From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Inspired by Andy Shevchenko's proposal to use get_unaligned_leXX().
The whole one time programable memory is treated as a single 64bit
little endian value. Thus we can avoid a lot of messy handling
of fields overlapping byte boundaries by just loading and manipulating
it as an __le64 converted to a u64. That lets us just use FIELD_GET()
and GENMASK() to extract the values desired.
Note only build tested.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/iio/gyro/mpu3050-core.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/drivers/iio/gyro/mpu3050-core.c b/drivers/iio/gyro/mpu3050-core.c
index 00e58060968c..6380fc1bdee3 100644
--- a/drivers/iio/gyro/mpu3050-core.c
+++ b/drivers/iio/gyro/mpu3050-core.c
@@ -13,6 +13,7 @@
* TODO: add support for setting up the low pass 3dB frequency.
*/
+#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/err.h>
@@ -784,7 +785,8 @@ static int mpu3050_read_mem(struct mpu3050 *mpu3050,
static int mpu3050_hw_init(struct mpu3050 *mpu3050)
{
int ret;
- u8 otp[8];
+ __le64 otp_le;
+ u64 otp;
/* Reset */
ret = regmap_update_bits(mpu3050->map,
@@ -815,29 +817,31 @@ static int mpu3050_hw_init(struct mpu3050 *mpu3050)
MPU3050_MEM_USER_BANK |
MPU3050_MEM_OTP_BANK_0),
0,
- sizeof(otp),
- otp);
+ sizeof(otp_le),
+ (u8 *)&otp_le);
if (ret)
return ret;
/* This is device-unique data so it goes into the entropy pool */
- add_device_randomness(otp, sizeof(otp));
+ add_device_randomness(&otp_le, sizeof(otp_le));
+
+ otp = le64_to_cpu(otp_le);
dev_info(mpu3050->dev,
- "die ID: %04X, wafer ID: %02X, A lot ID: %04X, "
- "W lot ID: %03X, WP ID: %01X, rev ID: %02X\n",
+ "die ID: %04lX, wafer ID: %02lX, A lot ID: %04lX, "
+ "W lot ID: %03lX, WP ID: %01lX, rev ID: %02lX\n",
/* Die ID, bits 0-12 */
- (otp[1] << 8 | otp[0]) & 0x1fff,
+ FIELD_GET(GENMASK(12, 0), otp),
/* Wafer ID, bits 13-17 */
- ((otp[2] << 8 | otp[1]) & 0x03e0) >> 5,
+ FIELD_GET(GENMASK(17, 13), otp),
/* A lot ID, bits 18-33 */
- ((otp[4] << 16 | otp[3] << 8 | otp[2]) & 0x3fffc) >> 2,
+ FIELD_GET(GENMASK(33, 18), otp),
/* W lot ID, bits 34-45 */
- ((otp[5] << 8 | otp[4]) & 0x3ffc) >> 2,
+ FIELD_GET(GENMASK(45, 34), otp),
/* WP ID, bits 47-49 */
- ((otp[6] << 8 | otp[5]) & 0x0380) >> 7,
+ FIELD_GET(GENMASK(49, 47), otp),
/* rev ID, bits 50-55 */
- otp[6] >> 2);
+ FIELD_GET(GENMASK(55, 50), otp));
return 0;
}
--
2.29.2
