Allow for waiting for DRSM bit for specified stream to be cleared from
HDAudio library level. Drivers may utilize this optional step during the
stream resume procedure.
Suggested-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Cezary Rojewski <cezary.rojewski@xxxxxxxxx>
---
include/sound/hdaudio.h | 1 +
sound/hda/hdac_stream.c | 21 +++++++++++++++++++++
2 files changed, 22 insertions(+)
diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h
index 78f1809a4ad6..a6872537724d 100644
--- a/include/sound/hdaudio.h
+++ b/include/sound/hdaudio.h
@@ -597,6 +597,7 @@ int snd_hdac_stream_get_spbmaxfifo(struct hdac_bus *bus,
struct hdac_stream *azx_dev);
void snd_hdac_stream_drsm_enable(struct hdac_bus *bus,
bool enable, int index);
+int snd_hdac_stream_wait_drsm(struct hdac_stream *azx_dev);
int snd_hdac_stream_set_dpibr(struct hdac_bus *bus,
struct hdac_stream *azx_dev, u32 value);
int snd_hdac_stream_set_lpib(struct hdac_stream *azx_dev, u32 value);
diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c
index 35fe2bd582ac..59e8bfe4feca 100644
--- a/sound/hda/hdac_stream.c
+++ b/sound/hda/hdac_stream.c
@@ -821,6 +821,27 @@ void snd_hdac_stream_drsm_enable(struct hdac_bus *bus,
}
EXPORT_SYMBOL_GPL(snd_hdac_stream_drsm_enable);
+/*
+ * snd_hdac_stream_wait_drsm - wait for HW to clear RSM for a stream
+ * @azx_dev: HD-audio core stream to await RSM for
+ *
+ * Returns 0 on success and -ETIMEDOUT upon a timeout.
+ */
+int snd_hdac_stream_wait_drsm(struct hdac_stream *azx_dev)
+{
+ struct hdac_bus *bus = azx_dev->bus;
+ u32 mask, reg;
+ int ret;
+
+ mask = 1 << azx_dev->index;
+
+ ret = readb_poll_timeout(bus->drsmcap + AZX_REG_DRSM_CTL, reg, !(reg & mask), 250, 2000);
+ if (ret)
+ dev_dbg(bus->dev, "polling RSM 0x%08x failed: %d\n", mask, ret);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(snd_hdac_stream_wait_drsm);
+
/**
* snd_hdac_stream_set_dpibr - sets the dpibr value of a stream
* @bus: HD-audio core bus
--
2.25.1
