serial: atmel_usart: Use fixed clock value in SPL version with DM_SERIAL

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>
This commit is contained in:
Stefan Roese 2019-04-03 15:24:19 +02:00 committed by Eugen Hristev
parent ce4d04af99
commit e567dfb213
2 changed files with 21 additions and 0 deletions

View File

@ -508,6 +508,15 @@ 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 ATMEL_USART && SPL && !SPL_CLK
default 132096000 if ARCH_AT91
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.
config BCM283X_MU_SERIAL
bool "Support for BCM283x Mini-UART"
depends on DM_SERIAL && ARCH_BCM283X

View File

@ -218,6 +218,17 @@ static const struct dm_serial_ops atmel_serial_ops = {
.setbrg = atmel_serial_setbrg,
};
#if defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_CLK)
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 = CONFIG_SPL_UART_CLOCK;
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)
{