[PATCH skeleton v3] Refactored LED control dbus methods

OpenBMC Patches openbmc-patches at stwcx.xyz
Sat Jan 30 04:30:39 AEDT 2016


From: vishwa <vishwanath at in.ibm.com>

---
 Makefile                     |   5 +-
 objects/led_controller_new.c | 488 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 492 insertions(+), 1 deletion(-)
 create mode 100755 objects/led_controller_new.c

diff --git a/Makefile b/Makefile
index ea2dde2..bdf619a 100755
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@ LIBS=$(shell pkg-config --libs gio-unix-2.0 glib-2.0) -Llib -lopenbmc_intf
 %.o: objects/pflash/libflash/%.c
 	$(CC) -c -o obj/$@ $< $(CFLAGS) $(INCLUDES)
 
-all: setup libopenbmc_intf power_control led_controller button_power button_reset control_host host_watchdog control_bmc board_vpd pcie_slot_present flash_bios flasher control_bmc_barreleye pflash hwmons_barreleye
+all: setup libopenbmc_intf power_control led_controller button_power button_reset control_host host_watchdog control_bmc board_vpd pcie_slot_present flash_bios flasher control_bmc_barreleye pflash hwmons_barreleye led_controller_new
 
 setup: 
 	mkdir -p obj lib
@@ -39,6 +39,9 @@ power_control: power_control_obj.o gpio.o object_mapper.o libopenbmc_intf
 led_controller: led_controller.o gpio.o object_mapper.o libopenbmc_intf
 	$(CC) -o bin/$@.exe obj/gpio.o obj/led_controller.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
 
+led_controller_new: led_controller_new.o
+	$(CC) -o bin/$@.exe obj/led_controller_new.o $(LDFLAGS) $(LIBS) -lsystemd
+
 button_power: button_power_obj.o gpio.o object_mapper.o libopenbmc_intf
 	$(CC) -o bin/$@.exe obj/button_power_obj.o obj/gpio.o obj/object_mapper.o $(LDFLAGS) $(LIBS)
 
diff --git a/objects/led_controller_new.c b/objects/led_controller_new.c
new file mode 100755
index 0000000..c8b3f92
--- /dev/null
+++ b/objects/led_controller_new.c
@@ -0,0 +1,488 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <dirent.h>
+#include <systemd/sd-bus.h>
+
+/*
+ * These are control files that are present for each led under
+ *'/sys/class/leds/<led_name>/' which are used to trigger action
+ * on the respective leds by writing predefined data.
+ */
+const char *power_ctrl = "brightness";
+const char *blink_ctrl = "trigger";
+const char *duty_on    = "delay_on";
+const char *duty_off   = "delay_off";
+
+/*
+ * --------------------------------------------------
+ * Given the dbus path, returns the name of the LED
+ * --------------------------------------------------
+ */
+char *get_led_name(const char *dbus_path)
+{
+    char *led_name = NULL;
+
+    /* Get the led name from /org/openbmc/control/led/<name> */
+    led_name = strrchr(dbus_path, '/');
+    if(led_name)
+    {
+        led_name++;
+    }
+
+    return led_name;
+}
+
+/*
+ * -------------------------------------------------------------------------
+ * Writes the 'on / off / blink' trigger to leds.
+ * -------------------------------------------------------------------------
+ */
+int write_to_led(const char *name, const char *ctrl_file, const char *value)
+{
+    /* Generic error reporter. */
+    int rc = -1;
+
+    /* To get /sys/class/leds/<name>/<control file> */
+    char led_path[128] = {0};
+
+    int len = 0;
+    len = snprintf(led_path, sizeof(led_path), 
+                   "/sys/class/leds/%s/%s",name, ctrl_file);
+    if(len >= sizeof(led_path))
+    {
+        fprintf(stderr, "Error. LED path is too long. :[%d]\n",len);
+        return rc;
+    }
+
+    FILE *fp = fopen(led_path,"w");
+    if(fp == NULL)
+    {
+        perror("Error:");
+        fprintf(stderr,"Error opening:[%s]\n",led_path);
+        return rc;
+    }
+
+    rc = fwrite(value, strlen(value), 1, fp);
+    if(rc != 1)
+    {
+        perror("Error:");
+        fprintf(stderr, "Error writing to :[%s]\n",led_path);
+    }
+
+    fclose(fp);
+
+    /* When we get here, rc would be what it was from writing to the file */
+    return (rc == 1) ? 0 : -1;
+}
+
+/*
+ * ----------------------------------------------------------------
+ * Router function for any LED operations that come via dbus
+ *----------------------------------------------------------------
+ */
+static int led_function_router(sd_bus_message *msg, void *user_data,
+                               sd_bus_error *ret_error)
+{
+    /* Generic error reporter. */
+    int rc = -1;
+
+    /* Extract the led name from the full dbus path */
+    const char *led_path = sd_bus_message_get_path(msg);
+    if(led_path == NULL)
+    {
+        fprintf(stderr, "Error. LED path is empty");
+        return sd_bus_reply_method_return(msg, "i", rc);
+    }
+
+    char *led_name = get_led_name(led_path);
+    if(led_name == NULL)
+    {
+        fprintf(stderr, "Invalid LED name for path :[%s]\n",led_path);
+        return sd_bus_reply_method_return(msg, "i", rc);
+    }
+
+    /* Now that we have the LED name, get the Operation. */
+    const char *led_function = sd_bus_message_get_member(msg);
+    if(led_function == NULL)
+    {
+        fprintf(stderr, "Null LED function specificed for : [%s]\n",led_name);
+        return sd_bus_reply_method_return(msg, "i", rc);
+    }
+
+    /* Route the user action to appropriate handlers. */
+    if( (strcmp(led_function, "setOn") == 0) ||
+        (strcmp(led_function, "setOff") == 0))
+    {
+        rc = led_stable_state_function(led_name, led_function);
+        return sd_bus_reply_method_return(msg, "i", rc);
+    }
+    else if( (strcmp(led_function, "setBlinkFast") == 0) ||
+             (strcmp(led_function, "setBlinkSlow") == 0))
+    {
+        rc = led_default_blink(led_name, led_function);
+        return sd_bus_reply_method_return(msg, "i", rc);
+    }
+    else if(strcmp(led_function, "GetLedState") == 0)
+    {
+        char value_str[10] = {0};
+        const char *led_state = NULL;
+
+        rc = read_led(led_name, power_ctrl, value_str, sizeof(value_str));
+        if(rc >= 0)
+        {
+            /* LED is active low */
+            led_state = strtoul(value_str, NULL, 0) ? "Off" : "On";
+        }
+        return sd_bus_reply_method_return(msg, "is", rc, led_state);
+    }
+    else
+    {
+        fprintf(stderr,"Invalid LED function:[%s]\n",led_function);
+    }
+
+    return sd_bus_reply_method_return(msg, "i", rc);
+}
+
+/*
+ * --------------------------------------------------------------
+ * Turn On or Turn Off the LED
+ * --------------------------------------------------------------
+ */
+int led_stable_state_function(char *led_name, char *led_function)
+{
+    /* Generic error reporter. */
+    int rc = -1;
+
+    const char *value = NULL;
+    if(strcmp(led_function, "setOn") == 0)
+    {
+        /* LED active low */
+        value = "0";
+    }
+    else if(strcmp(led_function, "setOff") == 0)
+    {
+        value  = "255";
+    }
+    else
+    {
+        fprintf(stderr,"Invalid LED stable state operation:[%s] \n",led_function);
+        return rc;
+    }
+
+    /*
+     * Before doing anything, need to turn off the blinking
+     * if there is one in progress by writing 'none' to trigger
+     */
+    rc = write_to_led(led_name, blink_ctrl, "none");
+    if(rc < 0)
+    {
+        fprintf(stderr,"Error disabling blink. Function:[%s]\n", led_function);
+        return rc;
+    }
+
+    /*
+     * Open the brightness file and write corresponding values.
+     */
+    rc = write_to_led(led_name, power_ctrl, value);
+    if(rc < 0)
+    {
+        fprintf(stderr,"Error driving LED. Function:[%s]\n", led_function);
+    }
+
+    return rc;
+}
+
+//-----------------------------------------------------------------------------------
+// Given the on and off duration, applies the action on the specified LED.
+//-----------------------------------------------------------------------------------
+int blink_led(const char *led_name, const char *on_duration, const char *off_duration)
+{
+    /* Generic error reporter */
+    int rc = -1;
+
+    /* Protocol demands that 'timer' be echoed to 'trigger' */
+    rc = write_to_led(led_name, blink_ctrl, "timer");
+    if(rc < 0)
+    {
+        fprintf(stderr,"Error writing timer to Led:[%s]\n", led_name);
+        return rc;
+    }
+
+    /*
+     * After writing 'timer to 'trigger', 2 new files get generated namely
+     *'delay_on' and 'delay_off' which are telling the time duration for a
+     * particular LED on and off.
+     */
+    rc = write_to_led(led_name, duty_on, on_duration);
+    if(rc < 0)
+    {
+        fprintf(stderr,"Error writing [%s] to delay_on:[%s]\n",on_duration,led_name);
+        return rc;
+    }
+
+    rc = write_to_led(led_name, duty_off, off_duration);
+    if(rc < 0)
+    {
+        fprintf(stderr,"Error writing [%s] to delay_off:[%s]\n",off_duration,led_name);
+    }
+
+    return rc;
+}
+
+/*
+ * ----------------------------------------------------
+ * Default blink action on the LED.
+ * ----------------------------------------------------
+ */
+int led_default_blink(char *led_name, char *blink_type)
+{
+    /* Generic error reporter */
+    int rc = -1;
+
+    /* How long the LED needs to be in on and off state while blinking */
+    const char *on_duration = NULL;
+    const char *off_duration = NULL;
+    if(strcmp(blink_type, "setBlinkSlow") == 0)
+    {
+        //*Delay 900 millisec before 'on' and delay 900 millisec before off */
+        on_duration = "900";
+        off_duration = "900";
+    }
+    else if(strcmp(blink_type, "setBlinkFast") == 0)
+    {
+        /* Delay 200 millisec before 'on' and delay 200 millisec before off */
+        on_duration = "200";
+        off_duration = "200";
+    }
+    else
+    {
+        fprintf(stderr,"Invalid blink operation:[%s]\n",blink_type);
+        return rc;
+    }
+
+    rc = blink_led(led_name, on_duration, off_duration);
+
+    return rc;
+}
+
+/*
+ * ---------------------------------------------------------------
+ * Gets the current value of passed in LED file
+ * Mainly used for reading 'brightness'
+ * NOTE : It is the responsibility of the caller to allocate
+ * sufficient space for buffer. This will read upto user supplied 
+ * size -or- entire contents of file whichever is smaller
+ * ----------------------------------------------------------------
+ */
+int read_led(const char *name, const char *ctrl_file, 
+             void *value, const size_t len)
+{
+    /* Generic error reporter. */
+    int rc = -1;
+    int count = 0;
+
+    if(value == NULL || len <= 0)
+    {
+        fprintf(stderr, "Invalid buffer passed to LED read\n");
+        return rc;
+    }
+
+    /* To get /sys/class/leds/<name>/<control file> */
+    char led_path[128] = {0};
+
+    int led_len = 0;
+    led_len = snprintf(led_path, sizeof(led_path), 
+                   "/sys/class/leds/%s/%s",name, ctrl_file);
+    if(led_len >= sizeof(led_path))
+    {
+        fprintf(stderr, "Error. LED path is too long. :[%d]\n",led_len);
+        return rc;
+    }
+
+    FILE *fp = fopen(led_path,"rb");
+    if(fp == NULL)
+    {
+        perror("Error:");
+        fprintf(stderr,"Error opening:[%s]\n",led_path);
+        return rc;
+    }
+
+    char *sysfs_value = (char *)value;
+    while(!feof(fp) && (count < len))
+    {
+        sysfs_value[count++] = fgetc(fp);
+    }
+    sysfs_value[count]='\0';
+
+    fclose(fp);
+    return 0;
+}
+
+/*
+ * -----------------------------------------------
+ * Dbus Services offered by this LED controller
+ * -----------------------------------------------
+ */
+static const sd_bus_vtable led_control_vtable[] =
+{
+    SD_BUS_VTABLE_START(0),
+    SD_BUS_METHOD("setOn", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED),
+    SD_BUS_METHOD("setOff", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED),
+    SD_BUS_METHOD("setBlinkFast", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED),
+    SD_BUS_METHOD("setBlinkSlow", "", "i", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED),
+    SD_BUS_METHOD("GetLedState", "", "is", &led_function_router, SD_BUS_VTABLE_UNPRIVILEGED),
+    SD_BUS_VTABLE_END,
+};
+
+/*
+ * ---------------------------------------------
+ * Interested in all files except standard ones
+ * ---------------------------------------------
+ */
+int led_select(const struct dirent *entry)
+{
+    if( (strcmp(entry->d_name, ".") == 0) ||
+        (strcmp(entry->d_name, "..") == 0))
+    {
+        return 0;
+    }
+    return 1;
+}
+
+/*
+ * ------------------------------------------------
+ * Called as part of setting up skeleton services.
+ * -----------------------------------------------
+ */
+int start_led_services()
+{
+    /* Generic error reporter. */
+    int rc = -1;
+    int num_leds = 0;
+    int count_leds = 0;
+
+    /* Bus and slot where we are offering the LED dbus service. */
+    sd_bus *bus_type = NULL;
+    sd_bus_slot *led_slot = NULL;
+
+    /* For walking '/sys/class/leds/' looking for names of LED.*/
+    struct dirent **led_list;
+
+    /* Get a hook onto system bus. */
+    rc = sd_bus_open_system(&bus_type);
+    if(rc < 0)
+    {
+        fprintf(stderr,"Error opening system bus.\n");
+        return rc;
+    }
+
+    count_leds = num_leds = scandir("/sys/class/leds/", 
+                                    &led_list, led_select, alphasort);
+    if(num_leds <= 0)
+    {
+        fprintf(stderr,"No LEDs present in the system\n");
+
+        sd_bus_slot_unref(led_slot);
+        sd_bus_unref(bus_type);
+        return rc;
+    }
+
+    /* Fully qualified Dbus object for a particular LED */
+    char led_object[128] = {0};
+    int len = 0;
+
+    /* For each led present, announce the service on dbus. */
+    while(num_leds--)
+    {
+        memset(led_object, 0x0, sizeof(led_object));
+
+        len = snprintf(led_object, sizeof(led_object), "%s%s",
+                "/org/openbmc/controller/led/", led_list[num_leds]->d_name);
+
+        if(len >= sizeof(led_object))
+        {
+            fprintf(stderr, "Error. LED object is too long:[%d]\n",len);
+            rc = -1;
+            break;
+        }
+
+        /* Install the object */
+        rc = sd_bus_add_object_vtable(bus_type,
+                                      &led_slot,
+                                      led_object,                     /* object path */
+                                      "org.openbmc.controller.led",   /* interface name */
+                                      led_control_vtable,
+                                      NULL);
+
+        if (rc < 0)
+        {
+            fprintf(stderr, "Failed to add object to dbus: %s\n", strerror(-rc));
+            break;
+        }
+    }
+
+    /* Done with all registration. */
+    while (count_leds > 0)
+    {
+        free(led_list[--count_leds]);
+        if(count_leds == 0)
+        {
+            free(led_list);
+        }
+    }
+
+    /* If we had success in adding the providers, request for a bus name. */
+    if(rc == 0)
+    {
+        /* Take one in OpenBmc */
+        rc = sd_bus_request_name(bus_type, "org.openbmc.controller.led", 0);
+        if (rc < 0)
+        {
+            fprintf(stderr, "Failed to acquire service name: %s\n", strerror(-rc));
+        }
+        else
+        {
+            for (;;)
+            {
+                /* Process requests */
+                rc = sd_bus_process(bus_type, NULL);
+                if (rc < 0)
+                {
+                    fprintf(stderr, "Failed to process bus: %s\n", strerror(-rc));
+                    break;
+                }
+                if (rc > 0)
+                {
+                    continue;
+                }
+
+                rc = sd_bus_wait(bus_type, (uint64_t) - 1);
+                if (rc < 0)
+                {
+                    fprintf(stderr, "Failed to wait on bus: %s\n", strerror(-rc));
+                    break;
+                }
+            }
+        }
+    }
+    sd_bus_slot_unref(led_slot);
+    sd_bus_unref(bus_type);
+
+    return rc;
+}
+
+int main(void)
+{
+    int rc = 0;
+
+    /* This call is not supposed to return. If it does, then an error */
+    rc = start_led_services();
+    if(rc < 0)
+    {
+        fprintf(stderr, "Error starting LED Services. Exiting");
+    }
+
+    return rc;
+}
-- 
2.6.4




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