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-rw-r--r--os/various/chprintf.c54
-rw-r--r--os/various/chprintf.h7
-rw-r--r--readme.txt1
3 files changed, 59 insertions, 3 deletions
diff --git a/os/various/chprintf.c b/os/various/chprintf.c
index 3936226c1..d7472b3a4 100644
--- a/os/various/chprintf.c
+++ b/os/various/chprintf.c
@@ -17,25 +17,42 @@
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+/*
+ Concepts and parts of this file have been contributed by Fabio Utzig.
+ */
#include <stdarg.h>
#include "ch.h"
+#include "chprintf.h"
#define MAX_FILLER 11
+#define FLOAT_PRECISION 100000
-static char *ltoa(char *p, long num, unsigned radix) {
+static char *long_to_string_with_divisor(char *p,
+ long num,
+ unsigned radix,
+ long divisor) {
int i;
char *q;
+ long l, ll;
+
+ l = num;
+ if (divisor == 0) {
+ ll = num;
+ } else {
+ ll = divisor;
+ }
q = p + MAX_FILLER;
do {
- i = (int)(num % radix);
+ i = (int)(l % radix);
i += '0';
if (i > '9')
i += 'A' - '0' - 10;
*--q = i;
- } while ((num /= radix) != 0);
+ l /= radix;
+ } while ((ll /= radix) != 0);
i = (int)(p + MAX_FILLER - q);
do
@@ -45,6 +62,24 @@ static char *ltoa(char *p, long num, unsigned radix) {
return p;
}
+static char *ltoa(char *p, long num, unsigned radix) {
+
+ return long_to_string_with_divisor(p, num, radix, 0);
+}
+
+#if CHPRINTF_USE_FLOAT
+static char *ftoa(char *p, double num) {
+ long l;
+ unsigned long precision = FLOAT_PRECISION;
+
+ l = num;
+ p = long_to_string_with_divisor(p, l, 10, 0);
+ *p++ = '.';
+ l = (num - l) * precision;
+ return long_to_string_with_divisor(p, l, 10, precision / 10);
+}
+#endif
+
/**
* @brief System formatted output function.
* @details This function implements a minimal @p printf() like functionality
@@ -75,6 +110,9 @@ void chprintf(BaseChannel *chp, const char *fmt, ...) {
int i, precision, width;
bool_t is_long, left_align;
long l;
+#if CHPRINTF_USE_FLOAT
+ float f;
+#endif
va_start(ap, fmt);
while (TRUE) {
@@ -160,6 +198,16 @@ void chprintf(BaseChannel *chp, const char *fmt, ...) {
}
p = ltoa(p, l, 10);
break;
+#if CHPRINTF_USE_FLOAT
+ case 'f':
+ f = (float) va_arg(ap, double);
+ if (f < 0) {
+ *p++ = '-';
+ f = -f;
+ }
+ p = ftoa(p, f);
+ break;
+#endif
case 'X':
case 'x':
c = 16;
diff --git a/os/various/chprintf.h b/os/various/chprintf.h
index 929da639e..866dfa067 100644
--- a/os/various/chprintf.h
+++ b/os/various/chprintf.h
@@ -29,6 +29,13 @@
#ifndef _CHPRINTF_H_
#define _CHPRINTF_H_
+/**
+ * @brief Float type support.
+ */
+#if !defined(CHPRINTF_USE_FLOAT) || defined(__DOXYGEN__)
+#define CHPRINTF_USE_FLOAT FALSE
+#endif
+
#ifdef __cplusplus
extern "C" {
#endif
diff --git a/readme.txt b/readme.txt
index 639793ae3..a27ef1fe6 100644
--- a/readme.txt
+++ b/readme.txt
@@ -97,6 +97,7 @@
3484947)(backported to 2.4.1).
- FIX: Fixed various minor documentation errors (bug 3484942)(backported
to 2.4.1).
+- NEW: Added float support (optional) to chprintf(), by Fabio Utzig.
- NEW: Added overflow handling in the ICU driver (contributed by Xo).
- NEW: Updated debug plugin 1.0.8 (backported to 2.4.0).
- NEW: Added more accurate UBRR calculation in AVR serial driver (backported