico Huber 
---
M payloads/libpayload/drivers/i8042/i8042.c
M payloads/libpayload/include/libpayload.h
2 files changed, 22 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/92/47592/1

diff --git a/payloads/libpayload/drivers/i8042/i8042.c b/payloads/libpayload/drivers/i8042/i8042.c
index 7dbc6e7..71f81f4 100644
--- a/payloads/libpayload/drivers/i8042/i8042.c
+++ b/payloads/libpayload/drivers/i8042/i8042.c
@@ -112,6 +112,19 @@
    return ret;
 }

+/** Peek on the head of fifo queue.
+ * Returns the oldest object on the queue if any.
+ * In case the queue is empty 0 is returned.
+ * @fifo: Fifo to use
+ */
+static u8 fifo_peek(struct fifo *fifo)
+{
+	if (fifo_is_empty(fifo))
+		return 0;
+
+	return fifo->buf[fifo->rx];
+}
+
 /** Destroys a fifo queue.
  * @fifo: Fifo to use
  */
@@ -391,6 +404,14 @@
 }

/**
+ * Returns available keyboard data without advancing the queue.
+ */
+u8 i8042_peek_data_ps2(void)
+{
+	return fifo_peek(ps2_fifo);
+}
+
+/**
  * Returns available mouse data, if any.
  */
 u8 i8042_read_data_aux(void)
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 371471f..a33d8bb 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -233,6 +233,7 @@
 u8 i8042_data_ready_aux(void);

u8 i8042_read_data_ps2(void);
+u8 i8042_peek_data_ps2(void);
 u8 i8042_read_data_aux(void);

int i8042_wait_read_ps2(void);

[Angel Pons (Code Review)]

Angel Pons has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/47592 )

Change subject: libpayload/i8042: Add API to peek on keyboard input queue
......................................................................

Patch Set 2: Code-Review+2

[Hung-Te Lin (Code Review)]

Hung-Te Lin has submitted this change. ( https://review.coreboot.org/c/coreboot/+/47592 )

Change subject: libpayload/i8042: Add API to peek on keyboard input queue
......................................................................

libpayload/i8042: Add API to peek on keyboard input queue

Change-Id: I60699e044b5bacd3f5292fed7edbf529ae133284
Signed-off-by: Nico Huber 
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47592
Reviewed-by: Angel Pons 
Tested-by: build bot (Jenkins) 
---
M payloads/libpayload/drivers/i8042/i8042.c
M payloads/libpayload/include/libpayload.h
2 files changed, 22 insertions(+), 0 deletions(-)

Approvals:
  build bot (Jenkins): Verified
  Angel Pons: Looks good to me, approved

diff --git a/payloads/libpayload/drivers/i8042/i8042.c b/payloads/libpayload/drivers/i8042/i8042.c
index 476139e..a89b9d9 100644
--- a/payloads/libpayload/drivers/i8042/i8042.c
+++ b/payloads/libpayload/drivers/i8042/i8042.c
@@ -112,6 +112,19 @@
    return ret;
 }

+/** Peek on the head of fifo queue.
+ * Returns the oldest object on the queue if any.
+ * In case the queue is empty 0 is returned.
+ * @fifo: Fifo to use
+ */
+static u8 fifo_peek(struct fifo *fifo)
+{
+	if (fifo_is_empty(fifo))
+		return 0;
+
+	return fifo->buf[fifo->rx];
+}
+
 /** Destroys a fifo queue.
  * @fifo: Fifo to use
  */
@@ -391,6 +404,14 @@
 }

/**
+ * Returns available keyboard data without advancing the queue.
+ */
+u8 i8042_peek_data_ps2(void)
+{
+	return fifo_peek(ps2_fifo);
+}
+
+/**
  * Returns available mouse data, if any.
  */
 u8 i8042_read_data_aux(void)
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 371471f..a33d8bb 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -233,6 +233,7 @@
 u8 i8042_data_ready_aux(void);

u8 i8042_read_data_ps2(void);
+u8 i8042_peek_data_ps2(void);
 u8 i8042_read_data_aux(void);

int i8042_wait_read_ps2(void);