Re: [PATCH v5 17/17] serial: 8250: Add 8250_acpi driver

Greg Kroah-Hartman
2024-05-04T15:53:41Z

On Wed, May 01, 2024 at 05:47:42PM +0530, Sunil V L wrote:
> RISC-V has non-PNP generic 16550A compatible UART which needs to be
> enumerated as ACPI platform device. Add driver support for such devices
> similar to 8250_of.
>
> The driver is enabled when the CONFIG_SERIAL_ACPI_PLATFORM option is
> enabled. Enable this option for RISC-V.
>
> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> ---
> arch/riscv/configs/defconfig | 1 +
> drivers/tty/serial/8250/8250_acpi.c | 96 +++++++++++++++++++++++++++++
> drivers/tty/serial/8250/Kconfig | 8 +++
> drivers/tty/serial/8250/Makefile | 1 +
> 4 files changed, 106 insertions(+)
> create mode 100644 drivers/tty/serial/8250/8250_acpi.c
>
> diff --git a/arch/riscv/configs/defconfig b/arch/riscv/configs/defconfig
> index 3cae018f9315..bea8241f52eb 100644
> --- a/arch/riscv/configs/defconfig
> +++ b/arch/riscv/configs/defconfig
> @@ -150,6 +150,7 @@ CONFIG_SERIAL_8250=y
> CONFIG_SERIAL_8250_CONSOLE=y
> CONFIG_SERIAL_8250_DW=y
> CONFIG_SERIAL_OF_PLATFORM=y
> +CONFIG_SERIAL_ACPI_PLATFORM=y
> CONFIG_SERIAL_SH_SCI=y
> CONFIG_SERIAL_EARLYCON_RISCV_SBI=y
> CONFIG_VIRTIO_CONSOLE=y
> diff --git a/drivers/tty/serial/8250/8250_acpi.c b/drivers/tty/serial/8250/8250_acpi.c
> new file mode 100644
> index 000000000000..3682443bb69c
> --- /dev/null
> +++ b/drivers/tty/serial/8250/8250_acpi.c
> @@ -0,0 +1,96 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Serial Port driver for ACPI platform devices
> + *
> + * This driver is for generic 16550 compatible UART enumerated via ACPI
> + * platform bus instead of PNP bus like PNP0501. This is not a full
> + * driver but mostly provides the ACPI wrapper and uses generic
> + * 8250 framework for rest of the functionality.

No copyright line? Odd, but ok, I'll take it, glad to see your company
finally realizes the lack of needing them :)

And as Andy said, please use the existing driver and extend what you
need, don't write a new one, we really don't need a new one.

> +static int acpi_platform_serial_probe(struct platform_device *pdev)
> +{
> + struct acpi_serial_info *data;
> + struct uart_8250_port port8250;
> + struct device *dev = &pdev->dev;
> + struct resource *regs;
> +
> + int ret, irq;
> +
> + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!regs) {
> + dev_err(dev, "no registers defined\n");
> + return -EINVAL;
> + }
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0)
> + return irq;
> +
> + memset(&port8250, 0, sizeof(port8250));
> +
> + spin_lock_init(&port8250.port.lock);

Are you sure this works?

thanks,

greg k-h