tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/gpio/generic.h>
20#include <linux/io.h>
21#include <linux/kernel.h>
22#include <linux/mod_devicetable.h>
23#include <linux/module.h>
24#include <linux/platform_device.h>
25#include <linux/property.h>
26#include <linux/slab.h>
27
28#define GEF_GPIO_DIRECT 0x00
29#define GEF_GPIO_IN 0x04
30#define GEF_GPIO_OUT 0x08
31#define GEF_GPIO_TRIG 0x0C
32#define GEF_GPIO_POLAR_A 0x10
33#define GEF_GPIO_POLAR_B 0x14
34#define GEF_GPIO_INT_STAT 0x18
35#define GEF_GPIO_OVERRUN 0x1C
36#define GEF_GPIO_MODE 0x20
37
38static const struct of_device_id gef_gpio_ids[] = {
39 {
40 .compatible = "gef,sbc610-gpio",
41 .data = (void *)19,
42 }, {
43 .compatible = "gef,sbc310-gpio",
44 .data = (void *)6,
45 }, {
46 .compatible = "ge,imp3a-gpio",
47 .data = (void *)16,
48 },
49 { }
50};
51MODULE_DEVICE_TABLE(of, gef_gpio_ids);
52
53static int __init gef_gpio_probe(struct platform_device *pdev)
54{
55 struct gpio_generic_chip_config config;
56 struct device *dev = &pdev->dev;
57 struct gpio_generic_chip *chip;
58 struct gpio_chip *gc;
59 void __iomem *regs;
60 int ret;
61
62 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
63 if (!chip)
64 return -ENOMEM;
65
66 regs = devm_platform_ioremap_resource(pdev, 0);
67 if (IS_ERR(regs))
68 return PTR_ERR(regs);
69
70 config = (struct gpio_generic_chip_config) {
71 .dev = dev,
72 .sz = 4,
73 .dat = regs + GEF_GPIO_IN,
74 .set = regs + GEF_GPIO_OUT,
75 .dirin = regs + GEF_GPIO_DIRECT,
76 .flags = GPIO_GENERIC_BIG_ENDIAN_BYTE_ORDER,
77 };
78
79 ret = gpio_generic_chip_init(chip, &config);
80 if (ret)
81 return dev_err_probe(dev, ret,
82 "failed to initialize the generic GPIO chip\n");
83
84 gc = &chip->gc;
85
86 /* Setup pointers to chip functions */
87 gc->label = devm_kasprintf(dev, GFP_KERNEL, "%pfw", dev_fwnode(dev));
88 if (!gc->label)
89 return -ENOMEM;
90
91 gc->base = -1;
92 gc->ngpio = (uintptr_t)device_get_match_data(dev);
93
94 /* This function adds a memory mapped GPIO chip */
95 ret = devm_gpiochip_add_data(dev, gc, NULL);
96 if (ret)
97 return dev_err_probe(dev, ret, "GPIO chip registration failed\n");
98
99 return 0;
100};
101
102static struct platform_driver gef_gpio_driver = {
103 .driver = {
104 .name = "gef-gpio",
105 .of_match_table = gef_gpio_ids,
106 },
107};
108module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
109
110MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
111MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
112MODULE_LICENSE("GPL");