On 20.03.2019 09:30, Stefan Roese wrote:
On 20.03.19 08:25, Eugen.Hristev@microchip.com wrote:
On 19.03.2019 17:56, Stefan Roese wrote:
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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.
If some boards need a different clock than the one provided with this patch, then support for this needs to be added later.
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
drivers/serial/atmel_usart.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/serial/atmel_usart.c b/drivers/serial/atmel_usart.c index aa8cdff840..049172baef 100644 --- a/drivers/serial/atmel_usart.c +++ b/drivers/serial/atmel_usart.c @@ -218,6 +218,17 @@ static const struct dm_serial_ops atmel_serial_ops = { .setbrg = atmel_serial_setbrg, }; +#ifdef CONFIG_SPL_BUILD +static int atmel_serial_enable_clk(struct udevice *dev) +{ + struct atmel_serial_priv *priv = dev_get_priv(dev);
+ /* Use fixed clock value in SPL */ + priv->usart_clk_rate = 132096000;
Hi Stefan,
Does this mean that the SPL will work *if and only if* this clock matches the board's clock, for all at91 boards? (thus, boards having a different clock , the serial will not function correctly anymore ?)
Yes, thats the case (as explained in the commit message above). For this to work on all boards we need to add some macro like CONFIG_DEBUG_UART_CLOCK which can be set by each board port individually.
If agreed on such an idea, I can add this new Kconfig option in a later version of this patch. Perhaps something like CONFIG_SPL_UART_CLOCK?
If this breaks the serial for the other boards... it's not good. I think either we do a patch that fixes a thing, but does not break other functionality... or we leave it as is. Would hate to see serial failing on all other SPLs
How big is the SPL reduction with this ? Maybe just keep old code in case CONFIG_SPL_UART_CLOCK is *not* defined ? and if defined, use the hardcoded value from config ?
Eugen
Thanks, Stefan