adc: add ioctl command to get the number of configured channels

Number of configured ADC channels is currently only defined in board
level section, typically in xxx_adc.c file. This commit introduces
ioctl command ANIOC_GET_NCHANNELS that returns the number of configured
channels which is determined by the driver code. The change can allow the
applications to be more flexible when it comes to multiple ADC devices
with different number of configured channels.

Signed-off-by: Michal Lenc <michallenc@seznam.cz>

arch/arm/src/cxd56xx/cxd56_adc.c

@@ -929,6 +929,14 @@ static int cxd56_adc_ioctl(FAR struct file *filep, int cmd,
           }
         break;
 
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = 1;
+        }
+        break;
+
       default:
         {
           if (adc_validcheck(cmd))

arch/arm/src/efm32/efm32_adc.c

@@ -39,6 +39,7 @@
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 #include <nuttx/analog/adc.h>
+#include <nuttx/analog/ioctl.h>
 
 #include "arm_internal.h"
 #include "arm_arch.h"
@@ -1174,7 +1175,28 @@ static void adc_rxint(FAR struct adc_dev_s *dev, bool enable)
 
 static int adc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
 {
-  return -ENOTTY;
+  FAR struct efm32_dev_s *priv = (FAR struct efm32_dev_s *)dev->ad_priv;
+  int ret = -ENOTTY;
+
+  switch (cmd)
+    {
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->nchannels;
+        }
+        break;
+
+      default:
+        {
+          aerr("ERROR: Unknown cmd: %d\n", cmd);
+          ret = -ENOTTY;
+        }
+        break;
+    }
+
+  return ret;
 }
 
 /****************************************************************************

arch/arm/src/imxrt/imxrt_adc.c

@@ -37,6 +37,7 @@
 #include <nuttx/irq.h>
 #include <nuttx/arch.h>
 #include <nuttx/analog/adc.h>
+#include <nuttx/analog/ioctl.h>
 
 #include "arm_internal.h"
 #include "arm_arch.h"
@@ -458,11 +459,30 @@ static void adc_rxint(FAR struct adc_dev_s *dev, bool enable)
 
 static int adc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
 {
-  /* No ioctl commands supported */
-
   /* TODO: ANIOC_TRIGGER, for SW triggered conversion */
 
-  return -ENOTTY;
+  FAR struct imxrt_dev_s *priv = (FAR struct imxrt_dev_s *)dev->ad_priv;
+  int ret = -ENOTTY;
+
+  switch (cmd)
+    {
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->nchannels;
+        }
+        break;
+
+      default:
+        {
+          aerr("ERROR: Unknown cmd: %d\n", cmd);
+          ret = -ENOTTY;
+        }
+        break;
+    }
+
+  return ret;
 }
 
 /****************************************************************************

arch/arm/src/lc823450/lc823450_adc.c

@@ -456,35 +456,46 @@ static int lc823450_adc_ioctl(FAR struct adc_dev_s *dev, int cmd,
   switch (cmd)
     {
       case ANIOC_TRIGGER: /* Software trigger */
+        {
+          lc823450_adc_standby(0);
 
-        lc823450_adc_standby(0);
+          lc823450_adc_start(priv);
 
-        lc823450_adc_start(priv);
+          /* Get ADC data */
 
-        /* Get ADC data */
+          for (ch = 0; ch < CONFIG_LC823450_ADC_NCHANNELS; ch++)
+            {
+              val = getreg32(LC823450_ADC0DT(ch));
 
-        for (ch = 0; ch < CONFIG_LC823450_ADC_NCHANNELS; ch++)
-          {
-            val = getreg32(LC823450_ADC0DT(ch));
+              /* Give the ADC data to the ADC driver framework.
+               * adc_receive accepts 3 parameters:
+               *
+               * 1) The first is the ADC device instance for this ADC block.
+               * 2) The second is the channel number for the data, and
+               * 3) The third is the converted data for the channel.
+               */
 
-            /* Give the ADC data to the ADC driver framework.
-             * adc_receive accepts 3 parameters:
-             *
-             * 1) The first is the ADC device instance for this ADC block.
-             * 2) The second is the channel number for the data, and
-             * 3) The third is the converted data for the channel.
-             */
+              priv->cb->au_receive(dev, priv->chanlist[ch], val);
+              DEBUGASSERT(ret == OK);
+            }
 
-            priv->cb->au_receive(dev, priv->chanlist[ch], val);
-            DEBUGASSERT(ret == OK);
-          }
+          lc823450_adc_standby(1);
+        }
+        break;
+
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
 
-        lc823450_adc_standby(1);
+          ret = CONFIG_LC823450_ADC_NCHANNELS;
+        }
         break;
 
-    default:
-      ret = -ENOTTY;
-      break;
+      default:
+        {
+          ret = -ENOTTY;
+        }
+        break;
     }
 
   lc823450_adc_sem_post(priv);

arch/arm/src/nrf52/nrf52_adc.c

@@ -879,16 +879,23 @@ static int nrf52_adc_ioctl(FAR struct adc_dev_s *dev, int cmd,
           /* Trigger first sample */
 
           nrf52_adc_putreg(priv, NRF52_SAADC_TASKS_SAMPLE_OFFSET, 1);
+        }
+        break;
 
-          break;
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->chan_len;
         }
+        break;
 
       default:
         {
           aerr("ERROR: Unknown cmd: %d\n", cmd);
           ret = -ENOTTY;
-          break;
         }
+        break;
     }
 
   return ret;

arch/arm/src/sama5/sam_adc.c

@@ -1258,10 +1258,20 @@ static int sam_adc_ioctl(struct adc_dev_s *dev, int cmd, unsigned long arg)
         break;
 #endif
 
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = SAMA5_NCHANNELS;
+        }
+        break;
+
       /* Unsupported or invalid command */
 
       default:
-        ret = -ENOTTY;
+        {
+          ret = -ENOTTY;
+        }
         break;
     }
 

arch/arm/src/samd2l2/sam_adc.c

@@ -37,6 +37,7 @@
 #include <nuttx/signal.h>
 #include <nuttx/fs/fs.h>
 #include <nuttx/analog/adc.h>
+#include <nuttx/analog/ioctl.h>
 #include <nuttx/kmalloc.h>
 
 #include <arch/chip/sam_adc.h>
@@ -387,35 +388,51 @@ static int sam_adc_ioctl(FAR struct adc_dev_s *dev,
   struct sam_adc_param_s *params = (struct sam_adc_param_s *)arg;
 
   switch (cmd)
-  {
-    case SAMD_ADC_IOCTL_START:
-      sam_adc_setup(dev);
-      sam_adc_rxint(dev, true);
-      break;
-
-    case SAMD_ADC_IOCTL_STOP:
-      sam_adc_rxint(dev, false);
-      sam_adc_shutdown(dev);
-      break;
-
-    case SAMD_ADC_IOCTL_SET_PARAMS:
-      if ((getreg8(SAM_ADC_CTRLA) & ADC_CTRLA_ENABLE) != 0)
+    {
+      case SAMD_ADC_IOCTL_START:
+        {
+          sam_adc_setup(dev);
+          sam_adc_rxint(dev, true);
+          break;
+        }
+
+      case SAMD_ADC_IOCTL_STOP:
+        {
+          sam_adc_rxint(dev, false);
+          sam_adc_shutdown(dev);
+          break;
+        }
+
+      case SAMD_ADC_IOCTL_SET_PARAMS:
         {
-          ret = -EBUSY;
+          if ((getreg8(SAM_ADC_CTRLA) & ADC_CTRLA_ENABLE) != 0)
+            {
+              ret = -EBUSY;
+              break;
+            }
+
+          priv->averaging = params->averaging;
+          priv->prescaler = params->prescaler;
+          priv->samplen = params->samplen;
           break;
         }
 
-      priv->averaging = params->averaging;
-      priv->prescaler = params->prescaler;
-      priv->samplen = params->samplen;
-      break;
-
-    case SAMD_ADC_IOCTL_GET_PARAMS:
-      params->averaging = priv->averaging;
-      params->prescaler = priv->prescaler;
-      params->samplen = priv->samplen;
-      break;
-  }
+      case SAMD_ADC_IOCTL_GET_PARAMS:
+        {
+          params->averaging = priv->averaging;
+          params->prescaler = priv->prescaler;
+          params->samplen = priv->samplen;
+          break;
+        }
+
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->num_channels;
+        }
+        break;
+    }
 
   return ret;
 }

arch/arm/src/stm32/stm32_adc.c

@@ -3871,6 +3871,14 @@ static int adc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
           break;
         }
 
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->rnchannels;
+        }
+        break;
+
       case IO_TRIGGER_REG:
         {
           /* Start regular conversion if regular channels configured */

arch/arm/src/stm32/stm32_sdadc.c

@@ -1193,12 +1193,24 @@ static int sdadc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
   switch (cmd)
     {
       case ANIOC_TRIGGER:
-        sdadc_startconv(priv, true);
+        {
+          sdadc_startconv(priv, true);
+        }
+        break;
+
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->cchannels;
+        }
         break;
 
       default:
-        aerr("ERROR: Unknown cmd: %d\n", cmd);
-        ret = -ENOTTY;
+        {
+          aerr("ERROR: Unknown cmd: %d\n", cmd);
+          ret = -ENOTTY;
+        }
         break;
     }
 

arch/arm/src/stm32f0l0g0/stm32_adc.c

@@ -1960,6 +1960,14 @@ static int adc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
           break;
         }
 
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->cr_channels;
+        }
+        break;
+
       case IO_TRIGGER_REG:
         {
           /* Start regular conversion if regular channels configured */

arch/arm/src/stm32f7/stm32_adc.c

@@ -1651,12 +1651,24 @@ static int adc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
   switch (cmd)
     {
       case ANIOC_TRIGGER:
-        adc_startconv(priv, true);
+        {
+          adc_startconv(priv, true);
+        }
+        break;
+
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->cchannels;
+        }
         break;
 
       default:
-        aerr("ERROR: Unknown cmd: %d\n", cmd);
-        ret = -ENOTTY;
+        {
+          aerr("ERROR: Unknown cmd: %d\n", cmd);
+          ret = -ENOTTY;
+        }
         break;
     }
 

arch/arm/src/stm32h7/stm32_adc.c

@@ -1760,7 +1760,17 @@ static int adc_ioctl(FAR struct adc_dev_s *dev, int cmd, unsigned long arg)
   switch (cmd)
     {
       case ANIOC_TRIGGER:
-        adc_startconv(priv, true);
+        {
+          adc_startconv(priv, true);
+        }
+        break;
+
+      case ANIOC_GET_NCHANNELS:
+        {
+          /* Return the number of configured channels */
+
+          ret = priv->cchannels;
+        }
         break;
 
       case ANIOC_WDOG_UPPER: /* Set watchdog upper threshold */