Use cJSON to get the GPIO definitions
In gpio_init, read the GPIO definitions out of the JSON
instead of D-Bus.
As many applications configure several GPIOs at once, the
cJSON structure for the GPIOs stays loaded in memory until
explicitly freed by calling gpio_inits_done().
Change-Id: I3ba216545a4a367744ce1fac09ca19c4d8d9d302
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
diff --git a/libopenbmc_intf/gpio.c b/libopenbmc_intf/gpio.c
index 291f9c3..8e4917c 100644
--- a/libopenbmc_intf/gpio.c
+++ b/libopenbmc_intf/gpio.c
@@ -11,7 +11,11 @@
#include <sys/mman.h>
#include "openbmc_intf.h"
#include "gpio.h"
+#include "gpio_json.h"
+#define GPIO_BASE_PATH "/sys/class/gpio"
+
+cJSON* gpio_json = NULL;
int gpio_writec(GPIO* gpio, char value)
{
@@ -101,42 +105,117 @@
return r;
}
+int convert_gpio_to_num(const char* gpio)
+{
+ /* TODO */
+ return 0;
+}
+
+/**
+ * Returns the cJSON pointer to the GPIO definition
+ * for the GPIO passed in.
+ *
+ * @param[in] gpio_name - the GPIO name, like BMC_POWER_UP
+ *
+ * @return cJSON* - pointer to the cJSON object or NULL
+ * if not found.
+ */
+cJSON* get_gpio_def(const char* gpio_name)
+{
+ if (gpio_json == NULL)
+ {
+ gpio_json = load_json();
+ if (gpio_json == NULL)
+ {
+ return NULL;
+ }
+ }
+
+ cJSON* gpio_defs = cJSON_GetObjectItem(gpio_json, "gpio_definitions");
+ g_assert(gpio_defs != NULL);
+
+ cJSON* def;
+ cJSON_ArrayForEach(def, gpio_defs)
+ {
+ cJSON* name = cJSON_GetObjectItem(def, "name");
+ g_assert(name != NULL);
+
+ if (strcmp(name->valuestring, gpio_name) == 0)
+ {
+ return def;
+ }
+ }
+ return NULL;
+}
+
+/**
+ * Frees the gpio_json memory
+ *
+ * Can be called once when callers are done calling making calls
+ * to gpio_init() so that the JSON only needs to be loaded once.
+ */
+void gpio_inits_done()
+{
+ if (gpio_json != NULL)
+ {
+ cJSON_Delete(gpio_json);
+ gpio_json = NULL;
+ }
+}
+
+/**
+ * Fills in the dev, direction, and num elements in
+ * the GPIO structure.
+ *
+ * @param gpio - the GPIO structure to fill in
+ *
+ * @return GPIO_OK if successful
+ */
+int gpio_get_params(GPIO* gpio)
+{
+ gpio->dev = g_strdup(GPIO_BASE_PATH);
+
+ const cJSON* def = get_gpio_def(gpio->name);
+ if (def == NULL)
+ {
+ fprintf(stderr, "Unable to find GPIO %s in the JSON\n",
+ gpio->name);
+ return GPIO_LOOKUP_ERROR;
+ }
+
+ const cJSON* dir = cJSON_GetObjectItem(def, "direction");
+ g_assert(dir != NULL);
+ gpio->direction = g_strdup(dir->valuestring);
+
+ /* Must use either 'num', like 87, or 'pin', like "A5" */
+ const cJSON* num = cJSON_GetObjectItem(def, "num");
+ if ((num != NULL) && cJSON_IsNumber(num))
+ {
+ gpio->num = num->valueint;
+ }
+ else
+ {
+ const cJSON* pin = cJSON_GetObjectItem(def, "pin");
+ g_assert(pin != NULL);
+
+ gpio->num = convert_gpio_to_num(pin->valuestring);
+ if (gpio->num < 0)
+ {
+ return GPIO_LOOKUP_ERROR;
+ }
+ }
+ return GPIO_OK;
+}
+
// Gets the gpio device path from gpio manager object
int gpio_init(GDBusConnection *connection, GPIO* gpio)
{
- int rc = GPIO_OK;
- GDBusProxy *proxy;
- GError *error;
- GVariant *result;
-
- error = NULL;
- g_assert_no_error (error);
- error = NULL;
- proxy = g_dbus_proxy_new_sync (connection,
- G_DBUS_PROXY_FLAGS_NONE,
- NULL, /* GDBusInterfaceInfo */
- "org.openbmc.managers.System", /* name */
- "/org/openbmc/managers/System", /* object path */
- "org.openbmc.managers.System", /* interface */
- NULL, /* GCancellable */
- &error);
- if (error != NULL) {
- return GPIO_LOOKUP_ERROR;
+ int rc = gpio_get_params(gpio);
+ if (rc != GPIO_OK)
+ {
+ return rc;
}
- result = g_dbus_proxy_call_sync (proxy,
- "gpioInit",
- g_variant_new ("(s)", gpio->name),
- G_DBUS_CALL_FLAGS_NONE,
- -1,
- NULL,
- &error);
-
- if (error != NULL) {
- return GPIO_LOOKUP_ERROR;
- }
- g_assert (result != NULL);
- g_variant_get (result, "(&si&s)", &gpio->dev,&gpio->num,&gpio->direction);
g_print("GPIO Lookup: %s = %d,%s\n",gpio->name,gpio->num,gpio->direction);
//export and set direction