From c2eb316039dfe6deca27ef1962e67363bcf7f62f Mon Sep 17 00:00:00 2001
From: Alexandre Abadie <alexandre.abadie@inria.fr>
Date: Fri, 25 May 2018 11:55:27 +0200
Subject: [PATCH] drivers/i2c: improve common i2c driver

- fix reag/write regs function (NOSTART/NOSTOP flags missing)
- use ret variable name instead of err (cosmetic)
- split PERIPH_I2C_NEED_READ/WRITE_REGS to simplify cpu side implementation
---
 drivers/periph_common/i2c.c | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/periph_common/i2c.c b/drivers/periph_common/i2c.c
index 4e47439402..dad1be98d2 100644
--- a/drivers/periph_common/i2c.c
+++ b/drivers/periph_common/i2c.c
@@ -24,22 +24,23 @@
 
 #ifdef I2C_NUMOF
 
-#ifdef PERIPH_I2C_NEED_READ_REGS
+#ifdef PERIPH_I2C_NEED_READ_REG
 int i2c_read_reg(i2c_t dev, uint16_t addr, uint16_t reg,
                  void *data, uint8_t flags)
 {
     return i2c_read_regs(dev, addr, reg, data, 1, flags);
 }
+#endif /* PERIPH_I2C_NEED_READ_REG */
 
+#ifdef PERIPH_I2C_NEED_READ_REGS
 int i2c_read_regs(i2c_t dev, uint16_t addr, uint16_t reg,
                   void *data, size_t len, uint8_t flags)
 {
-    int8_t err;
     /* First set ADDR and register with no stop */
-    err = i2c_write_bytes(dev, addr, &reg, (flags & I2C_REG16) ? 2 : 1,
-                          flags & I2C_NOSTOP );
-    if (err < 0) {
-        return err;
+    int8_t ret = i2c_write_bytes(dev, addr, &reg, (flags & I2C_REG16) ? 2 : 1,
+                                 flags | I2C_NOSTOP);
+    if (ret < 0) {
+        return ret;
     }
     /* Then get the data from device */
     return i2c_read_bytes(dev, addr, data, len, flags);
@@ -56,25 +57,26 @@ int i2c_write_byte(i2c_t dev, uint16_t addr, uint8_t data, uint8_t flags)
     return i2c_write_bytes(dev, addr, &data, 1, flags);
 }
 
-#ifdef PERIPH_I2C_NEED_WRITE_REGS
+#ifdef PERIPH_I2C_NEED_WRITE_REG
 int i2c_write_reg(i2c_t dev, uint16_t addr, uint16_t reg,
                   uint8_t data, uint8_t flags)
 {
     return i2c_write_regs(dev, addr, reg, &data, 1, flags);
 }
+#endif /* PERIPH_I2C_NEED_WRITE_REG */
 
+#ifdef PERIPH_I2C_NEED_WRITE_REGS
 int i2c_write_regs(i2c_t dev, uint16_t addr, uint16_t reg,
                    const void *data, size_t len, uint8_t flags)
 {
-    int8_t err;
     /* First set ADDR and register with no stop */
-    err = i2c_write_bytes(dev, addr, &reg, (flags & I2C_REG16) ? 2 : 1,
-                          flags & I2C_NOSTOP );
-    if (err < 0) {
-        return err;
+    int8_t ret = i2c_write_bytes(dev, addr, &reg, (flags & I2C_REG16) ? 2 : 1,
+                                 flags | I2C_NOSTOP);
+    if (ret < 0) {
+        return ret;
     }
     /* Then write data to the device */
-    return i2c_write_bytes(dev, addr, data, len, flags);
+    return i2c_write_bytes(dev, addr, data, len, flags | I2C_NOSTART);
 }
 #endif /* PERIPH_I2C_NEED_WRITE_REGS */