LXR linux/drivers/mfd/at91-usart.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Driver for AT91 USART
   4 *
   5 * Copyright (C) 2018 Microchip Technology
   6 *
   7 * Author: Radu Pirea <radu.pirea@microchip.com>
   8 *
   9 */
  10
  11#include <dt-bindings/mfd/at91-usart.h>
  12
  13#include <linux/module.h>
  14#include <linux/mfd/core.h>
  15#include <linux/of.h>
  16#include <linux/property.h>
  17
  18static const struct mfd_cell at91_usart_spi_subdev =
  19        MFD_CELL_NAME("at91_usart_spi");
  20
  21static const struct mfd_cell at91_usart_serial_subdev =
  22        MFD_CELL_NAME("atmel_usart_serial");
  23
  24static int at91_usart_mode_probe(struct platform_device *pdev)
  25{
  26        const struct mfd_cell *cell;
  27        u32 opmode = AT91_USART_MODE_SERIAL;
  28
  29        device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
  30
  31        switch (opmode) {
  32        case AT91_USART_MODE_SPI:
  33                cell = &at91_usart_spi_subdev;
  34                break;
  35        case AT91_USART_MODE_SERIAL:
  36                cell = &at91_usart_serial_subdev;
  37                break;
  38        default:
  39                dev_err(&pdev->dev, "atmel,usart-mode has an invalid value %u\n",
  40                        opmode);
  41                return -EINVAL;
  42        }
  43
  44        return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, cell, 1,
  45                              NULL, 0, NULL);
  46}
  47
  48static const struct of_device_id at91_usart_mode_of_match[] = {
  49        { .compatible = "atmel,at91rm9200-usart" },
  50        { .compatible = "atmel,at91sam9260-usart" },
  51        { /* sentinel */ }
  52};
  53
  54MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);
  55
  56static struct platform_driver at91_usart_mfd = {
  57        .probe  = at91_usart_mode_probe,
  58        .driver = {
  59                .name           = "at91_usart_mode",
  60                .of_match_table = at91_usart_mode_of_match,
  61        },
  62};
  63
  64module_platform_driver(at91_usart_mfd);
  65
  66MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
  67MODULE_DESCRIPTION("AT91 USART MFD driver");
  68MODULE_LICENSE("GPL v2");
  69