// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * AD7879/AD7889 touchscreen (SPI bus)
 *
 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
 */

#include <linux/input.h>        /* BUS_SPI */
#include <linux/pm.h>
#include <linux/spi/spi.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>

#include "ad7879.h"

#define AD7879_DEVID            0x7A    /* AD7879/AD7889 */

#define MAX_SPI_FREQ_HZ      5000000

#define AD7879_CMD_MAGIC     0xE0
#define AD7879_CMD_READ      BIT(2)

static const struct regmap_config ad7879_spi_regmap_config = {
        .reg_bits = 16,
        .val_bits = 16,
        .max_register = 15,
        .read_flag_mask = AD7879_CMD_MAGIC | AD7879_CMD_READ,
        .write_flag_mask = AD7879_CMD_MAGIC,
};

static int ad7879_spi_probe(struct spi_device *spi)
{
        struct regmap *regmap;

        /* don't exceed max specified SPI CLK frequency */
        if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
                dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
                return -EINVAL;
        }

        regmap = devm_regmap_init_spi(spi, &ad7879_spi_regmap_config);
        if (IS_ERR(regmap))
                return PTR_ERR(regmap);

        return ad7879_probe(&spi->dev, regmap, spi->irq, BUS_SPI, AD7879_DEVID);
}

#ifdef CONFIG_OF
static const struct of_device_id ad7879_spi_dt_ids[] = {
        { .compatible = "adi,ad7879", },
        { }
};
MODULE_DEVICE_TABLE(of, ad7879_spi_dt_ids);
#endif

static struct spi_driver ad7879_spi_driver = {
        .driver = {
                .name           = "ad7879",
                .dev_groups     = ad7879_groups,
                .pm             = &ad7879_pm_ops,
                .of_match_table = of_match_ptr(ad7879_spi_dt_ids),
        },
        .probe          = ad7879_spi_probe,
};

module_spi_driver(ad7879_spi_driver);

MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("AD7879(-1) touchscreen SPI bus driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("spi:ad7879");