iwlwifi: show current tx power

debugFs file show current tx power for all the transmit chains

Adding "tx_power" file in /sys/kernal/debug/ieee80211/phy0/iwlagn/debug
to display current tx power for all the active chains in 1/2 dB step.

Show tx power information "Not available" if uCode can not provide the
information or interface is down.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 55 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-debug.h b/drivers/net/wireless/iwlwifi/iwl-debug.h
index 723f38a023ce..cbc62904655d 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debug.h
+++ b/drivers/net/wireless/iwlwifi/iwl-debug.h
@@ -107,6 +107,7 @@ struct iwl_debugfs {
                 struct dentry *file_ucode_general_stats;
                 struct dentry *file_sensitivity;
                 struct dentry *file_chain_noise;
+                struct dentry *file_tx_power;
         } dbgfs_debug_files;
         u32 sram_offset;
         u32 sram_len;
diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index f68fb4711da2..fb844859a443 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -1563,6 +1563,57 @@ static ssize_t iwl_dbgfs_chain_noise_read(struct file *file,
         return ret;
 }
 
+static ssize_t iwl_dbgfs_tx_power_read(struct file *file,
+                                        char __user *user_buf,
+                                        size_t count, loff_t *ppos) {
+
+        struct iwl_priv *priv = (struct iwl_priv *)file->private_data;
+        char buf[128];
+        int pos = 0;
+        ssize_t ret;
+        const size_t bufsz = sizeof(buf);
+        struct statistics_tx *tx;
+
+        if (!iwl_is_alive(priv))
+                pos += scnprintf(buf + pos, bufsz - pos, "N/A\n");
+        else {
+                /* make request to uCode to retrieve statistics information */
+                mutex_lock(&priv->mutex);
+                ret = iwl_send_statistics_request(priv, 0);
+                mutex_unlock(&priv->mutex);
+
+                if (ret) {
+                        IWL_ERR(priv, "Error sending statistics request: %zd\n",
+                                ret);
+                        return -EAGAIN;
+                }
+                tx = &priv->statistics.tx;
+                if (tx->tx_power.ant_a ||
+                    tx->tx_power.ant_b ||
+                    tx->tx_power.ant_c) {
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                "tx power: (1/2 dB step)\n");
+                        if ((priv->cfg->valid_tx_ant & ANT_A) &&
+                            tx->tx_power.ant_a)
+                                pos += scnprintf(buf + pos, bufsz - pos,
+                                                "\tantenna A: 0x%X\n",
+                                                tx->tx_power.ant_a);
+                        if ((priv->cfg->valid_tx_ant & ANT_B) &&
+                            tx->tx_power.ant_b)
+                                pos += scnprintf(buf + pos, bufsz - pos,
+                                                "\tantenna B: 0x%X\n",
+                                                tx->tx_power.ant_b);
+                        if ((priv->cfg->valid_tx_ant & ANT_C) &&
+                            tx->tx_power.ant_c)
+                                pos += scnprintf(buf + pos, bufsz - pos,
+                                                "\tantenna C: 0x%X\n",
+                                                tx->tx_power.ant_c);
+                } else
+                        pos += scnprintf(buf + pos, bufsz - pos, "N/A\n");
+        }
+        return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+}
+
 DEBUGFS_READ_WRITE_FILE_OPS(rx_statistics);
 DEBUGFS_READ_WRITE_FILE_OPS(tx_statistics);
 DEBUGFS_READ_WRITE_FILE_OPS(traffic_log);
@@ -1573,6 +1624,7 @@ DEBUGFS_READ_FILE_OPS(ucode_tx_stats);
 DEBUGFS_READ_FILE_OPS(ucode_general_stats);
 DEBUGFS_READ_FILE_OPS(sensitivity);
 DEBUGFS_READ_FILE_OPS(chain_noise);
+DEBUGFS_READ_FILE_OPS(tx_power);
 
 /*
  * Create the debugfs files and directories
@@ -1621,6 +1673,7 @@ int iwl_dbgfs_register(struct iwl_priv *priv, const char *name)
         DEBUGFS_ADD_FILE(traffic_log, debug);
         DEBUGFS_ADD_FILE(rx_queue, debug);
         DEBUGFS_ADD_FILE(tx_queue, debug);
+        DEBUGFS_ADD_FILE(tx_power, debug);
         if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) != CSR_HW_REV_TYPE_3945) {
                 DEBUGFS_ADD_FILE(ucode_rx_stats, debug);
                 DEBUGFS_ADD_FILE(ucode_tx_stats, debug);
@@ -1674,6 +1727,7 @@ void iwl_dbgfs_unregister(struct iwl_priv *priv)
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_traffic_log);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_rx_queue);
         DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_tx_queue);
+        DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.file_tx_power);
         if ((priv->hw_rev & CSR_HW_REV_TYPE_MSK) != CSR_HW_REV_TYPE_3945) {
                 DEBUGFS_REMOVE(priv->dbgfs->dbgfs_debug_files.
                         file_ucode_rx_stats);