[PATCH 2/2] bsps/microblaze: Add device tree support to GPIO

[Alex White]

---
 .../microblaze_fpga/gpio/microblaze-gpio.c    | 63 +++++++++++++++++++
 .../include/bsp/microblaze-gpio.h             | 18 ++++++
 2 files changed, 81 insertions(+)

diff --git a/bsps/microblaze/microblaze_fpga/gpio/microblaze-gpio.c b/bsps/microblaze/microblaze_fpga/gpio/microblaze-gpio.c
index a12158f1b7..98cc863fd2 100644
--- a/bsps/microblaze/microblaze_fpga/gpio/microblaze-gpio.c
+++ b/bsps/microblaze/microblaze_fpga/gpio/microblaze-gpio.c
@@ -36,12 +36,75 @@
 #include <assert.h>
 
 #include <bsp/fatal.h>
+#include <bsp/fdt.h>
 #include <bsp/microblaze-gpio.h>
 
+#include <libfdt.h>
+
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
 
+#ifdef BSP_MICROBLAZE_FPGA_USE_FDT
+rtems_status_code microblaze_gpio_init_context_from_fdt(
+  Microblaze_GPIO_context *context,
+  int index
+)
+{
+  if ( context == NULL ) {
+    return RTEMS_INVALID_ADDRESS;
+  }
+
+  const char* compatible = "xlnx,xps-gpio-1.00.a";
+  const void *fdt = bsp_fdt_get();
+  int node = fdt_node_offset_by_compatible( fdt, -1, compatible );
+  if ( node < 0 ) {
+    return RTEMS_INVALID_NUMBER;
+  }
+  
+  /* Get the desired GPIO node if index is greater than zero. */
+  for(int i = 0; i < index; i++) {
+    node = fdt_node_offset_by_compatible( fdt, node, compatible );
+    if ( node < 0 ) {
+      return RTEMS_INVALID_NUMBER;
+    }
+  }
+
+  const uint32_t *prop;
+  prop = fdt_getprop( fdt, node, "reg", NULL );
+  if ( prop != NULL ) {
+    context->regs = (Microblaze_GPIO_registers *) fdt32_to_cpu( prop[0] );
+  } else {
+    return RTEMS_INVALID_NUMBER;
+  }
+
+  prop = fdt_getprop( fdt, node, "xlnx,is-dual", NULL );
+  if ( prop != NULL ) {
+    context->is_dual = fdt32_to_cpu( prop[0] ) != 0 ? true : false;
+  } else {
+    return RTEMS_INVALID_NUMBER;
+  }
+
+  prop = fdt_getprop( fdt, node, "xlnx,interrupt-present", NULL );
+  if ( prop != NULL ) {
+    context->has_interrupts = fdt32_to_cpu( prop[0] ) != 0 ? true : false;
+  } else {
+    return RTEMS_INVALID_NUMBER;
+  }
+
+  if ( context->has_interrupts ) {
+    prop = fdt_getprop( fdt, node, "interrupts", NULL );
+    if ( prop != NULL ) {
+      context->irq = fdt32_to_cpu( prop[0] );
+    } else {
+      return RTEMS_INVALID_NUMBER;
+    }
+  }
+
+  return RTEMS_SUCCESSFUL;
+}
+#endif /* BSP_MICROBLAZE_FPGA_USE_FDT */
+
 void microblaze_gpio_set_data_direction(
   Microblaze_GPIO_context *ctx,
   uint32_t                 channel,
diff --git a/bsps/microblaze/microblaze_fpga/include/bsp/microblaze-gpio.h b/bsps/microblaze/microblaze_fpga/include/bsp/microblaze-gpio.h
index a3d79ff70f..e68e0a78cb 100644
--- a/bsps/microblaze/microblaze_fpga/include/bsp/microblaze-gpio.h
+++ b/bsps/microblaze/microblaze_fpga/include/bsp/microblaze-gpio.h
@@ -129,6 +129,24 @@ typedef struct {
   bool                       has_interrupts;
 } Microblaze_GPIO_context;
 
+#ifdef BSP_MICROBLAZE_FPGA_USE_FDT
+/**
+ * @brief Initialize GPIO context from FDT.
+ * 
+ * @param[in] context the GPIO context to initialize
+ * @param[in] index the zero-based GPIO index in the FDT
+ * 
+ * @retval RTEMS_SUCCESSFUL on success
+ * @retval RTEMS_INVALID_NUMBER if the index is invalid or the node is missing a
+ *         required property
+ * @retval RTEMS_INVALID_ADDRESS if the context is NULL
+ */
+rtems_status_code microblaze_gpio_init_context_from_fdt(
+  Microblaze_GPIO_context *context,
+  int index
+);
+#endif /* BSP_MICROBLAZE_FPGA_USE_FDT */
+
 /**
  * @brief Set pin configuration for the specified GPIO channel.
  *
-- 
2.34.1