On 25.03.19 15:27, eugen.hris...@microchip.com wrote:
On 20.03.2019 09:30, Stefan Roese wrote:
On 20.03.19 08:25, eugen.hris...@microchip.com wrote:
On 19.03.2019 17:56, Stefan Roese wrote:
External E-Mail
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 <s...@denx.de>
Cc: Heiko Schocher <h...@denx.de>
Cc: Andreas Bießmann <andr...@biessmann.org>
Cc: Eugen Hristev <eugen.hris...@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.
Currently it breaks no other board port, as no other board port uses
SPL with DM_SERIAL support on AT91, AFAICT. So no breakage is introduced
with this patch (please correct me if I'm wrong).
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
Again, this is only for ports that will move to DM_SERIAL in SPL in
the future.
How big is the SPL reduction with this ?
Frankly I can't tell.
Maybe just keep old code in case CONFIG_SPL_UART_CLOCK is *not* defined ?
and if defined, use the hardcoded value from config ?
Which old code are you referring to? Again, this code is new for the
newly introduced SPL & DM_SERIAL support in this driver.
Thanks,
Stefan
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