trying to decrease time dma channel is disabled for sake of jr cards

without fifo.  Also got rid of deprecated virt_to_bus() calls.

diff --git a/comedi/drivers/das16.c b/comedi/drivers/das16.c
index d0dd7012c7a2ad7f141a4608b821881b58f59cd7..f5793d7314f149c7e42735bb1baccf7d5b6c6c54 100644 (file)
--- a/comedi/drivers/das16.c
+++ b/comedi/drivers/das16.c
@@ -5,7 +5,7 @@
     COMEDI - Linux Control and Measurement Device Interface
     Copyright (C) 2000 David A. Schleef <ds@schleef.org>
     Copyright (C) 2000 Chris R. Baugher <baugher@enteract.com>
-    Copyright (C) 2001 Frank Mori Hess <fmhess@uiuc.edu>
+    Copyright (C) 2001,2002 Frank Mori Hess <fmhess@users.sourceforge.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -39,7 +39,7 @@ Devices: [Keithley Metrabyte] DAS-16 (das-16), DAS-16G (das-16g),
   CIO-DAS1601/12 (cio-das1601/12), CIO-DAS1602/12 (cio-das1602/12),
   CIO-DAS1602/16 (cio-das1602/16), CIO-DAS16/330 (cio-das16/330)
 Status: works
-Updated: 2002-04-17
+Updated: 2002-09-30
 
 A rewrite of the das16 and das1600 drivers.
 Options:
@@ -57,13 +57,17 @@ Options:
        [6] - analog output range lowest voltage in microvolts (optional)
        [7] - analog output range highest voltage in microvolts (optional)
        [8] - use timer mode for DMA, needed e.g. for buggy DMA controller
-               in NS CS5530A (Geode Companion).  If set, also allows
+               in NS CS5530A (Geode Companion), and for 'jr' cards that
+               lack a hardware fifo.  If set, also allows
                comedi_command() to be run without an irq.
 
 Passing a zero for an option is the same as leaving it unspecified.
 
 Both a dma channel and an irq (or use of 'timer mode', option 8) are required
-for timed or externally triggered conversions.
+for timed or externally triggered conversions.  The JR versions of the boards
+should use 'timer mode' instead of an irq, due to their lack of a hardware
+fifo.
+
 */
 /*
 
@@ -87,6 +91,7 @@ Computer boards manuals also available from their website www.measurementcomputi
 #include <asm/io.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
+#include <linux/pci.h>
 #include <asm/dma.h>
 #include "8253.h"
 #include "8255.h"
@@ -724,11 +729,13 @@ struct das16_private_struct
        unsigned int    ai_singleended; // single ended flag
        unsigned int    clockbase;      // master clock speed in ns
        volatile unsigned int   control_state;  // dma, interrupt and trigger control bits
-       volatile unsigned int   adc_byte_count; // number of samples remaining
+       volatile unsigned long  adc_byte_count; // number of samples remaining
        unsigned int divisor1;  // divisor dividing master clock to get conversion frequency
        unsigned int divisor2;  // divisor dividing master clock to get conversion frequency
        unsigned int dma_chan;  // dma channel
-       uint16_t *dma_buffer;
+       uint16_t *dma_buffer[2];
+       dma_addr_t dma_buffer_addr[2];
+       unsigned int current_buffer;
        volatile unsigned int dma_transfer_size;        // target number of bytes to transfer per dma shot
        // user-defined analog input and output ranges defined from config options
        comedi_lrange *user_ai_range_table;
@@ -962,7 +969,9 @@ static int das16_cmd_exec(comedi_device *dev,comedi_subdevice *s)
        /* clear flip-flop to make sure 2-byte registers for
         * count and address get set correctly */
        clear_dma_ff(devpriv->dma_chan);
-       set_dma_addr(devpriv->dma_chan, virt_to_bus(devpriv->dma_buffer));
+       devpriv->current_buffer = 0;
+       set_dma_addr( devpriv->dma_chan,
+               devpriv->dma_buffer_addr[ devpriv->current_buffer ] );
        // set appropriate size of transfer
        devpriv->dma_transfer_size = das16_suggest_transfer_size(dev, *cmd);
        set_dma_count(devpriv->dma_chan, devpriv->dma_transfer_size);
@@ -1171,6 +1180,7 @@ static void das16_interrupt( comedi_device *dev )
        comedi_async *async;
        comedi_cmd *cmd;
        int num_bytes, residue;
+       int buffer_index;
 
        if(dev->attached == 0)
        {
@@ -1209,7 +1219,8 @@ static void das16_interrupt( comedi_device *dev )
                async->events |= COMEDI_CB_EOA;
        }
 
-       das16_write_array_to_buffer( dev, devpriv->dma_buffer, num_bytes );
+       buffer_index = devpriv->current_buffer;
+       devpriv->current_buffer = ( devpriv->current_buffer + 1 ) % 2;
        devpriv->adc_byte_count -= num_bytes;
 
        // figure out how many bytes for next transfer
@@ -1220,13 +1231,15 @@ static void das16_interrupt( comedi_device *dev )
        // re-enable  dma
        if(( async->events & COMEDI_CB_EOA ) == 0)
        {
-               set_dma_addr( devpriv->dma_chan, virt_to_bus( devpriv->dma_buffer ) );
+               set_dma_addr( devpriv->dma_chan,
+                       devpriv->dma_buffer_addr[ devpriv->current_buffer ] );
                set_dma_count( devpriv->dma_chan, devpriv->dma_transfer_size );
                enable_dma(devpriv->dma_chan);
        }
        release_dma_lock(flags);
 
-       async->events |= COMEDI_CB_BLOCK;
+       das16_write_array_to_buffer( dev,
+               devpriv->dma_buffer[ buffer_index ], num_bytes );
 
        cfc_handle_events( dev, s );
 }
@@ -1423,10 +1436,15 @@ static int das16_attach(comedi_device *dev, comedi_devconfig *it)
        dma_chan = it->options[2];
        if(dma_chan == 1 || dma_chan == 3)
        {
-               // allocate dma buffer
-               devpriv->dma_buffer = kmalloc(DAS16_DMA_SIZE, GFP_KERNEL | GFP_DMA);
-               if(devpriv->dma_buffer == NULL)
-                       return -ENOMEM;
+               // allocate dma buffers
+               int i;
+               for( i = 0; i < 2; i++)
+               {
+                       devpriv->dma_buffer[i] = pci_alloc_consistent( NULL,
+                               DAS16_DMA_SIZE, &devpriv->dma_buffer_addr[i] );
+                       if( devpriv->dma_buffer[i] == NULL )
+                               return -ENOMEM;
+               }
                if(request_dma(dma_chan, "das16"))
                {
                        printk(" failed to allocate dma channel %i\n", dma_chan);
@@ -1603,8 +1621,13 @@ static int das16_detach(comedi_device *dev)
 
        if(devpriv)
        {
-               if(devpriv->dma_buffer)
-                       kfree(devpriv->dma_buffer);
+               int i;
+               for( i = 0; i < 2; i++ )
+               {
+                       if( devpriv->dma_buffer[i] )
+                               pci_free_consistent( NULL, DAS16_DMA_SIZE, devpriv->dma_buffer[i],
+                                       devpriv->dma_buffer_addr[i] );
+               }
                if(devpriv->dma_chan)
                        free_dma(devpriv->dma_chan);
                if(devpriv->user_ai_range_table)