iwlwifi: mvm: add debugfs entry to read the current temperature

When read, this new debugfs entry requests the current temperature
from the firmware and outputs it.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/debugfs.c

@@ -326,6 +326,29 @@ out:
 	return count;
 }
 
+static ssize_t iwl_dbgfs_nic_temp_read(struct file *file,
+				       char __user *user_buf,
+				       size_t count, loff_t *ppos)
+{
+	struct iwl_mvm *mvm = file->private_data;
+	char buf[16];
+	int pos, temp;
+
+	if (!mvm->ucode_loaded)
+		return -EIO;
+
+	mutex_lock(&mvm->mutex);
+	temp = iwl_mvm_get_temp(mvm);
+	mutex_unlock(&mvm->mutex);
+
+	if (temp < 0)
+		return temp;
+
+	pos = scnprintf(buf , sizeof(buf), "%d\n", temp);
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+}
+
 static ssize_t iwl_dbgfs_stations_read(struct file *file, char __user *user_buf,
 				       size_t count, loff_t *ppos)
 {
@@ -1378,6 +1401,7 @@ MVM_DEBUGFS_WRITE_FILE_OPS(tx_flush, 16);
 MVM_DEBUGFS_WRITE_FILE_OPS(sta_drain, 8);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(sram, 64);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(set_nic_temperature, 64);
+MVM_DEBUGFS_READ_FILE_OPS(nic_temp);
 MVM_DEBUGFS_READ_FILE_OPS(stations);
 MVM_DEBUGFS_READ_FILE_OPS(bt_notif);
 MVM_DEBUGFS_READ_FILE_OPS(bt_cmd);
@@ -1420,6 +1444,7 @@ int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm, struct dentry *dbgfs_dir)
 	MVM_DEBUGFS_ADD_FILE(sram, mvm->debugfs_dir, S_IWUSR | S_IRUSR);
 	MVM_DEBUGFS_ADD_FILE(set_nic_temperature, mvm->debugfs_dir,
 			     S_IWUSR | S_IRUSR);
+	MVM_DEBUGFS_ADD_FILE(nic_temp, dbgfs_dir, S_IRUSR);
 	MVM_DEBUGFS_ADD_FILE(stations, dbgfs_dir, S_IRUSR);
 	MVM_DEBUGFS_ADD_FILE(fw_error_dump, dbgfs_dir, S_IRUSR);
 	MVM_DEBUGFS_ADD_FILE(bt_notif, dbgfs_dir, S_IRUSR);

drivers/net/wireless/iwlwifi/mvm/mvm.h

@@ -1188,6 +1188,7 @@ void iwl_mvm_tt_handler(struct iwl_mvm *mvm);
 void iwl_mvm_tt_initialize(struct iwl_mvm *mvm, u32 min_backoff);
 void iwl_mvm_tt_exit(struct iwl_mvm *mvm);
 void iwl_mvm_set_hw_ctkill_state(struct iwl_mvm *mvm, bool state);
+int iwl_mvm_get_temp(struct iwl_mvm *mvm);
 
 /* smart fifo */
 int iwl_mvm_sf_update(struct iwl_mvm *mvm, struct ieee80211_vif *vif,

drivers/net/wireless/iwlwifi/mvm/tt.c

@@ -135,7 +135,7 @@ static int iwl_mvm_get_temp_cmd(struct iwl_mvm *mvm)
 				    sizeof(cmd), &cmd);
 }
 
-static int iwl_mvm_get_temp(struct iwl_mvm *mvm)
+int iwl_mvm_get_temp(struct iwl_mvm *mvm)
 {
 	struct iwl_notification_wait wait_temp_notif;
 	static const u8 temp_notif[] = { DTS_MEASUREMENT_NOTIFICATION };