gpio-octeon.c
3.77 KB
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2011, 2012 Cavium Inc.
*/
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-gpio-defs.h>
#define RX_DAT 0x80
#define TX_SET 0x88
#define TX_CLEAR 0x90
/*
* The address offset of the GPIO configuration register for a given
* line.
*/
static unsigned int bit_cfg_reg(unsigned int offset)
{
/*
* The register stride is 8, with a discontinuity after the
* first 16.
*/
if (offset < 16)
return 8 * offset;
else
return 8 * (offset - 16) + 0x100;
}
struct octeon_gpio {
struct gpio_chip chip;
u64 register_base;
};
static int octeon_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
{
struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), 0);
return 0;
}
static void octeon_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
u64 mask = 1ull << offset;
u64 reg = gpio->register_base + (value ? TX_SET : TX_CLEAR);
cvmx_write_csr(reg, mask);
}
static int octeon_gpio_dir_out(struct gpio_chip *chip, unsigned offset,
int value)
{
struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
union cvmx_gpio_bit_cfgx cfgx;
octeon_gpio_set(chip, offset, value);
cfgx.u64 = 0;
cfgx.s.tx_oe = 1;
cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), cfgx.u64);
return 0;
}
static int octeon_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct octeon_gpio *gpio = container_of(chip, struct octeon_gpio, chip);
u64 read_bits = cvmx_read_csr(gpio->register_base + RX_DAT);
return ((1ull << offset) & read_bits) != 0;
}
static int octeon_gpio_probe(struct platform_device *pdev)
{
struct octeon_gpio *gpio;
struct gpio_chip *chip;
struct resource *res_mem;
int err = 0;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
chip = &gpio->chip;
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (res_mem == NULL) {
dev_err(&pdev->dev, "found no memory resource\n");
err = -ENXIO;
goto out;
}
if (!devm_request_mem_region(&pdev->dev, res_mem->start,
resource_size(res_mem),
res_mem->name)) {
dev_err(&pdev->dev, "request_mem_region failed\n");
err = -ENXIO;
goto out;
}
gpio->register_base = (u64)devm_ioremap(&pdev->dev, res_mem->start,
resource_size(res_mem));
pdev->dev.platform_data = chip;
chip->label = "octeon-gpio";
chip->dev = &pdev->dev;
chip->owner = THIS_MODULE;
chip->base = 0;
chip->can_sleep = false;
chip->ngpio = 20;
chip->direction_input = octeon_gpio_dir_in;
chip->get = octeon_gpio_get;
chip->direction_output = octeon_gpio_dir_out;
chip->set = octeon_gpio_set;
err = gpiochip_add(chip);
if (err)
goto out;
dev_info(&pdev->dev, "OCTEON GPIO driver probed.\n");
out:
return err;
}
static int octeon_gpio_remove(struct platform_device *pdev)
{
struct gpio_chip *chip = pdev->dev.platform_data;
return gpiochip_remove(chip);
}
static struct of_device_id octeon_gpio_match[] = {
{
.compatible = "cavium,octeon-3860-gpio",
},
{},
};
MODULE_DEVICE_TABLE(of, octeon_gpio_match);
static struct platform_driver octeon_gpio_driver = {
.driver = {
.name = "octeon_gpio",
.owner = THIS_MODULE,
.of_match_table = octeon_gpio_match,
},
.probe = octeon_gpio_probe,
.remove = octeon_gpio_remove,
};
module_platform_driver(octeon_gpio_driver);
MODULE_DESCRIPTION("Cavium Inc. OCTEON GPIO Driver");
MODULE_AUTHOR("David Daney");
MODULE_LICENSE("GPL");