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authorLee Leahy <leroy.p.leahy@intel.com>2016-05-04 13:13:20 -0700
committerLeroy P Leahy <leroy.p.leahy@intel.com>2016-05-09 18:44:47 +0200
commit148762110c8a00c88b8e0326ec69dc7392bf3739 (patch)
tree75073d645ac062177a466e9451db8796fd1fdde8 /src/include
parenta63398059bdd5911e9e5e670873183cdb376acf7 (diff)
downloadcoreboot-148762110c8a00c88b8e0326ec69dc7392bf3739.tar.xz
drivers/uart: Enable override for input clock divider
Allow the platform to override the input clock divider by adding the uart_input_clock_divider routine. This routine combines the baud-rate oversample divider with any other input clock divider. The default routine returns 16 which is the standard baud-rate oversampling value. A platform may override this default "weak" routine by providing a new routine and selecting UART_OVERRIDE_INPUT_CLOCK_DIVIDER. This works around ROMCC not supporting weak routines. Testing on Galileo: * Edit the src/mainboard/intel/galileo/Makefile.inc file: * Add "select ADD_FSP_PDAT_FILE" * Add "select ADD_FSP_RAW_BIN" * Add "select ADD_RMU_FILE" * Place the FSP.bin file in the location specified by CONFIG_FSP_FILE * Place the pdat.bin files in the location specified by CONFIG_FSP_PDAT_FILE * Place the rmu.bin file in the location specified by CONFIG_RMU_FILE * Build EDK2 CorebootPayloadPkg/CorebootPayloadPkgIa32.dsc to generate UEFIPAYLOAD.fd * Testing is successful when CorebootPayloadPkg is able to properly initialize the serial port without using built-in values. Change-Id: Ieb6453b045d84702b8f730988d0fed9f253f63e2 Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com> Reviewed-on: https://review.coreboot.org/14611 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/include')
-rw-r--r--src/include/console/uart.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/src/include/console/uart.h b/src/include/console/uart.h
index 8458086d49..a3d650b500 100644
--- a/src/include/console/uart.h
+++ b/src/include/console/uart.h
@@ -35,6 +35,10 @@ unsigned int default_baudrate(void);
unsigned int uart_baudrate_divisor(unsigned int baudrate,
unsigned int refclk, unsigned int oversample);
+/* Returns the oversample divisor multiplied by any other divisors that act
+ * on the input clock
+ */
+unsigned int uart_input_clock_divider(void);
void uart_init(int idx);
void uart_tx_byte(int idx, unsigned char data);