[RFC PATCH 6/5] CELL rtas console port to hvc_console backend driver

[David Woodhouse]

--- linux-2.6.14/drivers/char/hvc_rtas.c~	2005-12-07 18:12:59.000000000 +0100
+++ linux-2.6.14/drivers/char/hvc_rtas.c	2005-12-07 18:15:39.000000000 +0100
@@ -0,0 +1,161 @@
+/*
+ * 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 at us.ibm.com>
+ *          : Utz Bacher <utz.bacher at de.ibm.com>
+ *          : David Woodhouse <dwmw2 at infradead.org>
+ *
+ *    inspired by drivers/char/hvc_console.c
+ *    written by Anton Blanchard and Paul Mackerras
+ *
+ * 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 <linux/types.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <asm/rtas.h>
+#include <asm/irq.h>
+#include "hvc_console.h"
+
+static uint32_t hvc_rtas_vtermno = 0;
+struct hvc_struct *hvc_rtas_dev;
+
+#define RTASCONS_PUT_ATTEMPTS  16
+
+static int rtascons_put_char_token = -1;
+static int rtascons_get_char_token = -1;
+static int rtascons_put_delay;
+
+static inline int hvc_rtas_write_console(uint32_t vtermno, const char *buf, int count)
+{
+       int result = 0;
+       int attempts = RTASCONS_PUT_ATTEMPTS;
+       int done = 0;
+
+       /* if there is more than one character to be displayed, wait a bit */
+       for (; done < count && attempts; udelay(rtascons_put_delay)) {
+               attempts--;
+               result = rtas_call(rtascons_put_char_token, 1, 1, NULL, buf[done]);
+
+               if (!result) {
+			attempts = RTASCONS_PUT_ATTEMPTS;
+			done++;
+		}
+       }
+	/* the calling routine expects to receive the number of bytes sent */
+	return done?:result;
+}
+
+static inline int rtascons_get_char(void)
+{
+       int result;
+
+       if (rtas_call(rtascons_get_char_token, 0, 2, &result))
+               result = -1;
+
+       return result;
+}
+
+static int hvc_rtas_read_console(uint32_t vtermno, char *buf, int count)
+{
+	unsigned long got;
+	int c;	
+	int i;
+
+	for (got = 0, i = 0; i < count; i++) {
+	
+		if (( c = rtascons_get_char() ) != -1) {
+			buf[i] = c;
+			++got;
+		}
+		else
+			break;
+	}
+	return got;
+}
+
+static struct hv_ops hvc_rtas_get_put_ops = {
+	.get_chars = hvc_rtas_read_console,
+	.put_chars = hvc_rtas_write_console,
+};
+
+static int hvc_rtas_init(void)
+{
+	struct hvc_struct *hp;
+
+	if (rtascons_put_char_token == -1)
+		rtascons_put_char_token = rtas_token("put-term-char");
+	if (rtascons_put_char_token == -1)
+		return -EIO;
+
+	if (rtascons_get_char_token == -1)
+		rtascons_get_char_token = rtas_token("get-term-char");
+	if (rtascons_get_char_token == -1)
+		return -EIO;
+
+	if (__onsim())
+		rtascons_put_delay = 0;
+	else
+		rtascons_put_delay = 100;
+
+	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_vtermno, NO_IRQ, &hvc_rtas_get_put_ops);
+	if (IS_ERR(hp))
+		return PTR_ERR(hp);
+	hvc_rtas_dev = hp;
+	return 0;
+}
+module_init(hvc_rtas_init);
+
+/* This will tear down the tty portion of the driver */
+static void __exit hvc_rtas_exit(void)
+{
+	struct hvc_struct *hp_safe;
+	/* Hopefully this isn't premature */
+	if (!hvc_rtas_dev)
+		return;
+
+	hp_safe = hvc_rtas_dev;
+	hvc_rtas_dev = NULL;
+
+	/* Really the fun isn't over until the worker thread breaks down and the
+	 * tty cleans up */
+	hvc_remove(hp_safe);
+}
+module_exit(hvc_rtas_exit); /* before drivers/char/hvc_console.c */
+
+/* This will happen prior to module init.  There is no tty at this time? */
+static int hvc_rtas_console_init(void)
+{
+	rtascons_put_char_token = rtas_token("put-term-char");
+	if (rtascons_put_char_token == -1)
+		return -EIO;
+	rtascons_get_char_token = rtas_token("get-term-char");
+	if (rtascons_get_char_token == -1)
+		return -EIO;
+
+	hvc_instantiate(hvc_rtas_vtermno, 0, &hvc_rtas_get_put_ops );
+	return 0;
+}
+console_initcall(hvc_rtas_console_init);
--- linux-2.6.14/drivers/char/Makefile~	2005-12-07 17:47:05.000000000 +0100
+++ linux-2.6.14/drivers/char/Makefile	2005-12-07 18:12:07.000000000 +0100
@@ -43,6 +43,7 @@ obj-$(CONFIG_RIO)		+= rio/ generic_seria
 obj-$(CONFIG_HVC_DRIVER)	+= hvc_console.o
 obj-$(CONFIG_HVC_CONSOLE)	+= hvc_vio.o hvsi.o
 obj-$(CONFIG_HVC_FSS)		+= hvc_fss.o
+obj-$(CONFIG_HVC_RTAS)		+= hvc_rtas.o
 obj-$(CONFIG_RAW_DRIVER)	+= raw.o
 obj-$(CONFIG_SGI_SNSC)		+= snsc.o snsc_event.o
 obj-$(CONFIG_MMTIMER)		+= mmtimer.o
--- linux-2.6.14/drivers/char/Kconfig~	2005-12-07 17:47:05.000000000 +0100
+++ linux-2.6.14/drivers/char/Kconfig	2005-12-07 18:17:14.000000000 +0100
@@ -575,6 +575,13 @@ config HVC_FSS
 	  IBM Full System Simulator Console device driver which makes use of
 	  the HVC_DRIVER front end.
 
+config HVC_RTAS
+	bool "IBM RTAS Console support"
+	depends on PPC_RTAS
+	select HVC_DRIVER
+	help
+	  IBM Console device driver which makes use of RTAS
+
 config HVCS
 	tristate "IBM Hypervisor Virtual Console Server support"
 	depends on PPC_PSERIES

-- 
dwmw2