diff options
Diffstat (limited to 'arch/blackfin/cpu/jtag-console.c')
| -rw-r--r-- | arch/blackfin/cpu/jtag-console.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/arch/blackfin/cpu/jtag-console.c b/arch/blackfin/cpu/jtag-console.c new file mode 100644 index 0000000..7cddb85 --- /dev/null +++ b/arch/blackfin/cpu/jtag-console.c @@ -0,0 +1,228 @@ +/* + * 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 |
