#131 [patch] add -t command line option to specify i2c communication timeout

[Yann Sionneau]

Hello,
This patch adds -t timeout command line option to add i2c timeout.
This makes erase and flashing to work with i2c designware IP + stm32f723 combo.
Without this patch, I was able to dump flash content but not erase/write.
I was getting i2c designware driver timeouts, due to long clock stretches (seen with logic analyzer).

[Tormod Volden]

This version rounds up to next multiple of 10 ms.

[Yann Sionneau]

This patch looks good to me :)

[Anonymous]

When will this patch be applied to the mainline? At the moment the STM32F756VG has the same issue and cannot be programmed over i2c.

[Tormod Volden]

Do ST's own tools work around this? It is pretty bad that they haven't responded to Yann's customer request.

[Yann Sionneau]

I think our ST tools (stflash) use stlink probe which itself I am guessing is using JTAG.
With another tool (dfu util) we use stm32's bootloader USB DFU function.

[Yann Sionneau]

I would be in favor of integrating this patch, we use it as a local patch and so far it works great to flash our stm32f723.

[Yann Sionneau]

I am dropping by just to say that ST released a new version of AN4221 where bootloader v1.2 is "documented" https://www.st.com/resource/en/application_note/an4221-i2c-protocol-used-in-the-stm32-bootloader-stmicroelectronics.pdf