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");