1/*
2 * Driver for GE FPGA based GPIO
3 *
4 * Author: Martyn Welch <martyn.welch@ge.com>
5 *
6 * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
7 *
8 * This file is licensed under the terms of the GNU General Public License
9 * version 2.  This program is licensed "as is" without any warranty of any
10 * kind, whether express or implied.
11 */
12
13/* TODO
14 *
15 * Configuration of output modes (totem-pole/open-drain)
16 * Interrupt configuration - interrupts are always generated the FPGA relies on
17 * the I/O interrupt controllers mask to stop them propergating
18 */
19
20#include <linux/kernel.h>
21#include <linux/io.h>
22#include <linux/slab.h>
23#include <linux/of_device.h>
24#include <linux/of_gpio.h>
25#include <linux/of_address.h>
26#include <linux/module.h>
27#include <linux/basic_mmio_gpio.h>
28
29#define GEF_GPIO_DIRECT		0x00
30#define GEF_GPIO_IN		0x04
31#define GEF_GPIO_OUT		0x08
32#define GEF_GPIO_TRIG		0x0C
33#define GEF_GPIO_POLAR_A	0x10
34#define GEF_GPIO_POLAR_B	0x14
35#define GEF_GPIO_INT_STAT	0x18
36#define GEF_GPIO_OVERRUN	0x1C
37#define GEF_GPIO_MODE		0x20
38
39static const struct of_device_id gef_gpio_ids[] = {
40	{
41		.compatible	= "gef,sbc610-gpio",
42		.data		= (void *)19,
43	}, {
44		.compatible	= "gef,sbc310-gpio",
45		.data		= (void *)6,
46	}, {
47		.compatible	= "ge,imp3a-gpio",
48		.data		= (void *)16,
49	},
50	{ }
51};
52MODULE_DEVICE_TABLE(of, gef_gpio_ids);
53
54static int __init gef_gpio_probe(struct platform_device *pdev)
55{
56	const struct of_device_id *of_id =
57		of_match_device(gef_gpio_ids, &pdev->dev);
58	struct bgpio_chip *bgc;
59	void __iomem *regs;
60	int ret;
61
62	bgc = devm_kzalloc(&pdev->dev, sizeof(*bgc), GFP_KERNEL);
63	if (!bgc)
64		return -ENOMEM;
65
66	regs = of_iomap(pdev->dev.of_node, 0);
67	if (!regs)
68		return -ENOMEM;
69
70	ret = bgpio_init(bgc, &pdev->dev, 4, regs + GEF_GPIO_IN,
71			 regs + GEF_GPIO_OUT, NULL, NULL,
72			 regs + GEF_GPIO_DIRECT, BGPIOF_BIG_ENDIAN_BYTE_ORDER);
73	if (ret) {
74		dev_err(&pdev->dev, "bgpio_init failed\n");
75		goto err0;
76	}
77
78	/* Setup pointers to chip functions */
79	bgc->gc.label = devm_kstrdup(&pdev->dev, pdev->dev.of_node->full_name,
80				     GFP_KERNEL);
81	if (!bgc->gc.label) {
82		ret = -ENOMEM;
83		goto err0;
84	}
85
86	bgc->gc.base = -1;
87	bgc->gc.ngpio = (u16)(uintptr_t)of_id->data;
88	bgc->gc.of_gpio_n_cells = 2;
89	bgc->gc.of_node = pdev->dev.of_node;
90
91	/* This function adds a memory mapped GPIO chip */
92	ret = gpiochip_add(&bgc->gc);
93	if (ret)
94		goto err0;
95
96	return 0;
97err0:
98	iounmap(regs);
99	pr_err("%s: GPIO chip registration failed\n",
100			pdev->dev.of_node->full_name);
101	return ret;
102};
103
104static struct platform_driver gef_gpio_driver = {
105	.driver = {
106		.name		= "gef-gpio",
107		.of_match_table	= gef_gpio_ids,
108	},
109};
110module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);
111
112MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
113MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
114MODULE_LICENSE("GPL");
115