// SPDX-License-Identifier: GPL-2.0+
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/*
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* IBM RTAS driver interface to hvc_console.c
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*
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* (C) Copyright IBM Corporation 2001-2005
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* (C) Copyright Red Hat, Inc. 2005
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*
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* Author(s): Maximino Augilar <IBM STI Design Center>
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* : Ryan S. Arnold <rsa@us.ibm.com>
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* : Utz Bacher <utz.bacher@de.ibm.com>
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* : David Woodhouse <dwmw2@infradead.org>
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*
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* inspired by drivers/char/hvc_console.c
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* written by Anton Blanchard and Paul Mackerras
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*/
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#include <linux/console.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <asm/irq.h>
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#include <asm/rtas.h>
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#include "hvc_console.h"
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#define hvc_rtas_cookie 0x67781e15
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struct hvc_struct *hvc_rtas_dev;
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static int rtascons_put_char_token = RTAS_UNKNOWN_SERVICE;
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static int rtascons_get_char_token = RTAS_UNKNOWN_SERVICE;
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static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf,
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int count)
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{
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int i;
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for (i = 0; i < count; i++) {
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if (rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[i]))
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break;
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}
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return i;
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}
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static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
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{
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int i, c;
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for (i = 0; i < count; i++) {
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if (rtas_call(rtascons_get_char_token, 0, 2, &c))
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break;
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buf[i] = c;
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}
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return i;
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}
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static const struct hv_ops hvc_rtas_get_put_ops = {
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.get_chars = hvc_rtas_read_console,
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.put_chars = hvc_rtas_write_console,
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};
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static int __init hvc_rtas_init(void)
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{
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struct hvc_struct *hp;
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if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
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rtascons_put_char_token = rtas_token("put-term-char");
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if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
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return -EIO;
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if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
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rtascons_get_char_token = rtas_token("get-term-char");
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if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
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return -EIO;
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BUG_ON(hvc_rtas_dev);
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/* Allocate an hvc_struct for the console device we instantiated
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* earlier. Save off hp so that we can return it on exit */
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hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16);
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if (IS_ERR(hp))
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return PTR_ERR(hp);
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hvc_rtas_dev = hp;
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return 0;
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}
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device_initcall(hvc_rtas_init);
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/* This will happen prior to module init. There is no tty at this time? */
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static int __init hvc_rtas_console_init(void)
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{
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rtascons_put_char_token = rtas_token("put-term-char");
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if (rtascons_put_char_token == RTAS_UNKNOWN_SERVICE)
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return -EIO;
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rtascons_get_char_token = rtas_token("get-term-char");
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if (rtascons_get_char_token == RTAS_UNKNOWN_SERVICE)
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return -EIO;
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hvc_instantiate(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops);
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add_preferred_console("hvc", 0, NULL);
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return 0;
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}
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console_initcall(hvc_rtas_console_init);
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