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-rw-r--r--drivers/char/Kconfig9
-rw-r--r--drivers/char/Makefile1
-rw-r--r--drivers/char/hvc_dcc.c133
3 files changed, 143 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 43d3395325c5..d4a7776f4b77 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -682,6 +682,15 @@ config HVC_UDBG
select HVC_DRIVER
default n
+config HVC_DCC
+ bool "ARM JTAG DCC console"
+ depends on ARM
+ select HVC_DRIVER
+ help
+ This console uses the JTAG DCC on ARM to create a console under the HVC
+ driver. This console is used through a JTAG only on ARM. If you don't have
+ a JTAG then you probably don't want this option.
+
config VIRTIO_CONSOLE
tristate "Virtio console"
depends on VIRTIO
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index ba53ec956c95..fa0b824b7a65 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_HVC_CONSOLE) += hvc_vio.o hvsi.o
obj-$(CONFIG_HVC_ISERIES) += hvc_iseries.o
obj-$(CONFIG_HVC_RTAS) += hvc_rtas.o
obj-$(CONFIG_HVC_TILE) += hvc_tile.o
+obj-$(CONFIG_HVC_DCC) += hvc_dcc.o
obj-$(CONFIG_HVC_BEAT) += hvc_beat.o
obj-$(CONFIG_HVC_DRIVER) += hvc_console.o
obj-$(CONFIG_HVC_IRQ) += hvc_irq.o
diff --git a/drivers/char/hvc_dcc.c b/drivers/char/hvc_dcc.c
new file mode 100644
index 000000000000..6470f63deb4b
--- /dev/null
+++ b/drivers/char/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);