[U-Boot] [PATCH 03/12 v2] serial: atmel_usart: Use fixed clock value in SPL version with DM_SERIAL

[Stefan Roese]

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.

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 at denx.de>
Cc: Heiko Schocher <hs at denx.de>
Cc: Andreas Bießmann <andreas at biessmann.org>
Cc: Eugen Hristev <eugen.hristev at microchip.com>
---
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/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;
+
+	return 0;
+}
+#else
 static int atmel_serial_enable_clk(struct udevice *dev)
 {
 	struct atmel_serial_priv *priv = dev_get_priv(dev);
@@ -245,6 +256,7 @@ static int atmel_serial_enable_clk(struct udevice *dev)
 
 	return 0;
 }
+#endif
 
 static int atmel_serial_probe(struct udevice *dev)
 {
-- 
2.21.0