// SPDX-License-Identifier: GPL-2.0-only
/*
 * Samsung LSI S5C73M3 8M pixel camera driver
 *
 * Copyright (C) 2012, Samsung Electronics, Co., Ltd.
 * Sylwester Nawrocki <s.nawrocki@samsung.com>
 * Andrzej Hajda <a.hajda@samsung.com>
 */

#include <linux/sizes.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/media.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>

#include "s5c73m3.h"

#define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI"

static const struct of_device_id s5c73m3_spi_ids[] = {
        { .compatible = "samsung,s5c73m3" },
        { }
};
MODULE_DEVICE_TABLE(of, s5c73m3_spi_ids);

enum spi_direction {
        SPI_DIR_RX,
        SPI_DIR_TX
};

static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
                                                        enum spi_direction dir)
{
        struct spi_message msg;
        int r;
        struct spi_transfer xfer = {
                .len    = len,
        };

        if (dir == SPI_DIR_TX)
                xfer.tx_buf = addr;
        else
                xfer.rx_buf = addr;

        if (spi_dev == NULL) {
                pr_err("SPI device is uninitialized\n");
                return -ENODEV;
        }

        spi_message_init(&msg);
        spi_message_add_tail(&xfer, &msg);

        r = spi_sync(spi_dev, &msg);
        if (r < 0)
                dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);

        return r;
}

int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
                      const unsigned int len, const unsigned int tx_size)
{
        struct spi_device *spi_dev = state->spi_dev;
        u32 count = len / tx_size;
        u32 extra = len % tx_size;
        unsigned int i, j = 0;
        u8 padding[32];
        int r = 0;

        memset(padding, 0, sizeof(padding));

        for (i = 0; i < count; i++) {
                r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
                if (r < 0)
                        return r;
                j += tx_size;
        }

        if (extra > 0) {
                r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
                if (r < 0)
                        return r;
        }

        return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
}

int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
                     const unsigned int len, const unsigned int tx_size)
{
        struct spi_device *spi_dev = state->spi_dev;
        u32 count = len / tx_size;
        u32 extra = len % tx_size;
        unsigned int i, j = 0;
        int r = 0;

        for (i = 0; i < count; i++) {
                r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
                if (r < 0)
                        return r;
                j += tx_size;
        }

        if (extra > 0)
                return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);

        return 0;
}

static int s5c73m3_spi_probe(struct spi_device *spi)
{
        int r;
        struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
                                             spidrv.driver);
        spi->bits_per_word = 32;

        r = spi_setup(spi);
        if (r < 0) {
                dev_err(&spi->dev, "spi_setup() failed\n");
                return r;
        }

        mutex_lock(&state->lock);
        state->spi_dev = spi;
        mutex_unlock(&state->lock);

        v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
        return 0;
}

int s5c73m3_register_spi_driver(struct s5c73m3 *state)
{
        struct spi_driver *spidrv = &state->spidrv;

        spidrv->probe = s5c73m3_spi_probe;
        spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
        spidrv->driver.of_match_table = s5c73m3_spi_ids;

        return spi_register_driver(spidrv);
}

void s5c73m3_unregister_spi_driver(struct s5c73m3 *state)
{
        spi_unregister_driver(&state->spidrv);
}