2 * MEN 16Z127 GPIO driver
4 * Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de)
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; version 2 of the License.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
14 #include <linux/err.h>
15 #include <linux/mcb.h>
16 #include <linux/bitops.h>
17 #include <linux/gpio/driver.h>
19 #define MEN_Z127_CTRL 0x00
20 #define MEN_Z127_PSR 0x04
21 #define MEN_Z127_IRQR 0x08
22 #define MEN_Z127_GPIODR 0x0c
23 #define MEN_Z127_IER1 0x10
24 #define MEN_Z127_IER2 0x14
25 #define MEN_Z127_DBER 0x18
26 #define MEN_Z127_ODER 0x1C
27 #define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80)
29 #define MEN_Z127_DB_MIN_US 50
30 /* 16 bit compare register. Each bit represents 50us */
31 #define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US)
32 #define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \
33 (db <= MEN_Z127_DB_MAX_US))
35 struct men_z127_gpio
{
37 void __iomem
*reg_base
;
38 struct mcb_device
*mdev
;
43 static int men_z127_debounce(struct gpio_chip
*gc
, unsigned gpio
,
46 struct men_z127_gpio
*priv
= gpiochip_get_data(gc
);
47 struct device
*dev
= &priv
->mdev
->dev
;
51 if (!MEN_Z127_DB_IN_RANGE(debounce
)) {
52 dev_err(dev
, "debounce value %u out of range", debounce
);
57 /* round up or down depending on MSB-1 */
58 rnd
= fls(debounce
) - 1;
60 if (rnd
&& (debounce
& BIT(rnd
- 1)))
61 debounce
= round_up(debounce
, MEN_Z127_DB_MIN_US
);
63 debounce
= round_down(debounce
, MEN_Z127_DB_MIN_US
);
65 if (debounce
> MEN_Z127_DB_MAX_US
)
66 debounce
= MEN_Z127_DB_MAX_US
;
68 /* 50us per register unit */
72 spin_lock(&priv
->lock
);
74 db_en
= readl(priv
->reg_base
+ MEN_Z127_DBER
);
84 writel(db_en
, priv
->reg_base
+ MEN_Z127_DBER
);
85 writel(db_cnt
, priv
->reg_base
+ GPIO_TO_DBCNT_REG(gpio
));
87 spin_unlock(&priv
->lock
);
92 static int men_z127_request(struct gpio_chip
*gc
, unsigned gpio_pin
)
94 struct men_z127_gpio
*priv
= gpiochip_get_data(gc
);
97 if (gpio_pin
>= gc
->ngpio
)
100 spin_lock(&priv
->lock
);
101 od_en
= readl(priv
->reg_base
+ MEN_Z127_ODER
);
103 if (gpiochip_line_is_open_drain(gc
, gpio_pin
))
104 od_en
|= BIT(gpio_pin
);
106 od_en
&= ~BIT(gpio_pin
);
108 writel(od_en
, priv
->reg_base
+ MEN_Z127_ODER
);
109 spin_unlock(&priv
->lock
);
114 static int men_z127_probe(struct mcb_device
*mdev
,
115 const struct mcb_device_id
*id
)
117 struct men_z127_gpio
*men_z127_gpio
;
118 struct device
*dev
= &mdev
->dev
;
121 men_z127_gpio
= devm_kzalloc(dev
, sizeof(struct men_z127_gpio
),
126 men_z127_gpio
->mem
= mcb_request_mem(mdev
, dev_name(dev
));
127 if (IS_ERR(men_z127_gpio
->mem
)) {
128 dev_err(dev
, "failed to request device memory");
129 return PTR_ERR(men_z127_gpio
->mem
);
132 men_z127_gpio
->reg_base
= ioremap(men_z127_gpio
->mem
->start
,
133 resource_size(men_z127_gpio
->mem
));
134 if (men_z127_gpio
->reg_base
== NULL
) {
139 men_z127_gpio
->mdev
= mdev
;
140 mcb_set_drvdata(mdev
, men_z127_gpio
);
142 ret
= bgpio_init(&men_z127_gpio
->gc
, &mdev
->dev
, 4,
143 men_z127_gpio
->reg_base
+ MEN_Z127_PSR
,
144 men_z127_gpio
->reg_base
+ MEN_Z127_CTRL
,
146 men_z127_gpio
->reg_base
+ MEN_Z127_GPIODR
,
151 men_z127_gpio
->gc
.set_debounce
= men_z127_debounce
;
152 men_z127_gpio
->gc
.request
= men_z127_request
;
154 ret
= gpiochip_add_data(&men_z127_gpio
->gc
, men_z127_gpio
);
156 dev_err(dev
, "failed to register MEN 16Z127 GPIO controller");
160 dev_info(dev
, "MEN 16Z127 GPIO driver registered");
165 iounmap(men_z127_gpio
->reg_base
);
167 mcb_release_mem(men_z127_gpio
->mem
);
171 static void men_z127_remove(struct mcb_device
*mdev
)
173 struct men_z127_gpio
*men_z127_gpio
= mcb_get_drvdata(mdev
);
175 gpiochip_remove(&men_z127_gpio
->gc
);
176 iounmap(men_z127_gpio
->reg_base
);
177 mcb_release_mem(men_z127_gpio
->mem
);
180 static const struct mcb_device_id men_z127_ids
[] = {
184 MODULE_DEVICE_TABLE(mcb
, men_z127_ids
);
186 static struct mcb_driver men_z127_driver
= {
189 .owner
= THIS_MODULE
,
191 .probe
= men_z127_probe
,
192 .remove
= men_z127_remove
,
193 .id_table
= men_z127_ids
,
195 module_mcb_driver(men_z127_driver
);
197 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
198 MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");
199 MODULE_LICENSE("GPL v2");
200 MODULE_ALIAS("mcb:16z127");