Commit a3245bd7 authored by David Brownell's avatar David Brownell
Browse files

interface: define TMS sequence command



For support of SWD we need to be able to clock out special bit
sequences over TMS or SWDIO.  Create this as a generic operation,
not yet called by anything, which is split as usual into:

 - upper level abstraction ... here, jtag_add_tms_seq();
 - midlayer implementation logic hooking that to the lowlevel code;
 - lowlevel minidriver operation ... here, interface_add_tms_seq();
 - message type for request queue, here JTAG_TMS.

This is done slightly differently than other operations: there's a flag
saying whether the interface driver supports this request.  (In fact a
flag *word* so upper layers can learn about other capabilities too ...
for example, supporting SWD operations.)

That approach (flag) lets this method *eventually* be used to eliminate
pathmove() and statemove() support from most adapter drivers, by moving
all that logic into the mid-layer and increasing uniformity between the
various drivers.  (Which will in turn reduce subtle bugginess.)
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
parent 4a64820f
......@@ -98,19 +98,39 @@ struct sleep_command {
uint32_t us;
};
/**
* Encapsulates a series of bits to be clocked out, affecting state
* and mode of the interface.
*
* In JTAG mode these are clocked out on TMS, using TCK. They may be
* used for link resets, transitioning between JTAG and SWD modes, or
* to implement JTAG state machine transitions (implementing pathmove
* or statemove operations).
*
* In SWD mode these are clocked out on SWDIO, using SWCLK, and are
* used for link resets and transitioning between SWD and JTAG modes.
*/
struct tms_command {
/** How many bits should be clocked out. */
unsigned num_bits;
/** The bits to clock out; the LSB is bit 0 of bits[0]. */
const uint8_t *bits;
};
/**
* Defines a container type that hold a pointer to a JTAG command
* structure of any defined type.
*/
union jtag_command_container {
struct scan_command* scan;
struct statemove_command* statemove;
struct pathmove_command* pathmove;
struct runtest_command* runtest;
struct stableclocks_command* stableclocks;
struct reset_command* reset;
struct end_state_command* end_state;
struct sleep_command* sleep;
struct scan_command *scan;
struct statemove_command *statemove;
struct pathmove_command *pathmove;
struct runtest_command *runtest;
struct stableclocks_command *stableclocks;
struct reset_command *reset;
struct end_state_command *end_state;
struct sleep_command *sleep;
struct tms_command *tms;
};
/**
......@@ -124,7 +144,8 @@ enum jtag_command_type {
JTAG_RESET = 4,
JTAG_PATHMOVE = 6,
JTAG_SLEEP = 7,
JTAG_STABLECLOCKS = 8
JTAG_STABLECLOCKS = 8,
JTAG_TMS = 9,
};
struct jtag_command {
......
......@@ -488,6 +488,35 @@ void jtag_add_tlr(void)
jtag_notify_event(JTAG_TRST_ASSERTED);
}
/**
* If supported by the underlying adapter, this clocks a raw bit sequence
* onto TMS for switching betwen JTAG and SWD modes.
*
* DO NOT use this to bypass the integrity checks and logging provided
* by the jtag_add_pathmove() and jtag_add_statemove() calls.
*
* @param nbits How many bits to clock out.
* @param seq The bit sequence. The LSB is bit 0 of seq[0].
* @param state The JTAG tap state to record on completion. Use
* TAP_INVALID to represent being in in SWD mode.
*
* @todo Update naming conventions to stop assuming everything is JTAG.
*/
int jtag_add_tms_seq(unsigned nbits, const uint8_t *seq, enum tap_state state)
{
int retval;
if (!(jtag->supported & DEBUG_CAP_TMS_SEQ))
return ERROR_JTAG_NOT_IMPLEMENTED;
jtag_checks();
cmd_queue_cur_state = state;
retval = interface_add_tms_seq(nbits, seq);
jtag_set_error(retval);
return retval;
}
void jtag_add_pathmove(int num_states, const tap_state_t *path)
{
tap_state_t cur_state = cmd_queue_cur_state;
......
......@@ -388,6 +388,31 @@ int interface_jtag_add_tlr(void)
return ERROR_OK;
}
int interface_add_tms_seq(unsigned num_bits, const uint8_t *seq)
{
struct jtag_command *cmd;
cmd = cmd_queue_alloc(sizeof(struct jtag_command));
if (cmd == NULL)
return ERROR_FAIL;
cmd->type = JTAG_TMS;
cmd->cmd.tms = cmd_queue_alloc(sizeof(*cmd->cmd.tms));
if (!cmd->cmd.tms)
return ERROR_FAIL;
/* copy the bits; our caller doesn't guarantee they'll persist */
cmd->cmd.tms->num_bits = num_bits;
cmd->cmd.tms->bits = buf_cpy(seq,
cmd_queue_alloc(DIV_ROUND_UP(num_bits, 8)), num_bits);
if (!cmd->cmd.tms->bits)
return ERROR_FAIL;
jtag_queue_command(cmd);
return ERROR_OK;
}
int interface_jtag_add_pathmove(int num_states, const tap_state_t *path)
{
/* allocate memory for a new list member */
......
......@@ -184,10 +184,28 @@ static inline tap_state_t jtag_debug_state_machine(const void *tms_buf,
}
#endif // _DEBUG_JTAG_IO_
/**
* Represents a driver for a debugging interface.
*
* @todo Rename; perhaps "debug_driver". This isn't an interface,
* it's a driver! Also, not all drivers support JTAG.
*
* @todo We need a per-instance structure too, and changes to pass
* that structure to the driver. Instances can for example be in
* either SWD or JTAG modes. This will help remove globals, and
* eventually to cope with systems which have more than one such
* debugging interface.
*/
struct jtag_interface {
/// The name of the JTAG interface driver.
char* name;
/**
* Bit vector listing capabilities exposed by this driver.
*/
unsigned supported;
#define DEBUG_CAP_TMS_SEQ (1 << 0)
/**
* Execute queued commands.
* @returns ERROR_OK on success, or an error code on failure.
......
......@@ -575,6 +575,8 @@ tap_state_t jtag_get_end_state(void);
void jtag_add_sleep(uint32_t us);
int jtag_add_tms_seq(unsigned nbits, const uint8_t *seq, enum tap_state t);
/**
* Function jtag_add_clocks
* first checks that the state in which the clocks are to be issued is
......@@ -693,7 +695,7 @@ int jtag_error_clear(void);
/**
* Return true if it's safe for a background polling task to access the
* JTAG scan chain. Polling may be explicitly disallowed, and is also
* unsafe while nTRST is active or the JTAG clock is gated off.,
* unsafe while nTRST is active or the JTAG clock is gated off.
*/
bool is_jtag_poll_safe(void);
......
......@@ -67,6 +67,8 @@ int interface_jtag_add_tlr(void);
int interface_jtag_add_pathmove(int num_states, const tap_state_t* path);
int interface_jtag_add_runtest(int num_cycles, tap_state_t endstate);
int interface_add_tms_seq(unsigned num_bits, const uint8_t *bits);
/**
* This drives the actual srst and trst pins. srst will always be 0
* if jtag_reset_config & RESET_SRST_PULLS_TRST != 0 and ditto for
......
......@@ -147,6 +147,13 @@ int interface_jtag_add_pathmove(int num_states, const tap_state_t *path)
return ERROR_OK;
}
int interface_add_tms_seq(unsigned num_bits, const uint8_t *seq)
{
/* synchronously do the operation here */
return ERROR_OK;
}
void embeddedice_write_dcc(struct jtag_tap *tap, int reg_addr, uint8_t *buffer, int little, int count)
{
int i;
......
......@@ -804,7 +804,16 @@ int interface_jtag_add_pathmove(int num_states, const tap_state_t *path)
return ERROR_OK;
}
int interface_add_tms_seq(unsigned num_bits, const uint8_t *seq)
{
/* FIXME just implement this, like pathmove but without
* JTAG-specific state transition checking. Then update
* zy1000_interface to report that it's supported.
*
* Eventually interface_jtag_add_pathmove() could vanish.
*/
return ERROR_JTAG_NOT_IMPLEMENTED;
}
void embeddedice_write_dcc(struct jtag_tap *tap, int reg_addr, uint8_t *buffer, int little, int count)
{
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment