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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* MEN 16Z127 GPIO driver
*
* Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de)
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/mcb.h>
#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#define MEN_Z127_CTRL 0x00
#define MEN_Z127_PSR 0x04
#define MEN_Z127_IRQR 0x08
#define MEN_Z127_GPIODR 0x0c
#define MEN_Z127_IER1 0x10
#define MEN_Z127_IER2 0x14
#define MEN_Z127_DBER 0x18
#define MEN_Z127_ODER 0x1C
#define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80)
#define MEN_Z127_DB_MIN_US 50
/* 16 bit compare register. Each bit represents 50us */
#define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US)
#define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \
(db <= MEN_Z127_DB_MAX_US))
struct men_z127_gpio {
struct gpio_chip gc;
void __iomem *reg_base;
struct resource *mem;
};
static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio,
unsigned debounce)
{
struct men_z127_gpio *priv = gpiochip_get_data(gc);
struct device *dev = gc->parent;
unsigned int rnd;
u32 db_en, db_cnt;
if (!MEN_Z127_DB_IN_RANGE(debounce)) {
dev_err(dev, "debounce value %u out of range", debounce);
return -EINVAL;
}
if (debounce > 0) {
/* round up or down depending on MSB-1 */
rnd = fls(debounce) - 1;
if (rnd && (debounce & BIT(rnd - 1)))
debounce = roundup(debounce, MEN_Z127_DB_MIN_US);
else
debounce = rounddown(debounce, MEN_Z127_DB_MIN_US);
if (debounce > MEN_Z127_DB_MAX_US)
debounce = MEN_Z127_DB_MAX_US;
/* 50us per register unit */
debounce /= 50;
}
spin_lock(&gc->bgpio_lock);
db_en = readl(priv->reg_base + MEN_Z127_DBER);
if (debounce == 0) {
db_en &= ~BIT(gpio);
db_cnt = 0;
} else {
db_en |= BIT(gpio);
db_cnt = debounce;
}
writel(db_en, priv->reg_base + MEN_Z127_DBER);
writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio));
spin_unlock(&gc->bgpio_lock);
return 0;
}
static int men_z127_set_single_ended(struct gpio_chip *gc,
unsigned offset,
enum pin_config_param param)
{
struct men_z127_gpio *priv = gpiochip_get_data(gc);
u32 od_en;
spin_lock(&gc->bgpio_lock);
od_en = readl(priv->reg_base + MEN_Z127_ODER);
if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)
od_en |= BIT(offset);
else
/* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */
od_en &= ~BIT(offset);
writel(od_en, priv->reg_base + MEN_Z127_ODER);
spin_unlock(&gc->bgpio_lock);
return 0;
}
static int men_z127_set_config(struct gpio_chip *gc, unsigned offset,
unsigned long config)
{
enum pin_config_param param = pinconf_to_config_param(config);
switch (param) {
case PIN_CONFIG_DRIVE_OPEN_DRAIN:
case PIN_CONFIG_DRIVE_PUSH_PULL:
return men_z127_set_single_ended(gc, offset, param);
case PIN_CONFIG_INPUT_DEBOUNCE:
return men_z127_debounce(gc, offset,
pinconf_to_config_argument(config));
default:
break;
}
return -ENOTSUPP;
}
static int men_z127_probe(struct mcb_device *mdev,
const struct mcb_device_id *id)
{
struct men_z127_gpio *men_z127_gpio;
struct device *dev = &mdev->dev;
int ret;
men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio),
GFP_KERNEL);
if (!men_z127_gpio)
return -ENOMEM;
men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev));
if (IS_ERR(men_z127_gpio->mem)) {
dev_err(dev, "failed to request device memory");
return PTR_ERR(men_z127_gpio->mem);
}
men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start,
resource_size(men_z127_gpio->mem));
if (men_z127_gpio->reg_base == NULL) {
ret = -ENXIO;
goto err_release;
}
mcb_set_drvdata(mdev, men_z127_gpio);
ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4,
men_z127_gpio->reg_base + MEN_Z127_PSR,
men_z127_gpio->reg_base + MEN_Z127_CTRL,
NULL,
men_z127_gpio->reg_base + MEN_Z127_GPIODR,
NULL, 0);
if (ret)
goto err_unmap;
men_z127_gpio->gc.set_config = men_z127_set_config;
ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio);
if (ret) {
dev_err(dev, "failed to register MEN 16Z127 GPIO controller");
goto err_unmap;
}
dev_info(dev, "MEN 16Z127 GPIO driver registered");
return 0;
err_unmap:
iounmap(men_z127_gpio->reg_base);
err_release:
mcb_release_mem(men_z127_gpio->mem);
return ret;
}
static void men_z127_remove(struct mcb_device *mdev)
{
struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev);
gpiochip_remove(&men_z127_gpio->gc);
iounmap(men_z127_gpio->reg_base);
mcb_release_mem(men_z127_gpio->mem);
}
static const struct mcb_device_id men_z127_ids[] = {
{ .device = 0x7f },
{ }
};
MODULE_DEVICE_TABLE(mcb, men_z127_ids);
static struct mcb_driver men_z127_driver = {
.driver = {
.name = "z127-gpio",
},
.probe = men_z127_probe,
.remove = men_z127_remove,
.id_table = men_z127_ids,
};
module_mcb_driver(men_z127_driver);
MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("mcb:16z127");
MODULE_IMPORT_NS(MCB);
|
