On 03.04.2019 13:58, Stefan Roese wrote:
Hi Eugen,
On 03.04.19 12:52, Eugen.Hristev@microchip.com wrote:
On 02.04.2019 14:21, Stefan Roese wrote:
This patch adds an alterative SPL version of atmel_serial_enable_clk(). This enables the usage of this driver without full clock support (in drivers and DT nodes). This saves some space in the SPL image.
Please note that this fixed clock support is only added to the SPL code in the DM_SERIAL part of this file. All boards not using SPL & DM_SERIAL should not be affected.
This patch also introduces CONFIG_SPL_UART_CLOCK for the fixed UART input clock. It defaults to 132096000 for ARCH_AT91 but can be set to a different value if needed.
Signed-off-by: Stefan Roese sr@denx.de Cc: Heiko Schocher hs@denx.de Cc: Andreas Bießmann andreas@biessmann.org Cc: Eugen Hristev eugen.hristev@microchip.com
v4:
- Restrict SPL_UART_CLOCK on SPL && !SPL_CLK
- Provide default value for non AT91 platforms to not break the
build
- Fix typo in Kconfig text
v3:
- Depend fixed clock atmel_serial_enable_clk() function also on
!CONFIG_SPL_CLK so that board with full clocj support in SPL can still use the normal function here
- Introcude CONFIG_SPL_UART_CLOCK and use this Kconfig option instead
of the hardcoded value
v2:
- Reword patch subject and commit text to make it more clear, that
this change only affects ports with SPL and DM_SERIAL enabled drivers/serial/Kconfig | 10 ++++++++++ drivers/serial/atmel_usart.c | 12 ++++++++++++ 2 files changed, 22 insertions(+)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 887cd687c0..79fb397cf9 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -508,6 +508,16 @@ config ATMEL_USART configured in the device tree, and input clock frequency can be got from the clk node. +config SPL_UART_CLOCK + int "SPL fixed UART input clock" + depends on SPL && !SPL_CLK + default 132096000 if ARCH_AT91 + default 0 + help + Provide a fixed clock value as input to the UART controller. This + might be needed on platforms which can't enable CONFIG_SPL_CLK + because of SPL image size restrictions.
Hi Stefan,
Looking again over this, the Kconfig you added is useless and has no effect unless ATMEL_USART driver... Can you make it to depend on atmel usart or be named ATMEL_SPL_UART_CLOCK if this is not needed for anything else whatsoever (no other platforms/drivers) This way nobody gets confused that by enabling this Kconfig on their platform, something changes (like a fixed clock for their serial in SPL, which will not happen).
My first intention was to add this Kconfig option as a generic one, which can be used by other (non-AT91) platforms as well. This is the reasoning for its name and the non-exclusive availability.
But I have no hard feelings here. If nobody sees any use of this Kconfig option on other platforms (hard for us to guess), then I can definitely make your suggested changes from above.
Makes sense, but as it is now, it has no effect on other platforms. So I think it's best to make it a generic name indeed, but dependent on ATMEL_USART then... and other platforms can add their dependency once and if they implement it.
Sounds good to you ?
Thanks, Stefan