start rewriting software part of ST state machine

1 files changed, 148 insertions, 0 deletions

diff --git a/xhfc/xhfc_st_state.c b/xhfc/xhfc_st_state.c
new file mode 100644
index 0000000..f52425d
--- /dev/null
+++ b/xhfc/xhfc_st_state.c
@@ -0,0 +1,148 @@
+#include <linux/delay.h>
+#include <linux/timer.h>
+
+#include "xhfc.h"
+#include "xhfc_leb.h"
+
+/* Software-implemented timers for the S/T state machine, in milliseconds */
+#define T1_MS	100	/* NT activation timer.
+			   100..1000ms according to Cologne/ETSI TBR4 (??)
+			   100ms in Cologne's mISDN driver.  */
+#define T3_MS	30000	/* TE activation timer.
+			   according to I.430 "the value depends on the
+			   subscriber loop transmission technique. The worst
+			   case value is 30s." */
+
+enum te_state { F0, F1, F2, F3, F4, F5, F6, F7, F8 };
+enum nt_state { G0, G1, G2, G3 };
+
+void activate_request(struct xhfc_span* s);
+void deactivate_request(struct xhfc_span* s);
+void handle_state_change(struct xhfc_span* s);
+
+static void expiry_T1(struct xhfc_span* s);
+static void expiry_T3(struct xhfc_span* s);
+
+static void handle_state_change_nt(struct xhfc_span* s);
+static void handle_state_change_te(struct xhfc_span* s);
+static void activate_request_nt(struct xhfc_span* s);
+static void activate_request_te(struct xhfc_span* s);
+
+static void print_current_state(struct xhfc_span* s);
+
+void handle_state_change(struct xhfc_span* s)
+{
+	struct xhfc* x = s->xhfc;
+
+	s->prev_state = s->state;
+
+	write_xhfc(x, R_SU_SEL, s->port);
+	s->state = read_xhfc(x, A_SU_RD_STA);
+
+	if(debug & DEBUG_ST_STATE) //XXX only place where this is used
+		print_state(s);
+
+	if(s->prev_state = s->state) {
+		printk(KERN_WARNING DRIVER_NAME ": a state change has been "
+				"reported on port %d but it looks like the "
+				"state has not changed?", s->port + 1);
+		return;
+	}
+
+	if(s->nt)
+		handle_state_change_nt(s);
+	else
+		handle_state_change_te(s);
+}
+
+static void handle_state_change_nt(struct xhfc_span* s)
+{
+	switch (s->state) {
+		case G0:
+		case G1:
+		case G4:
+			s->span.alarms = DAHDI_ALARM_RED;
+			break;
+		case G2:
+			s->span.alarms = DAHDI_ALARM_YELLOW;
+			if(s->prev_state != G3)
+				/* Start T1 */ ;
+			break;
+		case G3:
+			s->span.alarms = DAHDI_ALARM_NONE;
+			/* Stop T1 */
+			break;
+	}
+}
+
+static void handle_state_change_te(struct xhfc_span* s)
+{
+	switch(s->state) {
+		case F0:
+		case F1:
+		case F2:
+		case F3:
+		case F8:
+			s->span.alarms = DAHDI_ALARM_RED;
+			break;
+		case F4:
+			/* XXX If in F3 and receiving INFO0, the state machine
+			 * should change to F4 and start T3. Is the jump to F4
+			 * done by the XHFC in hard, (in which case the timer
+			 * T3 will be started by the software when detecting a
+			 * change of state towards F4) or should it be driven
+			 * by the soft (in which case upon detection of the
+			 * reception of INFO0 in F3 state, the state would be
+			 * set to F4 and T3 started)? 
+			 *
+			 * Andrew did the latter, and I can't seem to get if
+			 * and how mISDN handles this.
+			 *
+			 * Here, the former hypothesis (state change driven by
+			 * hard) is assumed. 
+			 */
+
+			/* Start T3 */
+
+			/* Fall through */
+		case F5:
+		case F6:
+			s->span.alarms = DAHDI_ALARM_YELLOW;
+			break;
+		case F7:
+			s->span.alarms = DAHDI_ALARM_NONE;
+			/* Stop T3 */
+			break;
+
+}
+
+static char *state_descriptions[2][16] = {
+	{ /* TE */
+		/* F0 */ "reset",
+		/* F1 */ "inactive",
+		/* F2 */ "sensing",
+		/* F3 */ "deactivate",
+		/* F4 */ "awaiting signal",
+		/* F5 */ "identifying input",
+		/* F6 */ "synchronized",
+		/* F7 */ "activated",
+		/* F8 */ "lost framing",
+		"?", "?", "?", "?", "?", "?", "?" },
+	{ /* NT */
+		/* G0 */ "reset",
+		/* G1 */ "deactivated",
+		/* G2 */ "pending activation",
+		/* G3 */ "active",
+		/* G4 */ "pending deactivation",
+		"?", "?", "?", "?", "?", "?", "?", "?", "?", "?", "?" }};
+
+static void print_state(struct xhfc_span* s)
+{
+	printk(KERN_DEBUG DRIVER_NAME "port %d: %s state %c%d (%s)\n", 
+			s->port + 1, 
+			(s->nt ? "NT" : "TE"), 
+			(s->nt ? 'G' : 'F'), 
+			s->state,
+			state_description[s->nt][s->state]);
+}
+