The issue is introduced in 571864e8ae. The
esp_flash API tries to clear the QE bit when the flash is not working in
quad modes.
However this introduces a regression, compared to earlier versions and
the legacy API. When the chip is not detected, the generic chip driver
is used, which cannot 100% handle the QE bit properly for all flash
vendors. There may be some flash chips (e.g. MXIC) that can be used in
dual modes by legacy API, but output wrong data when the esp_flash API
clears the QE bit in a wrong way.
This commit reverts the QE force clearing behavior, so that it's safer
for the generic chip driver to work under dual modes.
There used to be dummy phase before out phase in common command
transactions. This corrupts the data.
The code before never actually operate (clear) the QE bit, once it finds
the QE bit is set. It's hard to check whether the QE set/disable
functions work well.
This commit:
1. Cancel the dummy phase
2. Set and clear the QE bit according to chip settings, allowing tests
for QE bits. However for some chips (Winbond for example), it's not
forced to clear the QE bit if not able to.
3. Also refactor to allow chip_generic and other chips to share the same
code to read and write qe bit; let common command and read command share
configure_host_io_mode.
4. Rename read mode to io mode since maybe we will write data with quad
mode one day.
Add support for get write protection support, fixed the duplicated
set_write_protection link.
All the write_protection check in the top layer are removed. The lower
levels (chip) should ensure to disable write protection before the
operation start.
