From d5e54913433fff89609adfc4b96fefcf807a9030 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 5 Nov 2008 14:20:17 +0000 Subject: [PATCH] powerpc: udbg-based backend for hvc_console This adds a new backend for the hvc console based on the low-level udbg callbacks. This effectively implements a working runtime console in terms of the simple udbg primitives. This is kind of a hack - since udbg isn't something you really want to be using routinely - but it's really useful during bringup. This can be used to quickly implement a userspace-usable console while you're working on a proper driver for whatever console I/O device the hardware has. Or, it can be used to avoid writing a full blown tty/console driver entirely for quick-and-dirty I/O hardware that will later be replaced by something else. Signed-off-by: David Gibson Signed-off-by: Paul Mackerras --- drivers/char/Kconfig | 6 +++ drivers/char/Makefile | 1 + drivers/char/hvc_udbg.c | 96 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 103 insertions(+) create mode 100644 drivers/char/hvc_udbg.c diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig index 43b35d0369d6..19e255c49f15 100644 --- a/drivers/char/Kconfig +++ b/drivers/char/Kconfig @@ -631,6 +631,12 @@ config HVC_XEN help Xen virtual console device driver +config HVC_UDBG + bool "udbg based fake hypervisor console" + depends on PPC && EXPERIMENTAL + select HVC_DRIVER + default n + config VIRTIO_CONSOLE tristate "Virtio console" depends on VIRTIO diff --git a/drivers/char/Makefile b/drivers/char/Makefile index 438f71317c5c..52e15524af39 100644 --- a/drivers/char/Makefile +++ b/drivers/char/Makefile @@ -50,6 +50,7 @@ obj-$(CONFIG_HVC_BEAT) += hvc_beat.o obj-$(CONFIG_HVC_DRIVER) += hvc_console.o obj-$(CONFIG_HVC_IRQ) += hvc_irq.o obj-$(CONFIG_HVC_XEN) += hvc_xen.o +obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o obj-$(CONFIG_RAW_DRIVER) += raw.o obj-$(CONFIG_SGI_SNSC) += snsc.o snsc_event.o diff --git a/drivers/char/hvc_udbg.c b/drivers/char/hvc_udbg.c new file mode 100644 index 000000000000..bd63ba878a56 --- /dev/null +++ b/drivers/char/hvc_udbg.c @@ -0,0 +1,96 @@ +/* + * udbg interface to hvc_console.c + * + * (C) Copyright David Gibson, IBM Corporation 2008. + * + * 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 + */ + +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "hvc_console.h" + +struct hvc_struct *hvc_udbg_dev; + +static int hvc_udbg_put(uint32_t vtermno, const char *buf, int count) +{ + int i; + + for (i = 0; i < count; i++) + udbg_putc(buf[i]); + + return i; +} + +static int hvc_udbg_get(uint32_t vtermno, char *buf, int count) +{ + int i, c; + + if (!udbg_getc_poll) + return 0; + + for (i = 0; i < count; i++) { + if ((c = udbg_getc_poll()) == -1) + break; + buf[i] = c; + } + + return i; +} + +static struct hv_ops hvc_udbg_ops = { + .get_chars = hvc_udbg_get, + .put_chars = hvc_udbg_put, +}; + +static int __init hvc_udbg_init(void) +{ + struct hvc_struct *hp; + + BUG_ON(hvc_udbg_dev); + + hp = hvc_alloc(0, NO_IRQ, &hvc_udbg_ops, 16); + if (IS_ERR(hp)) + return PTR_ERR(hp); + + hvc_udbg_dev = hp; + + return 0; +} +module_init(hvc_udbg_init); + +static void __exit hvc_udbg_exit(void) +{ + if (hvc_udbg_dev) + hvc_remove(hvc_udbg_dev); +} +module_exit(hvc_udbg_exit); + +static int __init hvc_udbg_console_init(void) +{ + hvc_instantiate(0, 0, &hvc_udbg_ops); + add_preferred_console("hvc", 0, NULL); + + return 0; +} +console_initcall(hvc_udbg_console_init); -- 2.20.1