1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * sl28cpld GPIO driver
4 *
5 * Copyright 2020 Michael Walle <michael@walle.cc>
6 */
7
8#include <linux/device.h>
9#include <linux/gpio/driver.h>
10#include <linux/gpio/regmap.h>
11#include <linux/interrupt.h>
12#include <linux/kernel.h>
13#include <linux/mod_devicetable.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/regmap.h>
17
18/* GPIO flavor */
19#define GPIO_REG_DIR	0x00
20#define GPIO_REG_OUT	0x01
21#define GPIO_REG_IN	0x02
22#define GPIO_REG_IE	0x03
23#define GPIO_REG_IP	0x04
24
25/* input-only flavor */
26#define GPI_REG_IN	0x00
27
28/* output-only flavor */
29#define GPO_REG_OUT	0x00
30
31enum sl28cpld_gpio_type {
32	SL28CPLD_GPIO = 1,
33	SL28CPLD_GPI,
34	SL28CPLD_GPO,
35};
36
37static const struct regmap_irq sl28cpld_gpio_irqs[] = {
38	REGMAP_IRQ_REG_LINE(0, 8),
39	REGMAP_IRQ_REG_LINE(1, 8),
40	REGMAP_IRQ_REG_LINE(2, 8),
41	REGMAP_IRQ_REG_LINE(3, 8),
42	REGMAP_IRQ_REG_LINE(4, 8),
43	REGMAP_IRQ_REG_LINE(5, 8),
44	REGMAP_IRQ_REG_LINE(6, 8),
45	REGMAP_IRQ_REG_LINE(7, 8),
46};
47
48static int sl28cpld_gpio_irq_init(struct platform_device *pdev,
49				  unsigned int base,
50				  struct gpio_regmap_config *config)
51{
52	struct regmap_irq_chip_data *irq_data;
53	struct regmap_irq_chip *irq_chip;
54	struct device *dev = &pdev->dev;
55	int irq, ret;
56
57	if (!device_property_read_bool(dev, "interrupt-controller"))
58		return 0;
59
60	irq = platform_get_irq(pdev, 0);
61	if (irq < 0)
62		return irq;
63
64	irq_chip = devm_kzalloc(dev, sizeof(*irq_chip), GFP_KERNEL);
65	if (!irq_chip)
66		return -ENOMEM;
67
68	irq_chip->name = "sl28cpld-gpio-irq";
69	irq_chip->irqs = sl28cpld_gpio_irqs;
70	irq_chip->num_irqs = ARRAY_SIZE(sl28cpld_gpio_irqs);
71	irq_chip->num_regs = 1;
72	irq_chip->status_base = base + GPIO_REG_IP;
73	irq_chip->unmask_base = base + GPIO_REG_IE;
74	irq_chip->ack_base = base + GPIO_REG_IP;
75
76	ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
77					      config->regmap, irq,
78					      IRQF_SHARED | IRQF_ONESHOT,
79					      0, irq_chip, &irq_data);
80	if (ret)
81		return ret;
82
83	config->irq_domain = regmap_irq_get_domain(irq_data);
84
85	return 0;
86}
87
88static int sl28cpld_gpio_probe(struct platform_device *pdev)
89{
90	struct gpio_regmap_config config = {0};
91	enum sl28cpld_gpio_type type;
92	struct regmap *regmap;
93	u32 base;
94	int ret;
95
96	if (!pdev->dev.parent)
97		return -ENODEV;
98
99	type = (uintptr_t)device_get_match_data(&pdev->dev);
100	if (!type)
101		return -ENODEV;
102
103	ret = device_property_read_u32(&pdev->dev, "reg", &base);
104	if (ret)
105		return -EINVAL;
106
107	regmap = dev_get_regmap(pdev->dev.parent, NULL);
108	if (!regmap)
109		return -ENODEV;
110
111	config.regmap = regmap;
112	config.parent = &pdev->dev;
113	config.ngpio = 8;
114
115	switch (type) {
116	case SL28CPLD_GPIO:
117		config.reg_dat_base = base + GPIO_REG_IN;
118		config.reg_set_base = base + GPIO_REG_OUT;
119		/* reg_dir_out_base might be zero */
120		config.reg_dir_out_base = GPIO_REGMAP_ADDR(base + GPIO_REG_DIR);
121
122		/* This type supports interrupts */
123		ret = sl28cpld_gpio_irq_init(pdev, base, &config);
124		if (ret)
125			return ret;
126		break;
127	case SL28CPLD_GPO:
128		config.reg_set_base = base + GPO_REG_OUT;
129		break;
130	case SL28CPLD_GPI:
131		config.reg_dat_base = base + GPI_REG_IN;
132		break;
133	default:
134		dev_err(&pdev->dev, "unknown type %d\n", type);
135		return -ENODEV;
136	}
137
138	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
139}
140
141static const struct of_device_id sl28cpld_gpio_of_match[] = {
142	{ .compatible = "kontron,sl28cpld-gpio", .data = (void *)SL28CPLD_GPIO },
143	{ .compatible = "kontron,sl28cpld-gpi", .data = (void *)SL28CPLD_GPI },
144	{ .compatible = "kontron,sl28cpld-gpo", .data = (void *)SL28CPLD_GPO },
145	{}
146};
147MODULE_DEVICE_TABLE(of, sl28cpld_gpio_of_match);
148
149static struct platform_driver sl28cpld_gpio_driver = {
150	.probe = sl28cpld_gpio_probe,
151	.driver = {
152		.name = "sl28cpld-gpio",
153		.of_match_table = sl28cpld_gpio_of_match,
154	},
155};
156module_platform_driver(sl28cpld_gpio_driver);
157
158MODULE_DESCRIPTION("sl28cpld GPIO Driver");
159MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
160MODULE_LICENSE("GPL");
161