Round the returned baudrate in ftdi_to_clkbits and adjust the changed values in test...

[libftdi] / src / ftdi.c

diff --git a/src/ftdi.c b/src/ftdi.c
index 66c159e..fba5288 100644 (file)
--- a/src/ftdi.c
+++ b/src/ftdi.c
@@ -1069,6 +1069,18 @@ static int ftdi_to_clkbits_AM(int baudrate, unsigned long *encoded_divisor)
    clk/2   -> 2
    From /2, 0.125 steps may be taken.
    The fractional part has frac_code encoding
+
+   value[13:0] of value is the divisor
+   index[9] mean 12 MHz Base(120 MHz/10) rate versus 3 MHz (48 MHz/16) else
+
+   H Type have all features above with
+   {index[8],value[15:14]} is the encoded subdivisor
+
+   FT232R, FT2232 and FT232BM have no option for 12 MHz and with 
+   {index[0],value[15:14]} is the encoded subdivisor
+
+   AM Type chips have only four fractional subdivisors at value[15:14]
+   for subdivisors 0, 0.5, 0.25, 0.125
 */
 static int ftdi_to_clkbits(int baudrate, unsigned int clk, int clk_div, unsigned long *encoded_divisor)
 {
@@ -1100,7 +1112,11 @@ static int ftdi_to_clkbits(int baudrate, unsigned int clk, int clk_div, unsigned
             best_divisor = divisor/2;
         if(best_divisor > 0x20000)
             best_divisor = 0x1ffff;
-        best_baud = clk*8/clk_div/best_divisor;
+        best_baud = clk*16/clk_div/best_divisor;
+        if (best_baud & 1) /* Decide if to round up or down*/
+            best_baud = best_baud /2 +1;
+        else
+            best_baud = best_baud /2;
         *encoded_divisor = (best_divisor >> 3) | (frac_code[best_divisor & 0x7] << 14);
     }
     return best_baud;
@@ -1149,7 +1165,7 @@ static int ftdi_convert_baudrate(int baudrate, struct ftdi_context *ftdi,
     }
     // Split into "value" and "index" values
     *value = (unsigned short)(encoded_divisor & 0xFFFF);
-    if (ftdi->type == TYPE_2232C || ftdi->type == TYPE_2232H || 
+    if (ftdi->type == TYPE_2232H || 
         ftdi->type == TYPE_4232H || ftdi->type == TYPE_232H )
     {
         *index = (unsigned short)(encoded_divisor >> 8);