--- /dev/null
+/*
+ * jtag-console.c - console driver over Blackfin JTAG
+ *
+ * Copyright (c) 2008-2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <malloc.h>
+#include <stdio_dev.h>
+#include <asm/blackfin.h>
+
+#ifdef DEBUG
+# define dprintf(...) serial_printf(__VA_ARGS__)
+#else
+# define dprintf(...) do { if (0) printf(__VA_ARGS__); } while (0)
+#endif
+
+static inline void dprintf_decode(const char *s, uint32_t len)
+{
+ uint32_t i;
+ for (i = 0; i < len; ++i)
+ if (s[i] < 0x20 || s[i] >= 0x7f)
+ dprintf("\\%o", s[i]);
+ else
+ dprintf("%c", s[i]);
+}
+
+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;
+}
+
+#ifndef CONFIG_JTAG_CONSOLE_TIMEOUT
+# define CONFIG_JTAG_CONSOLE_TIMEOUT 500
+#endif
+
+/* The Blackfin tends to be much much faster than the JTAG hardware. */
+static bool jtag_write_emudat(uint32_t emudat)
+{
+ static bool overflowed = false;
+ ulong timeout = get_timer(0);
+ while (bfin_read_DBGSTAT() & 0x1) {
+ if (overflowed)
+ return overflowed;
+ if (get_timer(timeout) > CONFIG_JTAG_CONSOLE_TIMEOUT)
+ overflowed = true;
+ }
+ overflowed = false;
+ bfin_write_emudat(emudat);
+ return overflowed;
+}
+/* Transmit a buffer. The format is:
+ * [32bit length][actual data]
+ */
+static void jtag_send(const char *raw_str, uint32_t len)
+{
+ const char *cooked_str;
+ uint32_t i, ex;
+
+ if (len == 0)
+ return;
+
+ /* Ugh, need to output \r after \n */
+ ex = 0;
+ for (i = 0; i < len; ++i)
+ if (raw_str[i] == '\n')
+ ++ex;
+ if (ex) {
+ char *c = malloc(len + ex);
+ cooked_str = c;
+ for (i = 0; i < len; ++i) {
+ *c++ = raw_str[i];
+ if (raw_str[i] == '\n')
+ *c++ = '\r';
+ }
+ len += ex;
+ } else
+ cooked_str = raw_str;
+
+ dprintf("%s(\"", __func__);
+ dprintf_decode(cooked_str, len);
+ dprintf("\", %i)\n", len);
+
+ /* First send the length */
+ if (jtag_write_emudat(len))
+ goto done;
+
+ /* Then send the data */
+ for (i = 0; i < len; i += 4) {
+ uint32_t emudat =
+ (cooked_str[i + 0] << 0) |
+ (cooked_str[i + 1] << 8) |
+ (cooked_str[i + 2] << 16) |
+ (cooked_str[i + 3] << 24);
+ if (jtag_write_emudat(emudat)) {
+ bfin_write_emudat(0);
+ goto done;
+ }
+ }
+
+ done:
+ if (cooked_str != raw_str)
+ free((char *)cooked_str);
+}
+static void jtag_putc(const char c)
+{
+ jtag_send(&c, 1);
+}
+static void jtag_puts(const char *s)
+{
+ jtag_send(s, strlen(s));
+}
+
+static size_t inbound_len, leftovers_len;
+
+/* Lower layers want to know when jtag has data */
+static int jtag_tstc_dbg(void)
+{
+ int ret = (bfin_read_DBGSTAT() & 0x2);
+ if (ret)
+ dprintf("%s: ret:%i\n", __func__, ret);
+ return ret;
+}
+
+/* Higher layers want to know when any data is available */
+static int jtag_tstc(void)
+{
+ return jtag_tstc_dbg() || leftovers_len;
+}
+
+/* Receive a buffer. The format is:
+ * [32bit length][actual data]
+ */
+static uint32_t leftovers;
+static int jtag_getc(void)
+{
+ int ret;
+ uint32_t emudat;
+
+ dprintf("%s: inlen:%zu leftlen:%zu left:%x\n", __func__,
+ inbound_len, leftovers_len, leftovers);
+
+ /* see if any data is left over */
+ if (leftovers_len) {
+ --leftovers_len;
+ ret = leftovers & 0xff;
+ leftovers >>= 8;
+ return ret;
+ }
+
+ /* wait for new data ! */
+ while (!jtag_tstc_dbg())
+ continue;
+ emudat = bfin_read_emudat();
+
+ if (inbound_len == 0) {
+ /* grab the length */
+ inbound_len = emudat;
+ } else {
+ /* store the bytes */
+ leftovers_len = min(4, inbound_len);
+ inbound_len -= leftovers_len;
+ leftovers = emudat;
+ }
+
+ return jtag_getc();
+}
+
+int drv_jtag_console_init(void)
+{
+ struct stdio_dev dev;
+ int ret;
+
+ memset(&dev, 0x00, sizeof(dev));
+ strcpy(dev.name, "jtag");
+ dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM;
+ dev.putc = jtag_putc;
+ dev.puts = jtag_puts;
+ dev.tstc = jtag_tstc;
+ dev.getc = jtag_getc;
+
+ ret = stdio_register(&dev);
+ return (ret == 0 ? 1 : ret);
+}
+
+#ifdef CONFIG_UART_CONSOLE_IS_JTAG
+#include <serial.h>
+/* Since the JTAG is always available (at power on), allow it to fake a UART */
+void jtag_serial_setbrg(void)
+{
+}
+
+int jtag_serial_init(void)
+{
+ return 0;
+}
+
+static struct serial_device serial_jtag_drv = {
+ .name = "jtag",
+ .start = jtag_serial_init,
+ .stop = NULL,
+ .setbrg = jtag_serial_setbrg,
+ .putc = jtag_putc,
+ .puts = jtag_puts,
+ .tstc = jtag_tstc,
+ .getc = jtag_getc,
+};
+
+void bfin_jtag_initialize(void)
+{
+ serial_register(&serial_jtag_drv);
+}
+
+struct serial_device *default_serial_console(void)
+{
+ return &serial_jtag_drv;
+}
+#endif
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