Use -B <bitclock> rather than -b <baudrate> to specify the clock rate

in linuxspi driver.

This offers the additional advantage of being able to parse kHz and
MHz values (in main.c).


git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1497 81a1dc3b-b13d-400b-aceb-764788c761c2

ChangeLog

@@ -1,3 +1,8 @@
+2021-11-27  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
+
+	* linuxspi.c: Use -B <bitclock> rather than -b <baudrate>
+	to specify the clock rate
+
 2021-11-27  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
 
 	Improve defaults and documentation of linuxspi

NEWS

@@ -21,6 +21,7 @@ Current:
     - extended UPDI device context (> 64 Ki flash)
     - major overhaul of ft245r driver (patch #9327/#9328)
     - some improvements in linuxspi driver
+    - Use -B <bitclock> rather than -b <baudrate> for linuxspi driver
 
   * New devices supported:
 
@@ -124,6 +125,7 @@ Current:
     patch #10030: linuxspi: Support inverted GPIO pin
     patch #10031: linuxspi: Support GPIO uAPI v2
     (no-id): Improve documentation of linuxspi driver, provide portname default
+    (no-id): Use -B <bitclock> rather than -b <baudrate> for linuxspi driver
 
   * Internals:
     - New avrdude.conf keyword "family_id", used to verify SIB attributes

linuxspi.c

@@ -78,8 +78,7 @@ static int linuxspi_spi_duplex(PROGRAMMER *pgm, const unsigned char *tx, unsigne
         .rx_buf = (unsigned long)rx,
         .len = len,
         .delay_usecs = 1,
-        //should settle around 400Khz, a standard SPI speed. Adjust using baud parameter (-b)
+	.speed_hz = 1.0 / pgm->bitclock, // seconds to Hz
-	.speed_hz = pgm->baudrate == 0 ? 400000 : pgm->baudrate,
         .bits_per_word = 8,
     };
 
@@ -213,6 +212,19 @@ static int linuxspi_open(PROGRAMMER *pgm, char *port)
     if (ret)
         goto close_out;
 
+    if (pgm->baudrate != 0) {
+      avrdude_message(MSG_INFO,
+		      "%s: obsolete use of -b <clock> option for bit clock; use -B <clock>\n",
+		      progname);
+      pgm->bitclock = 1E6 / pgm->baudrate;
+    }
+    if (pgm->bitclock == 0) {
+      avrdude_message(MSG_NOTICE,
+		      "%s: defaulting bit clock to 200 kHz\n",
+		      progname);
+      pgm->bitclock = 5E-6; // 200 kHz - 5 µs
+    }
+
     return 0;
 
 close_out:
@@ -306,7 +318,7 @@ static int linuxspi_program_enable(PROGRAMMER *pgm, AVRPART *p)
          */
         if (linuxspi_reset_mcu(pgm, false))
             return -1;
-        usleep(3 + (pgm->baudrate ? 500000 / pgm->baudrate : 1));
+        usleep(5);
         if (linuxspi_reset_mcu(pgm, true))
             return -1;
         usleep(20000);