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");