at: wake only when sending AT commands

Allow the modem to enter soft sleep when
we don't talk to the modem using AT commands.
This was already the case in suspend, but
not during runtime. By only waking the modem
from soft sleep when we need to send
an AT command, we can save some power.

src/at.c

@@ -6,6 +6,7 @@
 
 #include "at.h"
 #include "suspend.h"
+#include "gpio.h"
 
 #include <fcntl.h>
 #include <stdio.h>
@@ -59,6 +60,10 @@ static gboolean send_at_command(struct EG25Manager *manager)
     int ret, len = 0;
 
     if (at_cmd) {
+    	/* Wake up the modem from soft sleep before sending an AT command */
+    	gpio_sequence_wake(manager);
+
+	/* Send AT command */
         if (at_cmd->subcmd == NULL && at_cmd->value == NULL && at_cmd->expected == NULL)
             len = sprintf(command, "AT+%s\r\n", at_cmd->cmd);
         else if (at_cmd->subcmd == NULL && at_cmd->value == NULL)
@@ -75,7 +80,11 @@ static gboolean send_at_command(struct EG25Manager *manager)
             g_warning("Couldn't write full AT command: wrote %d/%d bytes", ret, len);
 
         g_message("Sending command: %s", g_strstrip(command));
-    } else if (manager->modem_state < EG25_STATE_CONFIGURED) {
+    } else {
+    	/* Allow the modem to enter soft sleep again when we sent the AT command*/
+    	gpio_sequence_sleep(manager);
+	
+	if (manager->modem_state < EG25_STATE_CONFIGURED) {
 	    if (manager->modem_iface == MODEM_IFACE_MODEMMANAGER) {
 #ifdef HAVE_MMGLIB
                 MMModemState modem_state = mm_modem_get_state(manager->mm_modem);
@@ -93,6 +102,7 @@ static gboolean send_at_command(struct EG25Manager *manager)
         } else if (manager->modem_state == EG25_STATE_RESETTING) {
             manager->modem_state = EG25_STATE_POWERED;
         }
+    }
 
     return FALSE;
 }

src/gpio.c

@@ -6,6 +6,8 @@
 
 #include "gpio.h"
 
+#include <unistd.h>
+
 #define GPIO_CHIP1_LABEL "1c20800.pinctrl"
 #define GPIO_CHIP2_LABEL "1f02c00.pinctrl"
 
@@ -52,7 +54,6 @@ int gpio_sequence_shutdown(struct EG25Manager *manager)
 int gpio_sequence_suspend(struct EG25Manager *manager)
 {
     gpiod_line_set_value(manager->gpio_out[GPIO_OUT_APREADY], 1);
-    gpiod_line_set_value(manager->gpio_out[GPIO_OUT_DTR], 1);
 
     g_message("Executed suspend sequence");
 
@@ -62,13 +63,32 @@ int gpio_sequence_suspend(struct EG25Manager *manager)
 int gpio_sequence_resume(struct EG25Manager *manager)
 {
     gpiod_line_set_value(manager->gpio_out[GPIO_OUT_APREADY], 0);
-    gpiod_line_set_value(manager->gpio_out[GPIO_OUT_DTR], 0);
 
     g_message("Executed resume sequence");
 
     return 0;
 }
 
+int gpio_sequence_wake(struct EG25Manager *manager)
+{
+    gpiod_line_set_value(manager->gpio_out[GPIO_OUT_DTR], 0);
+
+    /* Give the modem 5ms to wake from soft sleep */
+    usleep(5000);
+
+    g_message("Executed soft wake sequence");
+
+    return 0;
+}
+
+int gpio_sequence_sleep(struct EG25Manager *manager)
+{
+    gpiod_line_set_value(manager->gpio_out[GPIO_OUT_DTR], 1);
+    g_message("Executed soft sleep sequence");
+
+    return 0;
+}
+
 static guint get_config_gpio(toml_table_t *config, const char *id)
 {
     toml_datum_t value = toml_int_in(config, id);

src/gpio.h

@@ -15,5 +15,7 @@ int gpio_sequence_poweron(struct EG25Manager *state);
 int gpio_sequence_shutdown(struct EG25Manager *state);
 int gpio_sequence_suspend(struct EG25Manager *state);
 int gpio_sequence_resume(struct EG25Manager *state);
+int gpio_sequence_wake(struct EG25Manager *state);
+int gpio_sequence_sleep(struct EG25Manager *state);
 
 gboolean gpio_check_poweroff(struct EG25Manager *manager, gboolean keep_down);