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authorMike Frysinger <vapier@gentoo.org>2011-02-04 20:45:49 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2011-02-17 11:12:40 -0800
commit5427bcf5e95245d3e220742ac703182bdb973769 (patch)
tree6eed2090099d98a4bec5d150b3d0c5ee8e1b9354
parent9fc3de9c83565fcaa23df74c2fc414bb6e7efb0a (diff)
hvc: add Blackfin JTAG console support
This converts the existing bfin_jtag_comm TTY driver to the HVC layer so that the common HVC code can worry about all of the TTY/polling crap and leave the Blackfin code to worry about the Blackfin bits. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/char/Kconfig9
-rw-r--r--drivers/tty/hvc/Makefile1
-rw-r--r--drivers/tty/hvc/hvc_bfin_jtag.c105
3 files changed, 115 insertions, 0 deletions
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index b7980a83ce2d..17f9b968b988 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -691,6 +691,15 @@ config HVC_DCC
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 HVC_BFIN_JTAG
+ bool "Blackfin JTAG console"
+ depends on BLACKFIN
+ select HVC_DRIVER
+ help
+ This console uses the Blackfin JTAG to create a console under the
+ the HVC driver. If you don't have JTAG, then you probably don't
+ want this option.
+
config VIRTIO_CONSOLE
tristate "Virtio console"
depends on VIRTIO
diff --git a/drivers/tty/hvc/Makefile b/drivers/tty/hvc/Makefile
index e6bed5f177ff..7b0edbce9009 100644
--- a/drivers/tty/hvc/Makefile
+++ b/drivers/tty/hvc/Makefile
@@ -9,5 +9,6 @@ obj-$(CONFIG_HVC_IRQ) += hvc_irq.o
obj-$(CONFIG_HVC_XEN) += hvc_xen.o
obj-$(CONFIG_HVC_IUCV) += hvc_iucv.o
obj-$(CONFIG_HVC_UDBG) += hvc_udbg.o
+obj-$(CONFIG_HVC_BFIN_JTAG) += hvc_bfin_jtag.o
obj-$(CONFIG_HVCS) += hvcs.o
obj-$(CONFIG_VIRTIO_CONSOLE) += virtio_console.o
diff --git a/drivers/tty/hvc/hvc_bfin_jtag.c b/drivers/tty/hvc/hvc_bfin_jtag.c
new file mode 100644
index 000000000000..31d6cc6a77af
--- /dev/null
+++ b/drivers/tty/hvc/hvc_bfin_jtag.c
@@ -0,0 +1,105 @@
+/*
+ * Console via Blackfin JTAG Communication
+ *
+ * Copyright 2008-2011 Analog Devices Inc.
+ *
+ * Enter bugs at http://blackfin.uclinux.org/
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#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 "hvc_console.h"
+
+/* See the Debug/Emulation chapter in the HRM */
+#define EMUDOF 0x00000001 /* EMUDAT_OUT full & valid */
+#define EMUDIF 0x00000002 /* EMUDAT_IN full & valid */
+#define EMUDOOVF 0x00000004 /* EMUDAT_OUT overflow */
+#define EMUDIOVF 0x00000008 /* EMUDAT_IN overflow */
+
+/* Helper functions to glue the register API to simple C operations */
+static inline uint32_t bfin_write_emudat(uint32_t emudat)
+{
+ __asm__ __volatile__("emudat = %0;" : : "d"(emudat));
+ return emudat;
+}
+
+static inline uint32_t bfin_read_emudat(void)
+{
+ uint32_t emudat;
+ __asm__ __volatile__("%0 = emudat;" : "=d"(emudat));
+ return emudat;
+}
+
+/* Send data to the host */
+static int hvc_bfin_put_chars(uint32_t vt, const char *buf, int count)
+{
+ static uint32_t outbound_len;
+ uint32_t emudat;
+ int ret;
+
+ if (bfin_read_DBGSTAT() & EMUDOF)
+ return 0;
+
+ if (!outbound_len) {
+ outbound_len = count;
+ bfin_write_emudat(outbound_len);
+ return 0;
+ }
+
+ ret = min(outbound_len, (uint32_t)4);
+ memcpy(&emudat, buf, ret);
+ bfin_write_emudat(emudat);
+ outbound_len -= ret;
+
+ return ret;
+}
+
+/* Receive data from the host */
+static int hvc_bfin_get_chars(uint32_t vt, char *buf, int count)
+{
+ static uint32_t inbound_len;
+ uint32_t emudat;
+ int ret;
+
+ if (!(bfin_read_DBGSTAT() & EMUDIF))
+ return 0;
+ emudat = bfin_read_emudat();
+
+ if (!inbound_len) {
+ inbound_len = emudat;
+ return 0;
+ }
+
+ ret = min(inbound_len, (uint32_t)4);
+ memcpy(buf, &emudat, ret);
+ inbound_len -= ret;
+
+ return ret;
+}
+
+/* Glue the HVC layers to the Blackfin layers */
+static const struct hv_ops hvc_bfin_get_put_ops = {
+ .get_chars = hvc_bfin_get_chars,
+ .put_chars = hvc_bfin_put_chars,
+};
+
+static int __init hvc_bfin_console_init(void)
+{
+ hvc_instantiate(0, 0, &hvc_bfin_get_put_ops);
+ return 0;
+}
+console_initcall(hvc_bfin_console_init);
+
+static int __init hvc_bfin_init(void)
+{
+ hvc_alloc(0, 0, &hvc_bfin_get_put_ops, 128);
+ return 0;
+}
+device_initcall(hvc_bfin_init);