diff mbox series

[1/2] xen/arm: Add i.MX UART early printk support

Message ID 20240402120557.1822253-2-olekstysh@gmail.com (mailing list archive)
State New, archived
Headers show
Series Add UART support for i.MX 8M Mini EVKB | expand

Commit Message

Oleksandr Tyshchenko April 2, 2024, 12:05 p.m. UTC
From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>

Tested on i.MX 8M Mini only, but I guess, it should be
suitable for other i.MX8M* SoCs (those UART device tree nodes
contain "fsl,imx6q-uart" compatible string).

Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
---
I selected the following configs for enabling early printk:

 CONFIG_EARLY_UART_CHOICE_IMX_UART=y
 CONFIG_EARLY_UART_IMX_UART=y
 CONFIG_EARLY_PRINTK=y
 CONFIG_EARLY_UART_BASE_ADDRESS=0x30890000
 CONFIG_EARLY_PRINTK_INC="debug-imx-uart.inc"
---
---
 xen/arch/arm/Kconfig.debug            | 14 +++++
 xen/arch/arm/arm64/debug-imx-uart.inc | 38 ++++++++++++++
 xen/arch/arm/include/asm/imx-uart.h   | 76 +++++++++++++++++++++++++++
 3 files changed, 128 insertions(+)
 create mode 100644 xen/arch/arm/arm64/debug-imx-uart.inc
 create mode 100644 xen/arch/arm/include/asm/imx-uart.h

Comments

Michal Orzel April 3, 2024, 10:11 a.m. UTC | #1
Hi Oleksandr,

On 02/04/2024 14:05, Oleksandr Tyshchenko wrote:
> 
> 
> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> 
> Tested on i.MX 8M Mini only, but I guess, it should be
> suitable for other i.MX8M* SoCs (those UART device tree nodes
> contain "fsl,imx6q-uart" compatible string).
Please use imperative mood in commit msg. I would mention also that you are adding
macros that will be used by the runtime driver.

> 
> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
> ---
> I selected the following configs for enabling early printk:
> 
>  CONFIG_EARLY_UART_CHOICE_IMX_UART=y
>  CONFIG_EARLY_UART_IMX_UART=y
>  CONFIG_EARLY_PRINTK=y
>  CONFIG_EARLY_UART_BASE_ADDRESS=0x30890000
>  CONFIG_EARLY_PRINTK_INC="debug-imx-uart.inc"
> ---
> ---
>  xen/arch/arm/Kconfig.debug            | 14 +++++
>  xen/arch/arm/arm64/debug-imx-uart.inc | 38 ++++++++++++++
>  xen/arch/arm/include/asm/imx-uart.h   | 76 +++++++++++++++++++++++++++
>  3 files changed, 128 insertions(+)
>  create mode 100644 xen/arch/arm/arm64/debug-imx-uart.inc
>  create mode 100644 xen/arch/arm/include/asm/imx-uart.h
> 
> diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug
> index eec860e88e..a15d08f214 100644
> --- a/xen/arch/arm/Kconfig.debug
> +++ b/xen/arch/arm/Kconfig.debug
> @@ -68,6 +68,16 @@ choice
>                         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.
> +       config EARLY_UART_CHOICE_IMX_UART
> +               select EARLY_UART_IMX_UART
> +               depends on ARM_64
> +               bool "Early printk via i.MX UART"
> +               help
> +                       Say Y here if you wish the early printk to direct their
Do not take example from surrounding code. help text should be indented by 2 tabs and 2 spaces here.

> +                       output to a i.MX UART. You can use this option to
> +                       provide the parameters for the i.MX UART rather than
> +                       selecting one of the platform specific options below if
> +                       you know the parameters for the port.
>         config EARLY_UART_CHOICE_MESON
>                 select EARLY_UART_MESON
>                 depends on ARM_64
> @@ -199,6 +209,9 @@ config EARLY_UART_EXYNOS4210
>  config EARLY_UART_IMX_LPUART
>         select EARLY_PRINTK
>         bool
> +config EARLY_UART_IMX_UART
> +       select EARLY_PRINTK
> +       bool
>  config EARLY_UART_MESON
>         select EARLY_PRINTK
>         bool
> @@ -304,6 +317,7 @@ config EARLY_PRINTK_INC
>         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-imx-uart.inc" if EARLY_UART_IMX_UART
>         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-uart.inc b/xen/arch/arm/arm64/debug-imx-uart.inc
> new file mode 100644
> index 0000000000..27a68b1ed5
> --- /dev/null
> +++ b/xen/arch/arm/arm64/debug-imx-uart.inc
> @@ -0,0 +1,38 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * xen/arch/arm/arm64/debug-imx-uart.inc
> + *
> + * i.MX8M* specific debug code
> + *
> + * Copyright (C) 2024 EPAM Systems Inc.
> + */
> +
> +#include <asm/imx-uart.h>
> +
> +/*
> + * Wait UART to be ready to transmit
> + * rb: register which contains the UART base address
> + * rc: scratch register
> + */
> +.macro early_uart_ready xb, c
> +1:
> +        ldr   w\c, [\xb, #IMX21_UTS] /* <- Test register */
> +        tst   w\c, #UTS_TXFULL       /* Check TxFIFO FULL bit */
> +        bne   1b                     /* Wait for the UART to be ready */
> +.endm
> +
> +/*
> + * UART transmit character
> + * rb: register which contains the UART base address
> + * rt: register which contains the character to transmit
> + */
> +.macro early_uart_transmit xb, wt
> +        str   \wt, [\xb, #URTX0] /* -> Transmitter Register */
> +.endm
> +
> +/*
> + * Local variables:
> + * mode: ASM
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/include/asm/imx-uart.h b/xen/arch/arm/include/asm/imx-uart.h
> new file mode 100644
> index 0000000000..413a81dd44
> --- /dev/null
> +++ b/xen/arch/arm/include/asm/imx-uart.h
> @@ -0,0 +1,76 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * xen/arch/arm/include/asm/imx-uart.h
> + *
> + * Common constant definition between early printk and the UART driver
> + *
> + * Copyright (C) 2024 EPAM Systems Inc.
> + */
> +
> +#ifndef __ASM_ARM_IMX_UART_H__
> +#define __ASM_ARM_IMX_UART_H__
> +
> +/* 32-bit register definition */
> +#define URXD0        (0x00) /* Receiver Register */
There is no need to surround these values

> +#define URTX0        (0x40) /* Transmitter Register */
> +#define UCR1         (0x80) /* Control Register 1 */
> +#define UCR2         (0x84) /* Control Register 2 */
> +#define UCR3         (0x88) /* Control Register 3 */

> +#define UCR4         (0x8c) /* Control Register 4 */
> +#define UFCR         (0x90) /* FIFO Control Register */
> +#define USR1         (0x94) /* Status Register 1 */
> +#define USR2         (0x98) /* Status Register 2 */
> +#define IMX21_UTS    (0xb4) /* Test Register */
> +
> +#define URXD_ERR        BIT(14, UL) /* Error detect */
> +#define URXD_RX_DATA    GENMASK(7, 0) /* Received data mask */
> +
> +#define UCR1_TRDYEN      BIT(13, UL) /* Transmitter ready interrupt enable */
> +#define UCR1_RRDYEN      BIT(9, UL) /* Receiver ready interrupt enable */
NIT: please align comments within a block

Other than that:
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

~Michal
Oleksandr Tyshchenko April 18, 2024, 3:43 p.m. UTC | #2
On 03.04.24 13:11, Michal Orzel wrote:
> Hi Oleksandr,

Hello Michal

sorry for the late response

> 
> On 02/04/2024 14:05, Oleksandr Tyshchenko wrote:
>>
>>
>> From: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>>
>> Tested on i.MX 8M Mini only, but I guess, it should be
>> suitable for other i.MX8M* SoCs (those UART device tree nodes
>> contain "fsl,imx6q-uart" compatible string).
> Please use imperative mood in commit msg.

ok


> I would mention also that you are adding
> macros that will be used by the runtime driver.


will do

> 
>>
>> Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
>> ---
>> I selected the following configs for enabling early printk:
>>
>>   CONFIG_EARLY_UART_CHOICE_IMX_UART=y
>>   CONFIG_EARLY_UART_IMX_UART=y
>>   CONFIG_EARLY_PRINTK=y
>>   CONFIG_EARLY_UART_BASE_ADDRESS=0x30890000
>>   CONFIG_EARLY_PRINTK_INC="debug-imx-uart.inc"
>> ---
>> ---
>>   xen/arch/arm/Kconfig.debug            | 14 +++++
>>   xen/arch/arm/arm64/debug-imx-uart.inc | 38 ++++++++++++++
>>   xen/arch/arm/include/asm/imx-uart.h   | 76 +++++++++++++++++++++++++++
>>   3 files changed, 128 insertions(+)
>>   create mode 100644 xen/arch/arm/arm64/debug-imx-uart.inc
>>   create mode 100644 xen/arch/arm/include/asm/imx-uart.h
>>
>> diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug
>> index eec860e88e..a15d08f214 100644
>> --- a/xen/arch/arm/Kconfig.debug
>> +++ b/xen/arch/arm/Kconfig.debug
>> @@ -68,6 +68,16 @@ choice
>>                          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.
>> +       config EARLY_UART_CHOICE_IMX_UART
>> +               select EARLY_UART_IMX_UART
>> +               depends on ARM_64
>> +               bool "Early printk via i.MX UART"
>> +               help
>> +                       Say Y here if you wish the early printk to direct their
> Do not take example from surrounding code. help text should be indented by 2 tabs and 2 spaces here.

ok

> 
>> +                       output to a i.MX UART. You can use this option to
>> +                       provide the parameters for the i.MX UART rather than
>> +                       selecting one of the platform specific options below if
>> +                       you know the parameters for the port.
>>          config EARLY_UART_CHOICE_MESON
>>                  select EARLY_UART_MESON
>>                  depends on ARM_64
>> @@ -199,6 +209,9 @@ config EARLY_UART_EXYNOS4210
>>   config EARLY_UART_IMX_LPUART
>>          select EARLY_PRINTK
>>          bool
>> +config EARLY_UART_IMX_UART
>> +       select EARLY_PRINTK
>> +       bool
>>   config EARLY_UART_MESON
>>          select EARLY_PRINTK
>>          bool
>> @@ -304,6 +317,7 @@ config EARLY_PRINTK_INC
>>          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-imx-uart.inc" if EARLY_UART_IMX_UART
>>          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-uart.inc b/xen/arch/arm/arm64/debug-imx-uart.inc
>> new file mode 100644
>> index 0000000000..27a68b1ed5
>> --- /dev/null
>> +++ b/xen/arch/arm/arm64/debug-imx-uart.inc
>> @@ -0,0 +1,38 @@
>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>> +/*
>> + * xen/arch/arm/arm64/debug-imx-uart.inc
>> + *
>> + * i.MX8M* specific debug code
>> + *
>> + * Copyright (C) 2024 EPAM Systems Inc.
>> + */
>> +
>> +#include <asm/imx-uart.h>
>> +
>> +/*
>> + * Wait UART to be ready to transmit
>> + * rb: register which contains the UART base address
>> + * rc: scratch register
>> + */
>> +.macro early_uart_ready xb, c
>> +1:
>> +        ldr   w\c, [\xb, #IMX21_UTS] /* <- Test register */
>> +        tst   w\c, #UTS_TXFULL       /* Check TxFIFO FULL bit */
>> +        bne   1b                     /* Wait for the UART to be ready */
>> +.endm
>> +
>> +/*
>> + * UART transmit character
>> + * rb: register which contains the UART base address
>> + * rt: register which contains the character to transmit
>> + */
>> +.macro early_uart_transmit xb, wt
>> +        str   \wt, [\xb, #URTX0] /* -> Transmitter Register */
>> +.endm
>> +
>> +/*
>> + * Local variables:
>> + * mode: ASM
>> + * indent-tabs-mode: nil
>> + * End:
>> + */
>> diff --git a/xen/arch/arm/include/asm/imx-uart.h b/xen/arch/arm/include/asm/imx-uart.h
>> new file mode 100644
>> index 0000000000..413a81dd44
>> --- /dev/null
>> +++ b/xen/arch/arm/include/asm/imx-uart.h
>> @@ -0,0 +1,76 @@
>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>> +/*
>> + * xen/arch/arm/include/asm/imx-uart.h
>> + *
>> + * Common constant definition between early printk and the UART driver
>> + *
>> + * Copyright (C) 2024 EPAM Systems Inc.
>> + */
>> +
>> +#ifndef __ASM_ARM_IMX_UART_H__
>> +#define __ASM_ARM_IMX_UART_H__
>> +
>> +/* 32-bit register definition */
>> +#define URXD0        (0x00) /* Receiver Register */
> There is no need to surround these values

ok

> 
>> +#define URTX0        (0x40) /* Transmitter Register */
>> +#define UCR1         (0x80) /* Control Register 1 */
>> +#define UCR2         (0x84) /* Control Register 2 */
>> +#define UCR3         (0x88) /* Control Register 3 */
> 
>> +#define UCR4         (0x8c) /* Control Register 4 */
>> +#define UFCR         (0x90) /* FIFO Control Register */
>> +#define USR1         (0x94) /* Status Register 1 */
>> +#define USR2         (0x98) /* Status Register 2 */
>> +#define IMX21_UTS    (0xb4) /* Test Register */
>> +
>> +#define URXD_ERR        BIT(14, UL) /* Error detect */
>> +#define URXD_RX_DATA    GENMASK(7, 0) /* Received data mask */
>> +
>> +#define UCR1_TRDYEN      BIT(13, UL) /* Transmitter ready interrupt enable */
>> +#define UCR1_RRDYEN      BIT(9, UL) /* Receiver ready interrupt enable */
> NIT: please align comments within a block

ok

> 
> Other than that:
> Reviewed-by: Michal Orzel <michal.orzel@amd.com>


thanks

> 
> ~Michal
diff mbox series

Patch

diff --git a/xen/arch/arm/Kconfig.debug b/xen/arch/arm/Kconfig.debug
index eec860e88e..a15d08f214 100644
--- a/xen/arch/arm/Kconfig.debug
+++ b/xen/arch/arm/Kconfig.debug
@@ -68,6 +68,16 @@  choice
 			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.
+	config EARLY_UART_CHOICE_IMX_UART
+		select EARLY_UART_IMX_UART
+		depends on ARM_64
+		bool "Early printk via i.MX UART"
+		help
+			Say Y here if you wish the early printk to direct their
+			output to a i.MX UART. You can use this option to
+			provide the parameters for the i.MX UART rather than
+			selecting one of the platform specific options below if
+			you know the parameters for the port.
 	config EARLY_UART_CHOICE_MESON
 		select EARLY_UART_MESON
 		depends on ARM_64
@@ -199,6 +209,9 @@  config EARLY_UART_EXYNOS4210
 config EARLY_UART_IMX_LPUART
 	select EARLY_PRINTK
 	bool
+config EARLY_UART_IMX_UART
+	select EARLY_PRINTK
+	bool
 config EARLY_UART_MESON
 	select EARLY_PRINTK
 	bool
@@ -304,6 +317,7 @@  config EARLY_PRINTK_INC
 	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-imx-uart.inc" if EARLY_UART_IMX_UART
 	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-uart.inc b/xen/arch/arm/arm64/debug-imx-uart.inc
new file mode 100644
index 0000000000..27a68b1ed5
--- /dev/null
+++ b/xen/arch/arm/arm64/debug-imx-uart.inc
@@ -0,0 +1,38 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * xen/arch/arm/arm64/debug-imx-uart.inc
+ *
+ * i.MX8M* specific debug code
+ *
+ * Copyright (C) 2024 EPAM Systems Inc.
+ */
+
+#include <asm/imx-uart.h>
+
+/*
+ * Wait UART to be ready to transmit
+ * rb: register which contains the UART base address
+ * rc: scratch register
+ */
+.macro early_uart_ready xb, c
+1:
+        ldr   w\c, [\xb, #IMX21_UTS] /* <- Test register */
+        tst   w\c, #UTS_TXFULL       /* Check TxFIFO FULL bit */
+        bne   1b                     /* Wait for the UART to be ready */
+.endm
+
+/*
+ * UART transmit character
+ * rb: register which contains the UART base address
+ * rt: register which contains the character to transmit
+ */
+.macro early_uart_transmit xb, wt
+        str   \wt, [\xb, #URTX0] /* -> Transmitter Register */
+.endm
+
+/*
+ * Local variables:
+ * mode: ASM
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/arm/include/asm/imx-uart.h b/xen/arch/arm/include/asm/imx-uart.h
new file mode 100644
index 0000000000..413a81dd44
--- /dev/null
+++ b/xen/arch/arm/include/asm/imx-uart.h
@@ -0,0 +1,76 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * xen/arch/arm/include/asm/imx-uart.h
+ *
+ * Common constant definition between early printk and the UART driver
+ *
+ * Copyright (C) 2024 EPAM Systems Inc.
+ */
+
+#ifndef __ASM_ARM_IMX_UART_H__
+#define __ASM_ARM_IMX_UART_H__
+
+/* 32-bit register definition */
+#define URXD0        (0x00) /* Receiver Register */
+#define URTX0        (0x40) /* Transmitter Register */
+#define UCR1         (0x80) /* Control Register 1 */
+#define UCR2         (0x84) /* Control Register 2 */
+#define UCR3         (0x88) /* Control Register 3 */
+#define UCR4         (0x8c) /* Control Register 4 */
+#define UFCR         (0x90) /* FIFO Control Register */
+#define USR1         (0x94) /* Status Register 1 */
+#define USR2         (0x98) /* Status Register 2 */
+#define IMX21_UTS    (0xb4) /* Test Register */
+
+#define URXD_ERR        BIT(14, UL) /* Error detect */
+#define URXD_RX_DATA    GENMASK(7, 0) /* Received data mask */
+
+#define UCR1_TRDYEN      BIT(13, UL) /* Transmitter ready interrupt enable */
+#define UCR1_RRDYEN      BIT(9, UL) /* Receiver ready interrupt enable */
+#define UCR1_RXDMAEN     BIT(8, UL) /* Receiver ready DMA enable */
+#define UCR1_TXMPTYEN    BIT(6, UL) /* Transmitter empty interrupt enable */
+#define UCR1_RTSDEN      BIT(5, UL) /* RTS delta interrupt enable */
+#define UCR1_TXDMAEN     BIT(3, UL) /* Transmitter ready DMA enable */
+#define UCR1_ATDMAEN     BIT(2, UL) /* Aging DMA Timer enable */
+#define UCR1_UARTEN      BIT(0, UL) /* UART enable */
+
+#define UCR2_ATEN    BIT(3, UL) /* Aging Timer Enable */
+#define UCR2_TXEN    BIT(2, UL) /* Transmitter enable */
+#define UCR2_RXEN    BIT(1, UL) /* Receiver enable */
+
+#define UCR4_TCEN    BIT(3, UL) /* Transmit complete interrupt enable */
+#define UCR4_DREN    BIT(0, UL) /* Receive data ready interrupt enable */
+
+#define UFCR_TXTL_SHF    (10) /* Transmitter trigger level shift */
+#define UFCR_RFDIV       GENMASK(9, 7) /* Reference frequency divider mask */
+#define UFCR_DCEDTE      BIT(6, UL) /* DCE/DTE mode select */
+
+#define USR1_PARITYERR    BIT(15, UL) /* Parity error interrupt flag */
+#define USR1_TRDY         BIT(13, UL) /* Transmitter ready interrupt/DMA flag */
+#define USR1_FRAMERR      BIT(10, UL) /* Frame error interrupt flag */
+#define USR1_RRDY         BIT(9, UL) /* Receiver ready interrupt/DMA flag */
+#define USR1_AGTIM        BIT(8, UL) /* Aging timer interrupt flag */
+
+#define USR2_TXDC         BIT(3, UL) /* Transmitter complete */
+#define USR2_BRCD         BIT(2, UL) /* Break condition detected */
+#define USR2_ORE          BIT(1, UL) /* Overrun error */
+#define USR2_RDR          BIT(0, UL) /* Receive data ready */
+
+#define UTS_TXEMPTY    BIT(6, UL) /* TxFIFO empty */
+#define UTS_TXFULL     BIT(4, UL) /* TxFIFO full */
+
+#define TXTL_DEFAULT    (2)
+#define RXTL_DEFAULT    (8)
+
+#define TX_FIFO_SIZE    32
+
+#endif /* __ASM_ARM_IMX_UART_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */