Merge tag 'soundwire-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire into char-misc-next

Vinod writes:

soundwire updates for v5.3-rc1

Updates for 5.3 include:
 - module_sdw_driver macro for drivers
 - Documentation updates for code-blocks
 - Improvement from Pierre on intel and cadence driver
 - Clarification of DisCo properties and updates

* tag 'soundwire-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/soundwire:
  soundwire: add module_sdw_driver helper macro
  docs: soundwire: locking: fix tags for a code-block
  soundwire: intel_init: add checks on link numbers
  soundwire: fix typo in comments
  soundwire: Intel: add log for number of PCM and PDM PDIs
  soundwire: cadence_master: check the number of bidir PDIs
  soundwire: cadence_master: log Slave status mask on errors
  soundwire: cadence_master: use rate_limited dynamic debug
  soundwire: rename/clarify MIPI DisCo properties
  soundwire: clarify comment
  soundwire: mipi-disco: fix clock stop modes
  soundwire: rename 'freq' fields
  soundwire: mipi-disco: remove master_count property for masters
  soundwire: remove master data port properties
  soundwire: add port-related definitions
  soundwire: mipi_disco: fix master/link error
  soundwire: intel: filter SoundWire controller device search
  soundwire: cdns: Fix compilation error on arm64

1 files changed, 24 insertions, 1 deletions

diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c
index d3d6b54c5791..70637a0383d2 100644
--- a/drivers/soundwire/intel_init.c
+++ b/drivers/soundwire/intel_init.c
@@ -14,6 +14,7 @@
 #include <linux/soundwire/sdw_intel.h>
 #include "intel.h"
 
+#define SDW_LINK_TYPE		4 /* from Intel ACPI documentation */
 #define SDW_MAX_LINKS		4
 #define SDW_SHIM_LCAP		0x0
 #define SDW_SHIM_BASE		0x2C000
@@ -80,6 +81,7 @@ static struct sdw_intel_ctx
 
 	/* Check SNDWLCAP.LCOUNT */
 	caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
+	caps &= GENMASK(2, 0);
 
 	/* Check HW supported vs property value and use min of two */
 	count = min_t(u8, caps, count);
@@ -89,6 +91,9 @@ static struct sdw_intel_ctx
 		dev_err(&adev->dev, "Link count %d exceeds max %d\n",
 			count, SDW_MAX_LINKS);
 		return NULL;
+	} else if (!count) {
+		dev_warn(&adev->dev, "No SoundWire links detected\n");
+		return NULL;
 	}
 
 	dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
@@ -150,6 +155,12 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
 {
 	struct sdw_intel_res *res = cdata;
 	struct acpi_device *adev;
+	acpi_status status;
+	u64 adr;
+
+	status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
+	if (ACPI_FAILURE(status))
+		return AE_OK; /* keep going */
 
 	if (acpi_bus_get_device(handle, &adev)) {
 		pr_err("%s: Couldn't find ACPI handle\n", __func__);
@@ -157,7 +168,19 @@ static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
 	}
 
 	res->handle = handle;
-	return AE_OK;
+
+	/*
+	 * On some Intel platforms, multiple children of the HDAS
+	 * device can be found, but only one of them is the SoundWire
+	 * controller. The SNDW device is always exposed with
+	 * Name(_ADR, 0x40000000), with bits 31..28 representing the
+	 * SoundWire link so filter accordingly
+	 */
+	if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
+		return AE_OK; /* keep going */
+
+	/* device found, stop namespace walk */
+	return AE_CTRL_TERMINATE;
 }
 
 /**