Add print_freq() to display frequencies nicely

Add a function similar to print_size() that works for frequencies. It can
handle from Hz to GHz.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

diff --git a/include/display_options.h b/include/display_options.h
index 54bd41d10de66681a396efb4905db3e51cd19700..ac44c459b3bf1e44c1b69e92d2fc16b4b87bf649 100644 (file)
--- a/include/display_options.h
+++ b/include/display_options.h
@@ -22,6 +22,17 @@
  */
 void print_size(uint64_t size, const char *suffix);
 
+/**
+ * print_freq() - Print a frequency with a suffix
+ *
+ * Print frequencies as "x.xx GHz", "xxx KHz", etc as needed; allow for
+ * optional trailing string (like "\n")
+ *
+ * @freq:      Frequency to print in Hz
+ * @suffix     String to print after the frequency
+ */
+void print_freq(uint64_t freq, const char *suffix);
+
 /**
  * print_buffer() - Print data buffer in hex and ascii form
  *

diff --git a/lib/display_options.c b/lib/display_options.c
index 3f32bcd8cf2dff807f64e8f0185f6f1fd8116e18..24d8f554e51661d827f4bcdccedc83c40a8aba1b 100644 (file)
--- a/lib/display_options.c
+++ b/lib/display_options.c
@@ -7,6 +7,7 @@
 
 #include <config.h>
 #include <common.h>
+#include <div64.h>
 #include <inttypes.h>
 #include <version.h>
 #include <linux/ctype.h>
@@ -22,6 +23,47 @@ int display_options (void)
        return 0;
 }
 
+void print_freq(uint64_t freq, const char *s)
+{
+       unsigned long m = 0, n;
+       uint32_t f;
+       static const char names[] = {'G', 'M', 'K'};
+       unsigned long d = 1e9;
+       char c = 0;
+       unsigned int i;
+
+       for (i = 0; i < ARRAY_SIZE(names); i++, d /= 1000) {
+               if (freq >= d) {
+                       c = names[i];
+                       break;
+               }
+       }
+
+       if (!c) {
+               printf("%" PRIu64 " Hz%s", freq, s);
+               return;
+       }
+
+       f = do_div(freq, d);
+       n = freq;
+
+       /* If there's a remainder, show the first few digits */
+       if (f) {
+               m = f;
+               while (m > 1000)
+                       m /= 10;
+               while (m && !(m % 10))
+                       m /= 10;
+               if (m >= 100)
+                       m = (m / 10) + (m % 100 >= 50);
+       }
+
+       printf("%lu", n);
+       if (m)
+               printf(".%ld", m);
+       printf(" %cHz%s", c, s);
+}
+
 void print_size(uint64_t size, const char *s)
 {
        unsigned long m = 0, n;