soundwire: intel: fix channel number reported by hardware

On all released Intel controllers (CNL/CML/ICL), PDI2 reports an
invalid count, force the correct hardware-supported value

This may have to be revisited with platform-specific values if the
hardware changes, but for now this is good enough.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20190806005522.22642-3-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c
index 97e3205..716e4e4 100644 (file)
--- a/drivers/soundwire/intel.c
+++ b/drivers/soundwire/intel.c
@@ -289,6 +289,16 @@ intel_pdi_get_ch_cap(struct sdw_intel *sdw, unsigned int pdi_num, bool pcm)
 
        if (pcm) {
                count = intel_readw(shim, SDW_SHIM_PCMSYCHC(link_id, pdi_num));
+
+               /*
+                * WORKAROUND: on all existing Intel controllers, pdi
+                * number 2 reports channel count as 1 even though it
+                * supports 8 channels. Performing hardcoding for pdi
+                * number 2.
+                */
+               if (pdi_num == 2)
+                       count = 7;
+
        } else {
                count = intel_readw(shim, SDW_SHIM_PDMSCAP(link_id));
                count = ((count & SDW_SHIM_PDMSCAP_CPSS) >>