From f862a82a2da9c7d15912d99264ab211863e16bec Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Mon, 28 Jan 2013 21:06:00 -0300
Subject: [PATCH] ubb-la/ubb-la.c: new option -F freq_MHz to select "unsafe"
 frequencies

---
 ubb-la/README   |  4 ++++
 ubb-la/ubb-la.c | 16 +++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/ubb-la/README b/ubb-la/README
index fd375ab..be6f75f 100644
--- a/ubb-la/README
+++ b/ubb-la/README
@@ -26,6 +26,10 @@ Note that - unlike ubb-patgen - there are no SI prefixes or rounding
 modes to select. ubb-la simply picks the frequency closest to the one
 specified.
 
+The option -F works like -f but also allows frequencies that may
+exceed the hardware's capabilities. As a consequence, the MMC
+controller may hang.
+
 A list of available frequencies can be obtained with
 
 # ubb-patgen -q
diff --git a/ubb-la/ubb-la.c b/ubb-la/ubb-la.c
index 2bf259b..7a70e8d 100644
--- a/ubb-la/ubb-la.c
+++ b/ubb-la/ubb-la.c
@@ -331,11 +331,12 @@ static void do_bufs(int n_bufs, int nibbles)
  * It'll save a few nanoseconds.
  */
 
-static void frequency(struct mmcclk *clk, int hz)
+static void frequency(struct mmcclk *clk, int hz, int all)
 {
 	struct mmcclk mmc;
 
-	mmcclk_first(&mmc, 0, MMCCLK_FLAG_RD_ONLY);
+	mmcclk_first(&mmc, 0,
+	    MMCCLK_FLAG_RD_ONLY | (all ? MMCCLK_FLAG_ALL : 0));
 	*clk = mmc;
 	while (mmcclk_next(&mmc))
 		if (fabs(clk->bus_clk_hz-hz) > fabs(mmc.bus_clk_hz-hz) ||
@@ -361,9 +362,10 @@ static unsigned long xlat_pins(unsigned long pins)
 static void usage(const char *name)
 {
 	fprintf(stderr,
-"usage: %s [-C] [-t pattern/mask] [-f frequency_MHz] [-n N]\n\n"
+"usage: %s [-C] [-t pattern/mask] [(-f|-F) frequency_MHz] [-n N]\n\n"
 "  -C               output the MMC clock on CLK/TRIG (for debugging)\n"
 "  -f freq_MHz      select the specified frequency (default; 1 MHz)\n"
+"  -F freq_MHz      like -f, but also allow \"overclocking\"\n"
 "  -n N             capture N buffers worth of samples without waiting for a\n"
 "                   trigger\n"
 "  -t pattern/mask  start capture at the specified pattern (DAT0 = 1, etc.,\n"
@@ -376,6 +378,7 @@ static void usage(const char *name)
 int main(int argc, char **argv)
 {
 	double freq_mhz = 1;
+	int all = 0;
 	unsigned long trigger = 1, mask = 0;
 	unsigned long multi = 0;
 	int clkout = 0;
@@ -383,11 +386,14 @@ int main(int argc, char **argv)
 	char *end;
 	int c, res;
 
-	while ((c = getopt(argc, argv, "Cf:n:t:")) != EOF)
+	while ((c = getopt(argc, argv, "Cf:F:n:t:")) != EOF)
 		switch (c) {
 		case 'C':
 			clkout = 1;
 			break;
+		case 'F':
+			all = 1;
+			/* fall through */
 		case 'f':
 			freq_mhz = strtod(optarg, &end);
 			if (*end)
@@ -423,7 +429,7 @@ int main(int argc, char **argv)
 	CLR(UBB_CMD);
 	PDFUNC = UBB_CMD;
 
-	frequency(&clk, 1e6*freq_mhz);
+	frequency(&clk, 1e6*freq_mhz, all);
 	fprintf(stderr, "bus %g MHz controller %g MHz\n", clk.bus_clk_hz/1e6,
 	    clk.sys_clk_hz/(clk.clkdiv+1.0)/1e6);
 	mmcclk_start(&clk);