staging: comedi: icp_multi: absorb setup_channel_list()

This function is only called in one place and the 'n_chan' parameter
is always 1. This makes the for() loop a bit silly.

Absorb the function into the caller and simplify the code. This also
removes the need for the private data member 'AdcCmdStatus'.

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/icp_multi.c b/drivers/staging/comedi/drivers/icp_multi.c
index fbcaa2d..d3c37d5 100644 (file)
--- a/drivers/staging/comedi/drivers/icp_multi.c
+++ b/drivers/staging/comedi/drivers/icp_multi.c
@@ -55,6 +55,8 @@
 #define ICP_MULTI_ADC_CSR_BI   BIT(4)  /* Bipolar input range */
 #define ICP_MULTI_ADC_CSR_RA   BIT(5)  /* Input range 0 = 5V, 1 = 10V */
 #define ICP_MULTI_ADC_CSR_DI   BIT(6)  /* Input mode 1 = differential */
+#define ICP_MULTI_ADC_CSR_DI_CHAN(x) (((x) & 0x7) << 9)
+#define ICP_MULTI_ADC_CSR_SE_CHAN(x) (((x) & 0xf) << 8)
 #define ICP_MULTI_AI           2       /* R:   Analogue input data */
 #define ICP_MULTI_DAC_CSR      0x04    /* R/W: DAC command/status register */
 #define ICP_MULTI_DAC_CSR_ST   BIT(0)  /* Start DAC */
@@ -93,56 +95,11 @@ static const struct comedi_lrange icp_multi_ranges = {
 static const char range_codes_analog[] = { 0x00, 0x20, 0x10, 0x30 };
 
 struct icp_multi_private {
-       unsigned int AdcCmdStatus;      /*  ADC Command/Status register */
        unsigned int DacCmdStatus;      /*  DAC Command/Status register */
        unsigned int IntEnable; /*  Interrupt Enable register */
        unsigned int IntStatus; /*  Interrupt Status register */
 };
 
-static void setup_channel_list(struct comedi_device *dev,
-                              struct comedi_subdevice *s,
-                              unsigned int *chanlist, unsigned int n_chan)
-{
-       struct icp_multi_private *devpriv = dev->private;
-       unsigned int i, range, chanprog;
-       unsigned int diff;
-
-       for (i = 0; i < n_chan; i++) {
-               /*  Get channel */
-               chanprog = CR_CHAN(chanlist[i]);
-
-               /*  Determine if it is a differential channel (Bit 15  = 1) */
-               if (CR_AREF(chanlist[i]) == AREF_DIFF) {
-                       diff = 1;
-                       chanprog &= 0x0007;
-               } else {
-                       diff = 0;
-                       chanprog &= 0x000f;
-               }
-
-               /*  Clear channel, range and input mode bits
-                *  in A/D command/status register */
-               devpriv->AdcCmdStatus &= 0xf00f;
-
-               /*  Set channel number and differential mode status bit */
-               if (diff) {
-                       /*  Set channel number, bits 9-11 & mode, bit 6 */
-                       devpriv->AdcCmdStatus |= (chanprog << 9);
-                       devpriv->AdcCmdStatus |= ICP_MULTI_ADC_CSR_DI;
-               } else
-                       /*  Set channel number, bits 8-11 */
-                       devpriv->AdcCmdStatus |= (chanprog << 8);
-
-               /*  Get range for current channel */
-               range = range_codes_analog[CR_RANGE(chanlist[i])];
-               /*  Set range. bits 4-5 */
-               devpriv->AdcCmdStatus |= range;
-
-               /* Output channel, range, mode to ICP Multi */
-               writew(devpriv->AdcCmdStatus, dev->mmio + ICP_MULTI_ADC_CSR);
-       }
-}
-
 static int icp_multi_ai_eoc(struct comedi_device *dev,
                            struct comedi_subdevice *s,
                            struct comedi_insn *insn,
@@ -162,6 +119,10 @@ static int icp_multi_insn_read_ai(struct comedi_device *dev,
                                  unsigned int *data)
 {
        struct icp_multi_private *devpriv = dev->private;
+       unsigned int chan = CR_CHAN(insn->chanspec);
+       unsigned int range = CR_RANGE(insn->chanspec);
+       unsigned int aref = CR_AREF(insn->chanspec);
+       unsigned int adc_csr;
        int ret = 0;
        int n;
 
@@ -173,14 +134,20 @@ static int icp_multi_insn_read_ai(struct comedi_device *dev,
        devpriv->IntStatus |= ICP_MULTI_INT_ADC_RDY;
        writew(devpriv->IntStatus, dev->mmio + ICP_MULTI_INT_STAT);
 
-       /*  Set up appropriate channel, mode and range data, for specified ch */
-       setup_channel_list(dev, s, &insn->chanspec, 1);
+       /* Set mode and range data for specified channel */
+       if (aref == AREF_DIFF) {
+               adc_csr = ICP_MULTI_ADC_CSR_DI_CHAN(chan) |
+                         ICP_MULTI_ADC_CSR_DI;
+       } else {
+               adc_csr = ICP_MULTI_ADC_CSR_SE_CHAN(chan);
+       }
+       adc_csr |= range_codes_analog[range];
+       writew(adc_csr, dev->mmio + ICP_MULTI_ADC_CSR);
 
        for (n = 0; n < insn->n; n++) {
                /*  Set start ADC bit */
-               devpriv->AdcCmdStatus |= ICP_MULTI_ADC_CSR_ST;
-               writew(devpriv->AdcCmdStatus, dev->mmio + ICP_MULTI_ADC_CSR);
-               devpriv->AdcCmdStatus &= ~ICP_MULTI_ADC_CSR_ST;
+               writew(adc_csr | ICP_MULTI_ADC_CSR_ST,
+                      dev->mmio + ICP_MULTI_ADC_CSR);
 
                udelay(1);