// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for AT91 USART
 *
 * Copyright (C) 2018 Microchip Technology
 *
 * Author: Radu Pirea <radu.pirea@microchip.com>
 *
 */

#include <dt-bindings/mfd/at91-usart.h>

#include <linux/module.h>
#include <linux/mfd/core.h>
#include <linux/of.h>
#include <linux/property.h>

static const struct mfd_cell at91_usart_spi_subdev =
        MFD_CELL_NAME("at91_usart_spi");

static const struct mfd_cell at91_usart_serial_subdev =
        MFD_CELL_NAME("atmel_usart_serial");

static int at91_usart_mode_probe(struct platform_device *pdev)
{
        const struct mfd_cell *cell;
        u32 opmode = AT91_USART_MODE_SERIAL;

        device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);

        switch (opmode) {
        case AT91_USART_MODE_SPI:
                cell = &at91_usart_spi_subdev;
                break;
        case AT91_USART_MODE_SERIAL:
                cell = &at91_usart_serial_subdev;
                break;
        default:
                dev_err(&pdev->dev, "atmel,usart-mode has an invalid value %u\n",
                        opmode);
                return -EINVAL;
        }

        return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, cell, 1,
                              NULL, 0, NULL);
}

static const struct of_device_id at91_usart_mode_of_match[] = {
        { .compatible = "atmel,at91rm9200-usart" },
        { .compatible = "atmel,at91sam9260-usart" },
        { /* sentinel */ }
};

MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);

static struct platform_driver at91_usart_mfd = {
        .probe  = at91_usart_mode_probe,
        .driver = {
                .name           = "at91_usart_mode",
                .of_match_table = at91_usart_mode_of_match,
        },
};

module_platform_driver(at91_usart_mfd);

MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
MODULE_DESCRIPTION("AT91 USART MFD driver");
MODULE_LICENSE("GPL v2");