From 11361610b00500c4afe269ff5a4fe06d58f0a3d0 Mon Sep 17 00:00:00 2001 From: kuldip dwivedi Date: Thu, 3 Sep 2020 17:04:02 +0530 Subject: serial: 8250_fsl: Add ACPI support 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 Link: https://lore.kernel.org/r/20200903113402.12371-1-kuldip.dwivedi@puresoftware.com Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_fsl.c | 108 ++++++++++++++++++++++++++++++++++--- 1 file changed, 101 insertions(+), 7 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c index 0d0c80905c58..c3582d8938d6 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 -#include - -#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 +#include +#include + +#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) + return data->line; + + 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 -- cgit v1.2.3