cv1800-rtcsys.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Driver for Sophgo CV1800 series SoC RTC subsystem
 4 *
 5 * The RTC module comprises a 32kHz oscillator, Power-on-Reset (PoR) sub-module,
 6 * HW state machine to control chip power-on, power-off and reset. Furthermore,
 7 * the 8051 subsystem is located within RTCSYS including associated SRAM block.
 8 *
 9 * Copyright (C) 2025 Alexander Sverdlin <alexander.sverdlin@gmail.com>
10 *
11 */
12
13#include <linux/mfd/core.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/property.h>
17
18static struct resource cv1800_rtcsys_irq_resources[] = {
19	DEFINE_RES_IRQ_NAMED(0, "alarm"),
20};
21
22static const struct mfd_cell cv1800_rtcsys_subdev[] = {
23	{
24		.name = "cv1800b-rtc",
25		.num_resources = 1,
26		.resources = &cv1800_rtcsys_irq_resources[0],
27	},
28};
29
30static int cv1800_rtcsys_probe(struct platform_device *pdev)
31{
32	int irq;
33
34	irq = platform_get_irq_byname(pdev, "alarm");
35	if (irq < 0)
36		return irq;
37	cv1800_rtcsys_irq_resources[0].start = irq;
38	cv1800_rtcsys_irq_resources[0].end = irq;
39
40	return devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO,
41				    cv1800_rtcsys_subdev,
42				    ARRAY_SIZE(cv1800_rtcsys_subdev),
43				    NULL, 0, NULL);
44}
45
46static const struct of_device_id cv1800_rtcsys_of_match[] = {
47	{ .compatible = "sophgo,cv1800b-rtc" },
48	{ /* sentinel */ }
49};
50MODULE_DEVICE_TABLE(of, cv1800_rtcsys_of_match);
51
52static struct platform_driver cv1800_rtcsys_mfd = {
53	.probe	= cv1800_rtcsys_probe,
54	.driver	= {
55		.name		= "cv1800_rtcsys",
56		.of_match_table	= cv1800_rtcsys_of_match,
57	},
58};
59module_platform_driver(cv1800_rtcsys_mfd);
60
61MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@gmail.com>");
62MODULE_DESCRIPTION("Sophgo CV1800 series SoC RTC subsystem driver");
63MODULE_LICENSE("GPL");