From e4074602439ca64ab531a7cdc265975b082e59af Mon Sep 17 00:00:00 2001
From: Marian Buschsieweke <marian.buschsieweke@posteo.net>
Date: Fri, 24 Nov 2023 10:03:07 +0100
Subject: [PATCH] cpu/nrf51: fix periph_i2c driver

The `i2c_read_bytes()` and `i2c_write_bytes()` function return the
number of bytes written / read, instead of `0` as the API contract
says. This fixes the issue.
---
 cpu/nrf51/periph/i2c.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/cpu/nrf51/periph/i2c.c b/cpu/nrf51/periph/i2c.c
index cd2efd09e9..4bfd801655 100644
--- a/cpu/nrf51/periph/i2c.c
+++ b/cpu/nrf51/periph/i2c.c
@@ -103,7 +103,7 @@ static int write(i2c_t dev, uint16_t addr, const void *data, int len,
         }
     }
 
-    return len;
+    return 0;
 }
 
 void i2c_init(i2c_t dev)
@@ -198,7 +198,7 @@ int i2c_read_bytes(i2c_t dev, uint16_t address, void *data, size_t length,
     while (i2c(dev)->EVENTS_STOPPED == 0) {}
     NRF_PPI->CHENCLR = (1 << i2c_config[dev].ppi);
 
-    return length;
+    return 0;
 }
 
 int i2c_read_regs(i2c_t dev, uint16_t address, uint16_t reg,