shared-qmi: implement reworked mode and capabilities management

This commit introduces several improvements and changes in the way
modes and capabilities are managed in QMI capable devices. It is
organized into a single commit, as all changes in all 6 operations
(load current capabilities, load supported capabilities, set current
capabilities, load supported modes, load current modes, set current
modes) are related one to the other (given that the same QMI commands
are used for both capabilities and mode management).

The primary change is related to which capabilities are reported as
supported for a given device. In the previous implementation we
allowed switching between every combination possible for GSM/UMTS+LTE,
CDMA/EVDO+LTE or GSM/UMTS+CDMA/EVDO+LTE devices. E.g. we would allow
"LTE only" and "GSM/UMTS only" capabilities for GSM/UMTS+LTE devices,
even if they would both be managed in exactly the same way. That setup
wasn't ideal, because it meant that switching to a "LTE only"
configuration would require a power cycle, as capability switching
requires a power cycle, even if no change was expected in the exposed
DBus interfaces (which is why we require the power cycle). So, instead
of allowing every possible capability combination, we use capability
switching logic exclusively for configuring GSM/UMTS+CDMA/EVDO devices
(regardless of whether it has LTE or not) to add or remove the
GSM/UMTS and CDMA/EVDO capabilities. E.g. for a GSM/UMTS+CDMA/EVDO+LTE
device we would allow 3 combinatios: "GSM/UMTS+LTE", "CDMA/EVDO+LTE"
and "GSM/UMTS+CDMA/EVDO+LTE".

The "GSM/UMTS+CDMA/EVDO+LTE" is a special case because for this one we
allow switching to "LTE only" capabilities while we forbid switching
to "4G only" mode. As the same commands are used for mode and
capability switching, if we didn't have "LTE only" and we allowed "4G
only" mode instead and rebooted the device, we would end up not being
able to know which other capabilities (GSM/UMTS or CDMA/EVDO or both)
were also enabled.

Now that we have capability switching confined to a very subset of
combinations, we can use the mode switching logic to e.g. allow "4G
only" configurations in all non multimode devices, as well as masks of
allowed modes with one being preferred, which we didn't allow before.
In the previous implementation all mode switching logic was disabled
for LTE capable QMI devices. In the new implementation, we use the
"Acquisition Order Preference" TLV in NAS Set System Selection
Preference to define the full list of mode preferences for all
supported modes.

We also no longer just assume that NAS Technology Preference is always
available and NAS System Selection Preference only after NAS >= 1.1.
This logic is flawed, instead we're going to probe for those features
once when loading current capabilities, and we then just implement the
capabilities/mode switching logic based on that.

1 files changed, 125 insertions, 6 deletions

diff --git a/src/mm-modem-helpers-qmi.c b/src/mm-modem-helpers-qmi.c
index ccc2a912..5df34478 100644
--- a/src/mm-modem-helpers-qmi.c
+++ b/src/mm-modem-helpers-qmi.c
@@ -754,6 +754,25 @@ mm_modem_access_technologies_from_qmi_data_capability_array (GArray *data_capabi
 /*****************************************************************************/
 
 MMModemMode
+mm_modem_mode_from_qmi_nas_radio_interface (QmiNasRadioInterface iface)
+{
+    switch (iface) {
+        case QMI_NAS_RADIO_INTERFACE_CDMA_1X:
+        case QMI_NAS_RADIO_INTERFACE_GSM:
+            return MM_MODEM_MODE_2G;
+        case QMI_NAS_RADIO_INTERFACE_CDMA_1XEVDO:
+        case QMI_NAS_RADIO_INTERFACE_UMTS:
+            return MM_MODEM_MODE_3G;
+        case QMI_NAS_RADIO_INTERFACE_LTE:
+            return MM_MODEM_MODE_4G;
+        default:
+            return MM_MODEM_MODE_NONE;
+    }
+}
+
+/*****************************************************************************/
+
+MMModemMode
 mm_modem_mode_from_qmi_radio_technology_preference (QmiNasRadioTechnologyPreference qmi)
 {
     MMModemMode mode = MM_MODEM_MODE_NONE;
@@ -909,6 +928,94 @@ mm_modem_capability_to_qmi_rat_mode_preference (MMModemCapability caps)
 
 /*****************************************************************************/
 
+GArray *
+mm_modem_capability_to_qmi_acquisition_order_preference (MMModemCapability caps)
+{
+    GArray               *array;
+    QmiNasRadioInterface  value;
+
+    array = g_array_new (FALSE, FALSE, sizeof (QmiNasRadioInterface));
+
+    if (caps & MM_MODEM_CAPABILITY_LTE) {
+        value = QMI_NAS_RADIO_INTERFACE_LTE;
+        g_array_append_val (array, value);
+    }
+
+    if (caps & MM_MODEM_CAPABILITY_GSM_UMTS) {
+        value = QMI_NAS_RADIO_INTERFACE_UMTS;
+        g_array_append_val (array, value);
+        value = QMI_NAS_RADIO_INTERFACE_GSM;
+        g_array_append_val (array, value);
+    }
+
+    if (caps & MM_MODEM_CAPABILITY_CDMA_EVDO) {
+        value = QMI_NAS_RADIO_INTERFACE_CDMA_1XEVDO;
+        g_array_append_val (array, value);
+        value = QMI_NAS_RADIO_INTERFACE_CDMA_1X;
+        g_array_append_val (array, value);
+    }
+
+    return array;
+}
+
+GArray *
+mm_modem_mode_to_qmi_acquisition_order_preference (MMModemMode allowed,
+                                                   MMModemMode preferred,
+                                                   gboolean    is_cdma,
+                                                   gboolean    is_3gpp)
+{
+    GArray               *array;
+    QmiNasRadioInterface  value;
+
+    array = g_array_new (FALSE, FALSE, sizeof (QmiNasRadioInterface));
+
+    if (allowed & MM_MODEM_MODE_4G) {
+        value = QMI_NAS_RADIO_INTERFACE_LTE;
+        if (preferred == MM_MODEM_MODE_4G)
+            g_array_prepend_val (array, value);
+        else
+            g_array_append_val (array, value);
+    }
+
+    if (allowed & MM_MODEM_MODE_3G) {
+        if (is_cdma) {
+            value = QMI_NAS_RADIO_INTERFACE_CDMA_1XEVDO;
+            if (preferred == MM_MODEM_MODE_3G)
+                g_array_prepend_val (array, value);
+            else
+                g_array_append_val (array, value);
+        }
+        if (is_3gpp) {
+            value = QMI_NAS_RADIO_INTERFACE_UMTS;
+            if (preferred == MM_MODEM_MODE_3G)
+                g_array_prepend_val (array, value);
+            else
+                g_array_append_val (array, value);
+        }
+    }
+
+    if (allowed & MM_MODEM_MODE_2G) {
+        if (is_cdma) {
+            value = QMI_NAS_RADIO_INTERFACE_CDMA_1X;
+            if (preferred == MM_MODEM_MODE_2G)
+                g_array_prepend_val (array, value);
+            else
+                g_array_append_val (array, value);
+        }
+        if (is_3gpp) {
+            value = QMI_NAS_RADIO_INTERFACE_GSM;
+            if (preferred == MM_MODEM_MODE_2G)
+                g_array_prepend_val (array, value);
+            else
+                g_array_append_val (array, value);
+        }
+    }
+
+    return array;
+}
+
+/*****************************************************************************/
+
 MMModemCapability
 mm_modem_capability_from_qmi_radio_technology_preference (QmiNasRadioTechnologyPreference qmi)
 {
@@ -1200,6 +1307,15 @@ mm_bearer_allowed_auth_to_qmi_authentication (MMBearerAllowedAuth auth)
 
 /*****************************************************************************/
 
+/**
+ * The only case where we need to apply some logic to decide what the current
+ * capabilities are is when we have a multimode CDMA/EVDO+GSM/UMTS device, in
+ * which case we'll check the SSP and TP current values to decide which
+ * capabilities are present and which have been disabled.
+ *
+ * For all the other cases, the DMS capabilities are exactly the current ones,
+ * as there would be no capability switching support.
+ */
 MMModemCapability
 mm_modem_capability_from_qmi_capabilities_context (MMQmiCapabilitiesContext *ctx)
 {
@@ -1209,16 +1325,19 @@ mm_modem_capability_from_qmi_capabilities_context (MMQmiCapabilitiesContext *ctx
     gchar *dms_capabilities_str;
     gchar *tmp_str;
 
-    /* SSP logic to gather capabilities uses the Mode Preference TLV if available,
-     * and if not available it falls back to using Band Preference TLVs */
+    /* If not a multimode device, we're done */
+#define MULTIMODE (MM_MODEM_CAPABILITY_GSM_UMTS | MM_MODEM_CAPABILITY_CDMA_EVDO)
+    if ((ctx->dms_capabilities & MULTIMODE) != MULTIMODE)
+        return ctx->dms_capabilities;
+
+    /* We have a multimode CDMA/EVDO+GSM/UMTS device, check SSP and TP */
+
+    /* SSP logic to gather capabilities uses the Mode Preference TLV if available */
     if (ctx->nas_ssp_mode_preference_mask)
         tmp = mm_modem_capability_from_qmi_rat_mode_preference (ctx->nas_ssp_mode_preference_mask);
-
     /* If no value retrieved from SSP, check TP. We only process TP
      * values if not 'auto'. */
-    if (   tmp == MM_MODEM_CAPABILITY_NONE
-        && ctx->nas_tp_mask
-        && ctx->nas_tp_mask != QMI_NAS_RADIO_TECHNOLOGY_PREFERENCE_AUTO)
+    else if (ctx->nas_tp_mask && (ctx->nas_tp_mask != QMI_NAS_RADIO_TECHNOLOGY_PREFERENCE_AUTO))
         tmp = mm_modem_capability_from_qmi_radio_technology_preference (ctx->nas_tp_mask);
 
     /* Final capabilities are the intersection between the Technology