> -----Original Message-----
> From: Vabhav Sharma (OSS) <vabhav.sharma@xxxxxxxxxxx>
> Sent: Wednesday, September 2, 2020 9:10 PM
> To: kuldip dwivedi <kuldip.dwivedi@xxxxxxxxxxxxxxxx>; Greg Kroah-Hartman
> <gregkh@xxxxxxxxxxxxxxxxxxx>; Jiri Slaby <jirislaby@xxxxxxxxxx>; Dmitry
Safonov
> <0x7f454c46@xxxxxxxxx>; linux-serial@xxxxxxxxxxxxxxx
> Cc: Pankaj Bansal <pankaj.bansal@xxxxxxx>; Varun Sethi
<V.Sethi@xxxxxxx>;
> Arokia Samy <arokia.samy@xxxxxxx>; kuldip dwivedi
> <kuldip.dwivedi@xxxxxxxxxxxxxxxx>
> Subject: RE: [EXT] [PATCH v3] serial: 8250_fsl: Add ACPI support
>
>
> > -----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?
Addressed in v4
> > +
> > + 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
