// SPDX-License-Identifier: GPL-2.0
//
// tcan4x5x - Texas Instruments TCAN4x5x Family CAN controller driver
//
// Copyright (c) 2020 Pengutronix,
//                    Marc Kleine-Budde <kernel@pengutronix.de>
// Copyright (c) 2018-2019 Texas Instruments Incorporated
//                    http://www.ti.com/

#include "tcan4x5x.h"

#define TCAN4X5X_SPI_INSTRUCTION_WRITE (0x61 << 24)
#define TCAN4X5X_SPI_INSTRUCTION_READ (0x41 << 24)

#define TCAN4X5X_MAX_REGISTER 0x87fc

static int tcan4x5x_regmap_gather_write(void *context,
                                        const void *reg, size_t reg_len,
                                        const void *val, size_t val_len)
{
        struct spi_device *spi = context;
        struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
        struct tcan4x5x_map_buf *buf_tx = &priv->map_buf_tx;
        struct spi_transfer xfer[] = {
                {
                        .tx_buf = buf_tx,
                        .len = sizeof(buf_tx->cmd) + val_len,
                },
        };

        memcpy(&buf_tx->cmd, reg, sizeof(buf_tx->cmd.cmd) +
               sizeof(buf_tx->cmd.addr));
        tcan4x5x_spi_cmd_set_len(&buf_tx->cmd, val_len);
        memcpy(buf_tx->data, val, val_len);

        return spi_sync_transfer(spi, xfer, ARRAY_SIZE(xfer));
}

static int tcan4x5x_regmap_write(void *context, const void *data, size_t count)
{
        return tcan4x5x_regmap_gather_write(context, data, sizeof(__be32),
                                            data + sizeof(__be32),
                                            count - sizeof(__be32));
}

static int tcan4x5x_regmap_read(void *context,
                                const void *reg_buf, size_t reg_len,
                                void *val_buf, size_t val_len)
{
        struct spi_device *spi = context;
        struct tcan4x5x_priv *priv = spi_get_drvdata(spi);
        struct tcan4x5x_map_buf *buf_rx = &priv->map_buf_rx;
        struct tcan4x5x_map_buf *buf_tx = &priv->map_buf_tx;
        struct spi_transfer xfer[2] = {
                {
                        .tx_buf = buf_tx,
                }
        };
        struct spi_message msg;
        int err;

        spi_message_init(&msg);
        spi_message_add_tail(&xfer[0], &msg);

        memcpy(&buf_tx->cmd, reg_buf, sizeof(buf_tx->cmd.cmd) +
               sizeof(buf_tx->cmd.addr));
        tcan4x5x_spi_cmd_set_len(&buf_tx->cmd, val_len);

        if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {
                xfer[0].len = sizeof(buf_tx->cmd);

                xfer[1].rx_buf = val_buf;
                xfer[1].len = val_len;
                spi_message_add_tail(&xfer[1], &msg);
        } else {
                xfer[0].rx_buf = buf_rx;
                xfer[0].len = sizeof(buf_tx->cmd) + val_len;

                if (TCAN4X5X_SANITIZE_SPI)
                        memset(buf_tx->data, 0x0, val_len);
        }

        err = spi_sync(spi, &msg);
        if (err)
                return err;

        if (!(spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX))
                memcpy(val_buf, buf_rx->data, val_len);

        return 0;
}

static const struct regmap_range tcan4x5x_reg_table_wr_range[] = {
        /* Device ID and SPI Registers */
        regmap_reg_range(0x000c, 0x0010),
        /* Device configuration registers and Interrupt Flags*/
        regmap_reg_range(0x0800, 0x080c),
        regmap_reg_range(0x0820, 0x0820),
        regmap_reg_range(0x0830, 0x0830),
        /* M_CAN */
        regmap_reg_range(0x100c, 0x102c),
        regmap_reg_range(0x1048, 0x1048),
        regmap_reg_range(0x1050, 0x105c),
        regmap_reg_range(0x1080, 0x1088),
        regmap_reg_range(0x1090, 0x1090),
        regmap_reg_range(0x1098, 0x10a0),
        regmap_reg_range(0x10a8, 0x10b0),
        regmap_reg_range(0x10b8, 0x10c0),
        regmap_reg_range(0x10c8, 0x10c8),
        regmap_reg_range(0x10d0, 0x10d4),
        regmap_reg_range(0x10e0, 0x10e4),
        regmap_reg_range(0x10f0, 0x10f0),
        regmap_reg_range(0x10f8, 0x10f8),
        /* MRAM */
        regmap_reg_range(0x8000, 0x87fc),
};

static const struct regmap_range tcan4x5x_reg_table_rd_range[] = {
        regmap_reg_range(0x0000, 0x0010),       /* Device ID and SPI Registers */
        regmap_reg_range(0x0800, 0x0830),       /* Device configuration registers and Interrupt Flags*/
        regmap_reg_range(0x1000, 0x10fc),       /* M_CAN */
        regmap_reg_range(0x8000, 0x87fc),       /* MRAM */
};

static const struct regmap_access_table tcan4x5x_reg_table_wr = {
        .yes_ranges = tcan4x5x_reg_table_wr_range,
        .n_yes_ranges = ARRAY_SIZE(tcan4x5x_reg_table_wr_range),
};

static const struct regmap_access_table tcan4x5x_reg_table_rd = {
        .yes_ranges = tcan4x5x_reg_table_rd_range,
        .n_yes_ranges = ARRAY_SIZE(tcan4x5x_reg_table_rd_range),
};

static const struct regmap_config tcan4x5x_regmap = {
        .reg_bits = 24,
        .reg_stride = 4,
        .pad_bits = 8,
        .val_bits = 32,
        .wr_table = &tcan4x5x_reg_table_wr,
        .rd_table = &tcan4x5x_reg_table_rd,
        .max_register = TCAN4X5X_MAX_REGISTER,
        .cache_type = REGCACHE_NONE,
        .read_flag_mask = (__force unsigned long)
                cpu_to_be32(TCAN4X5X_SPI_INSTRUCTION_READ),
        .write_flag_mask = (__force unsigned long)
                cpu_to_be32(TCAN4X5X_SPI_INSTRUCTION_WRITE),
};

static const struct regmap_bus tcan4x5x_bus = {
        .write = tcan4x5x_regmap_write,
        .gather_write = tcan4x5x_regmap_gather_write,
        .read = tcan4x5x_regmap_read,
        .reg_format_endian_default = REGMAP_ENDIAN_BIG,
        .val_format_endian_default = REGMAP_ENDIAN_BIG,
        .max_raw_read = 256,
        .max_raw_write = 256,
};

int tcan4x5x_regmap_init(struct tcan4x5x_priv *priv)
{
        priv->regmap = devm_regmap_init(&priv->spi->dev, &tcan4x5x_bus,
                                        priv->spi, &tcan4x5x_regmap);
        return PTR_ERR_OR_ZERO(priv->regmap);
}