Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / tty / hvc / hvc_bfin_jtag.c

diff --git a/kernel/drivers/tty/hvc/hvc_bfin_jtag.c b/kernel/drivers/tty/hvc/hvc_bfin_jtag.c
new file mode 100644 (file)
index 0000000..31d6cc6
--- /dev/null
+++ b/kernel/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);