platform/x86: intel_telemetry: Add debugfs entry for S0ix residency

This adds a debugfs consumer for the exported kernel API
intel_pmc_read_s0ix_residency. This debugfs entry reads S0ix residency
directly from the PMC hardware counters.

TEST:
- echo freeze > /sys/power/state
- Wake the system, read the S0ix residency i.e.
  cat /sys/kernel/debug/telemetry/s0ix_residency_usec

Signed-off-by: Shanth Murthy <shanth.murthy@intel.com>
Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

diff --git a/drivers/platform/x86/intel_telemetry_debugfs.c b/drivers/platform/x86/intel_telemetry_debugfs.c
index b8be058..cd21df9 100644 (file)
--- a/drivers/platform/x86/intel_telemetry_debugfs.c
+++ b/drivers/platform/x86/intel_telemetry_debugfs.c
@@ -710,6 +710,24 @@ static const struct file_operations telem_socstate_ops = {
        .release        = single_release,
 };
 
+static int telem_s0ix_res_get(void *data, u64 *val)
+{
+       u64 s0ix_total_res;
+       int ret;
+
+       ret = intel_pmc_s0ix_counter_read(&s0ix_total_res);
+       if (ret) {
+               pr_err("Failed to read S0ix residency");
+               return ret;
+       }
+
+       *val = s0ix_total_res;
+
+       return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(telem_s0ix_fops, telem_s0ix_res_get, NULL, "%llu\n");
+
 static int telem_pss_trc_verb_show(struct seq_file *s, void *unused)
 {
        u32 verbosity;
@@ -987,6 +1005,14 @@ static int __init telemetry_debugfs_init(void)
                goto out;
        }
 
+       f = debugfs_create_file("s0ix_residency_usec", S_IFREG | S_IRUGO,
+                               debugfs_conf->telemetry_dbg_dir,
+                               NULL, &telem_s0ix_fops);
+       if (!f) {
+               pr_err("s0ix_residency_usec debugfs register failed\n");
+               goto out;
+       }
+
        f = debugfs_create_file("pss_trace_verbosity", S_IFREG | S_IRUGO,
                                debugfs_conf->telemetry_dbg_dir, NULL,
                                &telem_pss_trc_verb_ops);