diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_platform.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_platform.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_platform.c b/drivers/tty/serial/8250/8250_platform.c new file mode 100644 index 000000000000..c0343bfb8064 --- /dev/null +++ b/drivers/tty/serial/8250/8250_platform.c @@ -0,0 +1,414 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Universal/legacy platform driver for 8250/16550-type serial ports + * + * Supports: + * ISA-compatible 8250/16550 ports + * ACPI 8250/16550 ports + * PNP 8250/16550 ports + * "serial8250" platform devices + */ +#include <linux/acpi.h> +#include <linux/array_size.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/once.h> +#include <linux/platform_device.h> + +#include <linux/serial_8250.h> + +#ifdef CONFIG_SPARC +#include <linux/sunserialcore.h> +#endif + +#include "8250.h" + +/* + * Configuration: + * share_irqs: Whether we pass IRQF_SHARED to request_irq(). + * This option is unsafe when used on edge-triggered interrupts. + * skip_txen_test: Force skip of txen test at init time. + */ +unsigned int share_irqs = SERIAL8250_SHARE_IRQS; +unsigned int skip_txen_test; + +unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS; + +#include <asm/serial.h> + +/* + * SERIAL_PORT_DFNS tells us about built-in ports that have no + * standard enumeration mechanism. Platforms that can find all + * serial ports via mechanisms like ACPI or PCI need not supply it. + */ +#ifndef SERIAL_PORT_DFNS +#define SERIAL_PORT_DFNS +#endif + +static const struct old_serial_port old_serial_port[] = { + SERIAL_PORT_DFNS /* defined in asm/serial.h */ +}; + +serial8250_isa_config_fn serial8250_isa_config; +void serial8250_set_isa_configurator(serial8250_isa_config_fn v) +{ + serial8250_isa_config = v; +} +EXPORT_SYMBOL(serial8250_set_isa_configurator); + +static void __init __serial8250_isa_init_ports(void) +{ + int i, irqflag = 0; + + if (nr_uarts > UART_NR) + nr_uarts = UART_NR; + + /* + * Set up initial ISA ports based on nr_uart module param, or else + * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not + * need to increase nr_uarts when setting up the initial ISA ports. + */ + for (i = 0; i < nr_uarts; i++) + serial8250_setup_port(i); + + /* chain base port ops to support Remote Supervisor Adapter */ + univ8250_port_ops = *univ8250_port_base_ops; + univ8250_rsa_support(&univ8250_port_ops); + + if (share_irqs) + irqflag = IRQF_SHARED; + + for (i = 0; i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; i++) { + struct uart_8250_port *up = serial8250_get_port(i); + struct uart_port *port = &up->port; + + port->iobase = old_serial_port[i].port; + port->irq = irq_canonicalize(old_serial_port[i].irq); + port->irqflags = 0; + port->uartclk = old_serial_port[i].baud_base * 16; + port->flags = old_serial_port[i].flags; + port->hub6 = 0; + port->membase = old_serial_port[i].iomem_base; + port->iotype = old_serial_port[i].io_type; + port->regshift = old_serial_port[i].iomem_reg_shift; + + port->irqflags |= irqflag; + if (serial8250_isa_config != NULL) + serial8250_isa_config(i, &up->port, &up->capabilities); + } +} + +void __init serial8250_isa_init_ports(void) +{ + DO_ONCE(__serial8250_isa_init_ports); +} + +/* + * Generic 16550A platform devices + */ +static int serial8250_probe_acpi(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct uart_8250_port uart = { }; + struct resource *regs; + int ret, line; + + regs = platform_get_mem_or_io(pdev, 0); + if (!regs) + return dev_err_probe(dev, -EINVAL, "no registers defined\n"); + + switch (resource_type(regs)) { + case IORESOURCE_IO: + uart.port.iobase = regs->start; + break; + case IORESOURCE_MEM: + uart.port.mapbase = regs->start; + uart.port.mapsize = resource_size(regs); + uart.port.flags = UPF_IOREMAP; + break; + default: + return -EINVAL; + } + + /* default clock frequency */ + uart.port.uartclk = 1843200; + uart.port.type = PORT_16550A; + uart.port.dev = &pdev->dev; + uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF; + + ret = uart_read_and_validate_port_properties(&uart.port); + /* no interrupt -> fall back to polling */ + if (ret == -ENXIO) + ret = 0; + if (ret) + return ret; + + line = serial8250_register_8250_port(&uart); + if (line < 0) + return line; + + return 0; +} + +static int serial8250_probe_platform(struct platform_device *dev, struct plat_serial8250_port *p) +{ + struct uart_8250_port uart; + int ret, i, irqflag = 0; + + memset(&uart, 0, sizeof(uart)); + + if (share_irqs) + irqflag = IRQF_SHARED; + + for (i = 0; p && p->flags != 0; p++, i++) { + uart.port.iobase = p->iobase; + uart.port.membase = p->membase; + uart.port.irq = p->irq; + uart.port.irqflags = p->irqflags; + uart.port.uartclk = p->uartclk; + uart.port.regshift = p->regshift; + uart.port.iotype = p->iotype; + uart.port.flags = p->flags; + uart.port.mapbase = p->mapbase; + uart.port.mapsize = p->mapsize; + uart.port.hub6 = p->hub6; + uart.port.has_sysrq = p->has_sysrq; + uart.port.private_data = p->private_data; + uart.port.type = p->type; + uart.bugs = p->bugs; + uart.port.serial_in = p->serial_in; + uart.port.serial_out = p->serial_out; + uart.dl_read = p->dl_read; + uart.dl_write = p->dl_write; + uart.port.handle_irq = p->handle_irq; + uart.port.handle_break = p->handle_break; + uart.port.set_termios = p->set_termios; + uart.port.set_ldisc = p->set_ldisc; + uart.port.get_mctrl = p->get_mctrl; + uart.port.pm = p->pm; + uart.port.dev = &dev->dev; + uart.port.irqflags |= irqflag; + ret = serial8250_register_8250_port(&uart); + if (ret < 0) { + dev_err(&dev->dev, "unable to register port at index %d " + "(IO%lx MEM%llx IRQ%d): %d\n", i, + p->iobase, (unsigned long long)p->mapbase, + p->irq, ret); + } + } + return 0; +} + +/* + * Register a set of serial devices attached to a platform device. + * The list is terminated with a zero flags entry, which means we expect + * all entries to have at least UPF_BOOT_AUTOCONF set. + */ +static int serial8250_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct plat_serial8250_port *p; + + p = dev_get_platdata(dev); + if (p) + return serial8250_probe_platform(pdev, p); + + /* + * Probe platform UART devices defined using standard hardware + * discovery mechanism like ACPI or DT. Support only ACPI based + * serial device for now. + */ + if (has_acpi_companion(dev)) + return serial8250_probe_acpi(pdev); + + return 0; +} + +/* + * Remove serial ports registered against a platform device. + */ +static void serial8250_remove(struct platform_device *dev) +{ + int i; + + for (i = 0; i < nr_uarts; i++) { + struct uart_8250_port *up = serial8250_get_port(i); + + if (up->port.dev == &dev->dev) + serial8250_unregister_port(i); + } +} + +static int serial8250_suspend(struct platform_device *dev, pm_message_t state) +{ + int i; + + for (i = 0; i < UART_NR; i++) { + struct uart_8250_port *up = serial8250_get_port(i); + + if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) + uart_suspend_port(&serial8250_reg, &up->port); + } + + return 0; +} + +static int serial8250_resume(struct platform_device *dev) +{ + int i; + + for (i = 0; i < UART_NR; i++) { + struct uart_8250_port *up = serial8250_get_port(i); + + if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) + serial8250_resume_port(i); + } + + return 0; +} + +static const struct acpi_device_id acpi_platform_serial_table[] = { + { "RSCV0003" }, /* RISC-V Generic 16550A UART */ + { } +}; +MODULE_DEVICE_TABLE(acpi, acpi_platform_serial_table); + +static struct platform_driver serial8250_isa_driver = { + .probe = serial8250_probe, + .remove = serial8250_remove, + .suspend = serial8250_suspend, + .resume = serial8250_resume, + .driver = { + .name = "serial8250", + .acpi_match_table = acpi_platform_serial_table, + }, +}; + +/* + * This "device" covers _all_ ISA 8250-compatible serial devices listed + * in the table in include/asm/serial.h. + */ +struct platform_device *serial8250_isa_devs; + +static int __init serial8250_init(void) +{ + int ret; + + if (nr_uarts == 0) + return -ENODEV; + + serial8250_isa_init_ports(); + + pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n", + nr_uarts, str_enabled_disabled(share_irqs)); + +#ifdef CONFIG_SPARC + ret = sunserial_register_minors(&serial8250_reg, UART_NR); +#else + serial8250_reg.nr = UART_NR; + ret = uart_register_driver(&serial8250_reg); +#endif + if (ret) + goto out; + + ret = serial8250_pnp_init(); + if (ret) + goto unreg_uart_drv; + + serial8250_isa_devs = platform_device_alloc("serial8250", PLAT8250_DEV_LEGACY); + if (!serial8250_isa_devs) { + ret = -ENOMEM; + goto unreg_pnp; + } + + ret = platform_device_add(serial8250_isa_devs); + if (ret) + goto put_dev; + + serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev); + + ret = platform_driver_register(&serial8250_isa_driver); + if (ret == 0) + goto out; + + platform_device_del(serial8250_isa_devs); +put_dev: + platform_device_put(serial8250_isa_devs); +unreg_pnp: + serial8250_pnp_exit(); +unreg_uart_drv: +#ifdef CONFIG_SPARC + sunserial_unregister_minors(&serial8250_reg, UART_NR); +#else + uart_unregister_driver(&serial8250_reg); +#endif +out: + return ret; +} +module_init(serial8250_init); + +static void __exit serial8250_exit(void) +{ + struct platform_device *isa_dev = serial8250_isa_devs; + + /* + * This tells serial8250_unregister_port() not to re-register + * the ports (thereby making serial8250_isa_driver permanently + * in use). + */ + serial8250_isa_devs = NULL; + + platform_driver_unregister(&serial8250_isa_driver); + platform_device_unregister(isa_dev); + + serial8250_pnp_exit(); + +#ifdef CONFIG_SPARC + sunserial_unregister_minors(&serial8250_reg, UART_NR); +#else + uart_unregister_driver(&serial8250_reg); +#endif +} +module_exit(serial8250_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Generic 8250/16x50 serial platform driver"); + +module_param_hw(share_irqs, uint, other, 0644); +MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)"); + +module_param(nr_uarts, uint, 0644); +MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")"); + +module_param(skip_txen_test, uint, 0644); +MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time"); + +MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); + +#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS +#ifndef MODULE +/* + * This module was renamed to 8250_core in 3.7. Keep the old "8250" name + * working as well for the module options so we don't break people. We + * need to keep the names identical and the convenient macros will happily + * refuse to let us do that by failing the build with redefinition errors + * of global variables. So we stick them inside a dummy function to avoid + * those conflicts. The options still get parsed, and the redefined + * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive. + * + * This is hacky. I'm sorry. + */ +static void __used s8250_options(void) +{ +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "8250_core." + + module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644); + module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644); + module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644); +} +#else +MODULE_ALIAS("8250_core"); +#endif +#endif |