From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grant Likely Subject: Re: [PATCH 2/9] Add dtget utility to read property values from device tree Date: Wed, 6 Jul 2011 12:41:13 -0600 Message-ID: <20110706184113.GB4871@ponder.secretlab.ca> References: <1309892577-23828-1-git-send-email-sjg@chromium.org> <1309892577-23828-3-git-send-email-sjg@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1309892577-23828-3-git-send-email-sjg-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org Sender: devicetree-discuss-bounces+gldd-devicetree-discuss=m.gmane.org-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org To: Simon Glass Cc: Devicetree Discuss List-Id: devicetree@vger.kernel.org On Tue, Jul 05, 2011 at 12:02:50PM -0700, Simon Glass wrote: > This simply utility makes it easy for scripts to read values from the device > tree. > > Signed-off-by: Simon Glass Looks okay to me. g. > --- > .gitignore | 1 + > Makefile | 7 ++ > Makefile.dtget | 13 ++++ > dtget.c | 207 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 228 insertions(+), 0 deletions(-) > create mode 100644 Makefile.dtget > create mode 100644 dtget.c > > diff --git a/.gitignore b/.gitignore > index ae7a46a..cde4fa5 100644 > --- a/.gitignore > +++ b/.gitignore > @@ -10,3 +10,4 @@ lex.yy.c > /ftdump > /convert-dtsv0 > /version_gen.h > +/dtget > diff --git a/Makefile b/Makefile > index 22f79a0..3401a65 100644 > --- a/Makefile > +++ b/Makefile > @@ -106,10 +106,12 @@ endef > include Makefile.convert-dtsv0 > include Makefile.dtc > include Makefile.ftdump > +include Makefile.dtget > > BIN += convert-dtsv0 > BIN += dtc > BIN += ftdump > +BIN += dtget > > SCRIPTS = dtdiff > > @@ -120,6 +122,7 @@ ifneq ($(DEPTARGETS),) > -include $(DTC_OBJS:%.o=%.d) > -include $(CONVERT_OBJS:%.o=%.d) > -include $(FTDUMP_OBJS:%.o=%.d) > +-include $(DTGET_OBJS:%.o=%.d) > endif > > > @@ -180,6 +183,10 @@ convert-dtsv0: $(CONVERT_OBJS) > > ftdump: $(FTDUMP_OBJS) > > +dtget: $(DTGET_OBJS) $(LIBFDT_archive) > + $(VECHO) LD $@ > + $(LINK.c) -o $@ $^ > + > > # > # Testsuite rules > diff --git a/Makefile.dtget b/Makefile.dtget > new file mode 100644 > index 0000000..edda499 > --- /dev/null > +++ b/Makefile.dtget > @@ -0,0 +1,13 @@ > +# > +# This is not a complete Makefile. > +# Instead, it is designed to be easily embeddable > +# into other systems of Makefiles. > +# > + > +DTGET_SRCS = \ > + dtget.c \ > + util.c > + > +DTGET_GEN_SRCS = > + > +DTGET_OBJS = $(DTGET_SRCS:%.c=%.o) $(DTGET_GEN_SRCS:%.c=%.o) > diff --git a/dtget.c b/dtget.c > new file mode 100644 > index 0000000..0ee577c > --- /dev/null > +++ b/dtget.c > @@ -0,0 +1,207 @@ > +/* > + * Copyright (c) 2011 The Chromium OS Authors. All rights reserved. > + * Distributed under the terms of the GNU General Public License v2 > + * > + * is_printable_string from ftdump.c > + * Contributed by Pantelis Antoniou > + */ > + > +#include > +#include > +#include > +#include > +#include > + > +#include > + > +#include "util.h" > + > +#define FTDUMP_BUF_SIZE 65536 > + > +static void report_error(const char *where, int err) > +{ > + fprintf(stderr, "Error at '%s': %s\n", where, fdt_strerror(err)); > +} > + > +static void show_data(const char *format, int type, const char *data, int len) > +{ > + int i, size; > + const char *p = data, *s; > + int value; > + int is_string; > + > + /* no data, don't print */ > + if (len == 0) > + return; > + > + is_string = type == 's' || > + (!type && util_is_printable_string(data, len)); > + if (is_string) { > + for (s = data; s - data < len; s += strlen(s) + 1) { > + if (s != data) > + printf(" "); > + printf(format ? format : "%s", (const char *)s); > + } > + return; > + } > + if (type == 'i') > + size = 4; > + else if (type == 'b') > + size = 1; > + else > + size = len % 4 == 0 ? 4 : 1; > + for (i = 0; i < len; i += size, p += size) { > + if (i) > + printf(" "); > + value = size == 4 ? fdt32_to_cpu(*(const uint32_t *)p) : > + *(const unsigned char *)p; > + printf(format ? format : "%d", value); > + } > +} > + > +static int show_data_for_key(const void *blob, const char *format, int type, > + char *key) > +{ > + char *ptr, *prop; > + int node, guess_node = 0; > + const void *value; > + int len; > + > + /* First extract the property from the end */ > + ptr = strrchr(key, '/'); > + if (!ptr) { > + fprintf(stderr, "No node found in key '%s'\n", key); > + return 5; > + } > + > + if (ptr == key) { > + guess_node = fdt_path_offset(blob, key); > + node = fdt_path_offset(blob, "/"); > + } else { > + *ptr = '\0'; > + node = fdt_path_offset(blob, key); > + *ptr = '/'; > + } > + if (node < 0) { > + report_error(key, node); > + return 7; > + } > + prop = ptr + 1; > + value = fdt_getprop(blob, node, prop, &len); > + if (!value) { > + report_error(prop, len); > + if (guess_node) > + fprintf(stderr, "(Node %s exists but you didn't " > + "specify a property to print)\n", key); > + return 8; > + } > + show_data(format, type, value, len); > + printf("\n"); > + return 0; > +} > + > +static int do_dtget(const char *filename, const char *format, int type, > + char **key, int key_count) > +{ > + FILE *fp; > + char *buf; > + size_t size; > + int i, ret; > + > + if (strcmp(filename, "-") == 0) { > + fp = stdin; > + } else { > + fp = fopen(filename, "rb"); > + if (fp == NULL) { > + fprintf(stderr, "unable to open %s\n", filename); > + return 10; > + } > + } > + > + buf = malloc(FTDUMP_BUF_SIZE); > + if (!buf) { > + fprintf(stderr, "Couldn't allocate %d byte buffer\n", > + FTDUMP_BUF_SIZE); > + return 10; > + } > + > + size = fread(buf, 1, FTDUMP_BUF_SIZE, fp); > + if (!feof(fp)) { > + fprintf(stderr, "file too large (maximum is %d bytes)\n", > + FTDUMP_BUF_SIZE); > + return 10; > + } > + if (ferror(fp)) { > + fprintf(stderr, "file read error\n"); > + return 10; > + } > + for (i = 0; i < key_count; i++) { > + ret = show_data_for_key(buf, format, type, key[i]); > + if (ret) > + return ret; > + } > + return 0; > +} > + > +static void usage(const char *msg) > +{ > + if (msg) > + fprintf(stderr, "Error: %s\n\n", msg); > + fprintf(stderr, "dtget - read values from device tree\n\n"); > + fprintf(stderr, "Usage: dtget
...\n"); > + fprintf(stderr, "Options:\n"); > + fprintf(stderr, "\t-f, --format \tPrintf format string to use " > + "for value\n"); > + fprintf(stderr, "\t-t, --type \tForce type to be string " > + "(s), int(i) or byte(b)\n"); > + fprintf(stderr, "\t-h, --help\t\tPrint this help\n\n"); > + fprintf(stderr, "\t is /, for example " > + "/lcd/width for the width\n"); > + fprintf(stderr, "\tproperty in the LCD node\n"); > + exit(2); > +} > + > +int main(int argc, char *argv[]) > +{ > + int c; > + int ret; > + char *format = NULL; > + int type = 0; > + char *filename = NULL; > + static struct option long_options[] = { > + {"format", 1, 0, 'f'}, > + {"help", 1, 0, 'h'}, > + {"type", 1, 0, 't'}, > + {0, 0, 0, 0} > + }; > + > + for (;;) { > + c = getopt_long(argc, argv, "f:ht:", long_options, NULL); > + if (c == -1) > + break; > + > + switch (c) { > + case 'h': > + case '?': > + usage(""); > + > + case 'f': > + format = optarg; > + break; > + > + case 't': > + type = *optarg; > + break; > + } > + } > + > + if (optind < argc) > + filename = argv[optind++]; > + if (!filename) > + usage("Missing filename"); > + if (optind == argc) > + usage("Missing key(s)"); > + > + ret = do_dtget(filename, format, type, argv + optind, argc - optind); > + return ret; > +} > -- > 1.7.3.1 >