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");