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->mask_base = base + GPIO_REG_IE;
 74	irq_chip->mask_invert = true;
 75	irq_chip->ack_base = base + GPIO_REG_IP;
 76
 77	ret = devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),
 78					      config->regmap, irq,
 79					      IRQF_SHARED | IRQF_ONESHOT,
 80					      0, irq_chip, &irq_data);
 81	if (ret)
 82		return ret;
 83
 84	config->irq_domain = regmap_irq_get_domain(irq_data);
 85
 86	return 0;
 87}
 88
 89static int sl28cpld_gpio_probe(struct platform_device *pdev)
 90{
 91	struct gpio_regmap_config config = {0};
 92	enum sl28cpld_gpio_type type;
 93	struct regmap *regmap;
 94	u32 base;
 95	int ret;
 96
 97	if (!pdev->dev.parent)
 98		return -ENODEV;
 99
100	type = (uintptr_t)device_get_match_data(&pdev->dev);
101	if (!type)
102		return -ENODEV;
103
104	ret = device_property_read_u32(&pdev->dev, "reg", &base);
105	if (ret)
106		return -EINVAL;
107
108	regmap = dev_get_regmap(pdev->dev.parent, NULL);
109	if (!regmap)
110		return -ENODEV;
111
112	config.regmap = regmap;
113	config.parent = &pdev->dev;
114	config.ngpio = 8;
115
116	switch (type) {
117	case SL28CPLD_GPIO:
118		config.reg_dat_base = base + GPIO_REG_IN;
119		config.reg_set_base = base + GPIO_REG_OUT;
120		/* reg_dir_out_base might be zero */
121		config.reg_dir_out_base = GPIO_REGMAP_ADDR(base + GPIO_REG_DIR);
122
123		/* This type supports interrupts */
124		ret = sl28cpld_gpio_irq_init(pdev, base, &config);
125		if (ret)
126			return ret;
127		break;
128	case SL28CPLD_GPO:
129		config.reg_set_base = base + GPO_REG_OUT;
130		break;
131	case SL28CPLD_GPI:
132		config.reg_dat_base = base + GPI_REG_IN;
133		break;
134	default:
135		dev_err(&pdev->dev, "unknown type %d\n", type);
136		return -ENODEV;
137	}
138
139	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(&pdev->dev, &config));
140}
141
142static const struct of_device_id sl28cpld_gpio_of_match[] = {
143	{ .compatible = "kontron,sl28cpld-gpio", .data = (void *)SL28CPLD_GPIO },
144	{ .compatible = "kontron,sl28cpld-gpi", .data = (void *)SL28CPLD_GPI },
145	{ .compatible = "kontron,sl28cpld-gpo", .data = (void *)SL28CPLD_GPO },
146	{}
147};
148MODULE_DEVICE_TABLE(of, sl28cpld_gpio_of_match);
149
150static struct platform_driver sl28cpld_gpio_driver = {
151	.probe = sl28cpld_gpio_probe,
152	.driver = {
153		.name = "sl28cpld-gpio",
154		.of_match_table = sl28cpld_gpio_of_match,
155	},
156};
157module_platform_driver(sl28cpld_gpio_driver);
158
159MODULE_DESCRIPTION("sl28cpld GPIO Driver");
160MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
161MODULE_LICENSE("GPL");