staging: comedi: ni_labpc: fix 8254 timer programming

As pointed out by Ian Abbott, the i8254_load() function does not
use the I8254_MODE* values to specify the "mode".

The labpc_counter_load() function in this driver is passed an
I8254_MODE* value so we need to use the i8254_set_mode() and
i8254_write() helpers instead of i8254_load() to program the
timers.

The calls to labpc_counter_load() will not fail so change the
return to void and remove all the unnecessary error handling.

Similarly, change the return type of labpc_counter_set_mode() to
void and remove the unnecessary error handling.

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/ni_labpc.c b/drivers/staging/comedi/drivers/ni_labpc.c
index fc9d31420956ffdd278eb5a864836efc4cb775ea..c6e914dc70cfcb3d8d54b487592a3131a92663ae 100644 (file)
--- a/drivers/staging/comedi/drivers/ni_labpc.c
+++ b/drivers/staging/comedi/drivers/ni_labpc.c
@@ -171,32 +171,39 @@ static const struct labpc_boardinfo labpc_boards[] = {
 };
 #endif
 
-static int labpc_counter_load(struct comedi_device *dev,
-                             unsigned long base_address,
-                             unsigned int counter_number,
-                             unsigned int count, unsigned int mode)
+static void labpc_counter_load(struct comedi_device *dev,
+                              unsigned long base_address,
+                              unsigned int counter_number,
+                              unsigned int count,
+                              unsigned int mode)
 {
        const struct labpc_boardinfo *board = comedi_board(dev);
 
-       if (board->has_mmio)
-               return i8254_mm_load((void __iomem *)base_address, 0,
-                                    counter_number, count, mode);
-       else
-               return i8254_load(base_address, 0, counter_number, count, mode);
+       if (board->has_mmio) {
+               void __iomem *mmio_base = (void __iomem *)base_address;
+
+               i8254_mm_set_mode(mmio_base, 0, counter_number, mode);
+               i8254_mm_write(mmio_base, 0, counter_number, count);
+       } else {
+               i8254_set_mode(base_address, 0, counter_number, mode);
+               i8254_write(base_address, 0, counter_number, count);
+       }
 }
 
-static int labpc_counter_set_mode(struct comedi_device *dev,
-                                 unsigned long base_address,
-                                 unsigned int counter_number,
-                                 unsigned int mode)
+static void labpc_counter_set_mode(struct comedi_device *dev,
+                                  unsigned long base_address,
+                                  unsigned int counter_number,
+                                  unsigned int mode)
 {
        const struct labpc_boardinfo *board = comedi_board(dev);
 
-       if (board->has_mmio)
-               return i8254_mm_set_mode((void __iomem *)base_address, 0,
-                                        counter_number, mode);
-       else
-               return i8254_set_mode(base_address, 0, counter_number, mode);
+       if (board->has_mmio) {
+               void __iomem *mmio_base = (void __iomem *)base_address;
+
+               i8254_mm_set_mode(mmio_base, 0, counter_number, mode);
+       } else {
+               i8254_set_mode(base_address, 0, counter_number, mode);
+       }
 }
 
 static int labpc_cancel(struct comedi_device *dev, struct comedi_subdevice *s)
@@ -349,10 +356,8 @@ static int labpc_ai_insn_read(struct comedi_device *dev,
        devpriv->write_byte(devpriv->cmd4, dev->iobase + CMD4_REG);
 
        /* initialize pacer counter to prevent any problems */
-       ret = labpc_counter_set_mode(dev, dev->iobase + COUNTER_A_BASE_REG,
-                                    0, I8254_MODE2);
-       if (ret)
-               return ret;
+       labpc_counter_set_mode(dev, dev->iobase + COUNTER_A_BASE_REG,
+                              0, I8254_MODE2);
 
        labpc_clear_adc_fifo(dev);
 
@@ -730,7 +735,6 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
        unsigned int aref = CR_AREF(chanspec);
        enum transfer_type xfer;
        unsigned long flags;
-       int ret;
 
        /* make sure board is disabled before setting up acquisition */
        labpc_cancel(dev, s);
@@ -745,17 +749,12 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
                 * load counter a1 with count of 3
                 * (pc+ manual says this is minimum allowed) using mode 0
                 */
-               ret = labpc_counter_load(dev, dev->iobase + COUNTER_A_BASE_REG,
-                                        1, 3, I8254_MODE0);
+               labpc_counter_load(dev, dev->iobase + COUNTER_A_BASE_REG,
+                                  1, 3, I8254_MODE0);
        } else  {
                /* just put counter a1 in mode 0 to set its output low */
-               ret = labpc_counter_set_mode(dev,
-                                            dev->iobase + COUNTER_A_BASE_REG,
-                                            1, I8254_MODE0);
-       }
-       if (ret) {
-               comedi_error(dev, "error loading counter a1");
-               return ret;
+               labpc_counter_set_mode(dev, dev->iobase + COUNTER_A_BASE_REG,
+                                      1, I8254_MODE0);
        }
 
        /* figure out what method we will use to transfer data */
@@ -800,38 +799,25 @@ static int labpc_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
                /*  set up pacing */
                labpc_adc_timing(dev, cmd, mode);
                /*  load counter b0 in mode 3 */
-               ret = labpc_counter_load(dev, dev->iobase + COUNTER_B_BASE_REG,
-                                        0, devpriv->divisor_b0, I8254_MODE3);
-               if (ret < 0) {
-                       comedi_error(dev, "error loading counter b0");
-                       return -1;
-               }
+               labpc_counter_load(dev, dev->iobase + COUNTER_B_BASE_REG,
+                                  0, devpriv->divisor_b0, I8254_MODE3);
        }
        /*  set up conversion pacing */
        if (labpc_ai_convert_period(cmd, mode)) {
                /*  load counter a0 in mode 2 */
-               ret = labpc_counter_load(dev, dev->iobase + COUNTER_A_BASE_REG,
-                                        0, devpriv->divisor_a0, I8254_MODE2);
+               labpc_counter_load(dev, dev->iobase + COUNTER_A_BASE_REG,
+                                  0, devpriv->divisor_a0, I8254_MODE2);
        } else {
                /* initialize pacer counter to prevent any problems */
-               ret = labpc_counter_set_mode(dev,
-                                            dev->iobase + COUNTER_A_BASE_REG,
-                                            0, I8254_MODE2);
-       }
-       if (ret) {
-               comedi_error(dev, "error loading counter a0");
-               return ret;
+               labpc_counter_set_mode(dev, dev->iobase + COUNTER_A_BASE_REG,
+                                      0, I8254_MODE2);
        }
 
        /*  set up scan pacing */
        if (labpc_ai_scan_period(cmd, mode)) {
                /*  load counter b1 in mode 2 */
-               ret = labpc_counter_load(dev, dev->iobase + COUNTER_B_BASE_REG,
-                                        1, devpriv->divisor_b1, I8254_MODE2);
-               if (ret < 0) {
-                       comedi_error(dev, "error loading counter b1");
-                       return -1;
-               }
+               labpc_counter_load(dev, dev->iobase + COUNTER_B_BASE_REG,
+                                  1, devpriv->divisor_b1, I8254_MODE2);
        }
 
        labpc_clear_adc_fifo(dev);