> -----Original Message-----
> From: kuldip dwivedi <kuldip.dwivedi@xxxxxxxxxxxxxxxx>
> Sent: Saturday, August 29, 2020 8:13 PM
> To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Jiri Slaby
> <jirislaby@xxxxxxxxxx>; Dmitry Safonov <0x7f454c46@xxxxxxxxx>; linux-
> serial@xxxxxxxxxxxxxxx
> Cc: Vabhav Sharma <vabhav.sharma@xxxxxxx>; Pankaj Bansal
> <pankaj.bansal@xxxxxxx>; Varun Sethi <V.Sethi@xxxxxxx>; Arokia Samy
> <arokia.samy@xxxxxxx>; kuldip dwivedi
> <kuldip.dwivedi@xxxxxxxxxxxxxxxx>
> Subject: [EXT] [PATCH v3] serial: 8250_fsl: Add ACPI support
>
> Caution: EXT Email
>
> This adds support for ACPI enumerated FSL 16550 UARTs.
> For supporting ACPI, I added a wrapper so that this driver can be used if
> firmware has exposed the HID "NXP0018" in DSDT table.
>
> This will be built as object file if config "SERIAL_8250_FSL"
> is enabled which depends on config "SERIAL_8250_CONSOLE".
>
> Signed-off-by: kuldip dwivedi <kuldip.dwivedi@xxxxxxxxxxxxxxxx>
> ---
>
> Notes:
> 1. Move Copyright and File description at top of the file
> 2. Add ACPI wrapper code within CONFIG_ACPI macro
> 3. this change is tested with DT and ACPI boot on LS1046A platform
>
> drivers/tty/serial/8250/8250_fsl.c | 108 +++++++++++++++++++++++++++--
> 1 file changed, 101 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_fsl.c
> b/drivers/tty/serial/8250/8250_fsl.c
> index 0d0c80905c58..68bfbf392281 100644
> --- a/drivers/tty/serial/8250/8250_fsl.c
> +++ b/drivers/tty/serial/8250/8250_fsl.c
> @@ -1,15 +1,12 @@
> // SPDX-License-Identifier: GPL-2.0
> -#include <linux/serial_reg.h>
> -#include <linux/serial_8250.h>
> -
> -#include "8250.h"
> -
> /*
> * Freescale 16550 UART "driver", Copyright (C) 2011 Paul Gortmaker.
> + * Copyright 2020 NXP
> + * Copyright 2020 Puresoftware Ltd.
> *
> * This isn't a full driver; it just provides an alternate IRQ
> - * handler to deal with an errata. Everything else is just
> - * using the bog standard 8250 support.
> + * handler to deal with an errata and provide ACPI wrapper.
> + * Everything else is just using the bog standard 8250 support.
> *
> * We follow code flow of serial8250_default_handle_irq() but add
> * a check for a break and insert a dummy read on the Rx for the @@ -20,6
> +17,16 @@
> * IRQ event to the next one.
> */
>
> +#include <linux/acpi.h>
> +#include <linux/serial_reg.h>
> +#include <linux/serial_8250.h>
> +
> +#include "8250.h"
> +
> +struct fsl8250_data {
> + int line;
> +};
> +
> int fsl8250_handle_irq(struct uart_port *port) {
> unsigned char lsr, orig_lsr;
> @@ -79,3 +86,90 @@ int fsl8250_handle_irq(struct uart_port *port)
> return 1;
> }
> EXPORT_SYMBOL_GPL(fsl8250_handle_irq);
> +
> +#ifdef CONFIG_ACPI
> +static int fsl8250_acpi_probe(struct platform_device *pdev) {
> + struct fsl8250_data *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) {
> + if (irq != -EPROBE_DEFER)
> + dev_err(dev, "cannot get irq\n");
> + return irq;
> + }
> +
> + memset(&port8250, 0, sizeof(port8250));
> +
> + ret = device_property_read_u32(dev, "clock-frequency",
> + &port8250.port.uartclk);
> + if (ret)
> + return ret;
> +
> + spin_lock_init(&port8250.port.lock);
> +
> + port8250.port.mapbase = regs->start;
> + port8250.port.irq = irq;
> + port8250.port.handle_irq = fsl8250_handle_irq;
> + port8250.port.type = PORT_16550A;
> + port8250.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
> + | UPF_FIXED_PORT | UPF_IOREMAP
> + | UPF_FIXED_TYPE;
> + port8250.port.dev = dev;
> + port8250.port.mapsize = resource_size(regs);
> + port8250.port.iotype = UPIO_MEM;
> + port8250.port.irqflags = IRQF_SHARED;
> +
> + port8250.port.membase = devm_ioremap(dev, port8250.port.mapbase,
> + port8250.port.mapsize);
> + if (!port8250.port.membase)
> + return -ENOMEM;
> +
> + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->line = serial8250_register_8250_port(&port8250);
> + if (data->line < 0)
> + ret = data->line;
Would you like to return error here?
> +
> + platform_set_drvdata(pdev, data);
> + return 0;
> +}
> +
> +static int fsl8250_acpi_remove(struct platform_device *pdev) {
> + struct fsl8250_data *data = platform_get_drvdata(pdev);
> +
> + serial8250_unregister_port(data->line);
> + return 0;
> +}
> +
> +static const struct acpi_device_id fsl_8250_acpi_id[] = {
> + { "NXP0018", 0 },
> + { },
> +};
> +MODULE_DEVICE_TABLE(acpi, fsl_8250_acpi_id);
> +
> +static struct platform_driver fsl8250_platform_driver = {
> + .driver = {
> + .name = "fsl-16550-uart",
> + .acpi_match_table = ACPI_PTR(fsl_8250_acpi_id),
> + },
> + .probe = fsl8250_acpi_probe,
> + .remove = fsl8250_acpi_remove,
> +};
> +
> +module_platform_driver(fsl8250_platform_driver);
> +#endif
> --
> 2.17.1
