broadband-modem: read current capabilities via QCDM if available (bgo #698229)dcbw/qcdm-current-capabilities

Many multi-mode Qualcomm devices report all available modes in their
AT+GCAP response (for example, CDMA/EVDO and GSM/UMTS) but they cannot
actually function in all these modes at the same time.  The modem's
actual current capabilities are expressed by the QCDM NV ModePref
item, which is not reflected in the AT+GCAP response.

Reading the current capabilities from the NV ModePref item ensures
that ModemManager does not create interfaces for the modem which
the modem cannot actually implement.

Because the generic modem plugin does not implement the Modem
Capabilities hook (because there is no standard way to determine
what access technologies a modem supports), the Current Capabilities
are copied to the Modem Capabilities.  For devices that support
QCDM this means that Modem Capabilies which used to be created from
the GCAP response and thus would contain all available capabilities
now contain only current capabilities.  This isn't a problem though
since there was no way to switch the devices to use any of their
other capabilities, becuase there aren't any standard commands for
it.  Plugins that know how to switch their modem's capabilities
should (and they already do) override load_current_capabilities
and load_modem_capabilities to get the correct information.

1 files changed, 125 insertions, 8 deletions

diff --git a/src/mm-broadband-modem.c b/src/mm-broadband-modem.c
index abc5a5c3..f7b5b294 100644
--- a/src/mm-broadband-modem.c
+++ b/src/mm-broadband-modem.c
@@ -304,12 +304,17 @@ typedef struct {
     MMBroadbandModem *self;
     GSimpleAsyncResult *result;
     MMModemCapability caps;
+    MMQcdmSerialPort *qcdm_port;
 } LoadCapabilitiesContext;
 
 static void
 load_capabilities_context_complete_and_free (LoadCapabilitiesContext *ctx)
 {
     g_simple_async_result_complete (ctx->result);
+    if (ctx->qcdm_port) {
+        mm_serial_port_close (MM_SERIAL_PORT (ctx->qcdm_port));
+        g_object_unref (ctx->qcdm_port);
+    }
     g_object_unref (ctx->result);
     g_object_unref (ctx->self);
     g_slice_free (LoadCapabilitiesContext, ctx);
@@ -537,6 +542,122 @@ capabilities_sequence_ready (MMBaseModem *self,
 }
 
 static void
+load_current_capabilities_at (LoadCapabilitiesContext *ctx)
+{
+    /* Launch sequence, we will expect a "u" GVariant */
+    mm_base_modem_at_sequence (
+        MM_BASE_MODEM (ctx->self),
+        capabilities,
+        NULL, /* response_processor_context */
+        NULL, /* response_processor_context_free */
+        (GAsyncReadyCallback)capabilities_sequence_ready,
+        ctx);
+}
+
+static void
+mode_pref_qcdm_ready (MMQcdmSerialPort *port,
+                      GByteArray *response,
+                      GError *error,
+                      LoadCapabilitiesContext *ctx)
+{
+    QcdmResult *result;
+    gint err = QCDM_SUCCESS;
+    u_int8_t pref = 0;
+
+    if (error) {
+        /* Fall back to AT checking */
+        mm_dbg ("Failed to load NV ModePref: %s", error->message);
+        goto at_caps;
+    }
+
+    /* Parse the response */
+    result = qcdm_cmd_nv_get_mode_pref_result ((const gchar *) response->data,
+                                               response->len,
+                                               &err);
+    if (!result) {
+        mm_dbg ("Failed to parse NV ModePref result: %d", err);
+        goto at_caps;
+    }
+
+    err = qcdm_result_get_u8 (result, QCDM_CMD_NV_GET_MODE_PREF_ITEM_MODE_PREF, &pref);
+    if (err) {
+        mm_dbg ("Failed to read NV ModePref: %d", err);
+        goto at_caps;
+    }
+
+    /* Only parse explicit modes; for 'auto' just fall back to whatever
+     * the AT current capabilities probing figures out.
+     */
+    switch (pref) {
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_1X_HDR_LTE_ONLY:
+        ctx->caps |= MM_MODEM_CAPABILITY_LTE;
+        /* Fall through */
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_1X_ONLY:
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_HDR_ONLY:
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_1X_HDR_ONLY:
+        ctx->caps |= MM_MODEM_CAPABILITY_CDMA_EVDO;
+        break;
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_GSM_UMTS_LTE_ONLY:
+        ctx->caps |= MM_MODEM_CAPABILITY_LTE;
+        /* Fall through */
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_GPRS_ONLY:
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_UMTS_ONLY:
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_GSM_UMTS_ONLY:
+        ctx->caps |= MM_MODEM_CAPABILITY_GSM_UMTS;
+        break;
+    case QCDM_CMD_NV_MODE_PREF_ITEM_MODE_PREF_LTE_ONLY:
+        ctx->caps |= MM_MODEM_CAPABILITY_LTE;
+        break;
+    default:
+        break;
+    }
+
+    if (ctx->caps != MM_MODEM_CAPABILITY_NONE) {
+        g_simple_async_result_set_op_res_gpointer (
+            ctx->result,
+            GUINT_TO_POINTER (ctx->caps),
+            NULL);
+        load_capabilities_context_complete_and_free (ctx);
+        return;
+    }
+
+at_caps:
+    load_current_capabilities_at (ctx);
+}
+
+static void
+load_current_capabilities_qcdm (LoadCapabilitiesContext *ctx)
+{
+    GByteArray *cmd;
+    GError *error = NULL;
+
+    ctx->qcdm_port = mm_base_modem_peek_port_qcdm (MM_BASE_MODEM (ctx->self));
+    g_assert (ctx->qcdm_port);
+
+    if (!mm_serial_port_open (MM_SERIAL_PORT (ctx->qcdm_port), &error)) {
+        mm_dbg ("Failed to open QCDM port for NV ModePref request: %s",
+                error->message);
+        g_clear_error (&error);
+        ctx->qcdm_port = NULL;
+        load_current_capabilities_at (ctx);
+        return;
+    }
+
+    g_object_ref (ctx->qcdm_port);
+
+    cmd = g_byte_array_sized_new (300);
+    cmd->len = qcdm_cmd_nv_get_mode_pref_new ((char *) cmd->data, 300, 0);
+    g_assert (cmd->len);
+
+    mm_qcdm_serial_port_queue_command (ctx->qcdm_port,
+                                       cmd,
+                                       3,
+                                       NULL,
+                                       (MMQcdmSerialResponseFn) mode_pref_qcdm_ready,
+                                       ctx);
+}
+
+static void
 modem_load_current_capabilities (MMIfaceModem *self,
                                  GAsyncReadyCallback callback,
                                  gpointer user_data)
@@ -552,14 +673,10 @@ modem_load_current_capabilities (MMIfaceModem *self,
                                              user_data,
                                              modem_load_current_capabilities);
 
-    /* Launch sequence, we will expect a "u" GVariant */
-    mm_base_modem_at_sequence (
-        MM_BASE_MODEM (self),
-        capabilities,
-        NULL, /* response_processor_context */
-        NULL, /* response_processor_context_free */
-        (GAsyncReadyCallback)capabilities_sequence_ready,
-        ctx);
+    if (mm_base_modem_peek_port_qcdm (MM_BASE_MODEM (self)))
+        load_current_capabilities_qcdm (ctx);
+    else
+        load_current_capabilities_at (ctx);
 }
 
 /*****************************************************************************/