From cd62322a9767f9a0bcf855123c478187e38a10f4 Mon Sep 17 00:00:00 2001 From: Irina Tirdea Date: Mon, 13 Apr 2015 18:40:48 +0300 Subject: iio: accel: mma9553: fix endianness issue when reading status Refactor code for simplicity and clarity. This also fixes an endianness issue with the original code. When reading multiple registers, the received buffer of 16-bytes words is little endian (status, step count). On big endian machines, casting them to u32 would result in reversed order in the buffer (step count, status) leading to incorrect values for step count and activity. Signed-off-by: Irina Tirdea Reported-by: Hartmut Knaack Signed-off-by: Jonathan Cameron diff --git a/drivers/iio/accel/mma9553.c b/drivers/iio/accel/mma9553.c index 2df1af7..607dbfc 100644 --- a/drivers/iio/accel/mma9553.c +++ b/drivers/iio/accel/mma9553.c @@ -316,22 +316,19 @@ static int mma9553_set_config(struct mma9553_data *data, u16 reg, static int mma9553_read_activity_stepcnt(struct mma9553_data *data, u8 *activity, u16 *stepcnt) { - u32 status_stepcnt; - u16 status; + u16 buf[2]; int ret; ret = mma9551_read_status_words(data->client, MMA9551_APPID_PEDOMETER, - MMA9553_REG_STATUS, sizeof(u32), - (u16 *) &status_stepcnt); + MMA9553_REG_STATUS, sizeof(u32), buf); if (ret < 0) { dev_err(&data->client->dev, "error reading status and stepcnt\n"); return ret; } - status = status_stepcnt & MMA9553_MASK_CONF_WORD; - *activity = mma9553_get_bits(status, MMA9553_MASK_STATUS_ACTIVITY); - *stepcnt = status_stepcnt >> 16; + *activity = mma9553_get_bits(buf[0], MMA9553_MASK_STATUS_ACTIVITY); + *stepcnt = buf[1]; return 0; } -- cgit v0.10.2