Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / drivers / tty / hvc / hvc_dcc.c

diff --git a/drivers/tty/hvc/hvc_dcc.c b/drivers/tty/hvc/hvc_dcc.c
new file mode 100644 (file)
index 0000000..6470f63
--- /dev/null
+++ b/drivers/tty/hvc/hvc_dcc.c
@@ -0,0 +1,133 @@
+/* Copyright (c) 2010, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#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/processor.h>
+
+#include "hvc_console.h"
+
+/* DCC Status Bits */
+#define DCC_STATUS_RX          (1 << 30)
+#define DCC_STATUS_TX          (1 << 29)
+
+static inline u32 __dcc_getstatus(void)
+{
+       u32 __ret;
+
+       asm("mrc p14, 0, %0, c0, c1, 0  @ read comms ctrl reg"
+               : "=r" (__ret) : : "cc");
+
+       return __ret;
+}
+
+
+#if defined(CONFIG_CPU_V7)
+static inline char __dcc_getchar(void)
+{
+       char __c;
+
+       asm("get_wait:  mrc p14, 0, pc, c0, c1, 0                          \n\
+                       bne get_wait                                       \n\
+                       mrc p14, 0, %0, c0, c5, 0       @ read comms data reg"
+               : "=r" (__c) : : "cc");
+
+       return __c;
+}
+#else
+static inline char __dcc_getchar(void)
+{
+       char __c;
+
+       asm("mrc p14, 0, %0, c0, c5, 0  @ read comms data reg"
+               : "=r" (__c));
+
+       return __c;
+}
+#endif
+
+#if defined(CONFIG_CPU_V7)
+static inline void __dcc_putchar(char c)
+{
+       asm("put_wait:  mrc p14, 0, pc, c0, c1, 0                 \n\
+                       bcs put_wait                              \n\
+                       mcr p14, 0, %0, c0, c5, 0                   "
+       : : "r" (c) : "cc");
+}
+#else
+static inline void __dcc_putchar(char c)
+{
+       asm("mcr p14, 0, %0, c0, c5, 0  @ write a char"
+               : /* no output register */
+               : "r" (c));
+}
+#endif
+
+static int hvc_dcc_put_chars(uint32_t vt, const char *buf, int count)
+{
+       int i;
+
+       for (i = 0; i < count; i++) {
+               while (__dcc_getstatus() & DCC_STATUS_TX)
+                       cpu_relax();
+
+               __dcc_putchar((char)(buf[i] & 0xFF));
+       }
+
+       return count;
+}
+
+static int hvc_dcc_get_chars(uint32_t vt, char *buf, int count)
+{
+       int i;
+
+       for (i = 0; i < count; ++i) {
+               int c = -1;
+
+               if (__dcc_getstatus() & DCC_STATUS_RX)
+                       c = __dcc_getchar();
+               if (c < 0)
+                       break;
+               buf[i] = c;
+       }
+
+       return i;
+}
+
+static const struct hv_ops hvc_dcc_get_put_ops = {
+       .get_chars = hvc_dcc_get_chars,
+       .put_chars = hvc_dcc_put_chars,
+};
+
+static int __init hvc_dcc_console_init(void)
+{
+       hvc_instantiate(0, 0, &hvc_dcc_get_put_ops);
+       return 0;
+}
+console_initcall(hvc_dcc_console_init);
+
+static int __init hvc_dcc_init(void)
+{
+       hvc_alloc(0, 0, &hvc_dcc_get_put_ops, 128);
+       return 0;
+}
+device_initcall(hvc_dcc_init);