openwrt/package/boot/arm-trusted-firmware-mvebu/patches/100-fix-plat-marvell-a3720-uart-fix-UART-clock-rate-valu.patch
Andre Heider b40705b677 arm-trusted-firmware-mvebu: update to v2.5
Revert to using the checked in `tbb_linux` image tool binary since building
it drags in the rather big Crypto++ project.

Cherry-pick the post-release UART fixes.

Switch to AUTORELEASE while at it.

Signed-off-by: Andre Heider <a.heider@gmail.com>
2021-07-25 13:52:39 +02:00

61 lines
2.2 KiB
Diff

From 66a7752834382595d26214783ae4698fd1f00bd6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Thu, 13 May 2021 14:53:44 +0200
Subject: [PATCH] fix(plat/marvell/a3720/uart): fix UART clock rate value and
divisor calculation
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
UART parent clock is by default the platform's xtal clock, which is
25 MHz.
The value defined in the driver, though, is 25.8048 MHz. This is a hack
for the suboptimal divisor calculation
Divisor = UART clock / (16 * baudrate)
which does not use rounding division, resulting in a suboptimal value
for divisor if the correct parent clock rate was used.
Change the code for divisor calculation to
Divisor = Round(UART clock / (16 * baudrate))
and change the parent clock rate value to 25 MHz.
The final UART divisor for default baudrate 115200 is not affected by
this change.
(Note that the parent clock rate should not be defined via a macro,
since the xtal clock can also be 40 MHz. This is outside of the scope of
this fix, though.)
Signed-off-by: Pali Rohár <pali@kernel.org>
Change-Id: Iaa401173df87aec94f2dd1b38a90fb6ed0bf0ec6
---
drivers/marvell/uart/a3700_console.S | 3 ++-
plat/marvell/armada/a3k/common/include/platform_def.h | 2 +-
2 files changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/marvell/uart/a3700_console.S
+++ b/drivers/marvell/uart/a3700_console.S
@@ -45,8 +45,9 @@ func console_a3700_core_init
cbz w2, init_fail
/* Program the baudrate */
- /* Divisor = Uart clock / (16 * baudrate) */
+ /* Divisor = Round(Uartclock / (16 * baudrate)) */
lsl w2, w2, #4
+ add w1, w1, w2, lsr #1
udiv w2, w1, w2
and w2, w2, #0x3ff
--- a/plat/marvell/armada/a3k/common/include/platform_def.h
+++ b/plat/marvell/armada/a3k/common/include/platform_def.h
@@ -164,7 +164,7 @@
* PL011 related constants
*/
#define PLAT_MARVELL_BOOT_UART_BASE (MVEBU_REGS_BASE + 0x12000)
-#define PLAT_MARVELL_BOOT_UART_CLK_IN_HZ 25804800
+#define PLAT_MARVELL_BOOT_UART_CLK_IN_HZ 25000000
#define PLAT_MARVELL_CRASH_UART_BASE PLAT_MARVELL_BOOT_UART_BASE
#define PLAT_MARVELL_CRASH_UART_CLK_IN_HZ PLAT_MARVELL_BOOT_UART_CLK_IN_HZ