// SPDX-License-Identifier: GPL-2.0-or-later

/***************************************************************************
 *   ESP32-S2 target for OpenOCD                                           *
 *   Copyright (C) 2019 Espressif Systems Ltd.                             *
 ***************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <helper/time_support.h>
#include "assert.h"
#include <target/target.h>
#include <target/target_type.h>
#include <target/semihosting_common.h>
#include "esp_xtensa.h"
#include "esp_xtensa_semihosting.h"

#define ESP32_S2_RTC_DATA_LOW           0x50000000
#define ESP32_S2_RTC_DATA_HIGH          0x50002000
#define ESP32_S2_DR_REG_LOW             0x3f400000
#define ESP32_S2_DR_REG_HIGH            0x3f4d3FFC
#define ESP32_S2_SYS_RAM_LOW            0x60000000UL
#define ESP32_S2_SYS_RAM_HIGH           (ESP32_S2_SYS_RAM_LOW + 0x20000000UL)

/* ESP32 WDT */
#define ESP32_S2_WDT_WKEY_VALUE         0x50d83aa1
#define ESP32_S2_TIMG0_BASE             0x3f41F000
#define ESP32_S2_TIMG1_BASE             0x3f420000
#define ESP32_S2_TIMGWDT_CFG0_OFF       0x48
#define ESP32_S2_TIMGWDT_PROTECT_OFF    0x64
#define ESP32_S2_TIMG0WDT_CFG0          (ESP32_S2_TIMG0_BASE + ESP32_S2_TIMGWDT_CFG0_OFF)
#define ESP32_S2_TIMG1WDT_CFG0          (ESP32_S2_TIMG1_BASE + ESP32_S2_TIMGWDT_CFG0_OFF)
#define ESP32_S2_TIMG0WDT_PROTECT       (ESP32_S2_TIMG0_BASE + ESP32_S2_TIMGWDT_PROTECT_OFF)
#define ESP32_S2_TIMG1WDT_PROTECT       (ESP32_S2_TIMG1_BASE + ESP32_S2_TIMGWDT_PROTECT_OFF)
#define ESP32_S2_RTCCNTL_BASE           0x3f408000
#define ESP32_S2_RTCWDT_CFG_OFF         0x94
#define ESP32_S2_RTCWDT_PROTECT_OFF     0xAC
#define ESP32_S2_SWD_CONF_OFF           0xB0
#define ESP32_S2_SWD_WPROTECT_OFF       0xB4
#define ESP32_S2_RTC_CNTL_DIG_PWC_REG_OFF      0x8C
#define ESP32_S2_RTC_CNTL_DIG_PWC_REG   (ESP32_S2_RTCCNTL_BASE + ESP32_S2_RTC_CNTL_DIG_PWC_REG_OFF)
#define ESP32_S2_RTCWDT_CFG             (ESP32_S2_RTCCNTL_BASE + ESP32_S2_RTCWDT_CFG_OFF)
#define ESP32_S2_RTCWDT_PROTECT         (ESP32_S2_RTCCNTL_BASE + ESP32_S2_RTCWDT_PROTECT_OFF)
#define ESP32_S2_SWD_CONF_REG           (ESP32_S2_RTCCNTL_BASE + ESP32_S2_SWD_CONF_OFF)
#define ESP32_S2_SWD_WPROTECT_REG       (ESP32_S2_RTCCNTL_BASE + ESP32_S2_SWD_WPROTECT_OFF)
#define ESP32_S2_SWD_AUTO_FEED_EN_M     BIT(31)
#define ESP32_S2_SWD_WKEY_VALUE         0x8F1D312AU
#define ESP32_S2_OPTIONS0               (ESP32_S2_RTCCNTL_BASE + 0x0000)
#define ESP32_S2_SW_SYS_RST_M           0x80000000
#define ESP32_S2_SW_SYS_RST_V           0x1
#define ESP32_S2_SW_SYS_RST_S           31
#define ESP32_S2_SW_STALL_PROCPU_C0_M   ((ESP32_S2_SW_STALL_PROCPU_C0_V) << (ESP32_S2_SW_STALL_PROCPU_C0_S))
#define ESP32_S2_SW_STALL_PROCPU_C0_V   0x3
#define ESP32_S2_SW_STALL_PROCPU_C0_S   2
#define ESP32_S2_SW_CPU_STALL           (ESP32_S2_RTCCNTL_BASE + 0x00B8)
#define ESP32_S2_SW_STALL_PROCPU_C1_M   ((ESP32_S2_SW_STALL_PROCPU_C1_V) << (ESP32_S2_SW_STALL_PROCPU_C1_S))
#define ESP32_S2_SW_STALL_PROCPU_C1_V   0x3FU
#define ESP32_S2_SW_STALL_PROCPU_C1_S   26
#define ESP32_S2_CLK_CONF               (ESP32_S2_RTCCNTL_BASE + 0x0074)
#define ESP32_S2_CLK_CONF_DEF           0x1583218
#define ESP32_S2_STORE4                 (ESP32_S2_RTCCNTL_BASE + 0x00BC)
#define ESP32_S2_STORE5                 (ESP32_S2_RTCCNTL_BASE + 0x00C0)
#define ESP32_S2_DPORT_PMS_OCCUPY_3     0x3F4C10E0

#define ESP32_S2_TRACEMEM_BLOCK_SZ      0x4000

#define ESP32_S2_DR_REG_UART_BASE       0x3f400000
#define ESP32_S2_REG_UART_BASE(i)       (ESP32_S2_DR_REG_UART_BASE + (i) * 0x10000)
#define ESP32_S2_UART_DATE_REG(i)       (ESP32_S2_REG_UART_BASE(i) + 0x74)
struct esp32s2_common {
	struct esp_xtensa_common esp_xtensa;
};

static int esp32s2_soc_reset(struct target *target);
static int esp32s2_disable_wdts(struct target *target);

static int esp32s2_assert_reset(struct target *target)
{
	return ERROR_OK;
}

static int esp32s2_deassert_reset(struct target *target)
{
	struct xtensa *xtensa = target_to_xtensa(target);

	LOG_TARGET_DEBUG(target, "begin");

	int res = xtensa_deassert_reset(target);
	if (res != ERROR_OK)
		return res;

	/* restore configured value
	   esp32s2_soc_reset() modified it, but can not restore just after SW reset for some reason (???) */
	res = xtensa_smpbreak_write(xtensa, xtensa->smp_break);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to restore smpbreak (%d)!", res);
		return res;
	}
	return ERROR_OK;
}

static int esp32s2_soft_reset_halt(struct target *target)
{
	LOG_TARGET_DEBUG(target, "begin");

	/* Reset the SoC first */
	int res = esp32s2_soc_reset(target);
	if (res != ERROR_OK)
		return res;
	return xtensa_soft_reset_halt(target);
}

static int esp32s2_set_peri_reg_mask(struct target *target,
	target_addr_t addr,
	uint32_t mask,
	uint32_t val)
{
	uint32_t reg_val;
	int res = target_read_u32(target, addr, &reg_val);
	if (res != ERROR_OK)
		return res;
	reg_val = (reg_val & (~mask)) | val;
	res = target_write_u32(target, addr, reg_val);
	if (res != ERROR_OK)
		return res;

	return ERROR_OK;
}

static int esp32s2_stall_set(struct target *target, bool stall)
{
	LOG_TARGET_DEBUG(target, "begin");

	int res = esp32s2_set_peri_reg_mask(target,
		ESP32_S2_SW_CPU_STALL,
		ESP32_S2_SW_STALL_PROCPU_C1_M,
		stall ? 0x21U << ESP32_S2_SW_STALL_PROCPU_C1_S : 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_SW_CPU_STALL (%d)!", res);
		return res;
	}
	res = esp32s2_set_peri_reg_mask(target,
		ESP32_S2_OPTIONS0,
		ESP32_S2_SW_STALL_PROCPU_C0_M,
		stall ? 0x2 << ESP32_S2_SW_STALL_PROCPU_C0_S : 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_OPTIONS0 (%d)!", res);
		return res;
	}
	return ERROR_OK;
}

static inline int esp32s2_stall(struct target *target)
{
	return esp32s2_stall_set(target, true);
}

static inline int esp32s2_unstall(struct target *target)
{
	return esp32s2_stall_set(target, false);
}

/* Reset ESP32-S2's peripherals.
Postconditions: all peripherals except RTC_CNTL are reset, CPU's PC is undefined, PRO CPU is halted, APP CPU is in reset
How this works:
0. make sure target is halted; if not, try to halt it; if that fails, try to reset it (via OCD) and then halt
1. Resets clock related registers
2. Stalls CPU
3. trigger SoC reset using RTC_CNTL_SW_SYS_RST bit
4. CPU is reset and stalled at the first reset vector instruction
5. wait for the OCD to be reset
6. halt the target
7. Unstalls CPU
8. Disables WDTs and trace memory mapping
*/
static int esp32s2_soc_reset(struct target *target)
{
	int res;
	struct xtensa *xtensa = target_to_xtensa(target);

	LOG_DEBUG("start");

	/* In order to write to peripheral registers, target must be halted first */
	if (target->state != TARGET_HALTED) {
		LOG_TARGET_DEBUG(target, "Target not halted before SoC reset, trying to halt it first");
		xtensa_halt(target);
		res = target_wait_state(target, TARGET_HALTED, 1000);
		if (res != ERROR_OK) {
			LOG_TARGET_DEBUG(target, "Couldn't halt target before SoC reset, trying to do reset-halt");
			res = xtensa_assert_reset(target);
			if (res != ERROR_OK) {
				LOG_TARGET_ERROR(
					target,
					"Couldn't halt target before SoC reset! (xtensa_assert_reset returned %d)",
					res);
				return res;
			}
			alive_sleep(10);
			xtensa_poll(target);
			int reset_halt_save = target->reset_halt;
			target->reset_halt = 1;
			res = xtensa_deassert_reset(target);
			target->reset_halt = reset_halt_save;
			if (res != ERROR_OK) {
				LOG_TARGET_ERROR(
					target,
					"Couldn't halt target before SoC reset! (xtensa_deassert_reset returned %d)",
					res);
				return res;
			}
			alive_sleep(10);
			xtensa_poll(target);
			xtensa_halt(target);
			res = target_wait_state(target, TARGET_HALTED, 1000);
			if (res != ERROR_OK) {
				LOG_TARGET_ERROR(target, "Couldn't halt target before SoC reset");
				return res;
			}
		}
	}

	assert(target->state == TARGET_HALTED);

	/* Set some clock-related RTC registers to the default values */
	res = target_write_u32(target, ESP32_S2_STORE4, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_STORE4 (%d)!", res);
		return res;
	}
	res = target_write_u32(target, ESP32_S2_STORE5, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_STORE5 (%d)!", res);
		return res;
	}
	res = target_write_u32(target, ESP32_S2_RTC_CNTL_DIG_PWC_REG, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_RTC_CNTL_DIG_PWC_REG (%d)!", res);
		return res;
	}
	res = target_write_u32(target, ESP32_S2_CLK_CONF, ESP32_S2_CLK_CONF_DEF);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_CLK_CONF (%d)!", res);
		return res;
	}
	/* Stall CPU */
	res = esp32s2_stall(target);
	if (res != ERROR_OK)
		return res;
	/* enable stall */
	res = xtensa_smpbreak_write(xtensa, OCDDCR_RUNSTALLINEN);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to set smpbreak (%d)!", res);
		return res;
	}
	/* Reset CPU */
	xtensa->suppress_dsr_errors = true;
	res = esp32s2_set_peri_reg_mask(target,
		ESP32_S2_OPTIONS0,
		ESP32_S2_SW_SYS_RST_M,
		BIT(ESP32_S2_SW_SYS_RST_S));
	xtensa->suppress_dsr_errors = false;
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_OPTIONS0 (%d)!", res);
		return res;
	}
	/* Wait for SoC to reset */
	alive_sleep(100);
	int64_t timeout = timeval_ms() + 100;
	while (target->state != TARGET_RESET && target->state != TARGET_RUNNING) {
		alive_sleep(10);
		xtensa_poll(target);
		if (timeval_ms() >= timeout) {
			LOG_TARGET_ERROR(target, "Timed out waiting for CPU to be reset, target state %s",
				target_state_name(target));
			return ERROR_TARGET_TIMEOUT;
		}
	}

	xtensa_halt(target);
	res = target_wait_state(target, TARGET_HALTED, 1000);
	if (res != ERROR_OK) {
		LOG_TARGET_ERROR(target, "Couldn't halt target before SoC reset");
		return res;
	}
	/* Unstall CPU */
	res = esp32s2_unstall(target);
	if (res != ERROR_OK)
		return res;
	/* Disable WDTs */
	res = esp32s2_disable_wdts(target);
	if (res != ERROR_OK)
		return res;
	/* Disable trace memory mapping */
	res = target_write_u32(target, ESP32_S2_DPORT_PMS_OCCUPY_3, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_DPORT_PMS_OCCUPY_3 (%d)!", res);
		return res;
	}
	return ERROR_OK;
}

static int esp32s2_disable_wdts(struct target *target)
{
	/* TIMG1 WDT */
	int res = target_write_u32(target, ESP32_S2_TIMG0WDT_PROTECT, ESP32_S2_WDT_WKEY_VALUE);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_TIMG0WDT_PROTECT (%d)!", res);
		return res;
	}
	res = target_write_u32(target, ESP32_S2_TIMG0WDT_CFG0, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_TIMG0WDT_CFG0 (%d)!", res);
		return res;
	}
	/* TIMG2 WDT */
	res = target_write_u32(target, ESP32_S2_TIMG1WDT_PROTECT, ESP32_S2_WDT_WKEY_VALUE);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_TIMG1WDT_PROTECT (%d)!", res);
		return res;
	}
	res = target_write_u32(target, ESP32_S2_TIMG1WDT_CFG0, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_TIMG1WDT_CFG0 (%d)!", res);
		return res;
	}
	/* RTC WDT */
	res = target_write_u32(target, ESP32_S2_RTCWDT_PROTECT, ESP32_S2_WDT_WKEY_VALUE);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_RTCWDT_PROTECT (%d)!", res);
		return res;
	}
	res = target_write_u32(target, ESP32_S2_RTCWDT_CFG, 0);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_RTCWDT_CFG (%d)!", res);
		return res;
	}
	/* Enable SWD auto-feed */
	res = target_write_u32(target, ESP32_S2_SWD_WPROTECT_REG, ESP32_S2_SWD_WKEY_VALUE);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_SWD_WPROTECT_REG (%d)!", res);
		return res;
	}
	uint32_t swd_conf_reg = 0;
	res = target_read_u32(target, ESP32_S2_SWD_CONF_REG, &swd_conf_reg);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to read ESP32_S2_SWD_CONF_REG (%d)!", res);
		return res;
	}
	swd_conf_reg |= ESP32_S2_SWD_AUTO_FEED_EN_M;
	res = target_write_u32(target, ESP32_S2_SWD_CONF_REG, swd_conf_reg);
	if (res != ERROR_OK) {
		LOG_ERROR("Failed to write ESP32_S2_SWD_CONF_REG (%d)!", res);
		return res;
	}
	return ERROR_OK;
}

static int esp32s2_arch_state(struct target *target)
{
	return ERROR_OK;
}

static int esp32s2_on_halt(struct target *target)
{
	int ret = esp32s2_disable_wdts(target);
	if (ret == ERROR_OK)
		ret = esp_xtensa_on_halt(target);
	return ret;
}

static int esp32s2_step(struct target *target, bool current,
		target_addr_t address, bool handle_breakpoints)
{
	int ret = xtensa_step(target, current, address, handle_breakpoints);
	if (ret == ERROR_OK) {
		esp32s2_on_halt(target);
		target_call_event_callbacks(target, TARGET_EVENT_HALTED);
	}
	return ret;
}

static int esp32s2_poll(struct target *target)
{
	enum target_state old_state = target->state;
	int ret = esp_xtensa_poll(target);
	if (ret != ERROR_OK)
		return ret;

	if (old_state != TARGET_HALTED && target->state == TARGET_HALTED) {
		/* Call any event callbacks that are applicable */
		if (old_state == TARGET_DEBUG_RUNNING) {
			target_call_event_callbacks(target, TARGET_EVENT_DEBUG_HALTED);
		} else {
			if (esp_xtensa_semihosting(target, &ret) == SEMIHOSTING_HANDLED) {
				struct esp_xtensa_common *esp_xtensa = target_to_esp_xtensa(target);
				if (ret == ERROR_OK && esp_xtensa->semihost.need_resume) {
					esp_xtensa->semihost.need_resume = false;
					/* Resume xtensa_resume will handle BREAK instruction. */
					ret = target_resume(target, true, 0, true, false);
					if (ret != ERROR_OK) {
						LOG_ERROR("Failed to resume target");
						return ret;
					}
				}
				return ret;
			}
			esp32s2_on_halt(target);
			target_call_event_callbacks(target, TARGET_EVENT_HALTED);
		}
	}

	return ret;
}

static int esp32s2_virt2phys(struct target *target,
	target_addr_t virtual, target_addr_t *physical)
{
	*physical = virtual;
	return ERROR_OK;
}

static int esp32s2_target_init(struct command_context *cmd_ctx, struct target *target)
{
	int ret = esp_xtensa_target_init(cmd_ctx, target);
	if (ret != ERROR_OK)
		return ret;

	return esp_xtensa_semihosting_init(target);
}

static const struct xtensa_debug_ops esp32s2_dbg_ops = {
	.queue_enable = xtensa_dm_queue_enable,
	.queue_reg_read = xtensa_dm_queue_reg_read,
	.queue_reg_write = xtensa_dm_queue_reg_write
};

static const struct xtensa_power_ops esp32s2_pwr_ops = {
	.queue_reg_read = xtensa_dm_queue_pwr_reg_read,
	.queue_reg_write = xtensa_dm_queue_pwr_reg_write
};

static const struct esp_semihost_ops esp32s2_semihost_ops = {
	.prepare = esp32s2_disable_wdts
};

static int esp32s2_target_create(struct target *target)
{
	struct xtensa_debug_module_config esp32s2_dm_cfg = {
		.dbg_ops = &esp32s2_dbg_ops,
		.pwr_ops = &esp32s2_pwr_ops,
		.tap = target->tap,
		.queue_tdi_idle = NULL,
		.queue_tdi_idle_arg = NULL
	};

	/* creates xtensa object */
	struct esp32s2_common *esp32 = calloc(1, sizeof(*esp32));
	if (!esp32) {
		LOG_ERROR("Failed to alloc memory for arch info!");
		return ERROR_FAIL;
	}

	int ret = esp_xtensa_init_arch_info(target, &esp32->esp_xtensa, &esp32s2_dm_cfg, &esp32s2_semihost_ops);
	if (ret != ERROR_OK) {
		LOG_ERROR("Failed to init arch info!");
		free(esp32);
		return ret;
	}

	/* Assume running target. If different, the first poll will fix this */
	target->state = TARGET_RUNNING;
	target->debug_reason = DBG_REASON_NOTHALTED;
	return ERROR_OK;
}

static const struct command_registration esp32s2_command_handlers[] = {
	{
		.chain = xtensa_command_handlers,
	},
	{
		.name = "esp",
		.usage = "",
		.chain = esp32_apptrace_command_handlers,
	},
	{
		.name = "arm",
		.mode = COMMAND_ANY,
		.help = "ARM Command Group",
		.usage = "",
		.chain = semihosting_common_handlers
	},
	COMMAND_REGISTRATION_DONE
};

/* Holds methods for Xtensa targets. */
struct target_type esp32s2_target = {
	.name = "esp32s2",

	.poll = esp32s2_poll,
	.arch_state = esp32s2_arch_state,

	.halt = xtensa_halt,
	.resume = xtensa_resume,
	.step = esp32s2_step,

	.assert_reset = esp32s2_assert_reset,
	.deassert_reset = esp32s2_deassert_reset,
	.soft_reset_halt = esp32s2_soft_reset_halt,

	.virt2phys = esp32s2_virt2phys,
	.mmu = xtensa_mmu_is_enabled,
	.read_memory = xtensa_read_memory,
	.write_memory = xtensa_write_memory,

	.read_buffer = xtensa_read_buffer,
	.write_buffer = xtensa_write_buffer,

	.checksum_memory = xtensa_checksum_memory,

	.get_gdb_arch = xtensa_get_gdb_arch,
	.get_gdb_reg_list = xtensa_get_gdb_reg_list,

	.run_algorithm = xtensa_run_algorithm,
	.start_algorithm = xtensa_start_algorithm,
	.wait_algorithm = xtensa_wait_algorithm,

	.add_breakpoint = esp_xtensa_breakpoint_add,
	.remove_breakpoint = esp_xtensa_breakpoint_remove,

	.add_watchpoint = xtensa_watchpoint_add,
	.remove_watchpoint = xtensa_watchpoint_remove,

	.target_create = esp32s2_target_create,
	.init_target = esp32s2_target_init,
	.examine = xtensa_examine,
	.deinit_target = esp_xtensa_target_deinit,

	.commands = esp32s2_command_handlers,
};
