On Sat, Nov 28, 2020 at 7:54 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
> 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>
Are there any specific prerequisites? linux-next?
When I apply this and try to compile for an ARMv7 target I get
a lot of noise and an error:
In file included from <command-line>:0:0:
../drivers/iio/gyro/mpu3050-core.c: In function ‘mpu3050_hw_init’:
../include/linux/bits.h:36:11: warning: right shift count is negative
[-Wshift-count-negative]
(~UL(0) >> (BITS_PER_LONG - 1 - (h))))
^
./../include/linux/compiler_types.h:299:9: note: in definition of
macro ‘__compiletime_assert’
if (!(condition)) \
^~~~~~~~~
./../include/linux/compiler_types.h:319:2: note: in expansion of macro
‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:39:37: note: in expansion of macro
‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^~~~~~~~~~~~~~~~~~
../include/linux/bitfield.h:46:3: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(!__builtin_constant_p(_mask), \
^~~~~~~~~~~~~~~~
../include/linux/bitfield.h:108:3: note: in expansion of macro
‘__BF_FIELD_CHECK’
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^~~~~~~~~~~~~~~~
../include/linux/dev_printk.h:118:33: note: in expansion of macro ‘FIELD_GET’
_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
^~~~~~~~~~~
../include/linux/bits.h:38:31: note: in expansion of macro ‘__GENMASK’
(GENMASK_INPUT_CHECK(h, l) + __GENMASK(h, l))
^~~~~~~~~
../include/linux/dev_printk.h:118:33: note: in expansion of macro ‘GENMASK’
_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
^~~~~~~~~~~
../drivers/iio/gyro/mpu3050-core.c:830:2: note: in expansion of macro ‘dev_info’
dev_info(mpu3050->dev,
^~~~~~~~
../include/linux/bits.h:36:11: warning: right shift count is negative
[-Wshift-count-negative]
(~UL(0) >> (BITS_PER_LONG - 1 - (h))))
^
./../include/linux/compiler_types.h:299:9: note: in definition of
macro ‘__compiletime_assert’
if (!(condition)) \
^~~~~~~~~
./../include/linux/compiler_types.h:319:2: note: in expansion of macro
‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
^~~~~~~~~~~~~~~~~~~
../include/linux/build_bug.h:39:37: note: in expansion of macro
‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^~~~~~~~~~~~~~~~~~
../include/linux/bitfield.h:48:3: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG((_mask) == 0, _pfx "mask is zero"); \
^~~~~~~~~~~~~~~~
../include/linux/bitfield.h:108:3: note: in expansion of macro
‘__BF_FIELD_CHECK’
__BF_FIELD_CHECK(_mask, _reg, 0U, "FIELD_GET: "); \
^~~~~~~~~~~~~~~~
../include/linux/dev_printk.h:118:33: note: in expansion of macro ‘FIELD_GET’
_dev_info(dev, dev_fmt(fmt), ##__VA_ARGS__)
^~~~~~~~~~~
(...)
Yours,
Linus Walleij
