From: chalianis1@gmail.com
To: s.hauer@pengutronix.de
Cc: barebox@lists.infradead.org, Chali Anis <chalianis1@gmail.com>
Subject: [PATCH] bcm283x: debug_ll: add RaspberryPi 4 PL011 UART support
Date: Mon, 24 Aug 2026 00:13:29 +0200 [thread overview]
Message-ID: <20260823221329.513717-1-chalianis1@gmail.com> (raw)
From: Chali Anis <chalianis1@gmail.com>
Add a DEBUG_RPI4_UART choice for low-level debugging on RaspberryPi 4
and CM4 boards via the PL011 UART (uart0), for setups where the
disable-bt overlay routes it onto the GPIO header pins instead of the
mini UART. Mirrors the existing RPi1/RPi2-3 PL011 debug_ll support:
firmware configures the UART, so debug_ll_init() is a no-op.
Assisted-by: Claude Sonnet 5
Signed-off-by: Chali Anis <chalianis1@gmail.com>
---
common/Kconfig.debug_ll | 10 ++++++++++
include/mach/bcm283x/debug_ll.h | 10 ++++++++++
include/mach/bcm283x/platform.h | 1 +
3 files changed, 21 insertions(+)
diff --git a/common/Kconfig.debug_ll b/common/Kconfig.debug_ll
index 8445b4be0872..5a28dc4a61e7 100644
--- a/common/Kconfig.debug_ll
+++ b/common/Kconfig.debug_ll
@@ -275,6 +275,16 @@ config DEBUG_RPI2_3_UART
Say Y here if you want low-level debugging support on
RaspberryPi 2 and 3 boards.
+config DEBUG_RPI4_UART
+ bool "RaspberryPi 4 PL011 UART"
+ depends on ARCH_BCM283X
+ select DEBUG_BCM283X_UART
+ help
+ Say Y here if you want low-level debugging support on
+ RaspberryPi 4 / CM4 boards using the PL011 UART (uart0),
+ e.g. when the disable-bt overlay routes it onto the GPIO
+ header pins instead of the mini UART.
+
config DEBUG_RPI3_MINI_UART
bool "RaspberryPi 3 mini UART"
depends on ARCH_BCM283X
diff --git a/include/mach/bcm283x/debug_ll.h b/include/mach/bcm283x/debug_ll.h
index a6a3b8f08856..3f2d5ddc9857 100644
--- a/include/mach/bcm283x/debug_ll.h
+++ b/include/mach/bcm283x/debug_ll.h
@@ -40,6 +40,16 @@ static inline void debug_ll_init(void)
#define DEBUG_LL_UART_ADDR BCM2836_PL011_BASE
#include <debug_ll/pl011.h>
+#elif defined CONFIG_DEBUG_RPI4_UART
+
+static inline void debug_ll_init(void)
+{
+ /* Configured by ROM */
+}
+
+#define DEBUG_LL_UART_ADDR BCM2711_PL011_BASE
+#include <debug_ll/pl011.h>
+
#elif defined CONFIG_DEBUG_RPI3_MINI_UART
static inline uint8_t debug_ll_read_reg(void __iomem *base, int reg)
diff --git a/include/mach/bcm283x/platform.h b/include/mach/bcm283x/platform.h
index b957ac8de35e..54d8b38bd8ed 100644
--- a/include/mach/bcm283x/platform.h
+++ b/include/mach/bcm283x/platform.h
@@ -32,6 +32,7 @@
#define BCM2835_PL011_BASE 0x20201000
#define BCM2836_PL011_BASE 0x3f201000UL
+#define BCM2711_PL011_BASE 0xfe201000UL
#define BCM2835_MINIUART_BASE 0x20215040
#define BCM2836_MINIUART_BASE 0x3f215040UL
#define BCM2711_MINIUART_BASE 0xfe215040UL
next reply other threads:[~2026-08-23 22:15 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-23 22:13 chalianis1 [this message]
2026-08-24 6:58 ` Ahmad Fatoum
2026-08-24 7:37 ` Sascha Hauer
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