staging: comedi: adv_pci1710: change boardinfo 'fifo_half_size' to 'has_large_fifo'

The boards supported by this driver have a 4K or 1K FIFO that is used when reading
analog input samples when running an async command. The maximum number of samples
in the FIFO is half the FIFO size due to the 2 bytes/sample (12-bit resolution).

For aesthetics, change the 'fifo_half_size' member to a bit-field flag 'has_large_fifo'
and add a new member to the private data to hold the 'max_samples' available in the
FIFO. Refactor the board attach and pci1710_handle_fifo() accordingly.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/adv_pci1710.c b/drivers/staging/comedi/drivers/adv_pci1710.c
index 634b2a0..14aaa1e 100644 (file)
--- a/drivers/staging/comedi/drivers/adv_pci1710.c
+++ b/drivers/staging/comedi/drivers/adv_pci1710.c
@@ -197,8 +197,8 @@ struct boardtype {
        const struct comedi_lrange *rangelist_ai;       /*  rangelist for A/D */
        const char *rangecode_ai;       /*  range codes for programming */
        const struct comedi_lrange *rangelist_ao;       /*  rangelist for D/A */
-       unsigned int fifo_half_size;    /*  size of FIFO/2 */
        unsigned int has_irq:1;
+       unsigned int has_large_fifo:1;  /* 4K or 1K FIFO */
        unsigned int has_diff_ai:1;
        unsigned int has_di_do:1;
        unsigned int has_counter:1;
@@ -213,8 +213,8 @@ static const struct boardtype boardtypes[] = {
                .rangelist_ai   = &range_pci1710_3,
                .rangecode_ai   = range_codes_pci1710_3,
                .rangelist_ao   = &range_pci171x_da,
-               .fifo_half_size = 2048,
                .has_irq        = 1,
+               .has_large_fifo = 1,
                .has_diff_ai    = 1,
                .has_di_do      = 1,
                .has_counter    = 1,
@@ -227,8 +227,8 @@ static const struct boardtype boardtypes[] = {
                .rangelist_ai   = &range_pci1710hg,
                .rangecode_ai   = range_codes_pci1710hg,
                .rangelist_ao   = &range_pci171x_da,
-               .fifo_half_size = 2048,
                .has_irq        = 1,
+               .has_large_fifo = 1,
                .has_diff_ai    = 1,
                .has_di_do      = 1,
                .has_counter    = 1,
@@ -241,7 +241,6 @@ static const struct boardtype boardtypes[] = {
                .rangelist_ai   = &range_pci17x1,
                .rangecode_ai   = range_codes_pci17x1,
                .rangelist_ao   = &range_pci171x_da,
-               .fifo_half_size = 512,
                .has_irq        = 1,
                .has_di_do      = 1,
                .has_counter    = 1,
@@ -252,8 +251,8 @@ static const struct boardtype boardtypes[] = {
                .n_aichan       = 32,
                .rangelist_ai   = &range_pci1710_3,
                .rangecode_ai   = range_codes_pci1710_3,
-               .fifo_half_size = 2048,
                .has_irq        = 1,
+               .has_large_fifo = 1,
                .has_diff_ai    = 1,
        },
        [BOARD_PCI1720] = {
@@ -268,13 +267,13 @@ static const struct boardtype boardtypes[] = {
                .n_aichan       = 16,
                .rangelist_ai   = &range_pci17x1,
                .rangecode_ai   = range_codes_pci17x1,
-               .fifo_half_size = 512,
                .has_irq        = 1,
                .has_di_do      = 1,
        },
 };
 
 struct pci1710_private {
+       unsigned int max_samples;
        unsigned int CntrlReg;  /*  Control register */
        unsigned char ai_et;
        unsigned int ai_et_CntrlReg;
@@ -786,7 +785,7 @@ static int move_block_from_fifo(struct comedi_device *dev,
 static void pci1710_handle_fifo(struct comedi_device *dev,
                                struct comedi_subdevice *s)
 {
-       const struct boardtype *this_board = dev->board_ptr;
+       struct pci1710_private *devpriv = dev->private;
        struct comedi_cmd *cmd = &s->async->cmd;
        unsigned int nsamples;
        unsigned int m;
@@ -806,7 +805,7 @@ static void pci1710_handle_fifo(struct comedi_device *dev,
                return;
        }
 
-       nsamples = this_board->fifo_half_size;
+       nsamples = devpriv->max_samples;
        if (comedi_samples_to_bytes(s, nsamples) >= s->async->prealloc_bufsz) {
                m = comedi_bytes_to_samples(s, s->async->prealloc_bufsz);
                if (move_block_from_fifo(dev, s, m, 0))
@@ -1188,6 +1187,9 @@ static int pci1710_auto_attach(struct comedi_device *dev,
                subdev++;
        }
 
+       /* max_samples is half the FIFO size (2 bytes/sample) */
+       devpriv->max_samples = (this_board->has_large_fifo) ? 2048 : 512;
+
        return 0;
 }