From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
This helper provides an optional delay parameter to wait for devices
to resync in case of errors, and checks that devices are indeed
attached on the bus.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Reviewed-by: Rander Wang <rander.wang@xxxxxxxxx>
Signed-off-by: Bard Liao <yung-chuan.liao@xxxxxxxxxxxxxxx>
---
drivers/soundwire/bus.c | 32 ++++++++++++++++++++++++++++++++
include/linux/soundwire/sdw.h | 2 ++
2 files changed, 34 insertions(+)
diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 2772973eebb1..0a99ac791c7e 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -300,6 +300,38 @@ int sdw_transfer(struct sdw_bus *bus, struct sdw_msg *msg)
return ret;
}
+/**
+ * sdw_show_ping_status() - Direct report of PING status, to be used by Peripheral drivers
+ * @bus: SDW bus
+ * @sync_delay: Delay before reading status
+ */
+void sdw_show_ping_status(struct sdw_bus *bus, bool sync_delay)
+{
+ u32 status;
+
+ if (!bus->ops->read_ping_status)
+ return;
+
+ /*
+ * wait for peripheral to sync if desired. 10-15ms should be more than
+ * enough in most cases.
+ */
+ if (sync_delay)
+ usleep_range(10000, 15000);
+
+ mutex_lock(&bus->msg_lock);
+
+ status = bus->ops->read_ping_status(bus);
+
+ mutex_unlock(&bus->msg_lock);
+
+ if (!status)
+ dev_warn(bus->dev, "%s: no peripherals attached\n", __func__);
+ else
+ dev_dbg(bus->dev, "PING status: %#x\n", status);
+}
+EXPORT_SYMBOL(sdw_show_ping_status);
+
/**
* sdw_transfer_defer() - Asynchronously transfer message to a SDW Slave device
* @bus: SDW bus
diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h
index a85cf829bb77..9e4537f409c2 100644
--- a/include/linux/soundwire/sdw.h
+++ b/include/linux/soundwire/sdw.h
@@ -926,6 +926,8 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
struct fwnode_handle *fwnode);
void sdw_bus_master_delete(struct sdw_bus *bus);
+void sdw_show_ping_status(struct sdw_bus *bus, bool sync_delay);
+
/**
* sdw_port_config: Master or Slave Port configuration
*
--
2.25.1
