1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for GE FPGA based GPIO
4 *
5 * Author: Martyn Welch <martyn.welch@ge.com>
6 *
7 * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
8 */
9
10/*
11 * TODO:
12 *
13 * Configuration of output modes (totem-pole/open-drain).
14 * Interrupt configuration - interrupts are always generated, the FPGA relies
15 * on the I/O interrupt controllers mask to stop them from being propagated.
16 */
17
18#include <linux/gpio/driver.h>
19#include <linux/io.h>
20#include <linux/kernel.h>
21#include <linux/mod_devicetable.h>
22#include <linux/module.h>
23#include <linux/platform_device.h>
24#include <linux/property.h>
25#include <linux/slab.h>
26
27#define GEF_GPIO_DIRECT		0x00
28#define GEF_GPIO_IN		0x04
29#define GEF_GPIO_OUT		0x08
30#define GEF_GPIO_TRIG		0x0C
31#define GEF_GPIO_POLAR_A	0x10
32#define GEF_GPIO_POLAR_B	0x14
33#define GEF_GPIO_INT_STAT	0x18
34#define GEF_GPIO_OVERRUN	0x1C
35#define GEF_GPIO_MODE		0x20
36
37static const struct of_device_id gef_gpio_ids[] = {
38	{
39		.compatible	= "gef,sbc610-gpio",
40		.data		= (void *)19,
41	}, {
42		.compatible	= "gef,sbc310-gpio",
43		.data		= (void *)6,
44	}, {
45		.compatible	= "ge,imp3a-gpio",
46		.data		= (void *)16,
47	},
48	{ }
49};
50MODULE_DEVICE_TABLE(of, gef_gpio_ids);
51
52static int __init gef_gpio_probe(struct platform_device *pdev)
53{
54	struct device *dev = &pdev->dev;
55	struct gpio_chip *gc;
56	void __iomem *regs;
57	int ret;
58
59	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
60	if (!gc)
61		return -ENOMEM;
62
63	regs = devm_platform_ioremap_resource(pdev, 0);
64	if (IS_ERR(regs))
65		return PTR_ERR(regs);
66
67	ret = bgpio_init(gc, dev, 4, regs + GEF_GPIO_IN, regs + GEF_GPIO_OUT,
68			 NULL, NULL, regs + GEF_GPIO_DIRECT,
69			 BGPIOF_BIG_ENDIAN_BYTE_ORDER);
70	if (ret)
71		return dev_err_probe(dev, ret, "bgpio_init failed\n");
72
73	/* Setup pointers to chip functions */
74	gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pfw", dev_fwnode(dev));
75	if (!gc->label)
76		return -ENOMEM;
77
78	gc->base = -1;
79	gc->ngpio = (uintptr_t)device_get_match_data(dev);
80
81	/* This function adds a memory mapped GPIO chip */
82	ret = devm_gpiochip_add_data(dev, gc, NULL);
83	if (ret)
84		return dev_err_probe(dev, ret, "GPIO chip registration failed\n");
85
86	return 0;
87};
88
89static struct platform_driver gef_gpio_driver = {
90	.driver = {
91		.name		= "gef-gpio",
92		.of_match_table	= gef_gpio_ids,
93	},
94};
95module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
96
97MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
98MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
99MODULE_LICENSE("GPL");
100