From 8fba8acd399b70aeb262983d32baa9cbbf7dc981 Mon Sep 17 00:00:00 2001 From: Pierre-Louis Bossart Date: Wed, 14 Jul 2021 11:22:08 +0800 Subject: [PATCH] soundwire: cadence: add debugfs interface for PDI loopbacks 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 Reviewed-by: Rander Wang Signed-off-by: Bard Liao Link: https://lore.kernel.org/r/20210714032209.11284-10-yung-chuan.liao@linux.intel.com Signed-off-by: Vinod Koul --- 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 a9bd56f0d534..3670c0ebcace 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 b54c161a837f..e587aede63bf 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;