sys/saul: Add analog inputs to SAUL via periph/adc

Makefile.pseudomodules

@@ -38,6 +38,7 @@ PSEUDOMODULES += newlib
 PSEUDOMODULES += newlib_nano
 PSEUDOMODULES += pktqueue
 PSEUDOMODULES += printf_float
+PSEUDOMODULES += saul_adc
 PSEUDOMODULES += saul_default
 PSEUDOMODULES += saul_gpio
 PSEUDOMODULES += schedstatistics

drivers/include/saul/periph.h

@@ -19,12 +19,19 @@
 #ifndef SAUL_PERIPH_H
 #define SAUL_PERIPH_H
 
+#ifdef MODULE_SAUL_GPIO
 #include "periph/gpio.h"
+#endif /* MODULE_SAUL_GPIO */
+
+#ifdef MODULE_SAUL_ADC
+#include "periph/adc.h"
+#endif /* MODULE_SAUL_ADC */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#ifdef MODULE_SAUL_GPIO
 /**
  * @brief   Direct mapped GPIO configuration values
  */
@@ -33,6 +40,18 @@ typedef struct {
     gpio_t pin;             /**< GPIO pin to initialize and expose */
     gpio_mode_t mode;       /**< pin mode to use */
 } saul_gpio_params_t;
+#endif /* MODULE_SAUL_GPIO */
+
+#ifdef MODULE_SAUL_ADC
+/**
+ * @brief   Direct mapped ADC configuration values
+ */
+typedef struct {
+    const char *name;       /**< name of the device connected to this pin */
+    adc_t line;             /**< ADC line to initialize and expose */
+    adc_res_t res;          /**< ADC resolution */
+} saul_adc_params_t;
+#endif /* MODULE_SAUL_ADC */
 
 #ifdef __cplusplus
 }

drivers/saul/Makefile

@@ -3,5 +3,8 @@ SRC = saul.c saul_str.c
 ifneq (,$(filter saul_gpio,$(USEMODULE)))
   SRC += gpio_saul.c
 endif
+ifneq (,$(filter saul_adc,$(USEMODULE)))
+  SRC += adc_saul.c
+endif
 
 include $(RIOTBASE)/Makefile.base

drivers/saul/adc_saul.c

@@ -0,0 +1,44 @@
+/*
+ * Copyright (C) 2016 Eistec AB
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     drivers_saul
+ * @{
+ *
+ * @file
+ * @brief       SAUL wrapper for direct access to analog pins
+ *
+ * @author      Joakim Nohlgård <joakim.nohlgard@eistec.se>
+ *
+ * @}
+ */
+
+#include <string.h>
+
+#include "saul.h"
+#include "saul/periph.h"
+#include "phydat.h"
+#include "periph/adc.h"
+
+
+static int read_adc(void *dev, phydat_t *res)
+{
+    const saul_adc_params_t *params = *((const saul_adc_params_t **)dev);
+    res->val[0] = adc_sample(params->line, params->res);
+    memset(&(res->val[1]), 0, 2 * sizeof(res->val[1]));
+    /* Raw ADC reading has no unit */
+    res->unit = UNIT_NONE;
+    res->scale = 0;
+    return 1;
+}
+
+const saul_driver_t adc_saul_driver = {
+    .read = read_adc,
+    .write = saul_notsup,
+    .type = SAUL_SENSE_ANALOG,
+};

drivers/saul/saul_str.c

@@ -46,6 +46,7 @@ const char *saul_class_to_str(uint8_t class_id)
         case SAUL_SENSE_GYRO:   return "SENSE_GYRO";
         case SAUL_SENSE_COLOR:  return "SENSE_COLOR";
         case SAUL_SENSE_PRESS:  return "SENSE_PRESS";
+        case SAUL_SENSE_ANALOG: return "SENSE_ANALOG";
         case SAUL_CLASS_ANY:    return "CLASS_ANY";
         default:                return "CLASS_UNKNOWN";
     }

sys/auto_init/auto_init.c

@@ -221,6 +221,10 @@ void auto_init(void)
     extern void auto_init_gpio(void);
     auto_init_gpio();
 #endif
+#ifdef MODULE_SAUL_ADC
+    extern void auto_init_adc(void);
+    auto_init_adc();
+#endif
 #ifdef MODULE_LSM303DLHC
     extern void auto_init_lsm303dlhc(void);
     auto_init_lsm303dlhc();

sys/auto_init/saul/auto_init_adc.c

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2016 Eistec AB
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ *
+ */
+
+/**
+ * @ingroup     auto_init_saul
+ * @{
+ *
+ * @file
+ * @brief       Auto initialization of ADC lines directly mapped to SAUL reg
+ *
+ * @author      Joakim Nohlgård <joakim.nohlgard@eistec.se>
+ *
+ * @}
+ */
+
+#ifdef MODULE_SAUL_ADC
+
+#include "saul_reg.h"
+#include "saul/periph.h"
+#include "adc_params.h"
+#include "periph/gpio.h"
+
+#define ENABLE_DEBUG (0)
+#include "debug.h"
+
+/**
+ * @brief   Define the number of configured sensors
+ */
+#define SAUL_ADC_NUMOF    (sizeof(saul_adc_params)/sizeof(saul_adc_params[0]))
+
+/**
+ * @brief   Allocate memory for pointers to the ADC parameter structs
+ *
+ * We use this extra level of indirection to be able to keep the saul_adc_params
+ * array const and residing in ROM.
+ */
+static const saul_adc_params_t *saul_adcs[SAUL_ADC_NUMOF];
+
+/**
+ * @brief   Memory for the registry entries
+ */
+static saul_reg_t saul_reg_entries[SAUL_ADC_NUMOF];
+
+/**
+ * @brief   Reference the driver struct
+ */
+extern saul_driver_t adc_saul_driver;
+
+void auto_init_adc(void)
+{
+    DEBUG("auto init SAUL ADC\n");
+    for (int i = 0; i < SAUL_ADC_NUMOF; i++) {
+        const saul_adc_params_t *p = &saul_adc_params[i];
+        saul_adcs[i] = p;
+
+        DEBUG("[auto_init_saul] initializing direct ADC\n");
+        saul_reg_entries[i].dev = &saul_adcs[i];
+        saul_reg_entries[i].name = p->name;
+        saul_reg_entries[i].driver = &adc_saul_driver;
+        /* initialize the ADC line */
+        adc_init(p->line);
+        /* add to registry */
+        saul_reg_add(&(saul_reg_entries[i]));
+    }
+}
+
+#else
+typedef int dont_be_pedantic;
+#endif /* MODULE_SAUL_ADC */