// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for the 98626/98644/internal serial interface on hp300/hp400
 * (based on the National Semiconductor INS8250/NS16550AF/WD16C552 UARTs)
 *
 * Ported from 2.2 and modified to use the normal 8250 driver
 * by Kars de Jong <jongk@linux-m68k.org>, May 2004.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <linux/delay.h>
#include <linux/dio.h>
#include <linux/console.h>
#include <linux/slab.h>
#include <asm/io.h>

#include "8250.h"

#if !defined(CONFIG_HPDCA) && !defined(CONFIG_HPAPCI) && !defined(CONFIG_COMPILE_TEST)
#warning CONFIG_SERIAL_8250 defined but neither CONFIG_HPDCA nor CONFIG_HPAPCI defined, are you sure?
#endif

#ifdef CONFIG_HPAPCI
struct hp300_port {
        struct hp300_port *next;        /* next port */
        int line;                       /* line (tty) number */
};

static struct hp300_port *hp300_ports;
#endif

#ifdef CONFIG_HPDCA

static int hpdca_init_one(struct dio_dev *d,
                                        const struct dio_device_id *ent);
static void hpdca_remove_one(struct dio_dev *d);

static struct dio_device_id hpdca_dio_tbl[] = {
        { DIO_ID_DCA0 },
        { DIO_ID_DCA0REM },
        { DIO_ID_DCA1 },
        { DIO_ID_DCA1REM },
        { 0 }
};

static struct dio_driver hpdca_driver = {
        .name      = "hpdca",
        .id_table  = hpdca_dio_tbl,
        .probe     = hpdca_init_one,
        .remove    = hpdca_remove_one,
};

#endif

static unsigned int num_ports;

extern int hp300_uart_scode;

/* Offset to UART registers from base of DCA */
#define UART_OFFSET     17

#define DCA_ID          0x01    /* ID (read), reset (write) */
#define DCA_IC          0x03    /* Interrupt control        */

/* Interrupt control */
#define DCA_IC_IE       0x80    /* Master interrupt enable  */

#define HPDCA_BAUD_BASE 153600

/* Base address of the Frodo part */
#define FRODO_BASE      (0x41c000)

/*
 * Where we find the 8250-like APCI ports, and how far apart they are.
 */
#define FRODO_APCIBASE          0x0
#define FRODO_APCISPACE         0x20
#define FRODO_APCI_OFFSET(x)    (FRODO_APCIBASE + ((x) * FRODO_APCISPACE))

#define HPAPCI_BAUD_BASE 500400

#ifdef CONFIG_SERIAL_8250_CONSOLE
/*
 * Parse the bootinfo to find descriptions for headless console and
 * debug serial ports and register them with the 8250 driver.
 */
int __init hp300_setup_serial_console(void)
{
        int scode;
        struct uart_port port;

        memset(&port, 0, sizeof(port));

        if (hp300_uart_scode < 0 || hp300_uart_scode > DIO_SCMAX)
                return 0;

        if (DIO_SCINHOLE(hp300_uart_scode))
                return 0;

        scode = hp300_uart_scode;

        /* Memory mapped I/O */
        port.iotype = UPIO_MEM;
        port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
        port.type = PORT_UNKNOWN;

        /* Check for APCI console */
        if (scode == 256) {
#ifdef CONFIG_HPAPCI
                pr_info("Serial console is HP APCI 1\n");

                port.uartclk = HPAPCI_BAUD_BASE * 16;
                port.mapbase = (FRODO_BASE + FRODO_APCI_OFFSET(1));
                port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
                port.regshift = 2;
                add_preferred_console("ttyS", port.line, "9600n8");
#else
                pr_warn("Serial console is APCI but support is disabled (CONFIG_HPAPCI)!\n");
                return 0;
#endif
        } else {
#ifdef CONFIG_HPDCA
                unsigned long pa = dio_scodetophysaddr(scode);
                if (!pa)
                        return 0;

                pr_info("Serial console is HP DCA at select code %d\n", scode);

                port.uartclk = HPDCA_BAUD_BASE * 16;
                port.mapbase = (pa + UART_OFFSET);
                port.membase = (char *)(port.mapbase + DIO_VIRADDRBASE);
                port.regshift = 1;
                port.irq = DIO_IPL(pa + DIO_VIRADDRBASE);

                /* Enable board-interrupts */
                out_8(pa + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);

                if (DIO_ID(pa + DIO_VIRADDRBASE) & 0x80)
                        add_preferred_console("ttyS", port.line, "9600n8");
#else
                pr_warn("Serial console is DCA but support is disabled (CONFIG_HPDCA)!\n");
                return 0;
#endif
        }

        if (early_serial_setup(&port) < 0)
                pr_warn("%s: early_serial_setup() failed.\n", __func__);
        return 0;
}
#endif /* CONFIG_SERIAL_8250_CONSOLE */

#ifdef CONFIG_HPDCA
static int hpdca_init_one(struct dio_dev *d,
                                const struct dio_device_id *ent)
{
        struct uart_8250_port uart;
        int line;

#ifdef CONFIG_SERIAL_8250_CONSOLE
        if (hp300_uart_scode == d->scode) {
                /* Already got it. */
                return 0;
        }
#endif
        memset(&uart, 0, sizeof(uart));

        /* Memory mapped I/O */
        uart.port.iotype = UPIO_MEM;
        uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF;
        uart.port.irq = d->ipl;
        uart.port.uartclk = HPDCA_BAUD_BASE * 16;
        uart.port.mapbase = (d->resource.start + UART_OFFSET);
        uart.port.membase = (char *)(uart.port.mapbase + DIO_VIRADDRBASE);
        uart.port.regshift = 1;
        uart.port.dev = &d->dev;
        line = serial8250_register_8250_port(&uart);

        if (line < 0) {
                dev_notice(&d->dev,
                          "8250_hp300: register_serial() DCA scode %d irq %d failed\n",
                          d->scode, uart.port.irq);
                return -ENOMEM;
        }

        /* Enable board-interrupts */
        out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, DCA_IC_IE);
        dio_set_drvdata(d, (void *)line);

        /* Reset the DCA */
        out_8(d->resource.start + DIO_VIRADDRBASE + DCA_ID, 0xff);
        udelay(100);

        num_ports++;

        return 0;
}
#endif

static int __init hp300_8250_init(void)
{
        static int called;
#ifdef CONFIG_HPAPCI
        int line;
        unsigned long base;
        struct uart_8250_port uart;
        struct hp300_port *port;
        int i;
#endif
        if (called)
                return -ENODEV;
        called = 1;

        if (!MACH_IS_HP300)
                return -ENODEV;

#ifdef CONFIG_HPDCA
        dio_register_driver(&hpdca_driver);
#endif
#ifdef CONFIG_HPAPCI
        if (hp300_model < HP_400) {
                if (!num_ports)
                        return -ENODEV;
                return 0;
        }
        /* These models have the Frodo chip.
         * Port 0 is reserved for the Apollo Domain keyboard.
         * Port 1 is either the console or the DCA.
         */
        for (i = 1; i < 4; i++) {
                /* Port 1 is the console on a 425e, on other machines it's
                 * mapped to DCA.
                 */
#ifdef CONFIG_SERIAL_8250_CONSOLE
                if (i == 1)
                        continue;
#endif

                /* Create new serial device */
                port = kmalloc_obj(struct hp300_port);
                if (!port)
                        return -ENOMEM;

                memset(&uart, 0, sizeof(uart));

                base = (FRODO_BASE + FRODO_APCI_OFFSET(i));

                /* Memory mapped I/O */
                uart.port.iotype = UPIO_MEM;
                uart.port.flags = UPF_SKIP_TEST | UPF_SHARE_IRQ
                                | UPF_BOOT_AUTOCONF;
                /* XXX - no interrupt support yet */
                uart.port.irq = 0;
                uart.port.uartclk = HPAPCI_BAUD_BASE * 16;
                uart.port.mapbase = base;
                uart.port.membase = (char *)(base + DIO_VIRADDRBASE);
                uart.port.regshift = 2;

                line = serial8250_register_8250_port(&uart);

                if (line < 0) {
                        dev_notice(uart.port.dev,
                                   "8250_hp300: register_serial() APCI %d irq %d failed\n",
                                   i, uart.port.irq);
                        kfree(port);
                        continue;
                }

                port->line = line;
                port->next = hp300_ports;
                hp300_ports = port;

                num_ports++;
        }
#endif

        /* Any boards found? */
        if (!num_ports)
                return -ENODEV;

        return 0;
}

#ifdef CONFIG_HPDCA
static void hpdca_remove_one(struct dio_dev *d)
{
        int line;

        line = (int) dio_get_drvdata(d);
        if (d->resource.start) {
                /* Disable board-interrupts */
                out_8(d->resource.start + DIO_VIRADDRBASE + DCA_IC, 0);
        }
        serial8250_unregister_port(line);
}
#endif

static void __exit hp300_8250_exit(void)
{
#ifdef CONFIG_HPAPCI
        struct hp300_port *port, *to_free;

        for (port = hp300_ports; port; ) {
                serial8250_unregister_port(port->line);
                to_free = port;
                port = port->next;
                kfree(to_free);
        }

        hp300_ports = NULL;
#endif
#ifdef CONFIG_HPDCA
        dio_unregister_driver(&hpdca_driver);
#endif
}

module_init(hp300_8250_init);
module_exit(hp300_8250_exit);
MODULE_DESCRIPTION("HP DCA/APCI serial driver");
MODULE_AUTHOR("Kars de Jong <jongk@linux-m68k.org>");
MODULE_LICENSE("GPL");