GNU Linux-libre 5.10.219-gnu1
[releases.git] / 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
18 static const struct mfd_cell at91_usart_spi_subdev = {
19         .name = "at91_usart_spi",
20         .of_compatible = "microchip,at91sam9g45-usart-spi",
21 };
22
23 static const struct mfd_cell at91_usart_serial_subdev = {
24         .name = "atmel_usart_serial",
25         .of_compatible = "atmel,at91rm9200-usart-serial",
26 };
27
28 static 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
52 static const struct of_device_id at91_usart_mode_of_match[] = {
53         { .compatible = "atmel,at91rm9200-usart" },
54         { .compatible = "atmel,at91sam9260-usart" },
55         { /* sentinel */ }
56 };
57
58 MODULE_DEVICE_TABLE(of, at91_usart_mode_of_match);
59
60 static 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
68 module_platform_driver(at91_usart_mfd);
69
70 MODULE_AUTHOR("Radu Pirea <radu.pirea@microchip.com>");
71 MODULE_DESCRIPTION("AT91 USART MFD driver");
72 MODULE_LICENSE("GPL v2");