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