Re: [RFC PATCH] Soundwire: Initialize multi_link with fwnode props

Khalid Masum <khalid.masum.92@xxxxxxxxx> · Mon, 15 Aug 2022 10:08:07 +0600

On 8/14/22 15:45, Greg KH wrote:
On Sun, Aug 14, 2022 at 02:04:15PM +0600, Khalid Masum wrote:
According to the TODO, In sw_bus_master_add, bus->multi_link is to be
populated with properties from FW node props. Make this happen by
creating a new fwnode_handle flag FWNODE_FLAG_MULTI_LINKED and use
the flag to store the multi_link value from intel_link_startup. Use
this flag to initialize bus->multi_link.

Signed-off-by: Khalid Masum <khalid.masum.92@xxxxxxxxx>
---
I do not think adding a new flag for fwnode_handle is a good idea.
So, what would be the best way to initialize bus->multilink with
fwnode props?

   -- Khalid Masum

  drivers/soundwire/bus.c   | 4 ++--
  drivers/soundwire/intel.c | 1 +
  include/linux/fwnode.h    | 1 +
  3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index a2bfb0434a67..80df1672c60b 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -74,9 +74,9 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
  
  	/*
  	 * Initialize multi_link flag
-	 * TODO: populate this flag by reading property from FW node
  	 */
-	bus->multi_link = false;
+	bus->multi_link = (fwnode->flags & FWNODE_FLAG_MULTI_LINKED)
+		== FWNODE_FLAG_MULTI_LINKED;
  	if (bus->ops->read_prop) {
  		ret = bus->ops->read_prop(bus);
  		if (ret < 0) {
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 505c5ef061e3..034d1c523ddf 100644
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -1347,6 +1347,7 @@ int intel_link_startup(struct auxiliary_device *auxdev)
  		 */
  		bus->multi_link = true;
  		bus->hw_sync_min_links = 1;
+		dev->fwnode->flags |= FWNODE_FLAG_MULTI_LINKED;
  	}
  
  	/* Initialize shim, controller */
diff --git a/include/linux/fwnode.h b/include/linux/fwnode.h
index 9a81c4410b9f..446a52744953 100644
--- a/include/linux/fwnode.h
+++ b/include/linux/fwnode.h
@@ -32,6 +32,7 @@ struct device;
  #define FWNODE_FLAG_NOT_DEVICE			BIT(1)
  #define FWNODE_FLAG_INITIALIZED			BIT(2)
  #define FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD	BIT(3)
+#define FWNODE_FLAG_MULTI_LINKED		BIT(4)

What does this commit actually change?

The new flag will lets us save if the device has multilink in 
fwnode_handle whenever needed.
Then for soundwire/intel, save the multi_link flag into fwnode during 
startup.
Later at master_add, as written in todo, initialize the multilink flag 
with fwnode's flag property.


Did you test this on real hardware?

I did not test this on real hardware.

thanks,

greg k-h

thanks,
 -- Khalid Masum







