staging: comedi: ni_mio_common: Cleans up/clarifies ni_ao_reset

This patch implements ni_ao_reset much more closely organized like NI MHDDK
examples and DAQ-STC pseudo-code.  Adds comments with some more specific
references to the DAQ-STC.

Signed-off-by: Spencer E. Olson <olsonse@umich.edu>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/ni_mio_common.c b/drivers/staging/comedi/drivers/ni_mio_common.c
index 1978d65636fd2a19bc7fa9b93c02cdcd5880095b..7d2091d8b72b9882362c63db83053308846ee026 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_mio_common.c
+++ b/drivers/staging/comedi/drivers/ni_mio_common.c
@@ -3215,48 +3215,70 @@ static int ni_ao_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 
 static int ni_ao_reset(struct comedi_device *dev, struct comedi_subdevice *s)
 {
+       /* See 3.6.1.2 "Resetting", of DAQ-STC Technical Reference Manual */
+
+       /*
+        * In the following, the "--sync" comments are meant to denote
+        * asynchronous boundaries for setting the registers as described in the
+        * DAQ-STC mostly in the order also described in the DAQ-STC.
+        */
+
        struct ni_private *devpriv = dev->private;
 
        ni_release_ao_mite_channel(dev);
 
+       /* --sync (reset AO) */
+       if (devpriv->is_m_series)
+               /* following example in mhddk for m-series */
+               ni_stc_writew(dev, NISTC_RESET_AO, NISTC_RESET_REG);
+
+       /*--sync (start config) */
        ni_stc_writew(dev, NISTC_RESET_AO_CFG_START, NISTC_RESET_REG);
+
+       /*--sync (Disarm) */
        ni_stc_writew(dev, NISTC_AO_CMD1_DISARM, NISTC_AO_CMD1_REG);
-       ni_set_bits(dev, NISTC_INTB_ENA_REG, ~0, 0);
-       ni_stc_writew(dev, NISTC_AO_PERSONAL_BC_SRC_SEL, NISTC_AO_PERSONAL_REG);
-       ni_stc_writew(dev, NISTC_INTB_ACK_AO_ALL, NISTC_INTB_ACK_REG);
-       ni_stc_writew(dev, NISTC_AO_PERSONAL_BC_SRC_SEL |
-                          NISTC_AO_PERSONAL_UPDATE_PW |
-                          NISTC_AO_PERSONAL_TMRDACWR_PW,
-                     NISTC_AO_PERSONAL_REG);
-       ni_stc_writew(dev, 0, NISTC_AO_OUT_CTRL_REG);
-       ni_stc_writew(dev, 0, NISTC_AO_START_SEL_REG);
-       devpriv->ao_cmd1 = 0;
-       ni_stc_writew(dev, devpriv->ao_cmd1, NISTC_AO_CMD1_REG);
-       devpriv->ao_cmd2 = 0;
-       ni_stc_writew(dev, devpriv->ao_cmd2, NISTC_AO_CMD2_REG);
+
+       /*
+        * --sync
+        * (clear bunch of registers--mseries mhddk examples do not include
+        * this)
+        */
+       devpriv->ao_cmd1  = 0;
+       devpriv->ao_cmd2  = 0;
        devpriv->ao_mode1 = 0;
-       ni_stc_writew(dev, devpriv->ao_mode1, NISTC_AO_MODE1_REG);
        devpriv->ao_mode2 = 0;
-       ni_stc_writew(dev, devpriv->ao_mode2, NISTC_AO_MODE2_REG);
        if (devpriv->is_m_series)
                devpriv->ao_mode3 = NISTC_AO_MODE3_LAST_GATE_DISABLE;
        else
                devpriv->ao_mode3 = 0;
-       ni_stc_writew(dev, devpriv->ao_mode3, NISTC_AO_MODE3_REG);
        devpriv->ao_trigger_select = 0;
-       ni_stc_writew(dev, devpriv->ao_trigger_select,
-                     NISTC_AO_TRIG_SEL_REG);
-       if (devpriv->is_6xxx) {
-               unsigned immediate_bits = 0;
-               unsigned i;
 
-               for (i = 0; i < s->n_chan; ++i)
-                       immediate_bits |= 1 << i;
-               ni_ao_win_outw(dev, immediate_bits, NI671X_AO_IMMEDIATE_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_PERSONAL_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_CMD1_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_CMD2_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_MODE1_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_MODE2_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_OUT_CTRL_REG);
+       ni_stc_writew(dev, devpriv->ao_mode3, NISTC_AO_MODE3_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_START_SEL_REG);
+       ni_stc_writew(dev, 0, NISTC_AO_TRIG_SEL_REG);
+
+       /*--sync (disable interrupts) */
+       ni_set_bits(dev, NISTC_INTB_ENA_REG, ~0, 0);
+
+       /*--sync (ack) */
+       ni_stc_writew(dev, NISTC_AO_PERSONAL_BC_SRC_SEL, NISTC_AO_PERSONAL_REG);
+       ni_stc_writew(dev, NISTC_INTB_ACK_AO_ALL, NISTC_INTB_ACK_REG);
+
+       /*--not in DAQ-STC.  which doc? */
+       if (devpriv->is_6xxx) {
+               ni_ao_win_outw(dev, (1u << s->n_chan) - 1u,
+                              NI671X_AO_IMMEDIATE_REG);
                ni_ao_win_outw(dev, NI611X_AO_MISC_CLEAR_WG,
                               NI611X_AO_MISC_REG);
        }
        ni_stc_writew(dev, NISTC_RESET_AO_CFG_END, NISTC_RESET_REG);
+       /*--end */
 
        return 0;
 }