adiv6: add low level swd transport

During enter in SWD read DP_DPIDR without selecting the register
bank through DP_SELECT_DPBANK.
Handle the different format of DP_SELECT register.

Change-Id: Iea1b8eb6ec94177e16a430d5885595a38e833eeb
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6697
Tested-by: jenkins
This commit is contained in:
Antonio Borneo 2021-11-11 23:49:23 +01:00
parent 62058c0a32
commit 72fb88613f
1 changed files with 52 additions and 26 deletions

View File

@ -29,6 +29,7 @@
* for details, see "ARM IHI 0031A" * for details, see "ARM IHI 0031A"
* ARM Debug Interface v5 Architecture Specification * ARM Debug Interface v5 Architecture Specification
* especially section 5.3 for SWD protocol * especially section 5.3 for SWD protocol
* and "ARM IHI 0074C" ARM Debug Interface Architecture Specification ADIv6.0
* *
* On many chips (most current Cortex-M3 parts) SWD is a run-time alternative * On many chips (most current Cortex-M3 parts) SWD is a run-time alternative
* to JTAG. Boards may support one or both. There are also SWD-only chips, * to JTAG. Boards may support one or both. There are also SWD-only chips,
@ -112,20 +113,20 @@ static inline int check_sync(struct adiv5_dap *dap)
/** Select the DP register bank matching bits 7:4 of reg. */ /** Select the DP register bank matching bits 7:4 of reg. */
static int swd_queue_dp_bankselect(struct adiv5_dap *dap, unsigned int reg) static int swd_queue_dp_bankselect(struct adiv5_dap *dap, unsigned int reg)
{ {
/* Only register address 4 is banked. */ /* Only register address 0 and 4 are banked. */
if ((reg & 0xf) != 4) if ((reg & 0xf) > 4)
return ERROR_OK; return ERROR_OK;
uint32_t select_dp_bank = (reg & 0x000000F0) >> 4; uint64_t sel = (reg & 0x000000F0) >> 4;
uint32_t sel = select_dp_bank if (dap->select != DP_SELECT_INVALID)
| (dap->select & (DP_SELECT_APSEL | DP_SELECT_APBANK)); sel |= dap->select & ~0xfULL;
if (sel == dap->select) if (sel == dap->select)
return ERROR_OK; return ERROR_OK;
dap->select = sel; dap->select = sel;
int retval = swd_queue_dp_write_inner(dap, DP_SELECT, sel); int retval = swd_queue_dp_write_inner(dap, DP_SELECT, (uint32_t)sel);
if (retval != ERROR_OK) if (retval != ERROR_OK)
dap->select = DP_SELECT_INVALID; dap->select = DP_SELECT_INVALID;
@ -326,6 +327,21 @@ static int swd_connect_single(struct adiv5_dap *dap)
dap->do_reconnect = false; dap->do_reconnect = false;
dap_invalidate_cache(dap); dap_invalidate_cache(dap);
/* The sequences to enter in SWD (JTAG_TO_SWD and DORMANT_TO_SWD) end
* with a SWD line reset sequence (50 clk with SWDIO high).
* From ARM IHI 0074C ADIv6.0, chapter B4.3.3 "Connection and line reset
* sequence":
* - line reset sets DP_SELECT_DPBANK to zero;
* - read of DP_DPIDR takes the connection out of reset;
* - write of DP_TARGETSEL keeps the connection in reset;
* - other accesses return protocol error (SWDIO not driven by target).
*
* Read DP_DPIDR to get out of reset. Initialize dap->select to zero to
* skip the write to DP_SELECT, avoiding the protocol error. Set again
* dap->select to DP_SELECT_INVALID because the rest of the register is
* unknown after line reset.
*/
dap->select = 0;
retval = swd_queue_dp_read_inner(dap, DP_DPIDR, &dpidr); retval = swd_queue_dp_read_inner(dap, DP_DPIDR, &dpidr);
if (retval == ERROR_OK) { if (retval == ERROR_OK) {
retval = swd_run_inner(dap); retval = swd_run_inner(dap);
@ -337,6 +353,7 @@ static int swd_connect_single(struct adiv5_dap *dap)
dap->switch_through_dormant = !dap->switch_through_dormant; dap->switch_through_dormant = !dap->switch_through_dormant;
} while (timeval_ms() < timeout); } while (timeval_ms() < timeout);
dap->select = DP_SELECT_INVALID;
if (retval != ERROR_OK) { if (retval != ERROR_OK) {
LOG_ERROR("Error connecting DP: cannot read IDR"); LOG_ERROR("Error connecting DP: cannot read IDR");
@ -473,17 +490,42 @@ static int swd_queue_dp_write(struct adiv5_dap *dap, unsigned reg,
/** Select the AP register bank matching bits 7:4 of reg. */ /** Select the AP register bank matching bits 7:4 of reg. */
static int swd_queue_ap_bankselect(struct adiv5_ap *ap, unsigned reg) static int swd_queue_ap_bankselect(struct adiv5_ap *ap, unsigned reg)
{ {
int retval;
struct adiv5_dap *dap = ap->dap; struct adiv5_dap *dap = ap->dap;
uint32_t sel = ((uint32_t)ap->ap_num << 24) uint64_t sel;
| (reg & 0x000000F0)
| (dap->select & DP_SELECT_DPBANK); if (is_adiv6(dap)) {
sel = ap->ap_num | (reg & 0x00000FF0);
if (sel == (dap->select & ~0xfULL))
return ERROR_OK;
if (dap->select != DP_SELECT_INVALID)
sel |= dap->select & 0xf;
dap->select = sel;
LOG_DEBUG("AP BANKSEL: %" PRIx64, sel);
retval = swd_queue_dp_write(dap, DP_SELECT, (uint32_t)sel);
if (retval == ERROR_OK && dap->asize > 32)
retval = swd_queue_dp_write(dap, DP_SELECT1, (uint32_t)(sel >> 32));
if (retval != ERROR_OK)
dap->select = DP_SELECT_INVALID;
return retval;
}
/* ADIv5 */
sel = (ap->ap_num << 24) | (reg & 0x000000F0);
if (dap->select != DP_SELECT_INVALID)
sel |= dap->select & DP_SELECT_DPBANK;
if (sel == dap->select) if (sel == dap->select)
return ERROR_OK; return ERROR_OK;
dap->select = sel; dap->select = sel;
int retval = swd_queue_dp_write_inner(dap, DP_SELECT, sel); retval = swd_queue_dp_write_inner(dap, DP_SELECT, sel);
if (retval != ERROR_OK) if (retval != ERROR_OK)
dap->select = DP_SELECT_INVALID; dap->select = DP_SELECT_INVALID;
@ -497,14 +539,6 @@ static int swd_queue_ap_read(struct adiv5_ap *ap, unsigned reg,
const struct swd_driver *swd = adiv5_dap_swd_driver(dap); const struct swd_driver *swd = adiv5_dap_swd_driver(dap);
assert(swd); assert(swd);
if (is_adiv6(dap)) {
static bool error_flagged;
if (!error_flagged)
LOG_ERROR("ADIv6 dap not supported in SWD mode");
error_flagged = true;
return ERROR_FAIL;
}
int retval = swd_check_reconnect(dap); int retval = swd_check_reconnect(dap);
if (retval != ERROR_OK) if (retval != ERROR_OK)
return retval; return retval;
@ -530,14 +564,6 @@ static int swd_queue_ap_write(struct adiv5_ap *ap, unsigned reg,
const struct swd_driver *swd = adiv5_dap_swd_driver(dap); const struct swd_driver *swd = adiv5_dap_swd_driver(dap);
assert(swd); assert(swd);
if (is_adiv6(dap)) {
static bool error_flagged;
if (!error_flagged)
LOG_ERROR("ADIv6 dap not supported in SWD mode");
error_flagged = true;
return ERROR_FAIL;
}
int retval = swd_check_reconnect(dap); int retval = swd_check_reconnect(dap);
if (retval != ERROR_OK) if (retval != ERROR_OK)
return retval; return retval;