From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
For debug, it's interesting to create a loopback stream for each link and use debugfs to set a source and target PDI. The target PDI would need to be an RX port and use the same register configurations as the source PDI. This capability allows e.g. for the headphone playback stream to be snooped on the headset capture stream, or alternatively for the addition of a dedicated loopback stream, in addition of regular capture for that link.
This patch only adds the debugfs part, the port/PDI handling will be handled in the next patches.
Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Reviewed-by: Rander Wang rander.wang@intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/cadence_master.c | 44 ++++++++++++++++++++++++++++++ drivers/soundwire/cadence_master.h | 3 ++ 2 files changed, 47 insertions(+)
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 9a9b6110e763..3e740fcebdfe 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -450,6 +450,40 @@ static int cdns_parity_error_injection(void *data, u64 value) DEFINE_DEBUGFS_ATTRIBUTE(cdns_parity_error_fops, NULL, cdns_parity_error_injection, "%llu\n");
+static int cdns_set_pdi_loopback_source(void *data, u64 value) +{ + struct sdw_cdns *cdns = data; + unsigned int pdi_out_num = cdns->pcm.num_bd + cdns->pcm.num_out; + + if (value > pdi_out_num) + return -EINVAL; + + /* Userspace changed the hardware state behind the kernel's back */ + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + + cdns->pdi_loopback_source = value; + + return 0; +} +DEFINE_DEBUGFS_ATTRIBUTE(cdns_pdi_loopback_source_fops, NULL, cdns_set_pdi_loopback_source, "%llu\n"); + +static int cdns_set_pdi_loopback_target(void *data, u64 value) +{ + struct sdw_cdns *cdns = data; + unsigned int pdi_in_num = cdns->pcm.num_bd + cdns->pcm.num_in; + + if (value > pdi_in_num) + return -EINVAL; + + /* Userspace changed the hardware state behind the kernel's back */ + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + + cdns->pdi_loopback_target = value; + + return 0; +} +DEFINE_DEBUGFS_ATTRIBUTE(cdns_pdi_loopback_target_fops, NULL, cdns_set_pdi_loopback_target, "%llu\n"); + /** * sdw_cdns_debugfs_init() - Cadence debugfs init * @cdns: Cadence instance @@ -464,6 +498,16 @@ void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
debugfs_create_file("cdns-parity-error-injection", 0200, root, cdns, &cdns_parity_error_fops); + + cdns->pdi_loopback_source = -1; + cdns->pdi_loopback_target = -1; + + debugfs_create_file("cdns-pdi-loopback-source", 0200, root, cdns, + &cdns_pdi_loopback_source_fops); + + debugfs_create_file("cdns-pdi-loopback-target", 0200, root, cdns, + &cdns_pdi_loopback_target_fops); + } EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);
diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index 0e7f8b35bb21..6c039d456ba8 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -129,6 +129,9 @@ struct sdw_cdns { struct sdw_cdns_streams pcm; struct sdw_cdns_streams pdm;
+ int pdi_loopback_source; + int pdi_loopback_target; + void __iomem *registers;
bool link_up;