Hi Peng,
On 28/02/2022 01:07, Peng Fan (OSS) wrote:
From: Peng Fan <peng....@nxp.com>
Signed-off-by: Peng Fan <peng....@nxp.com>
---
xen/arch/arm/Kconfig.debug | 18 ++++++++++
xen/arch/arm/arm64/debug-imx-lpuart.inc | 48 +++++++++++++++++++++++++
2 files changed, 66 insertions(+)
create mode 100644 xen/arch/arm/arm64/debug-imx-lpuart.inc
diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug
index 35ccd13273..9ecb446b3a 100644
--- a/xen/arch/arm/Kconfig.debug
+++ b/xen/arch/arm/Kconfig.debug
@@ -55,6 +55,20 @@ choice
selecting one of the platform specific options below if
you know the parameters for the port.
+ This option is preferred over the platform specific
+ options; the platform specific options are deprecated
+ and will soon be removed.
+ config EARLY_UART_CHOICE_IMX_LPUART
+ select EARLY_UART_IMX_LPUART
+ depends on ARM_64
+ bool "Early printk via i.MX LPUART"
+ help
+ Say Y here if you wish the early printk to direct their
+ output to a i.MX LPUART. You can use this option to
+ provide the parameters for the i.MX LPUART rather than
+ selecting one of the platform specific options below if
+ you know the parameters for the port.
Plaform specific early printk are deprecated. So I would rather prefer
we are not introducing new one. Can you adjust the description to remove
any mention of platform specific options?
+
This option is preferred over the platform specific
options; the platform specific options are deprecated
and will soon be removed.
@@ -186,6 +200,9 @@ config EARLY_UART_CADENCE
config EARLY_UART_EXYNOS4210
select EARLY_PRINTK
bool
+config EARLY_UART_IMX_LPUART
+ select EARLY_PRINTK
+ bool
config EARLY_UART_MESON
select EARLY_PRINTK
bool
@@ -283,6 +300,7 @@ config EARLY_PRINTK_INC
default "debug-8250.inc" if EARLY_UART_8250
default "debug-cadence.inc" if EARLY_UART_CADENCE
default "debug-exynos4210.inc" if EARLY_UART_EXYNOS4210
+ default "debug-imx-lpuart.inc" if EARLY_UART_IMX_LPUART
default "debug-meson.inc" if EARLY_UART_MESON
default "debug-mvebu.inc" if EARLY_UART_MVEBU
default "debug-pl011.inc" if EARLY_UART_PL011
diff --git a/xen/arch/arm/arm64/debug-imx-lpuart.inc
b/xen/arch/arm/arm64/debug-imx-lpuart.inc
new file mode 100644
index 0000000000..7510210d46
--- /dev/null
+++ b/xen/arch/arm/arm64/debug-imx-lpuart.inc
@@ -0,0 +1,48 @@
+/*
+ * xen/arch/arm/arm64/debug-imx8qm.inc
+ *
+ * i.MX8QM specific debug code
+ *
+ * Peng Fan <peng....@nxp.com>
+ * Copyright (C) 2016 Freescale Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <xen/imx-lpuart.h>
+
+.macro early_uart_init wb wc wd
+/* Already initialized in bootloader */
+.endm
NIT: I would add a newline to separate with this macro from next one.
+/* i.MX8QM wait LPUART to be ready to transmit
+ * rb: register which contains the UART base address
+ * rc: scratch register
+ */
The coding style for multi-lines comment is:
/*
* Foo
* Bar
*/
+.macro early_uart_ready xb, c
+1:
+ ldr w\c, [\xb, #UARTSTAT] /* <- Flag register */
+ tst w\c, #UARTSTAT_TDRE /* Check FIFO EMPTY bit */
+ beq 1b /* Wait for the UART to be ready */
+.endm
+
+/* i.MX8QM LPUART transmit character
+ * rb: register which contains the UART base address
+ * rt: register which contains the character to transmit */
Coding style:
/*
* Foo
* Bar
*/
+.macro early_uart_transmit xb, wt
+ str \wt, [\xb, #UARTDATA] /* -> Data Register */
+.endm
+
+/*
+ * Local variables:
+ * mode: ASM
+ * indent-tabs-mode: nil
+ * End:
+ */
Cheers,
--
Julien Grall
