hvc_opal.c

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/*
 * opal driver interface to hvc_console.c
 *
 * Copyright 2011 Benjamin Herrenschmidt <[email protected]>, IBM Corp.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 */

#undef DEBUG

#include <linux/types.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/console.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/export.h>

#include <asm/hvconsole.h>
#include <asm/prom.h>
#include <asm/firmware.h>
#include <asm/hvsi.h>
#include <asm/udbg.h>
#include <asm/opal.h>

#include "hvc_console.h"

static const char hvc_opal_name[] = "hvc_opal";

static struct of_device_id hvc_opal_match[] __devinitdata = {
    { .name = "serial", .compatible = "ibm,opal-console-raw" },
    { .name = "serial", .compatible = "ibm,opal-console-hvsi" },
    { },
};

typedef enum hv_protocol {
    HV_PROTOCOL_RAW,
    HV_PROTOCOL_HVSI
} hv_protocol_t;

struct hvc_opal_priv {
    hv_protocol_t       proto;  /* Raw data or HVSI packets */
    struct hvsi_priv    hvsi;   /* HVSI specific data */
};
static struct hvc_opal_priv *hvc_opal_privs[MAX_NR_HVC_CONSOLES];

/* For early boot console */
static struct hvc_opal_priv hvc_opal_boot_priv;
static u32 hvc_opal_boot_termno;

static const struct hv_ops hvc_opal_raw_ops = {
    .get_chars = opal_get_chars,
    .put_chars = opal_put_chars,
    .notifier_add = notifier_add_irq,
    .notifier_del = notifier_del_irq,
    .notifier_hangup = notifier_hangup_irq,
};

static int hvc_opal_hvsi_get_chars(uint32_t vtermno, char *buf, int count)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];

    if (WARN_ON(!pv))
        return -ENODEV;

    return hvsilib_get_chars(&pv->hvsi, buf, count);
}

static int hvc_opal_hvsi_put_chars(uint32_t vtermno, const char *buf, int count)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[vtermno];

    if (WARN_ON(!pv))
        return -ENODEV;

    return hvsilib_put_chars(&pv->hvsi, buf, count);
}

static int hvc_opal_hvsi_open(struct hvc_struct *hp, int data)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];
    int rc;

    pr_devel("HVSI@%x: do open !\n", hp->vtermno);

    rc = notifier_add_irq(hp, data);
    if (rc)
        return rc;

    return hvsilib_open(&pv->hvsi, hp);
}

static void hvc_opal_hvsi_close(struct hvc_struct *hp, int data)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

    pr_devel("HVSI@%x: do close !\n", hp->vtermno);

    hvsilib_close(&pv->hvsi, hp);

    notifier_del_irq(hp, data);
}

void hvc_opal_hvsi_hangup(struct hvc_struct *hp, int data)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

    pr_devel("HVSI@%x: do hangup !\n", hp->vtermno);

    hvsilib_close(&pv->hvsi, hp);

    notifier_hangup_irq(hp, data);
}

static int hvc_opal_hvsi_tiocmget(struct hvc_struct *hp)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

    if (!pv)
        return -EINVAL;
    return pv->hvsi.mctrl;
}

static int hvc_opal_hvsi_tiocmset(struct hvc_struct *hp, unsigned int set,
                unsigned int clear)
{
    struct hvc_opal_priv *pv = hvc_opal_privs[hp->vtermno];

    pr_devel("HVSI@%x: Set modem control, set=%x,clr=%x\n",
         hp->vtermno, set, clear);

    if (set & TIOCM_DTR)
        hvsilib_write_mctrl(&pv->hvsi, 1);
    else if (clear & TIOCM_DTR)
        hvsilib_write_mctrl(&pv->hvsi, 0);

    return 0;
}

static const struct hv_ops hvc_opal_hvsi_ops = {
    .get_chars = hvc_opal_hvsi_get_chars,
    .put_chars = hvc_opal_hvsi_put_chars,
    .notifier_add = hvc_opal_hvsi_open,
    .notifier_del = hvc_opal_hvsi_close,
    .notifier_hangup = hvc_opal_hvsi_hangup,
    .tiocmget = hvc_opal_hvsi_tiocmget,
    .tiocmset = hvc_opal_hvsi_tiocmset,
};

static int __devinit hvc_opal_probe(struct platform_device *dev)
{
    const struct hv_ops *ops;
    struct hvc_struct *hp;
    struct hvc_opal_priv *pv;
    hv_protocol_t proto;
    unsigned int termno, boot = 0;
    const __be32 *reg;

    if (of_device_is_compatible(dev->dev.of_node, "ibm,opal-console-raw")) {
        proto = HV_PROTOCOL_RAW;
        ops = &hvc_opal_raw_ops;
    } else if (of_device_is_compatible(dev->dev.of_node,
                       "ibm,opal-console-hvsi")) {
        proto = HV_PROTOCOL_HVSI;
        ops = &hvc_opal_hvsi_ops;
    } else {
        pr_err("hvc_opal: Unkown protocol for %s\n",
               dev->dev.of_node->full_name);
        return -ENXIO;
    }

    reg = of_get_property(dev->dev.of_node, "reg", NULL);
    termno = reg ? be32_to_cpup(reg) : 0;

    /* Is it our boot one ? */
    if (hvc_opal_privs[termno] == &hvc_opal_boot_priv) {
        pv = hvc_opal_privs[termno];
        boot = 1;
    } else if (hvc_opal_privs[termno] == NULL) {
        pv = kzalloc(sizeof(struct hvc_opal_priv), GFP_KERNEL);
        if (!pv)
            return -ENOMEM;
        pv->proto = proto;
        hvc_opal_privs[termno] = pv;
        if (proto == HV_PROTOCOL_HVSI)
            hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars,
                     termno, 0);

        /* Instanciate now to establish a mapping index==vtermno */
        hvc_instantiate(termno, termno, ops);
    } else {
        pr_err("hvc_opal: Device %s has duplicate terminal number #%d\n",
               dev->dev.of_node->full_name, termno);
        return -ENXIO;
    }

    pr_info("hvc%d: %s protocol on %s%s\n", termno,
        proto == HV_PROTOCOL_RAW ? "raw" : "hvsi",
        dev->dev.of_node->full_name,
        boot ? " (boot console)" : "");

    /* We don't do IRQ yet */
    hp = hvc_alloc(termno, 0, ops, MAX_VIO_PUT_CHARS);
    if (IS_ERR(hp))
        return PTR_ERR(hp);
    dev_set_drvdata(&dev->dev, hp);

    return 0;
}

static int __devexit hvc_opal_remove(struct platform_device *dev)
{
    struct hvc_struct *hp = dev_get_drvdata(&dev->dev);
    int rc, termno;

    termno = hp->vtermno;
    rc = hvc_remove(hp);
    if (rc == 0) {
        if (hvc_opal_privs[termno] != &hvc_opal_boot_priv)
            kfree(hvc_opal_privs[termno]);
        hvc_opal_privs[termno] = NULL;
    }
    return rc;
}

static struct platform_driver hvc_opal_driver = {
    .probe      = hvc_opal_probe,
    .remove     = __devexit_p(hvc_opal_remove),
    .driver     = {
        .name   = hvc_opal_name,
        .owner  = THIS_MODULE,
        .of_match_table = hvc_opal_match,
    }
};

static int __init hvc_opal_init(void)
{
    if (!firmware_has_feature(FW_FEATURE_OPAL))
        return -ENODEV;

    /* Register as a vio device to receive callbacks */
    return platform_driver_register(&hvc_opal_driver);
}
module_init(hvc_opal_init);

static void __exit hvc_opal_exit(void)
{
    platform_driver_unregister(&hvc_opal_driver);
}
module_exit(hvc_opal_exit);

static void udbg_opal_putc(char c)
{
    unsigned int termno = hvc_opal_boot_termno;
    int count = -1;

    if (c == '\n')
        udbg_opal_putc('\r');

    do {
        switch(hvc_opal_boot_priv.proto) {
        case HV_PROTOCOL_RAW:
            count = opal_put_chars(termno, &c, 1);
            break;
        case HV_PROTOCOL_HVSI:
            count = hvc_opal_hvsi_put_chars(termno, &c, 1);
            break;
        }
    } while(count == 0 || count == -EAGAIN);
}

static int udbg_opal_getc_poll(void)
{
    unsigned int termno = hvc_opal_boot_termno;
    int rc = 0;
    char c;

    switch(hvc_opal_boot_priv.proto) {
    case HV_PROTOCOL_RAW:
        rc = opal_get_chars(termno, &c, 1);
        break;
    case HV_PROTOCOL_HVSI:
        rc = hvc_opal_hvsi_get_chars(termno, &c, 1);
        break;
    }
    if (!rc)
        return -1;
    return c;
}

static int udbg_opal_getc(void)
{
    int ch;
    for (;;) {
        ch = udbg_opal_getc_poll();
        if (ch == -1) {
            /* This shouldn't be needed...but... */
            volatile unsigned long delay;
            for (delay=0; delay < 2000000; delay++)
                ;
        } else {
            return ch;
        }
    }
}

static void udbg_init_opal_common(void)
{
    udbg_putc = udbg_opal_putc;
    udbg_getc = udbg_opal_getc;
    udbg_getc_poll = udbg_opal_getc_poll;
    tb_ticks_per_usec = 0x200; /* Make udelay not suck */
}

void __init hvc_opal_init_early(void)
{
    struct device_node *stdout_node = NULL;
    const u32 *termno;
    const char *name = NULL;
    const struct hv_ops *ops;
    u32 index;

    /* find the boot console from /chosen/stdout */
    if (of_chosen)
        name = of_get_property(of_chosen, "linux,stdout-path", NULL);
    if (name) {
        stdout_node = of_find_node_by_path(name);
        if (!stdout_node) {
            pr_err("hvc_opal: Failed to locate default console!\n");
            return;
        }
    } else {
        struct device_node *opal, *np;

        /* Current OPAL takeover doesn't provide the stdout
         * path, so we hard wire it
         */
        opal = of_find_node_by_path("/ibm,opal/consoles");
        if (opal)
            pr_devel("hvc_opal: Found consoles in new location\n");
        if (!opal) {
            opal = of_find_node_by_path("/ibm,opal");
            if (opal)
                pr_devel("hvc_opal: "
                     "Found consoles in old location\n");
        }
        if (!opal)
            return;
        for_each_child_of_node(opal, np) {
            if (!strcmp(np->name, "serial")) {
                stdout_node = np;
                break;
            }
        }
        of_node_put(opal);
    }
    if (!stdout_node)
        return;
    termno = of_get_property(stdout_node, "reg", NULL);
    index = termno ? *termno : 0;
    if (index >= MAX_NR_HVC_CONSOLES)
        return;
    hvc_opal_privs[index] = &hvc_opal_boot_priv;

    /* Check the protocol */
    if (of_device_is_compatible(stdout_node, "ibm,opal-console-raw")) {
        hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
        ops = &hvc_opal_raw_ops;
        pr_devel("hvc_opal: Found RAW console\n");
    }
    else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) {
        hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI;
        ops = &hvc_opal_hvsi_ops;
        hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars,
                 opal_put_chars, index, 1);
        /* HVSI, perform the handshake now */
        hvsilib_establish(&hvc_opal_boot_priv.hvsi);
        pr_devel("hvc_opal: Found HVSI console\n");
    } else
        goto out;
    hvc_opal_boot_termno = index;
    udbg_init_opal_common();
    add_preferred_console("hvc", index, NULL);
    hvc_instantiate(index, index, ops);
out:
    of_node_put(stdout_node);
}

#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
void __init udbg_init_debug_opal_raw(void)
{
    u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
    hvc_opal_privs[index] = &hvc_opal_boot_priv;
    hvc_opal_boot_priv.proto = HV_PROTOCOL_RAW;
    hvc_opal_boot_termno = index;
    udbg_init_opal_common();
}
#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_RAW */

#ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI
void __init udbg_init_debug_opal_hvsi(void)
{
    u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
    hvc_opal_privs[index] = &hvc_opal_boot_priv;
    hvc_opal_boot_termno = index;
    udbg_init_opal_common();
    hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars,
             index, 1);
    hvsilib_establish(&hvc_opal_boot_priv.hvsi);
}
#endif /* CONFIG_PPC_EARLY_DEBUG_OPAL_HVSI */