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authorPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>2019-10-22 18:54:45 -0500
committerVinod Koul <vkoul@kernel.org>2019-10-24 17:22:01 +0530
commit675d4c9aba86cf3345bc61880e2edfd6762ef4ae (patch)
tree7e970610c564a347ccc04694c73ba841fb4ab9d0 /drivers/soundwire
parent49ea07d33d9a32c17e18b322e789507280ceb2a3 (diff)
soundwire: cadence_master: add hw_reset capability in debugfs
Provide debugfs capability to kick link and devices into hard-reset (as defined by MIPI). This capability is really useful when some devices are no longer responsive and/or to check the software handling of resynchronization. Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Link: https://lore.kernel.org/r/20191022235448.17586-3-pierre-louis.bossart@linux.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/soundwire')
-rw-r--r--drivers/soundwire/cadence_master.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 5337ccacccd1..7476e867468d 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -333,6 +333,26 @@ static int cdns_reg_show(struct seq_file *s, void *data)
}
DEFINE_SHOW_ATTRIBUTE(cdns_reg);
+static int cdns_hw_reset(void *data, u64 value)
+{
+ struct sdw_cdns *cdns = data;
+ int ret;
+
+ if (value != 1)
+ return -EINVAL;
+
+ /* Userspace changed the hardware state behind the kernel's back */
+ add_taint(TAINT_USER, LOCKDEP_STILL_OK);
+
+ ret = sdw_cdns_exit_reset(cdns);
+
+ dev_dbg(cdns->dev, "link hw_reset done: %d\n", ret);
+
+ return ret;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(cdns_hw_reset_fops, NULL, cdns_hw_reset, "%llu\n");
+
/**
* sdw_cdns_debugfs_init() - Cadence debugfs init
* @cdns: Cadence instance
@@ -341,6 +361,9 @@ DEFINE_SHOW_ATTRIBUTE(cdns_reg);
void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root)
{
debugfs_create_file("cdns-registers", 0400, root, cdns, &cdns_reg_fops);
+
+ debugfs_create_file("cdns-hw-reset", 0200, root, cdns,
+ &cdns_hw_reset_fops);
}
EXPORT_SYMBOL_GPL(sdw_cdns_debugfs_init);