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        .name = "at91_usart_spi",
  20        .of_compatible = "microchip,at91sam9g45-usart-spi",
  21};
  22
  23static const struct mfd_cell at91_usart_serial_subdev = {
  24        .name = "atmel_usart_serial",
  25        .of_compatible = "atmel,at91rm9200-usart-serial",
  26};
  27
  28static int at91_usart_mode_probe(struct platform_device *pdev)
  29{
  30        const struct mfd_cell *cell;
  31        u32 opmode = AT91_USART_MODE_SERIAL;
  32
  33        device_property_read_u32(&pdev->dev, "atmel,usart-mode", &opmode);
  34
  35        switch (opmode) {
  36        case AT91_USART_MODE_SPI:
  37                cell = &at91_usart_spi_subdev;
  38                break;
  39        case AT91_USART_MODE_SERIAL:
  40                cell = &at91_usart_serial_subdev;
  41                break;
  42        default:
  43                dev_err(&pdev->dev, "atmel,usart-mode has an invalid value %u\n",
  44                        opmode);
  45                return -EINVAL;
  46        }
  47
  48        return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, cell, 1,
  49                              NULL, 0, NULL);
  50}
  51
  52static const struct of_device_id at91_usart_mode_of_match[] = {
  53        { .compatible = "atmel,at91rm9200-usart" },
  54        { .compatible = "atmel,at91sam9260-usart" },
  55        { /* sentinel */ }
  56};
  57
  58MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);
  59
  60static struct platform_driver at91_usart_mfd = {
  61        .probe  = at91_usart_mode_probe,
  62        .driver = {
  63                .name           = "at91_usart_mode",
  64                .of_match_table = at91_usart_mode_of_match,
  65        },
  66};
  67
  68module_platform_driver(at91_usart_mfd);
  69
  70MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
  71MODULE_DESCRIPTION("AT91 USART MFD driver");
  72MODULE_LICENSE("GPL v2");
  73