dt: run C pre-processor on *.dts, create some standard headers

This branch enhances the support for running dtc on device tree files.
 
 A dedicated directory is created for header files that provide constants
 for device-tree bindings.
 
 The kbuild dependency script processor is enhanced to support processing
 the dependency outputs from multiple separate commands at once.
 
 The kbuild dtc rule is modified so that the C pre-processor is always
 applied when compiling any device tree.
 
 Some standard headers are created which define common constants for GPIO,
 IRQ, and ARM GIC device tree bindings.
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Merge tag 'tegra-for-3.10-dtc-cpp-chroot-std-headers' of git://git.kernel.org/pub/scm/linux/kernel/git/swarren/linux-tegra into for-next

Pull DT C pre-processor changes from Stephen Warren:

dt: run C pre-processor on *.dts, create some standard headers

This branch enhances the support for running dtc on device tree files.

A dedicated directory is created for header files that provide constants
for device-tree bindings.

The kbuild dependency script processor is enhanced to support processing
the dependency outputs from multiple separate commands at once.

The kbuild dtc rule is modified so that the C pre-processor is always
applied when compiling any device tree.

Some standard headers are created which define common constants for GPIO,
IRQ, and ARM GIC device tree bindings.

arch/arm/boot/dts/include/dt-bindings

@@ -0,0 +1 @@
+../../../../../include/dt-bindings

include/dt-bindings/gpio/gpio.h

@@ -0,0 +1,15 @@
+/*
+ * This header provides constants for most GPIO bindings.
+ *
+ * Most GPIO bindings include a flags cell as part of the GPIO specifier.
+ * In most cases, the format of the flags cell uses the standard values
+ * defined in this header.
+ */
+
+#ifndef _DT_BINDINGS_GPIO_GPIO_H
+#define _DT_BINDINGS_GPIO_GPIO_H
+
+#define GPIO_ACTIVE_HIGH 0
+#define GPIO_ACTIVE_LOW 1
+
+#endif

include/dt-bindings/interrupt-controller/arm-gic.h

@@ -0,0 +1,22 @@
+/*
+ * This header provides constants for the ARM GIC.
+ */
+
+#ifndef _DT_BINDINGS_INTERRUPT_CONTROLLER_ARM_GIC_H
+#define _DT_BINDINGS_INTERRUPT_CONTROLLER_ARM_GIC_H
+
+#include <dt-bindings/interrupt-controller/irq.h>
+
+/* interrupt specific cell 0 */
+
+#define GIC_SPI 0
+#define GIC_PPI 1
+
+/*
+ * Interrupt specifier cell 2.
+ * The flaggs in irq.h are valid, plus those below.
+ */
+#define GIC_CPU_MASK_RAW(x) ((x) << 8)
+#define GIC_CPU_MASK_SIMPLE(num) GIC_CPU_MASK_RAW((1 << (num)) - 1)
+
+#endif

include/dt-bindings/interrupt-controller/irq.h

@@ -0,0 +1,19 @@
+/*
+ * This header provides constants for most IRQ bindings.
+ *
+ * Most IRQ bindings include a flags cell as part of the IRQ specifier.
+ * In most cases, the format of the flags cell uses the standard values
+ * defined in this header.
+ */
+
+#ifndef _DT_BINDINGS_INTERRUPT_CONTROLLER_IRQ_H
+#define _DT_BINDINGS_INTERRUPT_CONTROLLER_IRQ_H
+
+#define IRQ_TYPE_NONE		0
+#define IRQ_TYPE_EDGE_RISING	1
+#define IRQ_TYPE_EDGE_FALLING	2
+#define IRQ_TYPE_EDGE_BOTH	(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING)
+#define IRQ_TYPE_LEVEL_HIGH	4
+#define IRQ_TYPE_LEVEL_LOW	8
+
+#endif

scripts/Makefile.lib

@@ -156,9 +156,9 @@ cpp_flags      = -Wp,-MD,$(depfile) $(NOSTDINC_FLAGS) $(LINUXINCLUDE)     \
 
 ld_flags       = $(LDFLAGS) $(ldflags-y)
 
-dtc_cpp_flags  = -Wp,-MD,$(depfile) -nostdinc                            \
+dtc_cpp_flags  = -Wp,-MD,$(depfile).pre -nostdinc                        \
 		 -I$(srctree)/arch/$(SRCARCH)/boot/dts                   \
-		 -I$(srctree)/arch/$(SRCARCH)/include/dts                \
+		 -I$(srctree)/arch/$(SRCARCH)/boot/dts/include           \
 		 -undef -D__DTS__
 
 # Finds the multi-part object the current object will be linked into
@@ -269,20 +269,17 @@ $(obj)/%.dtb.S: $(obj)/%.dtb
 	$(call cmd,dt_S_dtb)
 
 quiet_cmd_dtc = DTC     $@
-cmd_dtc = $(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) -d $(depfile) $<
+cmd_dtc = $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
+	$(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 \
+		-i $(srctree)/arch/$(SRCARCH)/boot/dts $(DTC_FLAGS) \
+		-d $(depfile).dtc $(dtc-tmp) ; \
+	cat $(depfile).pre $(depfile).dtc > $(depfile)
 
 $(obj)/%.dtb: $(src)/%.dts FORCE
 	$(call if_changed_dep,dtc)
 
 dtc-tmp = $(subst $(comma),_,$(dot-target).dts)
 
-quiet_cmd_dtc_cpp = DTC+CPP $@
-cmd_dtc_cpp = $(CPP) $(dtc_cpp_flags) -x assembler-with-cpp -o $(dtc-tmp) $< ; \
-	$(objtree)/scripts/dtc/dtc -O dtb -o $@ -b 0 $(DTC_FLAGS) $(dtc-tmp)
-
-$(obj)/%.dtb: $(src)/%.dtsp FORCE
-	$(call if_changed_dep,dtc_cpp)
-
 # Bzip2
 # ---------------------------------------------------------------------------
 

scripts/basic/fixdep.c

@@ -320,49 +320,78 @@ static void parse_dep_file(void *map, size_t len)
 	char *end = m + len;
 	char *p;
 	char s[PATH_MAX];
-	int first;
+	int is_target;
-
+	int saw_any_target = 0;
-	p = strchr(m, ':');
+	int is_first_dep = 0;
-	if (!p) {
-		fprintf(stderr, "fixdep: parse error\n");
-		exit(1);
-	}
-	memcpy(s, m, p-m); s[p-m] = 0;
-	m = p+1;
 
 	clear_config();
 
-	first = 1;
 	while (m < end) {
+		/* Skip any "white space" */
 		while (m < end && (*m == ' ' || *m == '\\' || *m == '\n'))
 			m++;
+		/* Find next "white space" */
 		p = m;
-		while (p < end && *p != ' ') p++;
+		while (p < end && *p != ' ' && *p != '\\' && *p != '\n')
-		if (p == end) {
-			do p--; while (!isalnum(*p));
 			p++;
-		}
+		/* Is the token we found a target name? */
-		memcpy(s, m, p-m); s[p-m] = 0;
+		is_target = (*(p-1) == ':');
+		/* Don't write any target names into the dependency file */
+		if (is_target) {
+			/* The /next/ file is the first dependency */
+			is_first_dep = 1;
+		} else {
+			/* Save this token/filename */
+			memcpy(s, m, p-m);
+			s[p - m] = 0;
+
+			/* Ignore certain dependencies */
 			if (strrcmp(s, "include/generated/autoconf.h") &&
 			    strrcmp(s, "arch/um/include/uml-config.h") &&
 			    strrcmp(s, "include/linux/kconfig.h") &&
 			    strrcmp(s, ".ver")) {
 				/*
-			 * Do not list the source file as dependency, so that
+				 * Do not list the source file as dependency,
-			 * kbuild is not confused if a .c file is rewritten
+				 * so that kbuild is not confused if a .c file
-			 * into .S or vice versa. Storing it in source_* is
+				 * is rewritten into .S or vice versa. Storing
-			 * needed for modpost to compute srcversions.
+				 * it in source_* is needed for modpost to
+				 * compute srcversions.
 				 */
-			if (first) {
+				if (is_first_dep) {
-				printf("source_%s := %s\n\n", target, s);
+					/*
-				printf("deps_%s := \\\n", target);
+					 * If processing the concatenation of
+					 * multiple dependency files, only
+					 * process the first target name, which
+					 * will be the original source name,
+					 * and ignore any other target names,
+					 * which will be intermediate temporary
+					 * files.
+					 */
+					if (!saw_any_target) {
+						saw_any_target = 1;
+						printf("source_%s := %s\n\n",
+							target, s);
+						printf("deps_%s := \\\n",
+							target);
+					}
+					is_first_dep = 0;
 				} else
 					printf("  %s \\\n", s);
 				do_config_file(s);
 			}
-		first = 0;
+		}
+		/*
+		 * Start searching for next token immediately after the first
+		 * "whitespace" character that follows this token.
+		 */
 		m = p + 1;
 	}
+
+	if (!saw_any_target) {
+		fprintf(stderr, "fixdep: parse error; no targets found\n");
+		exit(1);
+	}
+
 	printf("\n%s: $(deps_%s)\n\n", target, target);
 	printf("$(deps_%s):\n", target);
 }