69 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Driver for AT91 USART4 *5 * Copyright (C) 2018 Microchip Technology6 *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