Contribution description

This fixes the handling of periph_flashpage for stm32_common. If a module would have required periph_flashpage it would not have worked and if an application would have said declared an optional feature it would not have worked either.

The does not fix the global handling of CPU dependencies but replaces using modules/periphs to declare module internal only selection of source files to only source file inclusion.
The fact that they are described as module is never used in the code.

This also fixes the i2c handling the same way.

More description in the commit messages.

Testing procedure

Not used that they are declared as modules:

There is no output for

git grep -e MODULE_PERIPH_I2C_1 -e MODULE_PERIPH_I2C_2 -e MODULE_PERIPH_FLASH_COMMON

Flashpage handling

Flashpage uses flash_common

This does not break master handling for periph_flashpage:

Both with master and this PR, flash_common is used

cd tests/periph_flashpage
make BOARD=iotlab-m3 clean all &>/dev/null && test -f bin/iotlab-m3/stm32_common_periph/flash_common.o && echo flash_common_compiled || echo ERROR_no_flash_common
flash_common_compiled

Handling dependency in Makefile.dep

With this diff applied, as if a module depended on it in Makefile.dep, it now works with this PR.

diff --git a/Makefile.dep b/Makefile.dep
index 4c55e2e27..92b939f42 100644
--- a/Makefile.dep
+++ b/Makefile.dep
@@ -788,6 +788,8 @@ ifneq (,$(filter periph_gpio_irq,$(USEMODULE)))
   FEATURES_REQUIRED += periph_gpio
 endif

+FEATURES_REQUIRED += periph_flashpage
+
 # always select gpio (until explicit dependencies are sorted out)
 FEATURES_OPTIONAL += periph_gpio

Compiling in examples/hello-world with the same test command it succeeds with this PR.
With master we get ERROR_no_flash_common

Flashpage works with FEATURES_OPTIONAL

With this PR, it also works with FEATURES_OPTIONAL += periph_flashpage in an application:

cd examples/hello-world
FEATURES_OPTIONAL=periph_flashpage make BOARD=iotlab-m3 clean all &>/dev/null && test -f bin/iotlab-m3/stm32_common_periph/flash_common.o && echo flash_common_compiled || echo ERROR_no_flash_common
flash_common_compiled

With master we get ERROR_no_flash_common

eeprom handling

The same tests can be run by using periph_eeprom feature, BOARD b-l072z-lrwan1 and tests/periph_eeprom.

i2c handling

The same i2c implementation is still used with this PR as with master.

cd tests/periph_i2c
make BOARD=nucleo-f091rc clean all &>/dev/null; ls bin/nucleo-f091rc/stm32_common_periph/i2c_1.o
bin/nucleo-f091rc/stm32_common_periph/i2c_1.o
make BOARD=iotlab-m3 clean all &>/dev/null; ls bin/iotlab-m3/stm32_common_periph/i2c_2.o
bin/iotlab-m3/stm32_common_periph/i2c_2.o

Issues/PRs references

Previous attempt to fix it:

#9892
#9913 (by fixing dependency handling globally)
#10146

Required for PRs

#9969
#8774