/*
 * Copyright (c) 2018 Karsten Koenig
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 */

#ifndef _MCP2515_H_
#define _MCP2515_H_

#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/can.h>

#define MCP2515_RX_CNT    2
/* Reduce the number of Tx buffers to 1 in order to avoid priority inversion. */
#define MCP2515_TX_CNT    1
#define MCP2515_FRAME_LEN 13

struct mcp2515_tx_cb {
	can_tx_callback_t cb;
	void *cb_arg;
};

struct mcp2515_data {
	struct can_driver_data common;

	/* interrupt data */
	struct gpio_callback int_gpio_cb;
	struct k_thread int_thread;
	k_thread_stack_t *int_thread_stack;
	struct k_sem int_sem;

	/* tx data */
	struct k_sem tx_sem;
	struct mcp2515_tx_cb tx_cb[MCP2515_TX_CNT];
	uint8_t tx_busy_map;

	/* filter data */
	uint32_t filter_usage;
	can_rx_callback_t rx_cb[CONFIG_CAN_MAX_FILTER];
	void *cb_arg[CONFIG_CAN_MAX_FILTER];
	struct can_filter filter[CONFIG_CAN_MAX_FILTER];

	/* general data */
	struct k_mutex mutex;
	enum can_state old_state;
	uint8_t mcp2515_mode;
};

struct mcp2515_config {
	const struct can_driver_config common;

	/* spi configuration */
	struct spi_dt_spec bus;

	/* interrupt configuration */
	struct gpio_dt_spec int_gpio;
	size_t int_thread_stack_size;
	int int_thread_priority;

	/* CAN timing */
	uint32_t osc_freq;
};

/*
 * Startup time of 128 OSC1 clock cycles at 1MHz (minimum clock in frequency)
 * see MCP2515 datasheet section 8.1 Oscillator Start-up Timer
 */
#define MCP2515_OSC_STARTUP_US 128U

/* MCP2515 Opcodes */
#define MCP2515_OPCODE_WRITE          0x02
#define MCP2515_OPCODE_READ           0x03
#define MCP2515_OPCODE_BIT_MODIFY     0x05
#define MCP2515_OPCODE_LOAD_TX_BUFFER 0x40
#define MCP2515_OPCODE_RTS            0x80
#define MCP2515_OPCODE_READ_RX_BUFFER 0x90
#define MCP2515_OPCODE_READ_STATUS    0xA0
#define MCP2515_OPCODE_RESET          0xC0

/* MCP2515 Registers */
#define MCP2515_ADDR_CANSTAT  0x0E
#define MCP2515_ADDR_CANCTRL  0x0F
#define MCP2515_ADDR_TEC      0x1C
#define MCP2515_ADDR_REC      0x1D
#define MCP2515_ADDR_CNF3     0x28
#define MCP2515_ADDR_CNF2     0x29
#define MCP2515_ADDR_CNF1     0x2A
#define MCP2515_ADDR_CANINTE  0x2B
#define MCP2515_ADDR_CANINTF  0x2C
#define MCP2515_ADDR_EFLG     0x2D
#define MCP2515_ADDR_TXB0CTRL 0x30
#define MCP2515_ADDR_TXB1CTRL 0x40
#define MCP2515_ADDR_TXB2CTRL 0x50
#define MCP2515_ADDR_RXB0CTRL 0x60
#define MCP2515_ADDR_RXB1CTRL 0x70

#define MCP2515_ADDR_OFFSET_FRAME2FRAME 0x10
#define MCP2515_ADDR_OFFSET_CTRL2FRAME  0x01

/* MCP2515 Operation Modes */
#define MCP2515_MODE_NORMAL        0x00
#define MCP2515_MODE_LOOPBACK      0x02
#define MCP2515_MODE_SILENT        0x03
#define MCP2515_MODE_CONFIGURATION 0x04

/* MCP2515_FRAME_OFFSET */
#define MCP2515_FRAME_OFFSET_SIDH 0
#define MCP2515_FRAME_OFFSET_SIDL 1
#define MCP2515_FRAME_OFFSET_EID8 2
#define MCP2515_FRAME_OFFSET_EID0 3
#define MCP2515_FRAME_OFFSET_DLC  4
#define MCP2515_FRAME_OFFSET_D0   5

/* MCP2515_CANINTF */
#define MCP2515_CANINTF_RX0IF BIT(0)
#define MCP2515_CANINTF_RX1IF BIT(1)
#define MCP2515_CANINTF_TX0IF BIT(2)
#define MCP2515_CANINTF_TX1IF BIT(3)
#define MCP2515_CANINTF_TX2IF BIT(4)
#define MCP2515_CANINTF_ERRIF BIT(5)
#define MCP2515_CANINTF_WAKIF BIT(6)
#define MCP2515_CANINTF_MERRF BIT(7)

#define MCP2515_INTE_RX0IE BIT(0)
#define MCP2515_INTE_RX1IE BIT(1)
#define MCP2515_INTE_TX0IE BIT(2)
#define MCP2515_INTE_TX1IE BIT(3)
#define MCP2515_INTE_TX2IE BIT(4)
#define MCP2515_INTE_ERRIE BIT(5)
#define MCP2515_INTE_WAKIE BIT(6)
#define MCP2515_INTE_MERRE BIT(7)

#define MCP2515_EFLG_EWARN  BIT(0)
#define MCP2515_EFLG_RXWAR  BIT(1)
#define MCP2515_EFLG_TXWAR  BIT(2)
#define MCP2515_EFLG_RXEP   BIT(3)
#define MCP2515_EFLG_TXEP   BIT(4)
#define MCP2515_EFLG_TXBO   BIT(5)
#define MCP2515_EFLG_RX0OVR BIT(6)
#define MCP2515_EFLG_RX1OVR BIT(7)

#define MCP2515_TXCTRL_TXREQ BIT(3)

#define MCP2515_CANSTAT_MODE_POS    5
#define MCP2515_CANSTAT_MODE_MASK   (0x07 << MCP2515_CANSTAT_MODE_POS)
#define MCP2515_CANCTRL_MODE_POS    5
#define MCP2515_CANCTRL_MODE_MASK   (0x07 << MCP2515_CANCTRL_MODE_POS)
#define MCP2515_TXBNCTRL_TXREQ_POS  3
#define MCP2515_TXBNCTRL_TXREQ_MASK (0x01 << MCP2515_TXBNCTRL_TXREQ_POS)

#endif /*_MCP2515_H_*/