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
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/*
* GPIO controller in LSI ZEVIO SoCs.
*
* Author: Fabian Vogt <fabian@ritter-vogt.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/slab.h>
#include <linux/gpio.h>
/*
* Memory layout:
* This chip has four gpio sections, each controls 8 GPIOs.
* Bit 0 in section 0 is GPIO 0, bit 2 in section 1 is GPIO 10.
* Disclaimer: Reverse engineered!
* For more information refer to:
* http://hackspire.unsads.com/wiki/index.php/Memory-mapped_I/O_ports#90000000_-_General_Purpose_I.2FO_.28GPIO.29
*
* 0x00-0x3F: Section 0
* +0x00: Masked interrupt status (read-only)
* +0x04: R: Interrupt status W: Reset interrupt status
* +0x08: R: Interrupt mask W: Mask interrupt
* +0x0C: W: Unmask interrupt (write-only)
* +0x10: Direction: I/O=1/0
* +0x14: Output
* +0x18: Input (read-only)
* +0x20: R: Level interrupt W: Set as level interrupt
* 0x40-0x7F: Section 1
* 0x80-0xBF: Section 2
* 0xC0-0xFF: Section 3
*/
#define ZEVIO_GPIO_SECTION_SIZE 0x40
/* Offsets to various registers */
#define ZEVIO_GPIO_INT_MASKED_STATUS 0x00
#define ZEVIO_GPIO_INT_STATUS 0x04
#define ZEVIO_GPIO_INT_UNMASK 0x08
#define ZEVIO_GPIO_INT_MASK 0x0C
#define ZEVIO_GPIO_DIRECTION 0x10
#define ZEVIO_GPIO_OUTPUT 0x14
#define ZEVIO_GPIO_INPUT 0x18
#define ZEVIO_GPIO_INT_STICKY 0x20
#define to_zevio_gpio(chip) container_of(to_of_mm_gpio_chip(chip), \
struct zevio_gpio, chip)
/* Bit number of GPIO in its section */
#define ZEVIO_GPIO_BIT(gpio) (gpio&7)
struct zevio_gpio {
spinlock_t lock;
struct of_mm_gpio_chip chip;
};
static inline u32 zevio_gpio_port_get(struct zevio_gpio *c, unsigned pin,
unsigned port_offset)
{
unsigned section_offset = ((pin >> 3) & 3)*ZEVIO_GPIO_SECTION_SIZE;
return readl(IOMEM(c->chip.regs + section_offset + port_offset));
}
static inline void zevio_gpio_port_set(struct zevio_gpio *c, unsigned pin,
unsigned port_offset, u32 val)
{
unsigned section_offset = ((pin >> 3) & 3)*ZEVIO_GPIO_SECTION_SIZE;
writel(val, IOMEM(c->chip.regs + section_offset + port_offset));
}
/* Functions for struct gpio_chip */
static int zevio_gpio_get(struct gpio_chip *chip, unsigned pin)
{
struct zevio_gpio *controller = to_zevio_gpio(chip);
/* Only reading allowed, so no spinlock needed */
u32 val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_INPUT);
return (val >> ZEVIO_GPIO_BIT(pin)) & 0x1;
}
static void zevio_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
{
struct zevio_gpio *controller = to_zevio_gpio(chip);
u32 val;
spin_lock(&controller->lock);
val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_OUTPUT);
if (value)
val |= BIT(ZEVIO_GPIO_BIT(pin));
else
val &= ~BIT(ZEVIO_GPIO_BIT(pin));
zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_OUTPUT, val);
spin_unlock(&controller->lock);
}
static int zevio_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
{
struct zevio_gpio *controller = to_zevio_gpio(chip);
u32 val;
spin_lock(&controller->lock);
val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_DIRECTION);
val |= BIT(ZEVIO_GPIO_BIT(pin));
zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_DIRECTION, val);
spin_unlock(&controller->lock);
return 0;
}
static int zevio_gpio_direction_output(struct gpio_chip *chip,
unsigned pin, int value)
{
struct zevio_gpio *controller = to_zevio_gpio(chip);
u32 val;
spin_lock(&controller->lock);
val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_OUTPUT);
if (value)
val |= BIT(ZEVIO_GPIO_BIT(pin));
else
val &= ~BIT(ZEVIO_GPIO_BIT(pin));
zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_OUTPUT, val);
val = zevio_gpio_port_get(controller, pin, ZEVIO_GPIO_DIRECTION);
val &= ~BIT(ZEVIO_GPIO_BIT(pin));
zevio_gpio_port_set(controller, pin, ZEVIO_GPIO_DIRECTION, val);
spin_unlock(&controller->lock);
return 0;
}
static int zevio_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
{
/*
* TODO: Implement IRQs.
* Not implemented yet due to weird lockups
*/
return -ENXIO;
}
static struct gpio_chip zevio_gpio_chip = {
.direction_input = zevio_gpio_direction_input,
.direction_output = zevio_gpio_direction_output,
.set = zevio_gpio_set,
.get = zevio_gpio_get,
.to_irq = zevio_gpio_to_irq,
.base = 0,
.owner = THIS_MODULE,
.ngpio = 32,
.of_gpio_n_cells = 2,
};
/* Initialization */
static int zevio_gpio_probe(struct platform_device *pdev)
{
struct zevio_gpio *controller;
int status, i;
controller = devm_kzalloc(&pdev->dev, sizeof(*controller), GFP_KERNEL);
if (!controller) {
dev_err(&pdev->dev, "not enough free memory\n");
return -ENOMEM;
}
/* Copy our reference */
controller->chip.gc = zevio_gpio_chip;
controller->chip.gc.dev = &pdev->dev;
status = of_mm_gpiochip_add(pdev->dev.of_node, &(controller->chip));
if (status) {
dev_err(&pdev->dev, "failed to add gpiochip: %d\n", status);
return status;
}
spin_lock_init(&controller->lock);
/* Disable interrupts, they only cause errors */
for (i = 0; i < controller->chip.gc.ngpio; i += 8)
zevio_gpio_port_set(controller, i, ZEVIO_GPIO_INT_MASK, 0xFF);
dev_dbg(controller->chip.gc.dev, "ZEVIO GPIO controller set up!\n");
return 0;
}
static struct of_device_id zevio_gpio_of_match[] = {
{ .compatible = "lsi,zevio-gpio", },
{ },
};
MODULE_DEVICE_TABLE(of, zevio_gpio_of_match);
static struct platform_driver zevio_gpio_driver = {
.driver = {
.name = "gpio-zevio",
.owner = THIS_MODULE,
.of_match_table = zevio_gpio_of_match,
},
.probe = zevio_gpio_probe,
};
module_platform_driver(zevio_gpio_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Fabian Vogt <fabian@ritter-vogt.de>");
MODULE_DESCRIPTION("LSI ZEVIO SoC GPIO driver");
|
