rt_device_write/read return data type as rt_ssize_t

rt_ssize_t can give negative error code, which follows the unix style correctly

1 files changed, 2 insertions, 2 deletions

diff --git a/libcpu/ppc/ppc405/serial.c b/libcpu/ppc/ppc405/serial.c
index 1fc9039769..3112a1823b 100644
--- a/libcpu/ppc/ppc405/serial.c
+++ b/libcpu/ppc/ppc405/serial.c
@@ -99,7 +99,7 @@ static rt_err_t rt_serial_control(rt_device_t dev, int cmd, void *args)
     return RT_EOK;
 }
 
-static rt_size_t rt_serial_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
+static rt_ssize_t rt_serial_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
 {
     rt_uint8_t* ptr;
     struct rt_ppc405_serial* device;
@@ -156,7 +156,7 @@ static rt_size_t rt_serial_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_
     return (rt_size_t)ptr - (rt_size_t)buffer;
 }
 
-static rt_size_t rt_serial_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
+static rt_ssize_t rt_serial_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
 {
     char *ptr;
     struct rt_ppc405_serial* device;