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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Universal/legacy platform driver for 8250/16550-type serial ports4 *5 * Supports:6 * ISA-compatible 8250/16550 ports7 * ACPI 8250/16550 ports8 * PNP 8250/16550 ports9 * "serial8250" platform devices10 */11#include <linux/acpi.h>12#include <linux/array_size.h>13#include <linux/io.h>14#include <linux/module.h>15#include <linux/moduleparam.h>16#include <linux/once.h>17#include <linux/platform_device.h>18 19#include <linux/serial_8250.h>20 21#ifdef CONFIG_SPARC22#include <linux/sunserialcore.h>23#endif24 25#include "8250.h"26 27/*28 * Configuration:29 * share_irqs: Whether we pass IRQF_SHARED to request_irq().30 * This option is unsafe when used on edge-triggered interrupts.31 * skip_txen_test: Force skip of txen test at init time.32 */33unsigned int share_irqs = SERIAL8250_SHARE_IRQS;34unsigned int skip_txen_test;35 36unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;37 38#include <asm/serial.h>39 40/*41 * SERIAL_PORT_DFNS tells us about built-in ports that have no42 * standard enumeration mechanism. Platforms that can find all43 * serial ports via mechanisms like ACPI or PCI need not supply it.44 */45#ifndef SERIAL_PORT_DFNS46#define SERIAL_PORT_DFNS47#endif48 49static const struct old_serial_port old_serial_port[] = {50 SERIAL_PORT_DFNS /* defined in asm/serial.h */51};52 53serial8250_isa_config_fn serial8250_isa_config;54void serial8250_set_isa_configurator(serial8250_isa_config_fn v)55{56 serial8250_isa_config = v;57}58EXPORT_SYMBOL(serial8250_set_isa_configurator);59 60static void __init __serial8250_isa_init_ports(void)61{62 int i, irqflag = 0;63 64 if (nr_uarts > UART_NR)65 nr_uarts = UART_NR;66 67 /*68 * Set up initial ISA ports based on nr_uart module param, or else69 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not70 * need to increase nr_uarts when setting up the initial ISA ports.71 */72 for (i = 0; i < nr_uarts; i++)73 serial8250_setup_port(i);74 75 /* chain base port ops to support Remote Supervisor Adapter */76 univ8250_port_ops = *univ8250_port_base_ops;77 univ8250_rsa_support(&univ8250_port_ops);78 79 if (share_irqs)80 irqflag = IRQF_SHARED;81 82 for (i = 0; i < ARRAY_SIZE(old_serial_port) && i < nr_uarts; i++) {83 struct uart_8250_port *up = serial8250_get_port(i);84 struct uart_port *port = &up->port;85 86 port->iobase = old_serial_port[i].port;87 port->irq = irq_canonicalize(old_serial_port[i].irq);88 port->irqflags = 0;89 port->uartclk = old_serial_port[i].baud_base * 16;90 port->flags = old_serial_port[i].flags;91 port->hub6 = 0;92 port->membase = old_serial_port[i].iomem_base;93 port->iotype = old_serial_port[i].io_type;94 port->regshift = old_serial_port[i].iomem_reg_shift;95 96 port->irqflags |= irqflag;97 if (serial8250_isa_config != NULL)98 serial8250_isa_config(i, &up->port, &up->capabilities);99 }100}101 102void __init serial8250_isa_init_ports(void)103{104 DO_ONCE(__serial8250_isa_init_ports);105}106 107/*108 * Generic 16550A platform devices109 */110static int serial8250_probe_acpi(struct platform_device *pdev)111{112 struct device *dev = &pdev->dev;113 struct uart_8250_port uart = { };114 struct resource *regs;115 unsigned char iotype;116 int ret, line;117 118 regs = platform_get_mem_or_io(pdev, 0);119 if (!regs)120 return dev_err_probe(dev, -EINVAL, "no registers defined\n");121 122 switch (resource_type(regs)) {123 case IORESOURCE_IO:124 uart.port.iobase = regs->start;125 iotype = UPIO_PORT;126 break;127 case IORESOURCE_MEM:128 uart.port.mapbase = regs->start;129 uart.port.mapsize = resource_size(regs);130 uart.port.flags = UPF_IOREMAP;131 iotype = UPIO_MEM;132 break;133 default:134 return -EINVAL;135 }136 137 /* default clock frequency */138 uart.port.uartclk = 1843200;139 uart.port.type = PORT_16550A;140 uart.port.dev = &pdev->dev;141 uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;142 143 ret = uart_read_and_validate_port_properties(&uart.port);144 /* no interrupt -> fall back to polling */145 if (ret == -ENXIO)146 ret = 0;147 if (ret)148 return ret;149 150 /*151 * The previous call may not set iotype correctly when reg-io-width152 * property is absent and it doesn't support IO port resource.153 */154 uart.port.iotype = iotype;155 156 line = serial8250_register_8250_port(&uart);157 if (line < 0)158 return line;159 160 return 0;161}162 163static int serial8250_probe_platform(struct platform_device *dev, struct plat_serial8250_port *p)164{165 struct uart_8250_port uart;166 int ret, i, irqflag = 0;167 168 memset(&uart, 0, sizeof(uart));169 170 if (share_irqs)171 irqflag = IRQF_SHARED;172 173 for (i = 0; p && p->flags != 0; p++, i++) {174 uart.port.iobase = p->iobase;175 uart.port.membase = p->membase;176 uart.port.irq = p->irq;177 uart.port.irqflags = p->irqflags;178 uart.port.uartclk = p->uartclk;179 uart.port.regshift = p->regshift;180 uart.port.iotype = p->iotype;181 uart.port.flags = p->flags;182 uart.port.mapbase = p->mapbase;183 uart.port.mapsize = p->mapsize;184 uart.port.hub6 = p->hub6;185 uart.port.has_sysrq = p->has_sysrq;186 uart.port.private_data = p->private_data;187 uart.port.type = p->type;188 uart.bugs = p->bugs;189 uart.port.serial_in = p->serial_in;190 uart.port.serial_out = p->serial_out;191 uart.dl_read = p->dl_read;192 uart.dl_write = p->dl_write;193 uart.port.handle_irq = p->handle_irq;194 uart.port.handle_break = p->handle_break;195 uart.port.set_termios = p->set_termios;196 uart.port.set_ldisc = p->set_ldisc;197 uart.port.get_mctrl = p->get_mctrl;198 uart.port.pm = p->pm;199 uart.port.dev = &dev->dev;200 uart.port.irqflags |= irqflag;201 ret = serial8250_register_8250_port(&uart);202 if (ret < 0) {203 dev_err(&dev->dev, "unable to register port at index %d "204 "(IO%lx MEM%llx IRQ%d): %d\n", i,205 p->iobase, (unsigned long long)p->mapbase,206 p->irq, ret);207 }208 }209 return 0;210}211 212/*213 * Register a set of serial devices attached to a platform device.214 * The list is terminated with a zero flags entry, which means we expect215 * all entries to have at least UPF_BOOT_AUTOCONF set.216 */217static int serial8250_probe(struct platform_device *pdev)218{219 struct device *dev = &pdev->dev;220 struct plat_serial8250_port *p;221 222 p = dev_get_platdata(dev);223 if (p)224 return serial8250_probe_platform(pdev, p);225 226 /*227 * Probe platform UART devices defined using standard hardware228 * discovery mechanism like ACPI or DT. Support only ACPI based229 * serial device for now.230 */231 if (has_acpi_companion(dev))232 return serial8250_probe_acpi(pdev);233 234 return 0;235}236 237/*238 * Remove serial ports registered against a platform device.239 */240static void serial8250_remove(struct platform_device *dev)241{242 int i;243 244 for (i = 0; i < nr_uarts; i++) {245 struct uart_8250_port *up = serial8250_get_port(i);246 247 if (up->port.dev == &dev->dev)248 serial8250_unregister_port(i);249 }250}251 252static int serial8250_suspend(struct platform_device *dev, pm_message_t state)253{254 int i;255 256 for (i = 0; i < UART_NR; i++) {257 struct uart_8250_port *up = serial8250_get_port(i);258 259 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)260 uart_suspend_port(&serial8250_reg, &up->port);261 }262 263 return 0;264}265 266static int serial8250_resume(struct platform_device *dev)267{268 int i;269 270 for (i = 0; i < UART_NR; i++) {271 struct uart_8250_port *up = serial8250_get_port(i);272 273 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)274 serial8250_resume_port(i);275 }276 277 return 0;278}279 280static const struct acpi_device_id acpi_platform_serial_table[] = {281 { "RSCV0003" }, /* RISC-V Generic 16550A UART */282 { }283};284MODULE_DEVICE_TABLE(acpi, acpi_platform_serial_table);285 286static struct platform_driver serial8250_isa_driver = {287 .probe = serial8250_probe,288 .remove_new = serial8250_remove,289 .suspend = serial8250_suspend,290 .resume = serial8250_resume,291 .driver = {292 .name = "serial8250",293 .acpi_match_table = acpi_platform_serial_table,294 },295};296 297/*298 * This "device" covers _all_ ISA 8250-compatible serial devices listed299 * in the table in include/asm/serial.h.300 */301struct platform_device *serial8250_isa_devs;302 303static int __init serial8250_init(void)304{305 int ret;306 307 if (nr_uarts == 0)308 return -ENODEV;309 310 serial8250_isa_init_ports();311 312 pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n",313 nr_uarts, str_enabled_disabled(share_irqs));314 315#ifdef CONFIG_SPARC316 ret = sunserial_register_minors(&serial8250_reg, UART_NR);317#else318 serial8250_reg.nr = UART_NR;319 ret = uart_register_driver(&serial8250_reg);320#endif321 if (ret)322 goto out;323 324 ret = serial8250_pnp_init();325 if (ret)326 goto unreg_uart_drv;327 328 serial8250_isa_devs = platform_device_alloc("serial8250", PLAT8250_DEV_LEGACY);329 if (!serial8250_isa_devs) {330 ret = -ENOMEM;331 goto unreg_pnp;332 }333 334 ret = platform_device_add(serial8250_isa_devs);335 if (ret)336 goto put_dev;337 338 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);339 340 ret = platform_driver_register(&serial8250_isa_driver);341 if (ret == 0)342 goto out;343 344 platform_device_del(serial8250_isa_devs);345put_dev:346 platform_device_put(serial8250_isa_devs);347unreg_pnp:348 serial8250_pnp_exit();349unreg_uart_drv:350#ifdef CONFIG_SPARC351 sunserial_unregister_minors(&serial8250_reg, UART_NR);352#else353 uart_unregister_driver(&serial8250_reg);354#endif355out:356 return ret;357}358module_init(serial8250_init);359 360static void __exit serial8250_exit(void)361{362 struct platform_device *isa_dev = serial8250_isa_devs;363 364 /*365 * This tells serial8250_unregister_port() not to re-register366 * the ports (thereby making serial8250_isa_driver permanently367 * in use).368 */369 serial8250_isa_devs = NULL;370 371 platform_driver_unregister(&serial8250_isa_driver);372 platform_device_unregister(isa_dev);373 374 serial8250_pnp_exit();375 376#ifdef CONFIG_SPARC377 sunserial_unregister_minors(&serial8250_reg, UART_NR);378#else379 uart_unregister_driver(&serial8250_reg);380#endif381}382module_exit(serial8250_exit);383 384MODULE_LICENSE("GPL");385MODULE_DESCRIPTION("Generic 8250/16x50 serial platform driver");386 387module_param_hw(share_irqs, uint, other, 0644);388MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)");389 390module_param(nr_uarts, uint, 0644);391MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");392 393module_param(skip_txen_test, uint, 0644);394MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");395 396MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);397 398#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS399#ifndef MODULE400/*401 * This module was renamed to 8250_core in 3.7. Keep the old "8250" name402 * working as well for the module options so we don't break people. We403 * need to keep the names identical and the convenient macros will happily404 * refuse to let us do that by failing the build with redefinition errors405 * of global variables. So we stick them inside a dummy function to avoid406 * those conflicts. The options still get parsed, and the redefined407 * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive.408 *409 * This is hacky. I'm sorry.410 */411static void __used s8250_options(void)412{413#undef MODULE_PARAM_PREFIX414#define MODULE_PARAM_PREFIX "8250_core."415 416 module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644);417 module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644);418 module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644);419}420#else421MODULE_ALIAS("8250_core");422#endif423#endif424