/* MSPDebug - debugging tool for MSP430 MCUs
 * Copyright (C) 2009-2012 Daniel Beer
 * Copyright (C) 2012-2015 Peter Bägel
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

/* jtag functions are taken from TIs SLAA149–September 2002
 *
 * breakpoint implementation influenced by a posting of Ruisheng Lin
 * to Travis Goodspeed at 2012-09-20 found at:
 * http://sourceforge.net/p/goodfet/mailman/message/29860790/
 *
 * 2012-10-03 Peter Bägel (DF5EQ)
 * 2012-10-03   initial release              Peter Bägel (DF5EQ)
 * 2014-12-26   jtag_single_step added       Peter Bägel (DF5EQ)
 *              jtag_read_reg    corrected
 *              jtag_write_reg   corrected
 * 2015-02-21   jtag_set_breakpoint added    Peter Bägel (DF5EQ)
 *              jtag_cpu_state      added
 * 2020-06-01   jtag_read_reg    corrected   Gabor Mayer (HG5OAP)
 *              jtag_write_reg   corrected
 */

#include <stdlib.h>
#include "jtaglib.h"
#include "output.h"
#include "jtaglib_defs.h"

/* Reset target JTAG interface and perform fuse-HW check */
static void jtag_default_reset_tap(struct jtdev *p)
{
	int loop_counter;

	/* TODO: replace with tms_sequence()? */
	jtag_tms_set(p);
	jtag_tck_set(p);

	/* Perform fuse check */
	jtag_tms_clr(p);
	jtag_tms_set(p);
	jtag_tms_clr(p);
	jtag_tms_set(p);

	/* Reset JTAG state machine */
	for (loop_counter = 6; loop_counter > 0; loop_counter--) {
		jtag_tck_clr(p);
		jtag_tck_set(p);

		if (p->failed)
			return;
	}

	/* Set JTAG state machine to Run-Test/IDLE */
	jtag_tck_clr(p);
	jtag_tms_clr(p);
	jtag_tck_set(p);
}

/* This function sets the target JTAG state machine
 * back into the Run-Test/Idle state after a shift access
 */
static void jtag_default_tclk_prep (struct jtdev *p)
{
	/* JTAG state = Exit-DR */
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Update-DR */
	jtag_tms_clr(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Run-Test/Idle */
}

/* Shift a value into TDI (MSB first) and simultaneously
 * shift out a value from TDO (MSB first)
 * num_bits: number of bits to shift
 * data_out: data to be shifted out
 * return  : scanned TDO value
 */
static unsigned int jtag_default_shift( struct jtdev *p,
				unsigned char num_bits,
				unsigned int  data_out )
{
	unsigned int data_in;
	unsigned int mask;
	unsigned int tclk_save;

	tclk_save = p->f->jtdev_tclk_get(p);

	data_in = 0;
	for (mask = 0x0001U << (num_bits - 1); mask != 0; mask >>= 1) {
		if ((data_out & mask) != 0)
			jtag_tdi_set(p);
		else
			jtag_tdi_clr(p);

		if (mask == 1)
			jtag_tms_set(p);

		jtag_tck_clr(p);
		jtag_tck_set(p);

		if (p->f->jtdev_tdo_get(p) == 1)
			data_in |= mask;
	}

	p->f->jtdev_tclk(p, tclk_save);

	/* Set JTAG state back to Run-Test/Idle */
	jtag_default_tclk_prep(p);

	return data_in;
}

/* Shifts a new instruction into the JTAG instruction register through TDI
 * MSB first, with interchanged MSB/LSB, to use the shifting function
 * instruction: 8 bit instruction
 * return     : scanned TDO value
 */
uint8_t jtag_default_ir_shift(struct jtdev *p, uint8_t instruction)
{
	/* JTAG state = Run-Test/Idle */
	jtag_tms_set(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Select DR-Scan */
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Select IR-Scan */
	jtag_tms_clr(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Capture-IR */
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Shift-IR, Shift in TDI (8-bit) */
	return jtag_default_shift(p, 8, instruction);

	/* JTAG state = Run-Test/Idle */
}

/* Shifts a given 8-bit byte into the JTAG data register through TDI.
 * data  : 8 bit data
 * return: scanned TDO value
 */
uint8_t jtag_default_dr_shift_8(struct jtdev *p, uint8_t data)
{
	/* JTAG state = Run-Test/Idle */
	jtag_tms_set(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Select DR-Scan */
	jtag_tms_clr(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Capture-DR */
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Shift-DR, Shift in TDI (16-bit) */
	return jtag_default_shift(p, 8, data);

	/* JTAG state = Run-Test/Idle */
}

/* Shifts a given 16-bit word into the JTAG data register through TDI.
 * data  : 16 bit data
 * return: scanned TDO value
 */
uint16_t jtag_default_dr_shift_16(struct jtdev *p, uint16_t data)
{
	/* JTAG state = Run-Test/Idle */
	jtag_tms_set(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Select DR-Scan */
	jtag_tms_clr(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Capture-DR */
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Shift-DR, Shift in TDI (16-bit) */
	return jtag_default_shift(p, 16, data);

	/* JTAG state = Run-Test/Idle */
}


/* Shifts a given 20-bit word into the JTAG data register through TDI.
 * data  : 20 bit data
 * return: scanned TDO value
 */
uint32_t jtag_default_dr_shift_20(struct jtdev *p, uint32_t data)
{
	/* JTAG state = Run-Test/Idle */
	jtag_tms_set(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Select DR-Scan */
	jtag_tms_clr(p);
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Capture-DR */
	jtag_tck_clr(p);
	jtag_tck_set(p);

	/* JTAG state = Shift-DR, Shift in TDI (20-bit) */
	return jtag_default_shift(p, 20, data);

	/* JTAG state = Run-Test/Idle */
}

void jtag_default_tms_sequence(struct jtdev *p, int bits, unsigned int value)
{
	for (int i = 0; i < bits; ++i) {
		jtag_tck_clr(p);
		if (value & (1u << i))
			jtag_tms_set(p);
		else
			jtag_tms_clr(p);
		jtag_tck_set(p);
	}
}

void jtag_default_init_dap(struct jtdev *p)
{
	jtag_rst_clr(p);
	p->f->jtdev_power_on(p);
	jtag_tdi_set(p);
	jtag_tms_set(p);
	jtag_tck_set(p);
	jtag_tclk_set(p);

	jtag_rst_set(p);
	jtag_tst_clr(p);

	jtag_tst_set(p);
	jtag_rst_clr(p);
	jtag_tst_clr(p);

	jtag_tst_set(p);

	p->f->jtdev_connect(p);
	jtag_rst_set(p);
	jtag_default_reset_tap(p);
}

/* ------------------------------------------------------------------------- */

static const struct jtaglib_funcs* get_jlf(struct jtdev *p)
{
	// FIXME: this function only looks at the chip ID, while the device info DB
	//        is more fine-grained about function mapping. so use that instead
	//        when possible

	static const struct jtaglib_funcs* lut[] = {
		NULL,
		&jlf_cpu16,
		&jlf_cpux,
		&jlf_cpuxv2
	};

	if (p->cpu_type != 0) {
		if (p->cpu_type < sizeof(lut)/sizeof(*lut)) {
			return lut[p->cpu_type];
		} else {
			printc_err("jtaglib: ERROR: bad CPU type %d\n", p->cpu_type);
			return NULL;
		}
	} else {
		if (p->jtag_id == 0) {
			printc_err("jtaglib: ERROR: no JTAG ID set!\n");
			return NULL;
		} else if (p->jtag_id == JTAG_ID_CPU16) {
			return &jlf_cpu16;
		} else {
			// Here, it's hard to predict whether the target is CPUX or Xv2
			// from the JTAG ID alone. However, this is only needed relatively
			// little as the actual MCU ID should be read from info memory
			// after connecting, so let's just assume Xv2 here, and add some
			// extra care to the few functions that will be called before the
			// ID readout happens to make it all work
			return &jlf_cpuxv2;
		}
	}
}

unsigned int jtag_get_device(struct jtdev *p)
{
	// NOTE: this is one of the special functions that have to be called early
	//       on before chip ID stuff is done

	unsigned int r = get_jlf(p)->jlf_get_device(p);

	if (r != 0) jtag_led_green_on(p);

	return r;
}

unsigned int jtag_chip_id(struct jtdev *p)
{
	// NOTE: this is one of the special functions that have to be called early
	//       on before chip ID stuff is done

	return get_jlf(p)->jlf_chip_id(p);
}

/* Reads one byte/word from a given address */
uint16_t jtag_read_mem(struct jtdev *p, unsigned int format, address_t address)
{
	// NOTE: this is one of the special functions that have to be called early
	//       on before chip ID stuff is done

	return get_jlf(p)->jlf_read_mem(p, format, address);
}

/* Execute a Power-Up Clear (PUC) using JTAG CNTRL SIG register */
unsigned int jtag_execute_puc(struct jtdev *p)
{
	// NOTE: this is one of the special functions that have to be called early
	//       on before chip ID stuff is done

	return get_jlf(p)->jlf_execute_puc(p);
}

/* Reads an array of words from target memory */
void jtag_read_mem_quick(struct jtdev *p, address_t start_address,
			 unsigned int word_count, uint16_t *data)
{
	get_jlf(p)->jlf_read_mem_quick(p, start_address, word_count, data);
}

/* Writes one byte/word at a given address */
void jtag_write_mem(struct jtdev *p, unsigned int format, address_t address,
		    uint16_t data)
{
	get_jlf(p)->jlf_write_mem(p, format, address, data);
}

/* Writes an array of words into target memory */
void jtag_write_mem_quick(struct jtdev *p, address_t start_address,
			  unsigned int word_count, const uint16_t *data)
{
	get_jlf(p)->jlf_write_mem_quick(p, start_address, word_count, data);
}

/* Release the target device from JTAG control */
void jtag_release_device(struct jtdev *p, address_t address)
{
	jtag_led_green_off(p);

	get_jlf(p)->jlf_release_device(p, address);
}

/* Performs a verification over the given memory range
 * return: 1 -  verification was successful
 *         0 -  otherwise
 */
int jtag_verify_mem(struct jtdev *p, address_t start_address,
		    unsigned int length, const uint16_t *data)
{
	return get_jlf(p)->jlf_verify_mem(p, start_address, length, data);
}

/* Performs an erase check over the given memory range
 * return: 1 - erase check was successful
 *         0 - otherwise
 */
int jtag_erase_check(struct jtdev *p,
		     address_t start_address,
		     unsigned int length)
{
	return get_jlf(p)->jlf_erase_check(p, start_address, length);
}

/* Programs/verifies an array of words into a FLASH */
void jtag_write_flash(struct jtdev *p, address_t start_address,
		      unsigned int word_count, const uint16_t *data)
{
	jtag_led_red_on(p);

	get_jlf(p)->jlf_write_flash(p, start_address, word_count, data);

	jtag_led_red_off(p);
}

/* Performs a mass erase or a segment erase of a FLASH module */
void jtag_erase_flash(struct jtdev *p, unsigned int erase_mode, address_t erase_address)
{
	jtag_led_red_on(p);

	get_jlf(p)->jlf_erase_flash(p, erase_mode, erase_address);

	jtag_led_red_off(p);
}

/* Reads a register from the target CPU */
address_t jtag_read_reg(struct jtdev *p, int reg)
{
	return get_jlf(p)->jlf_read_reg(p, reg);
}

/* Writes a value into a register of the target CPU */
void jtag_write_reg(struct jtdev *p, int reg, address_t value)
{
	get_jlf(p)->jlf_write_reg(p, reg, value);
}
void jtag_single_step(struct jtdev *p)
{
	get_jlf(p)->jlf_single_step(p);
}
unsigned int jtag_set_breakpoint(struct jtdev *p, int bp_num, address_t bp_addr)
{
	return get_jlf(p)->jlf_set_breakpoint(p, bp_num, bp_addr);

}
unsigned int jtag_cpu_state(struct jtdev *p)
{
	return get_jlf(p)->jlf_cpu_state(p);
}
int jtag_get_config_fuses(struct jtdev *p)
{
	return get_jlf(p)->jlf_get_config_fuses(p);
}

/* ------------------------------------------------------------------------- */

/* Take target device under JTAG control.
 * Disable the target watchdog.
 * return: 0 - fuse is blown
 *        >0 - jtag id
 */
unsigned int jtag_init(struct jtdev *p)
{
	unsigned int jtag_id;

	jtag_init_dap(p);

	/* Check fuse */
	if (jtag_is_fuse_blown(p)) {
		printc_err("jtag_init: fuse is blown\n");
		p->failed = 1;
		return 0;
	}

	/* Set device into JTAG mode */
	jtag_id = jtag_get_device(p);
	if (jtag_id == 0) {
		printc_err("jtag_init: invalid jtag_id: 0x%02x\n", jtag_id);
		p->failed = 1;
		return 0;
	}

	/* Perform PUC, includes target watchdog disable */
	if (jtag_execute_puc(p) != jtag_id) {
		printc_err("jtag_init: PUC failed\n");
		p->failed = 1;
		return 0;
	}

	return jtag_id;
}

/* This function checks if the JTAG access security fuse is blown
 * return: 1 - fuse is blown
 *         0 - otherwise
 */
int jtag_is_fuse_blown (struct jtdev *p)
{
	unsigned int loop_counter;

	/* First trial could be wrong */
	for (loop_counter = 3; loop_counter > 0; loop_counter--) {
		jtag_ir_shift(p, IR_CNTRL_SIG_CAPTURE);
		if (jtag_dr_shift_16(p, 0xAAAA) == 0x5555)
			/* Fuse is blown */
			return 1;
	}

	/* Fuse is not blown */
	return 0;
}

/*----------------------------------------------------------------------------*/
int jtag_refresh_bps(const char *module, device_t dev, struct jtdev *p)
{
	int i;
	int ret;
	struct device_breakpoint *bp;
	address_t addr;
	ret = 0;

	for (i = 0; i < dev->max_breakpoints; i++) {
		bp = &dev->breakpoints[i];

		printc_dbg("%s: refresh breakpoint %d: type=%d "
			   "addr=%04x flags=%04x\n", module,
			   i, bp->type, bp->addr, bp->flags);

		if ( (bp->flags &  DEVICE_BP_DIRTY) &&
		     (bp->type  == DEVICE_BPTYPE_BREAK) ) {
			addr = bp->addr;

			if ( !(bp->flags & DEVICE_BP_ENABLED) ) {
				addr = 0;
			}

			if ( jtag_set_breakpoint (p, i, addr) == 0) {
				printc_err("%s: failed to refresh "
					   "breakpoint #%d\n", module, i);
				ret = -1;
			} else {
				bp->flags &= ~DEVICE_BP_DIRTY;
			}
		}
	}

	return ret;
}