From 946256d26f4cff5c88c625ea770fe60650506f5a Mon Sep 17 00:00:00 2001
From: smlng <s@mlng.net>
Date: Mon, 26 Jun 2017 16:00:34 +0200
Subject: [PATCH] saul: use const for device parameter

---
 drivers/adcxx1c/adcxx1c_saul.c           |  4 ++--
 drivers/adxl345/adxl345_saul.c           |  5 ++---
 drivers/bmp180/bmp180_saul.c             | 12 ++++--------
 drivers/bmx280/bmx280_saul.c             | 18 ++++++------------
 drivers/dht/dht_saul.c                   | 12 ++++--------
 drivers/hdc1000/hdc1000_saul.c           | 12 ++++--------
 drivers/include/saul.h                   |  8 ++++----
 drivers/io1_xplained/io1_xplained_saul.c |  5 ++---
 drivers/isl29020/isl29020_saul.c         |  5 ++---
 drivers/jc42/jc42_saul.c                 |  5 ++---
 drivers/l3g4200d/l3g4200d_saul.c         |  5 ++---
 drivers/lis3dh/lis3dh_saul.c             |  5 ++---
 drivers/lps331ap/lps331ap_saul.c         |  5 ++---
 drivers/lsm303dlhc/lsm303dlhc_saul.c     |  9 +++++----
 drivers/lsm6dsl/lsm6dsl_saul.c           |  9 ++++-----
 drivers/mag3110/mag3110_saul.c           |  4 ++--
 drivers/mma8x5x/mma8x5x_saul.c           |  4 ++--
 drivers/saul/adc_saul.c                  |  2 +-
 drivers/saul/gpio_saul.c                 |  8 ++++----
 drivers/saul/saul.c                      |  2 +-
 drivers/saul/saul_str.c                  |  2 +-
 drivers/si70xx/si70xx_saul.c             | 12 ++++--------
 drivers/tcs37727/tcs37727_saul.c         |  5 ++---
 drivers/tmp006/tmp006_saul.c             |  5 +++--
 drivers/tsl2561/tsl2561_saul.c           |  6 ++----
 drivers/veml6070/veml6070_saul.c         |  6 ++----
 26 files changed, 71 insertions(+), 104 deletions(-)

diff --git a/drivers/adcxx1c/adcxx1c_saul.c b/drivers/adcxx1c/adcxx1c_saul.c
index a697de47f..775b4c7a5 100644
--- a/drivers/adcxx1c/adcxx1c_saul.c
+++ b/drivers/adcxx1c/adcxx1c_saul.c
@@ -24,9 +24,9 @@
 #include "saul.h"
 #include "adcxx1c.h"
 
-static int read_adc(void *dev, phydat_t *res)
+static int read_adc(const void *dev, phydat_t *res)
 {
-    adcxx1c_read_raw((adcxx1c_t *)dev, res->val);
+    adcxx1c_read_raw((const adcxx1c_t *)dev, res->val);
 
     res->unit = UNIT_NONE;
     res->scale = 0;
diff --git a/drivers/adxl345/adxl345_saul.c b/drivers/adxl345/adxl345_saul.c
index 1e31f97ef..fb680a7f8 100644
--- a/drivers/adxl345/adxl345_saul.c
+++ b/drivers/adxl345/adxl345_saul.c
@@ -21,10 +21,9 @@
 #include "saul.h"
 #include "adxl345.h"
 
-static int read_acc(void *dev, phydat_t *res)
+static int read_acc(const void *dev, phydat_t *res)
 {
-    adxl345_t *d = (adxl345_t *)dev;
-    adxl345_read(d, (adxl345_data_t *)res->val);
+    adxl345_read((const adxl345_t *)dev, (adxl345_data_t *)res->val);
 
     res->unit = UNIT_G;
     res->scale = -3;
diff --git a/drivers/bmp180/bmp180_saul.c b/drivers/bmp180/bmp180_saul.c
index 03158315e..7a5076d44 100644
--- a/drivers/bmp180/bmp180_saul.c
+++ b/drivers/bmp180/bmp180_saul.c
@@ -25,21 +25,17 @@
 #include "bmp180.h"
 #include "xtimer.h"
 
-static int read_temperature(void *dev, phydat_t *res)
+static int read_temperature(const void *dev, phydat_t *res)
 {
-    bmp180_t *d = (bmp180_t *)dev;
-
-    res->val[0] = bmp180_read_temperature(d);
+    res->val[0] = bmp180_read_temperature((const bmp180_t *)dev);
     res->unit = UNIT_TEMP_C;
     res->scale = -1;
     return 1;
 }
 
-static int read_pressure(void *dev, phydat_t *res)
+static int read_pressure(const void *dev, phydat_t *res)
 {
-    bmp180_t *d = (bmp180_t *)dev;
-
-    res->val[0] = bmp180_read_pressure(d) / 100;
+    res->val[0] = bmp180_read_pressure((const bmp180_t *)dev) / 100;
     res->unit = UNIT_PA;
     res->scale = 2;
     return 1;
diff --git a/drivers/bmx280/bmx280_saul.c b/drivers/bmx280/bmx280_saul.c
index e767d8402..d0d08dd4a 100644
--- a/drivers/bmx280/bmx280_saul.c
+++ b/drivers/bmx280/bmx280_saul.c
@@ -24,22 +24,18 @@
 
 #include "bmx280.h"
 
-static int read_temperature(void *dev, phydat_t *res)
+static int read_temperature(const void *dev, phydat_t *res)
 {
-    bmx280_t *d = (bmx280_t *)dev;
-
-    res->val[0] = bmx280_read_temperature(d);
+    res->val[0] = bmx280_read_temperature((const bmx280_t *)dev);
     res->unit = UNIT_TEMP_C;
     res->scale = -2;
 
     return 1;
 }
 
-static int read_pressure(void *dev, phydat_t *res)
+static int read_pressure(const void *dev, phydat_t *res)
 {
-    bmx280_t *d = (bmx280_t *)dev;
-
-    res->val[0] = bmx280_read_pressure(d) / 100;
+    res->val[0] = bmx280_read_pressure((const bmx280_t *)dev) / 100;
     res->unit = UNIT_PA;
     res->scale = 2;
 
@@ -47,11 +43,9 @@ static int read_pressure(void *dev, phydat_t *res)
 }
 
 #ifdef MODULE_BME280
-static int read_relative_humidity(void *dev, phydat_t *res)
+static int read_relative_humidity(const void *dev, phydat_t *res)
 {
-    bmx280_t *d = (bmx280_t *)dev;
-
-    res->val[0] = bme280_read_humidity(d);
+    res->val[0] = bme280_read_humidity((const bmx280_t *)dev);
     res->unit = UNIT_PERCENT;
     res->scale = -2;
 
diff --git a/drivers/dht/dht_saul.c b/drivers/dht/dht_saul.c
index 4cbb4a20f..1b5a9644c 100644
--- a/drivers/dht/dht_saul.c
+++ b/drivers/dht/dht_saul.c
@@ -37,18 +37,14 @@
 static int16_t temp, hum;
 static uint32_t last = 0;
 
-static int check_and_read(void *dev, phydat_t *res, int16_t *val, uint8_t unit)
+static int check_and_read(const void *dev, phydat_t *res, int16_t *val, uint8_t unit)
 {
-    dht_t *d = (dht_t *)dev;
     uint32_t now = xtimer_now_usec();
 
     if ((now - last) > DHT_SAUL_HOLD_TIME) {
-        dht_read(d, &temp, &hum);
+        dht_read((const dht_t *)dev, &temp, &hum);
         last = now;
     }
-    else {
-        (void)d;
-    }
 
     res->val[0] = *val;
     memset(&res->val[1], 0, 2 * sizeof(int16_t));
@@ -57,12 +53,12 @@ static int check_and_read(void *dev, phydat_t *res, int16_t *val, uint8_t unit)
     return 1;
 }
 
-static int read_temp(void *dev, phydat_t *res)
+static int read_temp(const void *dev, phydat_t *res)
 {
     return check_and_read(dev, res, &temp, UNIT_TEMP_C);
 }
 
-static int read_hum(void *dev, phydat_t *res)
+static int read_hum(const void *dev, phydat_t *res)
 {
     return check_and_read(dev, res, &hum, UNIT_PERCENT);
 }
diff --git a/drivers/hdc1000/hdc1000_saul.c b/drivers/hdc1000/hdc1000_saul.c
index 691408fd8..4cca369f7 100644
--- a/drivers/hdc1000/hdc1000_saul.c
+++ b/drivers/hdc1000/hdc1000_saul.c
@@ -23,11 +23,9 @@
 #include "saul.h"
 #include "hdc1000.h"
 
-static int read_temp(void *dev, phydat_t *res)
+static int read_temp(const void *dev, phydat_t *res)
 {
-    hdc1000_t *d = (hdc1000_t *)dev;
-
-    if (hdc1000_read(d, &(res->val[0]), NULL) != HDC1000_OK) {
+    if (hdc1000_read((const hdc1000_t *)dev, &(res->val[0]), NULL) != HDC1000_OK) {
         return -ECANCELED;
     }
     memset(&(res->val[1]), 0, 2 * sizeof(int16_t));
@@ -37,11 +35,9 @@ static int read_temp(void *dev, phydat_t *res)
     return 1;
 }
 
-static int read_hum(void *dev, phydat_t *res)
+static int read_hum(const void *dev, phydat_t *res)
 {
-    hdc1000_t *d = (hdc1000_t *)dev;
-
-    if (hdc1000_read(d, NULL, &(res->val[0])) != HDC1000_OK) {
+    if (hdc1000_read((const hdc1000_t *)dev, NULL, &(res->val[0])) != HDC1000_OK) {
         return -ECANCELED;
     }
     memset(&(res->val[1]), 0, 2 * sizeof(int16_t));
diff --git a/drivers/include/saul.h b/drivers/include/saul.h
index bb7cffb37..588251c0d 100644
--- a/drivers/include/saul.h
+++ b/drivers/include/saul.h
@@ -112,7 +112,7 @@ enum {
  * @return  -ENOTSUP if the device does not support this operation
  * @return  -ECANCELED on other errors
  */
-typedef int(*saul_read_t)(void *dev, phydat_t *res);
+typedef int(*saul_read_t)(const void *dev, phydat_t *res);
 
 /**
  * @brief   Write a value (a set of values) to a device
@@ -132,7 +132,7 @@ typedef int(*saul_read_t)(void *dev, phydat_t *res);
  * @return  -ENOTSUP if the device does not support this operation
  * @return  -ECANCELED on other errors
  */
-typedef int(*saul_write_t)(void *dev, phydat_t *data);
+typedef int(*saul_write_t)(const void *dev, phydat_t *data);
 
 /**
  * @brief   Definition of the RIOT actuator/sensor interface
@@ -146,7 +146,7 @@ typedef struct {
 /**
  * @brief   Default not supported function
  */
-int saul_notsup(void *dev, phydat_t *dat);
+int saul_notsup(const void *dev, phydat_t *dat);
 
 /**
  * @brief   Helper function converts a class ID to a string
@@ -156,7 +156,7 @@ int saul_notsup(void *dev, phydat_t *dat);
  * @return      string representation of the device class
  * @return      NULL if class ID is not known
  */
-const char *saul_class_to_str(uint8_t class_id);
+const char *saul_class_to_str(const uint8_t class_id);
 
 #ifdef __cplusplus
 }
diff --git a/drivers/io1_xplained/io1_xplained_saul.c b/drivers/io1_xplained/io1_xplained_saul.c
index 6864bb70b..ed56e621a 100644
--- a/drivers/io1_xplained/io1_xplained_saul.c
+++ b/drivers/io1_xplained/io1_xplained_saul.c
@@ -25,10 +25,9 @@
 
 static float temperature;
 
-static int read_temperature(void *dev, phydat_t *res)
+static int read_temperature(const void *dev, phydat_t *res)
 {
-    io1_xplained_t *d = (io1_xplained_t *)dev;
-    io1_xplained_read_temperature(d, &temperature);
+    io1_xplained_read_temperature((const io1_xplained_t *)dev, &temperature);
     res->val[0] = (int)(temperature * 100.0);
     res->unit = UNIT_TEMP_C;
     res->scale = -2;
diff --git a/drivers/isl29020/isl29020_saul.c b/drivers/isl29020/isl29020_saul.c
index 07127ee30..0faf82ae6 100644
--- a/drivers/isl29020/isl29020_saul.c
+++ b/drivers/isl29020/isl29020_saul.c
@@ -23,10 +23,9 @@
 #include "saul.h"
 #include "isl29020.h"
 
-static int read(void *dev, phydat_t *res)
+static int read(const void *dev, phydat_t *res)
 {
-    isl29020_t *d = (isl29020_t *)dev;
-    res->val[0] = (int16_t)isl29020_read(d);
+    res->val[0] = (int16_t)isl29020_read((const isl29020_t *)dev);
     memset(&(res->val[1]), 0, 2 * sizeof(int16_t));
     res->unit = UNIT_CD;
     res->scale = 0;
diff --git a/drivers/jc42/jc42_saul.c b/drivers/jc42/jc42_saul.c
index a0cebdb7e..391cee5b3 100644
--- a/drivers/jc42/jc42_saul.c
+++ b/drivers/jc42/jc42_saul.c
@@ -25,12 +25,11 @@
 
 
 
-static int read_temperature(void *dev, phydat_t *res)
+static int read_temperature(const void *dev, phydat_t *res)
 {
     int16_t temperature;
-    jc42_t *d = (jc42_t *)dev;
 
-    jc42_get_temperature(d, &temperature);
+    jc42_get_temperature((const jc42_t *)dev, &temperature);
     res->val[0] = temperature;
     res->unit = UNIT_TEMP_C;
     res->scale = -2;
diff --git a/drivers/l3g4200d/l3g4200d_saul.c b/drivers/l3g4200d/l3g4200d_saul.c
index 3e1021297..5c9379972 100644
--- a/drivers/l3g4200d/l3g4200d_saul.c
+++ b/drivers/l3g4200d/l3g4200d_saul.c
@@ -23,10 +23,9 @@
 #include "saul.h"
 #include "l3g4200d.h"
 
-static int read(void *dev, phydat_t *res)
+static int read(const void *dev, phydat_t *res)
 {
-    l3g4200d_t *d = (l3g4200d_t *)dev;
-    l3g4200d_read(d, (l3g4200d_data_t *)res);
+    l3g4200d_read((const l3g4200d_t *)dev, (l3g4200d_data_t *)res);
     res->unit = UNIT_DPS;
     res->scale = 0;
     return 3;
diff --git a/drivers/lis3dh/lis3dh_saul.c b/drivers/lis3dh/lis3dh_saul.c
index 2146e7938..e1df3e190 100644
--- a/drivers/lis3dh/lis3dh_saul.c
+++ b/drivers/lis3dh/lis3dh_saul.c
@@ -24,12 +24,11 @@
 #include "saul.h"
 #include "lis3dh.h"
 
-static int read_acc(void *dev, phydat_t *res)
+static int read_acc(const void *dev, phydat_t *res)
 {
     lis3dh_data_t xyz;
 
-    lis3dh_t *d = (lis3dh_t *)dev;
-    int err = lis3dh_read_xyz(d, &xyz);
+    int err = lis3dh_read_xyz((const lis3dh_t *)dev, &xyz);
     if (err != 0) {
         /* Something went wrong in the LIS3DH driver */
         return -ECANCELED;
diff --git a/drivers/lps331ap/lps331ap_saul.c b/drivers/lps331ap/lps331ap_saul.c
index cdb161094..50d2932c3 100644
--- a/drivers/lps331ap/lps331ap_saul.c
+++ b/drivers/lps331ap/lps331ap_saul.c
@@ -23,10 +23,9 @@
 #include "saul.h"
 #include "lps331ap.h"
 
-static int read(void *dev, phydat_t *res)
+static int read(const void *dev, phydat_t *res)
 {
-    lps331ap_t *d = (lps331ap_t *)dev;
-    res->val[0] = (int16_t)lps331ap_read_pres(d);
+    res->val[0] = (int16_t)lps331ap_read_pres((const lps331ap_t *)dev);
     memset(&(res->val[1]), 0, 2 * sizeof(int16_t));
     res->unit = UNIT_BAR;
     res->scale = -3;
diff --git a/drivers/lsm303dlhc/lsm303dlhc_saul.c b/drivers/lsm303dlhc/lsm303dlhc_saul.c
index 473ddaa2e..61b981c0e 100644
--- a/drivers/lsm303dlhc/lsm303dlhc_saul.c
+++ b/drivers/lsm303dlhc/lsm303dlhc_saul.c
@@ -23,9 +23,9 @@
 #include "saul.h"
 #include "lsm303dlhc.h"
 
-static int read_acc(void *dev, phydat_t *res)
+static int read_acc(const void *dev, phydat_t *res)
 {
-    lsm303dlhc_t *d = (lsm303dlhc_t *)dev;
+    const lsm303dlhc_t *d = (const lsm303dlhc_t *)dev;
     lsm303dlhc_read_acc(d, (lsm303dlhc_3d_data_t *)res);
 
     /* normalize result */
@@ -39,9 +39,10 @@ static int read_acc(void *dev, phydat_t *res)
     return 3;
 }
 
-static int read_mag(void *dev, phydat_t *res)
+static int read_mag(const void *dev, phydat_t *res)
 {
-    lsm303dlhc_t *d = (lsm303dlhc_t *)dev;
+    const lsm303dlhc_t *d = (const lsm303dlhc_t *)dev;
+
     lsm303dlhc_read_mag(d, (lsm303dlhc_3d_data_t *)res);
 
     /* normalize results */
diff --git a/drivers/lsm6dsl/lsm6dsl_saul.c b/drivers/lsm6dsl/lsm6dsl_saul.c
index 322e71037..4b86e6a74 100644
--- a/drivers/lsm6dsl/lsm6dsl_saul.c
+++ b/drivers/lsm6dsl/lsm6dsl_saul.c
@@ -17,9 +17,9 @@
 #include "lsm6dsl.h"
 #include "saul.h"
 
-static int read_acc(void *dev, phydat_t *res)
+static int read_acc(const void *dev, phydat_t *res)
 {
-    int ret = lsm6dsl_read_acc(dev, (lsm6dsl_3d_data_t *)res);
+    int ret = lsm6dsl_read_acc((const lsm6dsl_t *)dev, (lsm6dsl_3d_data_t *)res);
     if (ret < 0) {
         return -ECANCELED;
     }
@@ -30,9 +30,9 @@ static int read_acc(void *dev, phydat_t *res)
     return 3;
 }
 
-static int read_gyro(void *dev, phydat_t *res)
+static int read_gyro(const void *dev, phydat_t *res)
 {
-    int ret = lsm6dsl_read_gyro(dev, (lsm6dsl_3d_data_t *)res);
+    int ret = lsm6dsl_read_gyro((const lsm6dsl_t *)dev, (lsm6dsl_3d_data_t *)res);
     if (ret < 0) {
         return -ECANCELED;
     }
@@ -49,7 +49,6 @@ const saul_driver_t lsm6dsl_saul_acc_driver = {
     .type = SAUL_SENSE_ACCEL,
 };
 
-
 const saul_driver_t lsm6dsl_saul_gyro_driver = {
     .read = read_gyro,
     .write = saul_notsup,
diff --git a/drivers/mag3110/mag3110_saul.c b/drivers/mag3110/mag3110_saul.c
index c890ab4f5..221fc79b2 100644
--- a/drivers/mag3110/mag3110_saul.c
+++ b/drivers/mag3110/mag3110_saul.c
@@ -24,9 +24,9 @@
 #include "saul.h"
 #include "mag3110.h"
 
-static int read_mag(void *dev, phydat_t *res)
+static int read_mag(const void *dev, phydat_t *res)
 {
-    mag3110_read((mag3110_t *)dev, (mag3110_data_t *)res);
+    mag3110_read((const mag3110_t *)dev, (mag3110_data_t *)res);
 
     res->unit = UNIT_GS;
     res->scale = 2;
diff --git a/drivers/mma8x5x/mma8x5x_saul.c b/drivers/mma8x5x/mma8x5x_saul.c
index 5c1156daa..1998b1efb 100644
--- a/drivers/mma8x5x/mma8x5x_saul.c
+++ b/drivers/mma8x5x/mma8x5x_saul.c
@@ -25,9 +25,9 @@
 #include "saul.h"
 #include "mma8x5x.h"
 
-static int read_acc(void *dev, phydat_t *res)
+static int read_acc(const void *dev, phydat_t *res)
 {
-    mma8x5x_read((mma8x5x_t *)dev, (mma8x5x_data_t *)res);
+    mma8x5x_read((const mma8x5x_t *)dev, (mma8x5x_data_t *)res);
 
     res->unit = UNIT_G;
     res->scale = -3;
diff --git a/drivers/saul/adc_saul.c b/drivers/saul/adc_saul.c
index a7c81f279..c732b1a85 100644
--- a/drivers/saul/adc_saul.c
+++ b/drivers/saul/adc_saul.c
@@ -26,7 +26,7 @@
 #include "periph/adc.h"
 
 
-static int read_adc(void *dev, phydat_t *res)
+static int read_adc(const 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);
diff --git a/drivers/saul/gpio_saul.c b/drivers/saul/gpio_saul.c
index 8e1912d15..e32511585 100644
--- a/drivers/saul/gpio_saul.c
+++ b/drivers/saul/gpio_saul.c
@@ -25,9 +25,9 @@
 #include "periph/gpio.h"
 
 
-static int read(void *dev, phydat_t *res)
+static int read(const void *dev, phydat_t *res)
 {
-    gpio_t pin = *((gpio_t *)dev);
+    gpio_t pin = *((const gpio_t *)dev);
     res->val[0] = (gpio_read(pin)) ? 1 : 0;
     memset(&(res->val[1]), 0, 2 * sizeof(int16_t));
     res->unit = UNIT_BOOL;
@@ -35,9 +35,9 @@ static int read(void *dev, phydat_t *res)
     return 1;
 }
 
-static int write(void *dev, phydat_t *state)
+static int write(const void *dev, phydat_t *state)
 {
-    gpio_t pin = *((gpio_t *)dev);
+    gpio_t pin = *((const gpio_t *)dev);
     gpio_write(pin, state->val[0]);
     return 1;
 }
diff --git a/drivers/saul/saul.c b/drivers/saul/saul.c
index dbcb4f1b4..5f7dd72a6 100644
--- a/drivers/saul/saul.c
+++ b/drivers/saul/saul.c
@@ -22,7 +22,7 @@
 
 #include "saul.h"
 
-int saul_notsup(void *dev, phydat_t *dat)
+int saul_notsup(const void *dev, phydat_t *dat)
 {
     (void)dev;
     (void)dat;
diff --git a/drivers/saul/saul_str.c b/drivers/saul/saul_str.c
index 3e688563d..d912dec95 100644
--- a/drivers/saul/saul_str.c
+++ b/drivers/saul/saul_str.c
@@ -26,7 +26,7 @@
  * This is surely not the most beautiful implementation of a stringification
  * function, but works...
  */
-const char *saul_class_to_str(uint8_t class_id)
+const char *saul_class_to_str(const uint8_t class_id)
 {
     switch (class_id) {
         case SAUL_CLASS_UNDEF:  return "CLASS_UNDEF";
diff --git a/drivers/si70xx/si70xx_saul.c b/drivers/si70xx/si70xx_saul.c
index c56702808..09de1dca1 100644
--- a/drivers/si70xx/si70xx_saul.c
+++ b/drivers/si70xx/si70xx_saul.c
@@ -22,22 +22,18 @@
 
 #include "si70xx.h"
 
-static int read_temperature(void *dev, phydat_t *res)
+static int read_temperature(const void *dev, phydat_t *res)
 {
-    si70xx_t *d = (si70xx_t *)dev;
-
-    res->val[0] = (int32_t) si70xx_get_temperature(d);
+    res->val[0] = (int32_t) si70xx_get_temperature((const si70xx_t *)dev);
     res->unit = UNIT_TEMP_C;
     res->scale = -2;
 
     return 1;
 }
 
-static int read_relative_humidity(void *dev, phydat_t *res)
+static int read_relative_humidity(const void *dev, phydat_t *res)
 {
-    si70xx_t *d = (si70xx_t *)dev;
-
-    res->val[0] = (int32_t) si70xx_get_relative_humidity(d);
+    res->val[0] = (int32_t) si70xx_get_relative_humidity((const si70xx_t *)dev);
     res->unit = UNIT_PERCENT;
     res->scale = -2;
 
diff --git a/drivers/tcs37727/tcs37727_saul.c b/drivers/tcs37727/tcs37727_saul.c
index 887198677..d8c45e7a5 100644
--- a/drivers/tcs37727/tcs37727_saul.c
+++ b/drivers/tcs37727/tcs37727_saul.c
@@ -23,12 +23,11 @@
 #include "saul.h"
 #include "tcs37727.h"
 
-static int read(void *dev, phydat_t *res)
+static int read(const void *dev, phydat_t *res)
 {
-    tcs37727_t *d = (tcs37727_t *)dev;
     tcs37727_data_t val;
 
-    tcs37727_read(d, &val);
+    tcs37727_read((const tcs37727_t *)dev, &val);
 
     res->val[0] = (int16_t)val.red;
     res->val[1] = (int16_t)val.green;
diff --git a/drivers/tmp006/tmp006_saul.c b/drivers/tmp006/tmp006_saul.c
index bc817c6f6..194c46430 100644
--- a/drivers/tmp006/tmp006_saul.c
+++ b/drivers/tmp006/tmp006_saul.c
@@ -23,9 +23,10 @@
 #include "saul.h"
 #include "tmp006.h"
 
-static int read_temp(void *dev, phydat_t *res)
+static int read_temp(const void *dev, phydat_t *res)
 {
-    if (tmp006_read_temperature((tmp006_t *)dev, &res->val[0], &res->val[1]) != TMP006_OK) {
+    if (tmp006_read_temperature((const tmp006_t *)dev, &res->val[0],
+                                &res->val[1]) != TMP006_OK) {
         return -ECANCELED;
     }
     res->val[2] = 0;
diff --git a/drivers/tsl2561/tsl2561_saul.c b/drivers/tsl2561/tsl2561_saul.c
index 0e8aebd0d..9a2b4d5a1 100644
--- a/drivers/tsl2561/tsl2561_saul.c
+++ b/drivers/tsl2561/tsl2561_saul.c
@@ -23,11 +23,9 @@
 #include "tsl2561.h"
 #include "xtimer.h"
 
-static int read_illuminance(void *dev, phydat_t *res)
+static int read_illuminance(const void *dev, phydat_t *res)
 {
-    tsl2561_t *d = (tsl2561_t *)dev;
-
-    res->val[0] = tsl2561_read_illuminance(d);
+    res->val[0] = tsl2561_read_illuminance((const tsl2561_t *)dev);
     res->unit = UNIT_LUX;
     res->scale = 0;
     return 1;
diff --git a/drivers/veml6070/veml6070_saul.c b/drivers/veml6070/veml6070_saul.c
index c6f3fcf04..ce7477b83 100644
--- a/drivers/veml6070/veml6070_saul.c
+++ b/drivers/veml6070/veml6070_saul.c
@@ -24,11 +24,9 @@
 #include "veml6070.h"
 #include "xtimer.h"
 
-static int read_uv(void *dev, phydat_t *res)
+static int read_uv(const void *dev, phydat_t *res)
 {
-    veml6070_t *d = (veml6070_t *)dev;
-
-    res->val[0] = veml6070_read_uv(d);
+    res->val[0] = veml6070_read_uv((const veml6070_t *)dev);
     res->unit = UNIT_NONE;
     res->scale = -1;
     return 1;