2 * jtag-console.c - console driver over Blackfin JTAG
4 * Copyright (c) 2008-2010 Analog Devices Inc.
6 * Licensed under the GPL-2 or later.
11 #include <stdio_dev.h>
12 #include <asm/blackfin.h>
15 # define dprintf(...) serial_printf(__VA_ARGS__)
17 # define dprintf(...) do { if (0) printf(__VA_ARGS__); } while (0)
20 static inline void dprintf_decode(const char *s, uint32_t len)
23 for (i = 0; i < len; ++i)
24 if (s[i] < 0x20 || s[i] >= 0x7f)
25 dprintf("\\%o", s[i]);
30 static inline uint32_t bfin_write_emudat(uint32_t emudat)
32 __asm__ __volatile__("emudat = %0;" : : "d"(emudat));
36 static inline uint32_t bfin_read_emudat(void)
39 __asm__ __volatile__("%0 = emudat;" : "=d"(emudat));
43 #ifndef CONFIG_JTAG_CONSOLE_TIMEOUT
44 # define CONFIG_JTAG_CONSOLE_TIMEOUT 500
47 /* The Blackfin tends to be much much faster than the JTAG hardware. */
48 static bool jtag_write_emudat(uint32_t emudat)
50 static bool overflowed = false;
51 ulong timeout = get_timer(0);
52 while (bfin_read_DBGSTAT() & 0x1) {
55 if (get_timer(timeout) > CONFIG_JTAG_CONSOLE_TIMEOUT)
59 bfin_write_emudat(emudat);
62 /* Transmit a buffer. The format is:
63 * [32bit length][actual data]
65 static void jtag_send(const char *raw_str, uint32_t len)
67 const char *cooked_str;
73 /* Ugh, need to output \r after \n */
75 for (i = 0; i < len; ++i)
76 if (raw_str[i] == '\n')
79 char *c = malloc(len + ex);
81 for (i = 0; i < len; ++i) {
83 if (raw_str[i] == '\n')
90 dprintf("%s(\"", __func__);
91 dprintf_decode(cooked_str, len);
92 dprintf("\", %i)\n", len);
94 /* First send the length */
95 if (jtag_write_emudat(len))
98 /* Then send the data */
99 for (i = 0; i < len; i += 4) {
101 (cooked_str[i + 0] << 0) |
102 (cooked_str[i + 1] << 8) |
103 (cooked_str[i + 2] << 16) |
104 (cooked_str[i + 3] << 24);
105 if (jtag_write_emudat(emudat)) {
106 bfin_write_emudat(0);
112 if (cooked_str != raw_str)
113 free((char *)cooked_str);
115 static void jtag_putc(struct stdio_dev *dev, const char c)
119 static void jtag_puts(struct stdio_dev *dev, const char *s)
121 jtag_send(s, strlen(s));
124 static size_t inbound_len, leftovers_len;
126 /* Lower layers want to know when jtag has data */
127 static int jtag_tstc_dbg(void)
129 int ret = (bfin_read_DBGSTAT() & 0x2);
131 dprintf("%s: ret:%i\n", __func__, ret);
135 /* Higher layers want to know when any data is available */
136 static int jtag_tstc(struct stdio_dev *dev)
138 return jtag_tstc_dbg() || leftovers_len;
141 /* Receive a buffer. The format is:
142 * [32bit length][actual data]
144 static uint32_t leftovers;
145 static int jtag_getc(struct stdio_dev *dev)
150 dprintf("%s: inlen:%zu leftlen:%zu left:%x\n", __func__,
151 inbound_len, leftovers_len, leftovers);
153 /* see if any data is left over */
156 ret = leftovers & 0xff;
161 /* wait for new data ! */
162 while (!jtag_tstc_dbg())
164 emudat = bfin_read_emudat();
166 if (inbound_len == 0) {
167 /* grab the length */
168 inbound_len = emudat;
170 /* store the bytes */
171 leftovers_len = min((size_t)4, inbound_len);
172 inbound_len -= leftovers_len;
176 return jtag_getc(dev);
179 int drv_jtag_console_init(void)
181 struct stdio_dev dev;
184 memset(&dev, 0x00, sizeof(dev));
185 strcpy(dev.name, "jtag");
186 dev.flags = DEV_FLAGS_OUTPUT | DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM;
187 dev.putc = jtag_putc;
188 dev.puts = jtag_puts;
189 dev.tstc = jtag_tstc;
190 dev.getc = jtag_getc;
192 ret = stdio_register(&dev);
193 return (ret == 0 ? 1 : ret);
196 #ifdef CONFIG_UART_CONSOLE_IS_JTAG
198 /* Since the JTAG is always available (at power on), allow it to fake a UART */
199 void jtag_serial_setbrg(void)
203 int jtag_serial_init(void)
208 static struct serial_device serial_jtag_drv = {
210 .start = jtag_serial_init,
212 .setbrg = jtag_serial_setbrg,
219 void bfin_jtag_initialize(void)
221 serial_register(&serial_jtag_drv);
224 struct serial_device *default_serial_console(void)
226 return &serial_jtag_drv;