drivers/jtag: usb_blaster add pin controls

Add pin controls (pin6 and pin8). These pins can be
controled either :
 - with a fixed value (0 or 1)
 - by TRST or SRST reset signal (driven low when signal
 activated).

Change-Id: Ie6a3e57fc6ba6a38fdb9a009c976e3febab8f578
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Reviewed-on: http://openocd.zylin.com/1448
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Tested-by: jenkins

diff --git a/src/jtag/drivers/usb_blaster/usb_blaster.c b/src/jtag/drivers/usb_blaster/usb_blaster.c
index 3400ca58a39c4d2b747856fbbb972c3a354a24ff..ccbed0e2be58439f2a7ece61612f607961f5156e 100644 (file)
--- a/src/jtag/drivers/usb_blaster/usb_blaster.c
+++ b/src/jtag/drivers/usb_blaster/usb_blaster.c
@@ -82,11 +82,20 @@
  */
 #define BUF_LEN 4096
 
+enum gpio_steer {
+       FIXED_0 = 0,
+       FIXED_1,
+       SRST,
+       TRST,
+};
+
 struct ublast_info {
-       int pin6;
-       int pin8;
+       enum gpio_steer pin6;
+       enum gpio_steer pin8;
        int tms;
        int tdi;
+       bool trst_asserted;
+       bool srst_asserted;
        uint8_t buf[BUF_LEN];
        int bufidx;
 
@@ -103,6 +112,10 @@ static struct ublast_info info = {
        .ublast_vid = 0x09fb, /* Altera */
        .ublast_pid = 0x6001, /* USB-Blaster */
        .lowlevel_name = NULL,
+       .srst_asserted = false,
+       .trst_asserted = false,
+       .pin6 = FIXED_1,
+       .pin8 = FIXED_1,
 };
 
 /*
@@ -218,20 +231,6 @@ static void ublast_flush_buffer(void)
 #define SHMODE         (1 << 7)
 #define READ_TDO       (1 << 0)
 
-/**
- * ublast_reset - reset the JTAG device is possible
- * @trst: 1 if TRST is to be asserted
- * @srst: 1 if SRST is to be asserted
- *
- * This is not implemented yet. If pin6 or pin8 controlls the TRST/SRST, code
- * should be added so that this function makes use of it.
- */
-static void ublast_reset(int trst, int srst)
-{
-       DEBUG_JTAG_IO("TODO: ublast_reset(%d,%d) isn't implemented!",
-                 trst, srst);
-}
-
 /**
  * ublast_queue_byte - queue one 'bitbang mode' byte for USB Blaster
  * @abyte: the byte to queue
@@ -250,6 +249,28 @@ static void ublast_queue_byte(uint8_t abyte)
        DEBUG_JTAG_IO("(byte=0x%02x)", abyte);
 }
 
+/**
+ * ublast_compute_pin - compute if gpio should be asserted
+ * @steer: control (ie. TRST driven, SRST driven, of fixed)
+ *
+ * Returns pin value (1 means driven high, 0 mean driven low)
+ */
+bool ublast_compute_pin(enum gpio_steer steer)
+{
+       switch (steer) {
+       case FIXED_0:
+               return 0;
+       case FIXED_1:
+               return 1;
+       case SRST:
+               return !info.srst_asserted;
+       case TRST:
+               return !info.trst_asserted;
+       default:
+               return 1;
+       }
+}
+
 /**
  * ublast_build_out - build bitbang mode output byte
  * @type: says if reading back TDO is required
@@ -261,8 +282,8 @@ static uint8_t ublast_build_out(enum scan_type type)
        uint8_t abyte = 0;
 
        abyte |= info.tms ? TMS : 0;
-       abyte |= info.pin6 ? NCE : 0;
-       abyte |= info.pin8 ? NCS : 0;
+       abyte |= ublast_compute_pin(info.pin6) ? NCE : 0;
+       abyte |= ublast_compute_pin(info.pin8) ? NCS : 0;
        abyte |= info.tdi ? TDI : 0;
        abyte |= LED;
        if (type == SCAN_IN || type == SCAN_IO)
@@ -270,6 +291,22 @@ static uint8_t ublast_build_out(enum scan_type type)
        return abyte;
 }
 
+/**
+ * ublast_reset - reset the JTAG device is possible
+ * @trst: 1 if TRST is to be asserted
+ * @srst: 1 if SRST is to be asserted
+ */
+static void ublast_reset(int trst, int srst)
+{
+       uint8_t out_value;
+
+       info.trst_asserted = trst;
+       info.srst_asserted = srst;
+       out_value = ublast_build_out(SCAN_OUT);
+       ublast_queue_byte(out_value);
+       ublast_flush_buffer();
+}
+
 /**
  * ublast_clock_tms - clock a TMS transition
  * @tms: the TMS to be sent
@@ -841,24 +878,57 @@ COMMAND_HANDLER(ublast_handle_vid_pid_command)
 COMMAND_HANDLER(ublast_handle_pin_command)
 {
        uint8_t out_value;
+       const char * const pin_name = CMD_ARGV[0];
+       enum gpio_steer *steer = NULL;
+       static const char * const pin_val_str[] = {
+               [FIXED_0] = "0",
+               [FIXED_1] = "1",
+               [SRST] = "SRST driven",
+               [TRST] = "TRST driven",
+       };
 
-       if (CMD_ARGC == 2) {
-               const char * const pin_name = CMD_ARGV[0];
-               unsigned int state;
+       if (CMD_ARGC > 2) {
+               LOG_ERROR("%s takes exactly one or two arguments", CMD_NAME);
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
 
-               COMMAND_PARSE_NUMBER(uint, CMD_ARGV[1], state);
-               if ((state != 0) && (state != 1)) {
-                       LOG_ERROR("%s: pin state must be 0 or 1", CMD_NAME);
-                       return ERROR_COMMAND_SYNTAX_ERROR;
-               }
+       if (!strcmp(pin_name, "pin6"))
+               steer = &info.pin6;
+       if (!strcmp(pin_name, "pin8"))
+               steer = &info.pin8;
+       if (!steer) {
+               LOG_ERROR("%s: pin name must be \"pin6\" or \"pin8\"",
+                         CMD_NAME);
+               return ERROR_COMMAND_SYNTAX_ERROR;
+       }
+
+       if (CMD_ARGC == 1) {
+               LOG_INFO("%s: %s is set as %s\n", CMD_NAME, pin_name,
+                        pin_val_str[*steer]);
+       }
 
-               if (!strcmp(pin_name, "pin6")) {
-                       info.pin6 = state;
-               } else if (!strcmp(pin_name, "pin8")) {
-                       info.pin8 = state;
-               } else {
-                       LOG_ERROR("%s: pin name must be \"pin6\" or \"pin8\"",
-                                       CMD_NAME);
+       if (CMD_ARGC == 2) {
+               const char * const pin_value = CMD_ARGV[1];
+               char val = pin_value[0];
+
+               if (strlen(pin_value) > 1)
+                       val = '?';
+               switch (tolower(val)) {
+               case '0':
+                       *steer = FIXED_0;
+                       break;
+               case '1':
+                       *steer = FIXED_1;
+                       break;
+               case 't':
+                       *steer = TRST;
+                       break;
+               case 's':
+                       *steer = SRST;
+                       break;
+               default:
+                       LOG_ERROR("%s: pin value must be 0, 1, s (SRST) or t (TRST)",
+                               pin_value);
                        return ERROR_COMMAND_SYNTAX_ERROR;
                }
 
@@ -867,11 +937,8 @@ COMMAND_HANDLER(ublast_handle_pin_command)
                        ublast_queue_byte(out_value);
                        ublast_flush_buffer();
                }
-               return ERROR_OK;
-       } else {
-               LOG_ERROR("%s takes exactly two arguments", CMD_NAME);
-               return ERROR_COMMAND_SYNTAX_ERROR;
        }
+       return ERROR_OK;
 }
 
 COMMAND_HANDLER(ublast_handle_lowlevel_drv_command)
@@ -907,11 +974,11 @@ static const struct command_registration ublast_command_handlers[] = {
                .usage = "(ftdi|ftd2xx)",
        },
        {
-               .name = "usb_blaster",
+               .name = "usb_blaster_pin",
                .handler = ublast_handle_pin_command,
                .mode = COMMAND_ANY,
-               .help = "set pin state for the unused GPIO pins",
-               .usage = "(pin6|pin8) (0|1)",
+               .help = "show or set pin state for the unused GPIO pins",
+               .usage = "(pin6|pin8) (0|1|s|t)",
        },
        COMMAND_REGISTRATION_DONE
 };