summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/gpio-ge.c
blob: aea5c2a53cc0f482bd0579788a42d09676675623 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
/*
 * Driver for GE FPGA based GPIO
 *
 * Author: Martyn Welch <martyn.welch@ge.com>
 *
 * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc.
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2.  This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

/* TODO
 *
 * Configuration of output modes (totem-pole/open-drain)
 * Interrupt configuration - interrupts are always generated the FPGA relies on
 * the I/O interrupt controllers mask to stop them propergating
 */

#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/module.h>

#define GEF_GPIO_DIRECT		0x00
#define GEF_GPIO_IN		0x04
#define GEF_GPIO_OUT		0x08
#define GEF_GPIO_TRIG		0x0C
#define GEF_GPIO_POLAR_A	0x10
#define GEF_GPIO_POLAR_B	0x14
#define GEF_GPIO_INT_STAT	0x18
#define GEF_GPIO_OVERRUN	0x1C
#define GEF_GPIO_MODE		0x20

static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);
	unsigned int data;

	data = ioread32be(mmchip->regs + GEF_GPIO_OUT);
	if (value)
		data = data | BIT(offset);
	else
		data = data & ~BIT(offset);
	iowrite32be(data, mmchip->regs + GEF_GPIO_OUT);
}

static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
{
	unsigned int data;
	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);

	data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
	data = data | BIT(offset);
	iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);

	return 0;
}

static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value)
{
	unsigned int data;
	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);

	/* Set value before switching to output */
	gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value);

	data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT);
	data = data & ~BIT(offset);
	iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT);

	return 0;
}

static int gef_gpio_get(struct gpio_chip *chip, unsigned offset)
{
	struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip);

	return !!(ioread32be(mmchip->regs + GEF_GPIO_IN) & BIT(offset));
}

static const struct of_device_id gef_gpio_ids[] = {
	{
		.compatible	= "gef,sbc610-gpio",
		.data		= (void *)19,
	}, {
		.compatible	= "gef,sbc310-gpio",
		.data		= (void *)6,
	}, {
		.compatible	= "ge,imp3a-gpio",
		.data		= (void *)16,
	},
	{ }
};
MODULE_DEVICE_TABLE(of, gef_gpio_ids);

static int __init gef_gpio_probe(struct platform_device *pdev)
{
	const struct of_device_id *of_id =
		of_match_device(gef_gpio_ids, &pdev->dev);
	struct of_mm_gpio_chip *mmchip;

	mmchip = devm_kzalloc(&pdev->dev, sizeof(*mmchip), GFP_KERNEL);
	if (!mmchip)
		return -ENOMEM;

	/* Setup pointers to chip functions */
	mmchip->gc.ngpio = (u16)(uintptr_t)of_id->data;
	mmchip->gc.of_gpio_n_cells = 2;
	mmchip->gc.direction_input = gef_gpio_dir_in;
	mmchip->gc.direction_output = gef_gpio_dir_out;
	mmchip->gc.get = gef_gpio_get;
	mmchip->gc.set = gef_gpio_set;

	/* This function adds a memory mapped GPIO chip */
	return of_mm_gpiochip_add(pdev->dev.of_node, mmchip);
};

static struct platform_driver gef_gpio_driver = {
	.driver = {
		.name		= "gef-gpio",
		.of_match_table	= gef_gpio_ids,
	},
};
module_platform_driver_probe(gef_gpio_driver, gef_gpio_probe);

MODULE_DESCRIPTION("GE I/O FPGA GPIO driver");
MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
MODULE_LICENSE("GPL");