LXR linux/drivers/tty/serial/8250/8250

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Driver for the 98626/98644/internal serial interface on hp300/hp400
   4 * (based on the National Semiconductor INS8250/NS16550AF/WD16C552 UARTs)
   5 *
   6 * Ported from 2.2 and modified to use the normal 8250 driver
   7 * by Kars de Jong <jongk@linux-m68k.org>, May 2004.
   8 */
   9#include <linux/module.h>
  10#include <linux/init.h>
  11#include <linux/string.h>
  12#include <linux/kernel.h>
  13#include <linux/serial.h>
  14#include <linux/serial_8250.h>
  15#include <linux/delay.h>
  16#include <linux/dio.h>
  17#include <linux/console.h>
  18#include <linux/slab.h>
  19#include <asm/io.h>
  20
  21#include "8250.h"
  22
  23#if !defined(CONFIG_HPDCA) && !defined(CONFIG_HPAPCI) && !defined(CONFIG_COMPILE_TEST)
  24#warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
  25#endif
  26
  27#ifdef CONFIG_HPAPCI
  28struct hp300_port {
  29        struct hp300_port *next;        /* next port */
  30        int line;                       /* line (tty) number */
  31};
  32
  33static struct hp300_port *hp300_ports;
  34#endif
  35
  36#ifdef CONFIG_HPDCA
  37
  38static int hpdca_init_one(struct dio_dev *d,
  39                                        const struct dio_device_id *ent);
  40static void hpdca_remove_one(struct dio_dev *d);
  41
  42static struct dio_device_id hpdca_dio_tbl[] = {
  43        { DIO_ID_DCA0 },
  44        { DIO_ID_DCA0REM },
  45        { DIO_ID_DCA1 },
  46        { DIO_ID_DCA1REM },
  47        { 0 }
  48};
  49
  50static struct dio_driver hpdca_driver = {
  51        .name      = "hpdca",
  52        .id_table  = hpdca_dio_tbl,
  53        .probe     = hpdca_init_one,
  54        .remove    = hpdca_remove_one,
  55};
  56
  57#endif
  58
  59static unsigned int num_ports;
  60
  61extern int hp300_uart_scode;
  62
  63/* Offset to UART registers from base of DCA */
  64#define UART_OFFSET     17
  65
  66#define DCA_ID          0x01    /* ID (read), reset (write) */
  67#define DCA_IC          0x03    /* Interrupt control        */
  68
  69/* Interrupt control */
  70#define DCA_IC_IE       0x80    /* Master interrupt enable  */
  71
  72#define HPDCA_BAUD_BASE 153600
  73
  74/* Base address of the Frodo part */
  75#define FRODO_BASE      (0x41c000)
  76
  77/*
  78 * Where we find the 8250-like APCI ports, and how far apart they are.
  79 */
  80#define FRODO_APCIBASE          0x0
  81#define FRODO_APCISPACE         0x20
  82#define FRODO_APCI_OFFSET(x)    (FRODO_APCIBASE + ((x) * FRODO_APCISPACE))
  83
  84#define HPAPCI_BAUD_BASE 500400
  85
  86#ifdef CONFIG_SERIAL_8250_CONSOLE
  87/*
  88 * Parse the bootinfo to find descriptions for headless console and
  89 * debug serial ports and register them with the 8250 driver.
  90 */
  91int __init hp300_setup_serial_console(void)
  92{
  93        int scode;
  94        struct uart_port port;
  95
  96        memset(&port, 0, sizeof(port));
  97
  98        if (hp300_uart_scode < 0 || hp300_uart_scode > DIO_SCMAX)
  99                return 0;
 100
 101        if (DIO_SCINHOLE(hp300_uart_scode))
 102                return 0;
 103
 104        scode = hp300_uart_scode;
 105
 106        /* Memory mapped I/O */
 107        port.iotype = UPIO_MEM;
 108        port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
 109        port.type = PORT_UNKNOWN;
 110
 111        /* Check for APCI console */
 112        if (scode == 256) {
 113#ifdef CONFIG_HPAPCI
 114                pr_info("Serial console is HP APCI 1\n");
 115
 116                port.uartclk = HPAPCI_BAUD_BASE * 16;
 117                port.mapbase = (FRODO_BASE + FRODO_APCI_OFFSET(1));
 118                port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
 119                port.regshift = 2;
 120                add_preferred_console("ttyS", port.line, "9600n8");
 121#else
 122                pr_warn("Serial console is APCI but support is disabled (CONFIG_HPAPCI)!\n");
 123                return 0;
 124#endif
 125        } else {
 126#ifdef CONFIG_HPDCA
 127                unsigned long pa = dio_scodetophysaddr(scode);
 128                if (!pa)
 129                        return 0;
 130
 131                pr_info("Serial console is HP DCA at select code %d\n", scode);
 132
 133                port.uartclk = HPDCA_BAUD_BASE * 16;
 134                port.mapbase = (pa + UART_OFFSET);
 135                port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
 136                port.regshift = 1;
 137                port.irq = DIO_IPL(pa + DIO_VIRADDRBASE);
 138
 139                /* Enable board-interrupts */
 140                out_8(pa + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
 141
 142                if (DIO_ID(pa + DIO_VIRADDRBASE) & 0x80)
 143                        add_preferred_console("ttyS", port.line, "9600n8");
 144#else
 145                pr_warn("Serial console is DCA but support is disabled (CONFIG_HPDCA)!\n");
 146                return 0;
 147#endif
 148        }
 149
 150        if (early_serial_setup(&port) < 0)
 151                pr_warn("%s: early_serial_setup() failed.\n", __func__);
 152        return 0;
 153}
 154#endif /* CONFIG_SERIAL_8250_CONSOLE */
 155
 156#ifdef CONFIG_HPDCA
 157static int hpdca_init_one(struct dio_dev *d,
 158                                const struct dio_device_id *ent)
 159{
 160        struct uart_8250_port uart;
 161        int line;
 162
 163#ifdef CONFIG_SERIAL_8250_CONSOLE
 164        if (hp300_uart_scode == d->scode) {
 165                /* Already got it. */
 166                return 0;
 167        }
 168#endif
 169        memset(&uart, 0, sizeof(uart));
 170
 171        /* Memory mapped I/O */
 172        uart.port.iotype = UPIO_MEM;
 173        uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
 174        uart.port.irq = d->ipl;
 175        uart.port.uartclk = HPDCA_BAUD_BASE * 16;
 176        uart.port.mapbase = (d->resource.start + UART_OFFSET);
 177        uart.port.membase = (char *)(uart.port.mapbase + DIO_VIRADDRBASE);
 178        uart.port.regshift = 1;
 179        uart.port.dev = &d->dev;
 180        line = serial8250_register_8250_port(&uart);
 181
 182        if (line < 0) {
 183                dev_notice(&d->dev,
 184                          "8250_hp300: register_serial() DCA scode %d irq %d failed\n",
 185                          d->scode, uart.port.irq);
 186                return -ENOMEM;
 187        }
 188
 189        /* Enable board-interrupts */
 190        out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
 191        dio_set_drvdata(d, (void *)line);
 192
 193        /* Reset the DCA */
 194        out_8(d->resource.start + DIO_VIRADDRBASE + DCA_ID, 0xff);
 195        udelay(100);
 196
 197        num_ports++;
 198
 199        return 0;
 200}
 201#endif
 202
 203static int __init hp300_8250_init(void)
 204{
 205        static int called;
 206#ifdef CONFIG_HPAPCI
 207        int line;
 208        unsigned long base;
 209        struct uart_8250_port uart;
 210        struct hp300_port *port;
 211        int i;
 212#endif
 213        if (called)
 214                return -ENODEV;
 215        called = 1;
 216
 217        if (!MACH_IS_HP300)
 218                return -ENODEV;
 219
 220#ifdef CONFIG_HPDCA
 221        dio_register_driver(&hpdca_driver);
 222#endif
 223#ifdef CONFIG_HPAPCI
 224        if (hp300_model < HP_400) {
 225                if (!num_ports)
 226                        return -ENODEV;
 227                return 0;
 228        }
 229        /* These models have the Frodo chip.
 230         * Port 0 is reserved for the Apollo Domain keyboard.
 231         * Port 1 is either the console or the DCA.
 232         */
 233        for (i = 1; i < 4; i++) {
 234                /* Port 1 is the console on a 425e, on other machines it's
 235                 * mapped to DCA.
 236                 */
 237#ifdef CONFIG_SERIAL_8250_CONSOLE
 238                if (i == 1)
 239                        continue;
 240#endif
 241
 242                /* Create new serial device */
 243                port = kmalloc(sizeof(struct hp300_port), GFP_KERNEL);
 244                if (!port)
 245                        return -ENOMEM;
 246
 247                memset(&uart, 0, sizeof(uart));
 248
 249                base = (FRODO_BASE + FRODO_APCI_OFFSET(i));
 250
 251                /* Memory mapped I/O */
 252                uart.port.iotype = UPIO_MEM;
 253                uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ
 254                                | UPF_BOOT_AUTOCONF;
 255                /* XXX - no interrupt support yet */
 256                uart.port.irq = 0;
 257                uart.port.uartclk = HPAPCI_BAUD_BASE * 16;
 258                uart.port.mapbase = base;
 259                uart.port.membase = (char *)(base + DIO_VIRADDRBASE);
 260                uart.port.regshift = 2;
 261
 262                line = serial8250_register_8250_port(&uart);
 263
 264                if (line < 0) {
 265                        dev_notice(uart.port.dev,
 266                                   "8250_hp300: register_serial() APCI %d irq %d failed\n",
 267                                   i, uart.port.irq);
 268                        kfree(port);
 269                        continue;
 270                }
 271
 272                port->line = line;
 273                port->next = hp300_ports;
 274                hp300_ports = port;
 275
 276                num_ports++;
 277        }
 278#endif
 279
 280        /* Any boards found? */
 281        if (!num_ports)
 282                return -ENODEV;
 283
 284        return 0;
 285}
 286
 287#ifdef CONFIG_HPDCA
 288static void hpdca_remove_one(struct dio_dev *d)
 289{
 290        int line;
 291
 292        line = (int) dio_get_drvdata(d);
 293        if (d->resource.start) {
 294                /* Disable board-interrupts */
 295                out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, 0);
 296        }
 297        serial8250_unregister_port(line);
 298}
 299#endif
 300
 301static void __exit hp300_8250_exit(void)
 302{
 303#ifdef CONFIG_HPAPCI
 304        struct hp300_port *port, *to_free;
 305
 306        for (port = hp300_ports; port; ) {
 307                serial8250_unregister_port(port->line);
 308                to_free = port;
 309                port = port->next;
 310                kfree(to_free);
 311        }
 312
 313        hp300_ports = NULL;
 314#endif
 315#ifdef CONFIG_HPDCA
 316        dio_unregister_driver(&hpdca_driver);
 317#endif
 318}
 319
 320module_init(hp300_8250_init);
 321module_exit(hp300_8250_exit);
 322MODULE_DESCRIPTION("HP DCA/APCI serial driver");
 323MODULE_AUTHOR("Kars de Jong <jongk@linux-m68k.org>");
 324MODULE_LICENSE("GPL");
 325