diff options
authorPali Rohár <pali@kernel.org>2021-05-13 15:11:06 +0200
committerpali <pali@kernel.org>2021-06-01 16:32:10 +0200
commitb9185c75f7ec2b600ebe0d49281e216a2456b764 (patch)
parent66a7752834382595d26214783ae4698fd1f00bd6 (diff)
fix(plat/marvell/a3720/uart): fix configuring UART clock
When configuring the UART_BAUD_REG register, the function console_a3700_core_init() currently only changes the baud divisor field, leaving other fields to their previous value. This is incorrect, because the baud divisor is computed with the assumption that the parent clock rate is 25 MHz, and since the other fields in this register configure the parent clock, which could have been changed by U-Boot or Linux. Fix this function to also configure the other fields so that the UART parent clock is selected to be the xtal clock. For example without this change TF-A prints only ERROR: a3700_system_off needs to be implemented followed by garbage after plat_crash_console_init() is called. After applying this change instead of garbage it also print crash info: PANIC at PC : 0x0000000004023800 Signed-off-by: Pali Rohár <pali@kernel.org> Change-Id: I72f338355cc60d939b8bb978d9c7fdd576416b81
1 files changed, 2 insertions, 5 deletions
diff --git a/drivers/marvell/uart/a3700_console.S b/drivers/marvell/uart/a3700_console.S
index ad2ccf216d..218fd861ce 100644
--- a/drivers/marvell/uart/a3700_console.S
+++ b/drivers/marvell/uart/a3700_console.S
@@ -49,12 +49,9 @@ func console_a3700_core_init
lsl w2, w2, #4
add w1, w1, w2, lsr #1
udiv w2, w1, w2
- and w2, w2, #0x3ff
+ and w2, w2, #0x3ff /* clear all other bits to use default clock */
- ldr w3, [x0, #UART_BAUD_REG]
- bic w3, w3, 0x3ff
- orr w3, w3, w2
- str w3, [x0, #UART_BAUD_REG]/* set baud rate divisor */
+ str w2, [x0, #UART_BAUD_REG]/* set baud rate divisor */
/* Set UART to default 16X scheme */
mov w3, #0