Serial Flash: call spi_flash_free more coherently

Some board require spi_flash_free to be called after all the accesses, in order, for instance, to restore the pin multiplexing configuration in the case where the SPI pins are multiplexed.

This patch series tries to enhance this. Patch 1 adds spi_flash_free calls to env_sf so that the SPI interface is always "cleaned up" after the env read/writes. Patch 2 adds a 'sf release' command that implicitly calls spi_flash_free and is thus the pendant of 'sf probe'. Patch 3 uses the 'sf command' for the km_arm board scripts.

The whole series had already been sent more than 2 years ago [1] but it was rejected without any feedback. So I send this rebased v2 so that it finally gets reviewed and merged. This was not successfull either, again without any given feedback. So this is a 3rd attempt to get some feedback to get this mailined.

[1] http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/169723

Changes in v3:
- Rebased on v2015.10
- Rebased on v2015.10

Changes in v2:
- Rebased on v2014.10

Valentin Longchamp (3):
cmd_sf: add 'release' command
env_sf: generalize call to spi_flash_free after accesses
km_arm: call 'sf release' in the newenv and update scripts

 common/cmd_sf.c             | 11 +++++++++++
 common/env_sf.c             | 28 ++++++++++++++--------------
 include/configs/km/km_arm.h |  6 ++++--
 3 files changed, 29 insertions(+), 16 deletions(-)

1.8.3.1