From: Frank Mori Hess <fmhess@speakeasy.net>
Date: Mon, 8 Jan 2007 15:09:37 +0000 (+0000)
Subject: Ask board which load register will be used next, since it might have
X-Git-Tag: r0_7_74~119
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=fc6b31f2e55a3b5b885fa893ebde1f3105566220;p=comedi.git

Ask board which load register will be used next, since it might have
changed since the last time it was set by the driver.
---

diff --git a/comedi/drivers/ni_tio.c b/comedi/drivers/ni_tio.c
index 52520562..c23dd994 100644
--- a/comedi/drivers/ni_tio.c
+++ b/comedi/drivers/ni_tio.c
@@ -646,6 +646,11 @@ static inline unsigned Gi_Armed_Bit(unsigned counter_index)
 	if(counter_index % 2) return G1_Armed_Bit;
 	return G0_Armed_Bit;
 }
+static inline unsigned Gi_Next_Load_Source_Bit(unsigned counter_index)
+{
+	if(counter_index % 2) return G1_Next_Load_Source_Bit;
+	return G0_Next_Load_Source_Bit;
+}
 
 /* joint reset register bits */
 static inline unsigned Gi_Reset_Bit(unsigned counter_index)
@@ -1870,27 +1875,34 @@ int ni_tio_rinsn(struct ni_gpct *counter,
 	return 0;
 }
 
+static unsigned ni_tio_next_load_register(struct ni_gpct *counter)
+{
+	const unsigned bits = counter->read_register(counter, NITIO_Gxx_Status_Reg(counter->counter_index));
+
+	if(bits & Gi_Next_Load_Source_Bit(counter->counter_index))
+	{
+		return NITIO_Gi_LoadB_Reg(counter->counter_index);
+	}else
+	{
+		return NITIO_Gi_LoadA_Reg(counter->counter_index);
+	}
+}
+
 int ni_tio_winsn(struct ni_gpct *counter,
 	comedi_insn *insn,
 	lsampl_t * data)
 {
 	const unsigned channel = CR_CHAN(insn->chanspec);
 	const unsigned command_reg = NITIO_Gi_Command_Reg(counter->counter_index);
-	const unsigned mode_reg = NITIO_Gi_Mode_Reg(counter->counter_index);
 	unsigned load_reg;
 
 	if(insn->n < 1) return 0;
 	switch(channel)
 	{
 	case 0:
-		/* don't disturb load source select, just use whichever load register is already selected. */
-		if(counter->regs[mode_reg] & Gi_Load_Source_Select_Bit)
-		{
-			load_reg = NITIO_Gi_LoadB_Reg(counter->counter_index);
-		}else
-		{
-			load_reg = NITIO_Gi_LoadA_Reg(counter->counter_index);
-		}
+		/* Unsafe if counter is armed.  Should probably check status and return -EBUSY if armed. */
+		/* Don't disturb load source select, just use whichever load register is already selected. */
+		load_reg = ni_tio_next_load_register(counter);
 		counter->write_register(counter, data[0], load_reg);
 		counter->write_register(counter, counter->regs[command_reg] | Gi_Load_Bit, command_reg);
 		/* restore state of load reg to whatever the user set last set it to */