hosted: fix ephemeral max frequency

On hosted, the max frequency was being set on every scan routine to the value set by the command line options, even if the user set a new value with the monitor command

This adds storage to the max frequency, meaning the frequency set by the user will be remembered over the initial command line value

src/platforms/hosted/cli.c

@@ -173,10 +173,10 @@ static void cl_help(char **argv)
 			   "\t                   can be repeated for as many commands you wish to run.\n"
 			   "\t                   If the command contains spaces, use quotes around the\n"
 			   "\t                   complete command\n"
+			   "\t-f, --freq       Set an operating frequency for the debug interface\n"
 			   "\n"
 			   "SWD-specific configuration options [-f FREQUENCY | -m TARGET]:\n"
-			   "\t-f, --freq       Set an operating frequency for SWD\n"
-			   "\t-m, --mult-drop  Use the given target ID for selection in SWD multi-drop\n"
+			   "\t-m, --multi-drop  Use the given target ID for selection in SWD multi-drop\n"
 			   "\n"
 			   "Flash operation selection options [-E | -w | -V | -r]:\n"
 			   "\t-E, --erase      Erase the target device Flash\n"
@@ -233,7 +233,7 @@ void cl_init(bmda_cli_options_s *opt, int argc, char **argv)
 	opt->opt_target_dev = 1;
 	opt->opt_flash_size = 0xffffffff;
 	opt->opt_flash_start = 0xffffffff;
-	opt->opt_max_swj_frequency = 4000000;
+	opt->opt_max_frequency = 0;
 	opt->opt_scanmode = BMP_SCAN_SWD;
 	opt->opt_mode = BMP_MODE_DEBUG;
 	while (true) {
@@ -306,7 +306,7 @@ void cl_init(bmda_cli_options_s *opt, int argc, char **argv)
 					frequency *= 1000U * 1000U;
 					break;
 				}
-				opt->opt_max_swj_frequency = frequency;
+				opt->opt_max_frequency = frequency;
 			}
 			break;
 		case 's':

src/platforms/hosted/cli.h

@@ -65,7 +65,7 @@ typedef struct bmda_cli_options {
 	char *opt_monitor;
 	uint32_t opt_target_dev;
 	uint32_t opt_flash_start;
-	uint32_t opt_max_swj_frequency;
+	uint32_t opt_max_frequency;
 	size_t opt_flash_size;
 } bmda_cli_options_s;
 

src/platforms/hosted/platform.c

@@ -58,6 +58,8 @@ bmda_probe_s bmda_probe_info;
 jtag_proc_s jtag_proc;
 swd_proc_s swd_proc;
 
+static uint32_t max_frequency = 4000000U;
+
 static bmda_cli_options_s cl_opts;
 
 void gdb_ident(char *p, int count)
@@ -154,6 +156,9 @@ void platform_init(int argc, char **argv)
 		exit(1);
 	}
 
+	if (cl_opts.opt_max_frequency)
+		max_frequency = cl_opts.opt_max_frequency;
+
 	if (cl_opts.opt_mode != BMP_MODE_DEBUG)
 		exit(cl_execute(&cl_opts));
 	else {
@@ -168,7 +173,7 @@ void platform_init(int argc, char **argv)
 bool bmda_swd_scan(const uint32_t targetid)
 {
 	bmda_probe_info.is_jtag = false;
-	platform_max_frequency_set(cl_opts.opt_max_swj_frequency);
+	platform_max_frequency_set(max_frequency);
 
 	switch (bmda_probe_info.type) {
 	case PROBE_TYPE_BMP:
@@ -224,8 +229,7 @@ void bmda_add_jtag_dev(const uint32_t dev_index, const jtag_dev_s *const jtag_de
 bool bmda_jtag_scan(void)
 {
 	bmda_probe_info.is_jtag = true;
-
-	platform_max_frequency_set(cl_opts.opt_max_swj_frequency);
+	platform_max_frequency_set(max_frequency);
 
 	switch (bmda_probe_info.type) {
 	case PROBE_TYPE_BMP:
@@ -413,11 +417,15 @@ bool platform_nrst_get_val(void)
 	}
 }
 
-void platform_max_frequency_set(uint32_t freq)
+void platform_max_frequency_set(const uint32_t freq)
 {
 	if (!freq)
 		return;
 
+	// Remember the frequency we were asked to set,
+	// this will be re-set every time a scan is issued.
+	max_frequency = freq;
+
 	switch (bmda_probe_info.type) {
 	case PROBE_TYPE_BMP:
 		remote_max_frequency_set(freq);
@@ -442,14 +450,14 @@ void platform_max_frequency_set(uint32_t freq)
 #endif
 
 	default:
-		DEBUG_WARN("Setting max SWD/JTAG frequency not yet implemented\n");
+		DEBUG_WARN("Setting max debug interface frequency not available or not yet implemented\n");
 		break;
 	}
 
 	const uint32_t actual_freq = platform_max_frequency_get();
 	if (actual_freq == FREQ_FIXED)
 		DEBUG_INFO("Device has fixed frequency for %s\n", bmda_probe_info.is_jtag ? "JTAG" : "SWD");
-	else {
+	else if (actual_freq != 0) {
 		const uint16_t freq_mhz = actual_freq / 1000000U;
 		const uint16_t freq_khz = (actual_freq / 1000U) - (freq_mhz * 1000U);
 		DEBUG_INFO("Speed set to %u.%03uMHz for %s\n", freq_mhz, freq_khz, bmda_probe_info.is_jtag ? "JTAG" : "SWD");
@@ -477,7 +485,7 @@ uint32_t platform_max_frequency_get(void)
 #endif
 
 	default:
-		DEBUG_WARN("Reading max SWJ frequency not yet implemented\n");
+		DEBUG_WARN("Reading max debug interface frequency not available or not yet implemented\n");
 		return 0;
 	}
 }