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
;
42 static int men_z127_debounce(struct gpio_chip
*gc
, unsigned gpio
,
45 struct men_z127_gpio
*priv
= gpiochip_get_data(gc
);
46 struct device
*dev
= &priv
->mdev
->dev
;
50 if (!MEN_Z127_DB_IN_RANGE(debounce
)) {
51 dev_err(dev
, "debounce value %u out of range", debounce
);
56 /* round up or down depending on MSB-1 */
57 rnd
= fls(debounce
) - 1;
59 if (rnd
&& (debounce
& BIT(rnd
- 1)))
60 debounce
= round_up(debounce
, MEN_Z127_DB_MIN_US
);
62 debounce
= round_down(debounce
, MEN_Z127_DB_MIN_US
);
64 if (debounce
> MEN_Z127_DB_MAX_US
)
65 debounce
= MEN_Z127_DB_MAX_US
;
67 /* 50us per register unit */
71 spin_lock(&gc
->bgpio_lock
);
73 db_en
= readl(priv
->reg_base
+ MEN_Z127_DBER
);
83 writel(db_en
, priv
->reg_base
+ MEN_Z127_DBER
);
84 writel(db_cnt
, priv
->reg_base
+ GPIO_TO_DBCNT_REG(gpio
));
86 spin_unlock(&gc
->bgpio_lock
);
91 static int men_z127_request(struct gpio_chip
*gc
, unsigned gpio_pin
)
93 struct men_z127_gpio
*priv
= gpiochip_get_data(gc
);
96 if (gpio_pin
>= gc
->ngpio
)
99 spin_lock(&gc
->bgpio_lock
);
100 od_en
= readl(priv
->reg_base
+ MEN_Z127_ODER
);
102 if (gpiochip_line_is_open_drain(gc
, gpio_pin
))
103 od_en
|= BIT(gpio_pin
);
105 od_en
&= ~BIT(gpio_pin
);
107 writel(od_en
, priv
->reg_base
+ MEN_Z127_ODER
);
108 spin_unlock(&gc
->bgpio_lock
);
113 static int men_z127_probe(struct mcb_device
*mdev
,
114 const struct mcb_device_id
*id
)
116 struct men_z127_gpio
*men_z127_gpio
;
117 struct device
*dev
= &mdev
->dev
;
120 men_z127_gpio
= devm_kzalloc(dev
, sizeof(struct men_z127_gpio
),
125 men_z127_gpio
->mem
= mcb_request_mem(mdev
, dev_name(dev
));
126 if (IS_ERR(men_z127_gpio
->mem
)) {
127 dev_err(dev
, "failed to request device memory");
128 return PTR_ERR(men_z127_gpio
->mem
);
131 men_z127_gpio
->reg_base
= ioremap(men_z127_gpio
->mem
->start
,
132 resource_size(men_z127_gpio
->mem
));
133 if (men_z127_gpio
->reg_base
== NULL
) {
138 men_z127_gpio
->mdev
= mdev
;
139 mcb_set_drvdata(mdev
, men_z127_gpio
);
141 ret
= bgpio_init(&men_z127_gpio
->gc
, &mdev
->dev
, 4,
142 men_z127_gpio
->reg_base
+ MEN_Z127_PSR
,
143 men_z127_gpio
->reg_base
+ MEN_Z127_CTRL
,
145 men_z127_gpio
->reg_base
+ MEN_Z127_GPIODR
,
150 men_z127_gpio
->gc
.set_debounce
= men_z127_debounce
;
151 men_z127_gpio
->gc
.request
= men_z127_request
;
153 ret
= gpiochip_add_data(&men_z127_gpio
->gc
, men_z127_gpio
);
155 dev_err(dev
, "failed to register MEN 16Z127 GPIO controller");
159 dev_info(dev
, "MEN 16Z127 GPIO driver registered");
164 iounmap(men_z127_gpio
->reg_base
);
166 mcb_release_mem(men_z127_gpio
->mem
);
170 static void men_z127_remove(struct mcb_device
*mdev
)
172 struct men_z127_gpio
*men_z127_gpio
= mcb_get_drvdata(mdev
);
174 gpiochip_remove(&men_z127_gpio
->gc
);
175 iounmap(men_z127_gpio
->reg_base
);
176 mcb_release_mem(men_z127_gpio
->mem
);
179 static const struct mcb_device_id men_z127_ids
[] = {
183 MODULE_DEVICE_TABLE(mcb
, men_z127_ids
);
185 static struct mcb_driver men_z127_driver
= {
188 .owner
= THIS_MODULE
,
190 .probe
= men_z127_probe
,
191 .remove
= men_z127_remove
,
192 .id_table
= men_z127_ids
,
194 module_mcb_driver(men_z127_driver
);
196 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
197 MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");
198 MODULE_LICENSE("GPL v2");
199 MODULE_ALIAS("mcb:16z127");