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 --- drivers/soundwire/cadence_master.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
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);