[Minios-devel] [UNIKRAFT PATCH 4/8] lib/fdt: Add a fdt_interrupr_cells helper to parse irq

[Wei Chen <wei.chen@xxxxxxx>]

We will use this helper to parse IRQ number for devices, like
timers and UARTs.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 lib/fdt/Makefile.uk      |  1 +
 lib/fdt/exportsyms.uk    |  1 +
 lib/fdt/fdt_interrupts.c | 89 ++++++++++++++++++++++++++++++++++++++++
 lib/fdt/include/libfdt.h | 19 +++++++++
 4 files changed, 110 insertions(+)
 create mode 100644 lib/fdt/fdt_interrupts.c

diff --git a/lib/fdt/Makefile.uk b/lib/fdt/Makefile.uk
index 03251f6..0ba9cec 100644
--- a/lib/fdt/Makefile.uk
+++ b/lib/fdt/Makefile.uk
@@ -7,6 +7,7 @@ LIBFDT_CFLAGS-y += -Wno-sign-compare
 
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_addresses.c
+LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_interrupts.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_empty_tree.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_overlay.c
 LIBFDT_SRCS-y += $(LIBFDT_BASE)/fdt_ro.c
diff --git a/lib/fdt/exportsyms.uk b/lib/fdt/exportsyms.uk
index d64d9dc..b11df90 100644
--- a/lib/fdt/exportsyms.uk
+++ b/lib/fdt/exportsyms.uk
@@ -61,3 +61,4 @@ fdt_stringlist_contains
 fdt_resize
 fdt_overlay_apply
 fdt_getprop_u32_by_offset
+fdt_interrupt_cells
diff --git a/lib/fdt/fdt_interrupts.c b/lib/fdt/fdt_interrupts.c
new file mode 100644
index 0000000..45ae963
--- /dev/null
+++ b/lib/fdt/fdt_interrupts.c
@@ -0,0 +1,89 @@
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2014 David Gibson <david@xxxxxxxxxxxxxxxxxxxxx>
+ * Copyright (C) 2018 Arm Ltd,. <Wei.Chen@xxxxxxx>
+ *
+ * libfdt is dual licensed: you can use it either under the terms of
+ * the GPL, or the BSD license, at your option.
+ *
+ *  a) This library is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License as
+ *     published by the Free Software Foundation; either version 2 of the
+ *     License, or (at your option) any later version.
+ *
+ *     This library is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ *     You should have received a copy of the GNU General Public
+ *     License along with this library; if not, write to the Free
+ *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ *     MA 02110-1301 USA
+ *
+ * Alternatively,
+ *
+ *  b) Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *     1. Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *     2. Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "libfdt_env.h"
+
+#include <fdt.h>
+#include <libfdt.h>
+
+#include "libfdt_internal.h"
+
+int fdt_find_irq_parent_offset(const void *fdt, int offset)
+{
+       uint32_t irq_parent;
+
+       do {
+               /* Find the interrupt-parent phandle */
+               if (!fdt_getprop_u32_by_offset(fdt, offset,
+                               "interrupt-parent", &irq_parent))
+                       break;
+
+               /* Try to find in parent node */
+               offset = fdt_parent_offset(fdt, offset);
+       } while (offset >= 0);
+
+       if (offset < 0)
+               return offset;
+
+       /* Get interrupt parent node by phandle */
+       return fdt_node_offset_by_phandle(fdt, irq_parent);
+}
+
+int fdt_interrupt_cells(const void *fdt, int offset)
+{
+       int intc_offset;
+
+       intc_offset = fdt_find_irq_parent_offset(fdt, offset);
+       if (intc_offset < 0)
+               return intc_offset;
+
+       return fdt_get_cells(fdt, "#interrupt-cells", intc_offset);
+}
diff --git a/lib/fdt/include/libfdt.h b/lib/fdt/include/libfdt.h
index 798a57a..b0815af 100644
--- a/lib/fdt/include/libfdt.h
+++ b/lib/fdt/include/libfdt.h
@@ -1141,6 +1141,25 @@ int fdt_address_cells(const void *fdt, int nodeoffset);
  */
 int fdt_size_cells(const void *fdt, int nodeoffset);
 
+/**
+ * fdt_interrupt_cells - retrieve the number of cells needed to encode an
+ *                       interrupt source
+ * @fdt: pointer to the device tree blob
+ * @nodeoffset: offset of the node to find the interrupt for.
+ *
+ * When the node has a valid #interrupt-cells property, returns its value.
+ *
+ * returns:
+ *     0 <= n < FDT_MAX_NCELLS, on success
+ *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
+ *             #interrupt-cells property
+ *     -FDT_ERR_BADMAGIC,
+ *     -FDT_ERR_BADVERSION,
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_BADSTRUCTURE,
+ *     -FDT_ERR_TRUNCATED, standard meanings
+ */
+int fdt_interrupt_cells(const void *fdt, int nodeoffset);
 
 /**********************************************************************/
 /* Write-in-place functions                                           */
-- 
2.17.1


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