Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

drivers: flash: stm32f4: resets OPTCR register #18296

Closed
wants to merge 1 commit into from
Closed

drivers: flash: stm32f4: resets OPTCR register #18296

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
22 changes: 22 additions & 0 deletions drivers/flash/flash_stm32.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -329,6 +329,28 @@ static int stm32_flash_init(struct device *dev)
LL_AHB3_GRP1_EnableClock(LL_AHB3_GRP1_PERIPH_HSEM);
#endif /* CONFIG_SOC_SERIES_STM32WBX */

#ifdef CONFIG_SOC_SERIES_STM32F4X
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Since we'll need dedicated code for each series, this will soon get unreadable.
For code genericity, please use a function that will be implemented in each series dedicated file.

/*
* make sure that user options are disabled
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

"make sure that user options are disabled".
Well, this is your particular case. Other users may have correctly configured options they want to rely on.
And since this is the purpose of the option bytes, this should rather be the default behavior.
So I see this as a particular optional feature that should be default n.

Copy link
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I leave it to the ST guys to maintain the stm32 drivers. I quickly adopted the coding style from the code above. Think maybe a reset function for the flash driver would be useful. This function can be implemented different for each stm32.

* they affecting if flash read/write operations
* are allowed on the flash for spezific sectors
*/
struct stm32f4x_flash *regs = FLASH_STM32_REGS(dev);

/* check if we are not in the typical reset config*/
if (regs->optcr != 0x0FFFFFED) {
/* clear OPTLOCK */
regs->optkeyr = 0x08192A3B;
regs->optkeyr = 0x4C5D6E7F;
if (regs->optkeyr & 1) {
/* still locked so we failed*/
return -EIO;
}
/* write reset config register content*/
regs->optcr = 0x0FFFFFED;
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looking to 2 F4 variants ref man, I've found reset value to 0x0FFFAAED

Copy link
Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

check RM0402 from st, it's the reference manual for the stm32f412 series. On page 77 you will find the value.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This would work for F412 but not F401 not F446... at least, while this code will be used for all F4 series.

}
#endif

k_sem_init(&p->sem, 1, 1);

return flash_stm32_write_protection(dev, false);
Expand Down