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- /***************************************************************************
- * Copyright (C) 2009-2010 by David Brownell *
- * *
- * This program is free software; you can redistribute it and/or modify *
- * it under the terms of the GNU General Public License as published by *
- * the Free Software Foundation; either version 2 of the License, or *
- * (at your option) any later version. *
- * *
- * This program is distributed in the hope that it will be useful, *
- * but WITHOUT ANY WARRANTY; without even the implied warranty of *
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
- * GNU General Public License for more details. *
- * *
- * You should have received a copy of the GNU General Public License *
- * along with this program; if not, write to the *
- * Free Software Foundation, Inc., *
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *
- ***************************************************************************/
-
- #ifndef SWD_H
- #define SWD_H
-
- /* Bits in SWD command packets, written from host to target
- * first bit on the wire is START
- */
- #define SWD_CMD_START (1 << 0) /* always set */
- #define SWD_CMD_APnDP (1 << 1) /* set only for AP access */
- #define SWD_CMD_RnW (1 << 2) /* set only for read access */
- #define SWD_CMD_A32 (3 << 3) /* bits A[3:2] of register addr */
- #define SWD_CMD_PARITY (1 << 5) /* parity of APnDP|RnW|A32 */
- #define SWD_CMD_STOP (0 << 6) /* always clear for synch SWD */
- #define SWD_CMD_PARK (0 << 7) /* not driven by host (pull high) */
- /* followed by TRN, 3-bits of ACK, TRN */
-
- /* pbit16 holds precomputed parity bits for each nibble */
- #define pbit(parity, nibble) (parity << nibble)
-
- static const uint16_t pbit16 =
- pbit(0, 0) | pbit(1, 1) | pbit(1, 2) | pbit(0, 3)
- | pbit(1, 4) | pbit(0, 5) | pbit(0, 6) | pbit(1, 7)
- | pbit(1, 8) | pbit(0, 9) | pbit(0, 0xa) | pbit(1, 0xb)
- | pbit(0, 0xc) | pbit(1, 0xd) | pbit(1, 0xe) | pbit(0, 0xf);
-
- #define nibble_parity(nibble) (pbit16 & pbit(1, nibble))
-
- /**
- * Construct a "cmd" byte, in lSB bit order, which swd_driver.read_reg()
- * and swd_driver.write_reg() methods will use directly.
- */
- static inline uint8_t swd_cmd(bool is_read, bool is_ap, uint8_t regnum)
- {
- uint8_t cmd = (is_ap ? SWD_CMD_APnDP : 0)
- | (is_read ? SWD_CMD_RnW : 0)
- | ((regnum & 0xc) << 1);
-
- /* 8 cmd bits 4:1 may be set */
- if (nibble_parity(cmd >> 1))
- cmd |= SWD_CMD_PARITY;
-
- /* driver handles START, STOP, and TRN */
-
- return cmd;
- }
-
- /* SWD_ACK_* bits are defined in <target/arm_adi_v5.h> */
-
- /*
- * FOR NOW ... SWD driver ops are synchronous and return ACK
- * status ... no quueueing.
- *
- * Individual ops are request/response, and fast-fail permits much
- * better fault handling. Upper layers may queue if desired.
- */
-
- struct swd_driver {
- /**
- * Initialize the debug link so it can perform
- * synchronous SWD operations.
- * @param trn value from WCR: how many clocks
- * to not drive the SWDIO line at certain points in
- * the SWD protocol (at least 1 clock).
- *
- * As an example, this would switch a dual-mode debug adapter
- * into SWD mode and out of JTAG mode.
- *
- * @return ERROR_OK on success, else a negative fault code.
- */
- int (*init)(uint8_t trn);
-
-
- /**
- * Synchronous read of an AP or DP register.
- *
- * @param cmd with APnDP/RnW/addr/parity bits
- * @param where to store value to read from register
- *
- * @return SWD_ACK_* code for the transaction
- * or (negative) fault code
- */
- int (*read_reg)(uint8_t cmd, uint32_t *value);
-
- /**
- * Synchronous write of an AP or DP register.
- *
- * @param cmd with APnDP/RnW/addr/parity bits
- * @param value to be written to the register
- *
- * @return SWD_ACK_* code for the transaction
- * or (negative) fault code
- */
- int (*write_reg)(uint8_t cmd, uint32_t value);
-
- /* XXX START WITH enough to:
- * init (synch mode, WCR)
- * for async, TRN > 1
- * read IDCODE from DP
- */
-
- /**
- * Configures data collection from the Single-wire
- * trace (SWO) signal.
- * @param swo true if SWO data collection should be routed.
- *
- * For example, some debug adapters include a UART which
- * is normally connected to a microcontroller's UART TX,
- * but which may instead be connected to SWO for use in
- * collecting ITM (and possibly ETM) trace data.
- *
- * @return ERROR_OK on success, else a negative fault code.
- */
- int *(*trace)(bool swo);
- };
-
- int swd_init_reset(struct command_context *cmd_ctx);
- void swd_add_reset(int req_srst);
-
- bool transport_is_swd(void);
-
- #endif /* SWD_H */
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