Added support for x2 prescaling on ni general-purpose counters.

diff --git a/comedi/drivers/ni_tio.c b/comedi/drivers/ni_tio.c
index d0077270cf7c04b7978d8c628dc5819ce27e3c29..8dde74c3678c259c1baa8650ef34939381f72cf7 100644 (file)
--- a/comedi/drivers/ni_tio.c
+++ b/comedi/drivers/ni_tio.c
@@ -375,6 +375,25 @@ static inline unsigned Gi_Alternate_Sync_Bit(enum ni_gpct_variant variant)
        }
        return 0;
 }
+static inline unsigned Gi_Prescale_X2_Bit(enum ni_gpct_variant variant)
+{
+       switch(variant)
+       {
+       case ni_gpct_variant_e_series:
+               return 0;
+               break;
+       case ni_gpct_variant_m_series:
+               return Gi_M_Series_Prescale_X2_Bit;
+               break;
+       case ni_gpct_variant_660x:
+               return Gi_660x_Prescale_X2_Bit;
+               break;
+       default:
+               BUG();
+               break;
+       }
+       return 0;
+}
 static inline unsigned Gi_Prescale_X8_Bit(enum ni_gpct_variant variant)
 {
        switch(variant)
@@ -495,7 +514,6 @@ static inline unsigned NI_M_Series_PFI_Gate_Select(unsigned n)
 
 #define Gi_Source_Select_Shift 2
 #define Gi_Gate_Select_Shift 7
-/*FIXME: these gates are 660x specific.  See m-series example code for its gates/sources*/
 enum Gi_Input_Select_Bits
 {
        Gi_Source_Select_Mask = 0x7c,
@@ -975,7 +993,7 @@ static void ni_tio_update_clock_period(struct ni_gpct *counter, lsampl_t clock_s
        }
 }
 
-static void ni_tio_set_second_source_select(struct ni_gpct *counter, lsampl_t clock_source)
+static void ni_tio_set_source_subselect(struct ni_gpct *counter, lsampl_t clock_source)
 {
        const unsigned second_gate_reg = NITIO_Gi_Second_Gate_Reg(counter->counter_index);
 
@@ -1006,7 +1024,7 @@ static int ni_tio_set_clock_src(struct ni_gpct *counter, lsampl_t clock_source,
 
 /*FIXME: add support for prescale in counting mode register */
 /*FIXME: add support for prescale x2*/
-/*FIXME: is clock period specified before or after prescaling? */
+/*FIXME: is clock period specified before or after prescaling?  I'm going to say after. */
 /*FIXME: validate clock source */
        counter->regs[input_select_reg] &= ~Gi_Source_Select_Mask;
        switch(counter->variant)
@@ -1027,15 +1045,29 @@ static int ni_tio_set_clock_src(struct ni_gpct *counter, lsampl_t clock_source,
        else
                counter->regs[input_select_reg] &= ~Gi_Source_Polarity_Bit;
        counter->write_register(counter, counter->regs[input_select_reg], input_select_reg);
-       ni_tio_set_second_source_select(counter, clock_source);
+       ni_tio_set_source_subselect(counter, clock_source);
        if(ni_tio_counting_mode_registers_present(counter))
        {
                const unsigned counting_mode_reg = NITIO_Gi_Counting_Mode_Reg(counter->counter_index);
+               const unsigned prescaling_mode = clock_source & NI_GPCT_PRESCALE_MODE_CLOCK_SRC_MASK;
 
-               if(clock_source & NI_GPCT_PRESCALE_CLOCK_SRC_BIT)
-                       counter->regs[counting_mode_reg] |= Gi_Prescale_X8_Bit(counter->variant);
-               else
+               switch(prescaling_mode)
+               {
+               case NI_GPCT_NO_PRESCALE_CLOCK_SRC_BITS:
+                       counter->regs[counting_mode_reg] &= ~(Gi_Prescale_X2_Bit(counter->variant) | Gi_Prescale_X8_Bit(counter->variant));
+                       break;
+               case NI_GPCT_PRESCALE_X2_CLOCK_SRC_BITS:
+                       counter->regs[counting_mode_reg] |= Gi_Prescale_X2_Bit(counter->variant);
                        counter->regs[counting_mode_reg] &= ~Gi_Prescale_X8_Bit(counter->variant);
+                       break;
+               case NI_GPCT_PRESCALE_X8_CLOCK_SRC_BITS:
+                       counter->regs[counting_mode_reg] |= Gi_Prescale_X8_Bit(counter->variant);
+                       counter->regs[counting_mode_reg] &= ~Gi_Prescale_X2_Bit(counter->variant);
+                       break;
+               default:
+                       return -EINVAL;
+                       break;
+               }
                counter->write_register(counter, counter->regs[counting_mode_reg], counting_mode_reg);
        }
        ni_tio_update_clock_period(counter, clock_source, period_ns);
@@ -1051,8 +1083,10 @@ static unsigned ni_tio_clock_src_modifiers(struct ni_gpct *counter)
 
        if(counter->regs[input_select_reg] & Gi_Source_Polarity_Bit)
                bits |= NI_GPCT_INVERT_CLOCK_SRC_BIT;
+       if(counter->regs[counting_mode_reg] & Gi_Prescale_X2_Bit(counter->variant))
+               bits |= NI_GPCT_PRESCALE_X2_CLOCK_SRC_BITS;
        if(counter->regs[counting_mode_reg] & Gi_Prescale_X8_Bit(counter->variant))
-               bits |= NI_GPCT_PRESCALE_CLOCK_SRC_BIT;
+               bits |= NI_GPCT_PRESCALE_X8_CLOCK_SRC_BITS;
        return bits;
 }
 

diff --git a/include/linux/comedi.h b/include/linux/comedi.h
index 3c4059c5c1709a1d90d62e81d7d3640aa40abbeb..fededd4a29f249e71a49c85b605703dfa81917a5 100644 (file)
--- a/include/linux/comedi.h
+++ b/include/linux/comedi.h
@@ -566,7 +566,7 @@ enum ni_gpct_mode_bits
  * INSN_CONFIG_SET_CLOCK_SRC when using NI general-purpose counters. */
 enum ni_gpct_clock_source_bits
 {
-       NI_GPCT_CLOCK_SRC_SELECT_MASK = 0x2f,
+       NI_GPCT_CLOCK_SRC_SELECT_MASK = 0x1f,
        NI_GPCT_TIMEBASE_1_CLOCK_SRC_BITS = 0x0,
        NI_GPCT_TIMEBASE_2_CLOCK_SRC_BITS = 0x1,
        NI_GPCT_TIMEBASE_3_CLOCK_SRC_BITS = 0x2,
@@ -577,8 +577,10 @@ enum ni_gpct_clock_source_bits
        NI_GPCT_PXI10_CLOCK_SRC_BITS = 0x7,
        NI_GPCT_PXI_STAR_TRIGGER_CLOCK_SRC_BITS = 0x8,
        NI_GPCT_ANALOG_TRIGGER_OUT_CLOCK_SRC_BITS = 0x9,
-       /* modifier bits */
-       NI_GPCT_PRESCALE_CLOCK_SRC_BIT = 0x20000000,    /* divide source by 8 */
+       NI_GPCT_PRESCALE_MODE_CLOCK_SRC_MASK = 0x30000000,
+       NI_GPCT_NO_PRESCALE_CLOCK_SRC_BITS = 0x0,
+       NI_GPCT_PRESCALE_X2_CLOCK_SRC_BITS = 0x10000000,        /* divide source by 2 */
+       NI_GPCT_PRESCALE_X8_CLOCK_SRC_BITS = 0x20000000,        /* divide source by 8 */
        NI_GPCT_INVERT_CLOCK_SRC_BIT = 0x80000000
 };
 static inline unsigned NI_GPCT_SOURCE_PIN_CLOCK_SRC_BITS(unsigned n) /* NI 660x-specific */