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/components/drivers/hwtimer/hwtimer.c b/components/drivers/hwtimer/hwtimer.c
index 189ef7df49..f8e1a35275 100644
--- a/components/drivers/hwtimer/hwtimer.c
+++ b/components/drivers/hwtimer/hwtimer.c
@@ -143,7 +143,7 @@ static rt_err_t rt_hwtimer_close(struct rt_device *dev)
     return result;
 }
 
-static rt_size_t rt_hwtimer_read(struct rt_device *dev, rt_off_t pos, void *buffer, rt_size_t size)
+static rt_ssize_t rt_hwtimer_read(struct rt_device *dev, rt_off_t pos, void *buffer, rt_size_t size)
 {
     rt_hwtimer_t *timer;
     rt_hwtimerval_t tv;
@@ -175,7 +175,7 @@ static rt_size_t rt_hwtimer_read(struct rt_device *dev, rt_off_t pos, void *buff
     return size;
 }
 
-static rt_size_t rt_hwtimer_write(struct rt_device *dev, rt_off_t pos, const void *buffer, rt_size_t size)
+static rt_ssize_t rt_hwtimer_write(struct rt_device *dev, rt_off_t pos, const void *buffer, rt_size_t size)
 {
     rt_base_t level;
     rt_uint32_t t;