[Xen-devel] [PATCH v4] xen/arm: Add Amlogic Meson SoCs earlyprintk support

Amit Singh Tomar posted 1 patch 8 weeks ago
Patches applied successfully (tree, apply log)
git fetch https://github.com/patchew-project/xen tags/patchew/1555264206-19673-1-git-send-email-amittomer25@gmail.com
xen/arch/arm/arm64/debug-meson.inc | 55 ++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)
create mode 100644 xen/arch/arm/arm64/debug-meson.inc

[Xen-devel] [PATCH v4] xen/arm: Add Amlogic Meson SoCs earlyprintk support

Posted by Amit Singh Tomar 8 weeks ago
This patch adds earlyprintk support for Amlogic Meson SoC based
boards.

ATF[1] and U-boot[2] already initialize the UART for us. So no need to do it again.

Tested With:
 http://wiki.friendlyarm.com/wiki/index.php/NanoPi_K2

[1]: https://github.com/ARM-software/arm-trusted-firmware/blob/master/drivers/meson/console/aarch64/meson_console.S#L92
[2]: https://github.com/u-boot/u-boot/blob/master/drivers/serial/serial_meson.c#L44

Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
---
Changes since v3:
    
        * Change the commit message to include firmware names.

Changes since v2:

        * Added the commit message that talks about
          uart initialization.

        * Added dummy early_uart_init function.

Changes since v1:

        * Fixed coding style issue.
        * Undone changes in early-printk.txt.

Changes since RFC:

        * Replaced LDRH with LDR, with this there
          is no scattered output on console now.
        * Used tbnz instead of tst and b.ne.
        * Used AML_ prefix against register names.

---
 xen/arch/arm/arm64/debug-meson.inc | 55 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 xen/arch/arm/arm64/debug-meson.inc

diff --git a/xen/arch/arm/arm64/debug-meson.inc b/xen/arch/arm/arm64/debug-meson.inc
new file mode 100644
index 0000000..e1a8fa8
--- /dev/null
+++ b/xen/arch/arm/arm64/debug-meson.inc
@@ -0,0 +1,55 @@
+/*
+ * xen/arch/arm/arm64/debug-meson.inc
+ *
+ * MESON specific debug code.
+ *
+ * Copyright (c) 2019, Amit Singh Tomar <amittomer25@gmail.com>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms and conditions of the GNU General Public
+ * License, version 2, as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define AML_UART_WFIFO_REG      0x00
+#define AML_UART_STATUS_REG     0x0c
+
+#define AML_UART_TX_FIFO_FULL   21
+
+.macro early_uart_init xb, c
+/* Uart has already been initialized by Firmware, for instance by TF-A */
+.endm
+
+/*
+ * MESON UART wait UART to be ready to transmit
+ * xb: register which contains the UART base address
+ * c: scratch register
+ */
+.macro early_uart_ready xb c
+1:
+        ldr     w\c, [\xb, #AML_UART_STATUS_REG]        /* status register */
+        tbnz    w\c, #AML_UART_TX_FIFO_FULL, 1b         /* Check TXFIFO FULL bit */
+.endm
+
+/*
+ * MESON UART transmit character
+ * xb: register which contains the UART base address
+ * wt: register which contains the character to transmit
+ */
+.macro early_uart_transmit xb wt
+        str    \wt, [\xb, #AML_UART_WFIFO_REG]
+.endm
+
+/*
+ * Local variables:
+ * mode: ASM
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
2.7.4


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Re: [Xen-devel] [PATCH v4] xen/arm: Add Amlogic Meson SoCs earlyprintk support

Posted by Julien Grall 8 weeks ago
Hi,

On 14/04/2019 18:50, Amit Singh Tomar wrote:
> This patch adds earlyprintk support for Amlogic Meson SoC based
> boards.
> 
> ATF[1] and U-boot[2] already initialize the UART for us. So no need to do it again.
> 
> Tested With:
>   http://wiki.friendlyarm.com/wiki/index.php/NanoPi_K2
> 
> [1]: https://github.com/ARM-software/arm-trusted-firmware/blob/master/drivers/meson/console/aarch64/meson_console.S#L92
> [2]: https://github.com/u-boot/u-boot/blob/master/drivers/serial/serial_meson.c#L44
> 
> Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>

Acked-by: Julien Grall <julien.grall@arm.com>

I have pushed to my branch next-4.13 for now. It will be merged once the commit 
moratorium is lifted.

Cheers,

> ---
> Changes since v3:
>      
>          * Change the commit message to include firmware names.
> 
> Changes since v2:
> 
>          * Added the commit message that talks about
>            uart initialization.
> 
>          * Added dummy early_uart_init function.
> 
> Changes since v1:
> 
>          * Fixed coding style issue.
>          * Undone changes in early-printk.txt.
> 
> Changes since RFC:
> 
>          * Replaced LDRH with LDR, with this there
>            is no scattered output on console now.
>          * Used tbnz instead of tst and b.ne.
>          * Used AML_ prefix against register names.
> 
> ---
>   xen/arch/arm/arm64/debug-meson.inc | 55 ++++++++++++++++++++++++++++++++++++++
>   1 file changed, 55 insertions(+)
>   create mode 100644 xen/arch/arm/arm64/debug-meson.inc
> 
> diff --git a/xen/arch/arm/arm64/debug-meson.inc b/xen/arch/arm/arm64/debug-meson.inc
> new file mode 100644
> index 0000000..e1a8fa8
> --- /dev/null
> +++ b/xen/arch/arm/arm64/debug-meson.inc
> @@ -0,0 +1,55 @@
> +/*
> + * xen/arch/arm/arm64/debug-meson.inc
> + *
> + * MESON specific debug code.
> + *
> + * Copyright (c) 2019, Amit Singh Tomar <amittomer25@gmail.com>.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms and conditions of the GNU General Public
> + * License, version 2, as published by the Free Software Foundation.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public
> + * License along with this program; If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#define AML_UART_WFIFO_REG      0x00
> +#define AML_UART_STATUS_REG     0x0c
> +
> +#define AML_UART_TX_FIFO_FULL   21
> +
> +.macro early_uart_init xb, c
> +/* Uart has already been initialized by Firmware, for instance by TF-A */
> +.endm
> +
> +/*
> + * MESON UART wait UART to be ready to transmit
> + * xb: register which contains the UART base address
> + * c: scratch register
> + */
> +.macro early_uart_ready xb c
> +1:
> +        ldr     w\c, [\xb, #AML_UART_STATUS_REG]        /* status register */
> +        tbnz    w\c, #AML_UART_TX_FIFO_FULL, 1b         /* Check TXFIFO FULL bit */
> +.endm
> +
> +/*
> + * MESON UART transmit character
> + * xb: register which contains the UART base address
> + * wt: register which contains the character to transmit
> + */
> +.macro early_uart_transmit xb wt
> +        str    \wt, [\xb, #AML_UART_WFIFO_REG]
> +.endm
> +
> +/*
> + * Local variables:
> + * mode: ASM
> + * indent-tabs-mode: nil
> + * End:
> + */
> 

-- 
Julien Grall

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