1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Universal/legacy platform driver for 8250/16550-type serial ports 4 * 5 * Supports: 6 * ISA-compatible 8250/16550 ports 7 * ACPI 8250/16550 ports 8 * PNP 8250/16550 ports 9 * "serial8250" platform devices 10 */ 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_SPARC 22 #include <linux/sunserialcore.h> 23 #endif 24 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 */ 33 unsigned int share_irqs = SERIAL8250_SHARE_IRQS; 34 unsigned int skip_txen_test; 35 36 unsigned 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 no 42 * standard enumeration mechanism. Platforms that can find all 43 * serial ports via mechanisms like ACPI or PCI need not supply it. 44 */ 45 #ifndef SERIAL_PORT_DFNS 46 #define SERIAL_PORT_DFNS 47 #endif 48 49 static const struct old_serial_port old_serial_port[] = { 50 SERIAL_PORT_DFNS /* defined in asm/serial.h */ 51 }; 52 53 serial8250_isa_config_fn serial8250_isa_config; 54 void serial8250_set_isa_configurator(serial8250_isa_config_fn v) 55 { 56 serial8250_isa_config = v; 57 } 58 EXPORT_SYMBOL(serial8250_set_isa_configurator); 59 60 static 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 else 69 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not 70 * 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 } 101 102 void __init serial8250_isa_init_ports(void) 103 { 104 DO_ONCE(__serial8250_isa_init_ports); 105 } 106 107 /* 108 * Generic 16550A platform devices 109 */ 110 static 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 int ret, line; 116 117 regs = platform_get_mem_or_io(pdev, 0); 118 if (!regs) 119 return dev_err_probe(dev, -EINVAL, "no registers defined\n"); 120 121 switch (resource_type(regs)) { 122 case IORESOURCE_IO: 123 uart.port.iobase = regs->start; 124 break; 125 case IORESOURCE_MEM: 126 uart.port.mapbase = regs->start; 127 uart.port.mapsize = resource_size(regs); 128 uart.port.flags = UPF_IOREMAP; 129 break; 130 default: 131 return -EINVAL; 132 } 133 134 /* default clock frequency */ 135 uart.port.uartclk = 1843200; 136 uart.port.type = PORT_16550A; 137 uart.port.dev = &pdev->dev; 138 uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF; 139 140 ret = uart_read_and_validate_port_properties(&uart.port); 141 /* no interrupt -> fall back to polling */ 142 if (ret == -ENXIO) 143 ret = 0; 144 if (ret) 145 return ret; 146 147 line = serial8250_register_8250_port(&uart); 148 if (line < 0) 149 return line; 150 151 return 0; 152 } 153 154 static int serial8250_probe_platform(struct platform_device *dev, struct plat_serial8250_port *p) 155 { 156 struct uart_8250_port uart; 157 int ret, i, irqflag = 0; 158 159 memset(&uart, 0, sizeof(uart)); 160 161 if (share_irqs) 162 irqflag = IRQF_SHARED; 163 164 for (i = 0; p && p->flags != 0; p++, i++) { 165 uart.port.iobase = p->iobase; 166 uart.port.membase = p->membase; 167 uart.port.irq = p->irq; 168 uart.port.irqflags = p->irqflags; 169 uart.port.uartclk = p->uartclk; 170 uart.port.regshift = p->regshift; 171 uart.port.iotype = p->iotype; 172 uart.port.flags = p->flags; 173 uart.port.mapbase = p->mapbase; 174 uart.port.mapsize = p->mapsize; 175 uart.port.hub6 = p->hub6; 176 uart.port.has_sysrq = p->has_sysrq; 177 uart.port.private_data = p->private_data; 178 uart.port.type = p->type; 179 uart.bugs = p->bugs; 180 uart.port.serial_in = p->serial_in; 181 uart.port.serial_out = p->serial_out; 182 uart.dl_read = p->dl_read; 183 uart.dl_write = p->dl_write; 184 uart.port.handle_irq = p->handle_irq; 185 uart.port.handle_break = p->handle_break; 186 uart.port.set_termios = p->set_termios; 187 uart.port.set_ldisc = p->set_ldisc; 188 uart.port.get_mctrl = p->get_mctrl; 189 uart.port.pm = p->pm; 190 uart.port.dev = &dev->dev; 191 uart.port.irqflags |= irqflag; 192 ret = serial8250_register_8250_port(&uart); 193 if (ret < 0) { 194 dev_err(&dev->dev, "unable to register port at index %d " 195 "(IO%lx MEM%llx IRQ%d): %d\n", i, 196 p->iobase, (unsigned long long)p->mapbase, 197 p->irq, ret); 198 } 199 } 200 return 0; 201 } 202 203 /* 204 * Register a set of serial devices attached to a platform device. 205 * The list is terminated with a zero flags entry, which means we expect 206 * all entries to have at least UPF_BOOT_AUTOCONF set. 207 */ 208 static int serial8250_probe(struct platform_device *pdev) 209 { 210 struct device *dev = &pdev->dev; 211 struct plat_serial8250_port *p; 212 213 p = dev_get_platdata(dev); 214 if (p) 215 return serial8250_probe_platform(pdev, p); 216 217 /* 218 * Probe platform UART devices defined using standard hardware 219 * discovery mechanism like ACPI or DT. Support only ACPI based 220 * serial device for now. 221 */ 222 if (has_acpi_companion(dev)) 223 return serial8250_probe_acpi(pdev); 224 225 return 0; 226 } 227 228 /* 229 * Remove serial ports registered against a platform device. 230 */ 231 static void serial8250_remove(struct platform_device *dev) 232 { 233 int i; 234 235 for (i = 0; i < nr_uarts; i++) { 236 struct uart_8250_port *up = serial8250_get_port(i); 237 238 if (up->port.dev == &dev->dev) 239 serial8250_unregister_port(i); 240 } 241 } 242 243 static int serial8250_suspend(struct platform_device *dev, pm_message_t state) 244 { 245 int i; 246 247 for (i = 0; i < UART_NR; i++) { 248 struct uart_8250_port *up = serial8250_get_port(i); 249 250 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) 251 uart_suspend_port(&serial8250_reg, &up->port); 252 } 253 254 return 0; 255 } 256 257 static int serial8250_resume(struct platform_device *dev) 258 { 259 int i; 260 261 for (i = 0; i < UART_NR; i++) { 262 struct uart_8250_port *up = serial8250_get_port(i); 263 264 if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev) 265 serial8250_resume_port(i); 266 } 267 268 return 0; 269 } 270 271 static const struct acpi_device_id acpi_platform_serial_table[] = { 272 { "RSCV0003" }, /* RISC-V Generic 16550A UART */ 273 { } 274 }; 275 MODULE_DEVICE_TABLE(acpi, acpi_platform_serial_table); 276 277 static struct platform_driver serial8250_isa_driver = { 278 .probe = serial8250_probe, 279 .remove = serial8250_remove, 280 .suspend = serial8250_suspend, 281 .resume = serial8250_resume, 282 .driver = { 283 .name = "serial8250", 284 .acpi_match_table = acpi_platform_serial_table, 285 }, 286 }; 287 288 /* 289 * This "device" covers _all_ ISA 8250-compatible serial devices listed 290 * in the table in include/asm/serial.h. 291 */ 292 struct platform_device *serial8250_isa_devs; 293 294 static int __init serial8250_init(void) 295 { 296 int ret; 297 298 if (nr_uarts == 0) 299 return -ENODEV; 300 301 serial8250_isa_init_ports(); 302 303 pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n", 304 nr_uarts, str_enabled_disabled(share_irqs)); 305 306 #ifdef CONFIG_SPARC 307 ret = sunserial_register_minors(&serial8250_reg, UART_NR); 308 #else 309 serial8250_reg.nr = UART_NR; 310 ret = uart_register_driver(&serial8250_reg); 311 #endif 312 if (ret) 313 goto out; 314 315 ret = serial8250_pnp_init(); 316 if (ret) 317 goto unreg_uart_drv; 318 319 serial8250_isa_devs = platform_device_alloc("serial8250", PLAT8250_DEV_LEGACY); 320 if (!serial8250_isa_devs) { 321 ret = -ENOMEM; 322 goto unreg_pnp; 323 } 324 325 ret = platform_device_add(serial8250_isa_devs); 326 if (ret) 327 goto put_dev; 328 329 serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev); 330 331 ret = platform_driver_register(&serial8250_isa_driver); 332 if (ret == 0) 333 goto out; 334 335 platform_device_del(serial8250_isa_devs); 336 put_dev: 337 platform_device_put(serial8250_isa_devs); 338 unreg_pnp: 339 serial8250_pnp_exit(); 340 unreg_uart_drv: 341 #ifdef CONFIG_SPARC 342 sunserial_unregister_minors(&serial8250_reg, UART_NR); 343 #else 344 uart_unregister_driver(&serial8250_reg); 345 #endif 346 out: 347 return ret; 348 } 349 module_init(serial8250_init); 350 351 static void __exit serial8250_exit(void) 352 { 353 struct platform_device *isa_dev = serial8250_isa_devs; 354 355 /* 356 * This tells serial8250_unregister_port() not to re-register 357 * the ports (thereby making serial8250_isa_driver permanently 358 * in use). 359 */ 360 serial8250_isa_devs = NULL; 361 362 platform_driver_unregister(&serial8250_isa_driver); 363 platform_device_unregister(isa_dev); 364 365 serial8250_pnp_exit(); 366 367 #ifdef CONFIG_SPARC 368 sunserial_unregister_minors(&serial8250_reg, UART_NR); 369 #else 370 uart_unregister_driver(&serial8250_reg); 371 #endif 372 } 373 module_exit(serial8250_exit); 374 375 MODULE_LICENSE("GPL"); 376 MODULE_DESCRIPTION("Generic 8250/16x50 serial platform driver"); 377 378 module_param_hw(share_irqs, uint, other, 0644); 379 MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)"); 380 381 module_param(nr_uarts, uint, 0644); 382 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")"); 383 384 module_param(skip_txen_test, uint, 0644); 385 MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time"); 386 387 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); 388 389 #ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS 390 #ifndef MODULE 391 /* 392 * This module was renamed to 8250_core in 3.7. Keep the old "8250" name 393 * working as well for the module options so we don't break people. We 394 * need to keep the names identical and the convenient macros will happily 395 * refuse to let us do that by failing the build with redefinition errors 396 * of global variables. So we stick them inside a dummy function to avoid 397 * those conflicts. The options still get parsed, and the redefined 398 * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive. 399 * 400 * This is hacky. I'm sorry. 401 */ 402 static void __used s8250_options(void) 403 { 404 #undef MODULE_PARAM_PREFIX 405 #define MODULE_PARAM_PREFIX "8250_core." 406 407 module_param_cb(share_irqs, ¶m_ops_uint, &share_irqs, 0644); 408 module_param_cb(nr_uarts, ¶m_ops_uint, &nr_uarts, 0644); 409 module_param_cb(skip_txen_test, ¶m_ops_uint, &skip_txen_test, 0644); 410 } 411 #else 412 MODULE_ALIAS("8250_core"); 413 #endif 414 #endif 415