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, size: sizeof(*gc), GFP_KERNEL);
60 if (!gc)
61 return -ENOMEM;
62
63 regs = devm_platform_ioremap_resource(pdev, index: 0);
64 if (IS_ERR(ptr: regs))
65 return PTR_ERR(ptr: regs);
66
67 ret = bgpio_init(gc, dev, sz: 4, dat: regs + GEF_GPIO_IN, set: regs + GEF_GPIO_OUT,
68 NULL, NULL, dirin: regs + GEF_GPIO_DIRECT,
69 BGPIOF_BIG_ENDIAN_BYTE_ORDER);
70 if (ret)
71 return dev_err_probe(dev, err: ret, fmt: "bgpio_init failed\n");
72
73 /* Setup pointers to chip functions */
74 gc->label = devm_kasprintf(dev, GFP_KERNEL, fmt: "%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, err: ret, fmt: "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

source code of linux/drivers/gpio/gpio-ge.c