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;
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 = gc->parent;
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(&priv->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(&priv->lock);
91 static int men_z127_set_single_ended(struct gpio_chip *gc,
93 enum single_ended_mode mode)
95 struct men_z127_gpio *priv = gpiochip_get_data(gc);
98 if (mode != LINE_MODE_OPEN_DRAIN &&
99 mode != LINE_MODE_PUSH_PULL)
102 spin_lock(&priv->lock);
103 od_en = readl(priv->reg_base + MEN_Z127_ODER);
105 if (mode == LINE_MODE_OPEN_DRAIN)
106 od_en |= BIT(offset);
108 /* Implicitly LINE_MODE_PUSH_PULL */
109 od_en &= ~BIT(offset);
111 writel(od_en, priv->reg_base + MEN_Z127_ODER);
112 spin_unlock(&priv->lock);
117 static int men_z127_probe(struct mcb_device *mdev,
118 const struct mcb_device_id *id)
120 struct men_z127_gpio *men_z127_gpio;
121 struct device *dev = &mdev->dev;
124 men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio),
129 men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev));
130 if (IS_ERR(men_z127_gpio->mem)) {
131 dev_err(dev, "failed to request device memory");
132 return PTR_ERR(men_z127_gpio->mem);
135 men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start,
136 resource_size(men_z127_gpio->mem));
137 if (men_z127_gpio->reg_base == NULL) {
142 mcb_set_drvdata(mdev, men_z127_gpio);
144 ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4,
145 men_z127_gpio->reg_base + MEN_Z127_PSR,
146 men_z127_gpio->reg_base + MEN_Z127_CTRL,
148 men_z127_gpio->reg_base + MEN_Z127_GPIODR,
153 men_z127_gpio->gc.set_debounce = men_z127_debounce;
154 men_z127_gpio->gc.set_single_ended = men_z127_set_single_ended;
156 ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio);
158 dev_err(dev, "failed to register MEN 16Z127 GPIO controller");
162 dev_info(dev, "MEN 16Z127 GPIO driver registered");
167 iounmap(men_z127_gpio->reg_base);
169 mcb_release_mem(men_z127_gpio->mem);
173 static void men_z127_remove(struct mcb_device *mdev)
175 struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev);
177 gpiochip_remove(&men_z127_gpio->gc);
178 iounmap(men_z127_gpio->reg_base);
179 mcb_release_mem(men_z127_gpio->mem);
182 static const struct mcb_device_id men_z127_ids[] = {
186 MODULE_DEVICE_TABLE(mcb, men_z127_ids);
188 static struct mcb_driver men_z127_driver = {
191 .owner = THIS_MODULE,
193 .probe = men_z127_probe,
194 .remove = men_z127_remove,
195 .id_table = men_z127_ids,
197 module_mcb_driver(men_z127_driver);
199 MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
200 MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");
201 MODULE_LICENSE("GPL v2");
202 MODULE_ALIAS("mcb:16z127");