gpio-menz127.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * MEN 16Z127 GPIO driver
  4 *
  5 * Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de)
  6 */
  7
  8#include <linux/kernel.h>
  9#include <linux/module.h>
 10#include <linux/io.h>
 11#include <linux/err.h>
 12#include <linux/mcb.h>
 13#include <linux/bitops.h>
 14#include <linux/gpio/driver.h>
 15#include <linux/gpio/generic.h>
 16
 17#define MEN_Z127_CTRL	0x00
 18#define MEN_Z127_PSR	0x04
 19#define MEN_Z127_IRQR	0x08
 20#define MEN_Z127_GPIODR	0x0c
 21#define MEN_Z127_IER1	0x10
 22#define MEN_Z127_IER2	0x14
 23#define MEN_Z127_DBER	0x18
 24#define MEN_Z127_ODER	0x1C
 25#define GPIO_TO_DBCNT_REG(gpio)	((gpio * 4) + 0x80)
 26
 27/* MEN Z127 supported model ids*/
 28#define MEN_Z127_ID	0x7f
 29#define MEN_Z034_ID	0x22
 30#define MEN_Z037_ID	0x25
 31
 32#define MEN_Z127_DB_MIN_US	50
 33/* 16 bit compare register. Each bit represents 50us */
 34#define MEN_Z127_DB_MAX_US	(0xffff * MEN_Z127_DB_MIN_US)
 35#define MEN_Z127_DB_IN_RANGE(db)	((db >= MEN_Z127_DB_MIN_US) && \
 36					 (db <= MEN_Z127_DB_MAX_US))
 37
 38struct men_z127_gpio {
 39	struct gpio_generic_chip chip;
 40	void __iomem *reg_base;
 41	struct resource *mem;
 42};
 43
 44static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio,
 45			     unsigned debounce)
 46{
 47	struct men_z127_gpio *priv = gpiochip_get_data(gc);
 48	struct device *dev = gc->parent;
 49	unsigned int rnd;
 50	u32 db_en, db_cnt;
 51
 52	if (!MEN_Z127_DB_IN_RANGE(debounce)) {
 53		dev_err(dev, "debounce value %u out of range", debounce);
 54		return -EINVAL;
 55	}
 56
 57	if (debounce > 0) {
 58		/* round up or down depending on MSB-1 */
 59		rnd = fls(debounce) - 1;
 60
 61		if (rnd && (debounce & BIT(rnd - 1)))
 62			debounce = roundup(debounce, MEN_Z127_DB_MIN_US);
 63		else
 64			debounce = rounddown(debounce, MEN_Z127_DB_MIN_US);
 65
 66		if (debounce > MEN_Z127_DB_MAX_US)
 67			debounce = MEN_Z127_DB_MAX_US;
 68
 69		/* 50us per register unit */
 70		debounce /= 50;
 71	}
 72
 73	guard(gpio_generic_lock)(&priv->chip);
 74
 75	db_en = readl(priv->reg_base + MEN_Z127_DBER);
 76
 77	if (debounce == 0) {
 78		db_en &= ~BIT(gpio);
 79		db_cnt = 0;
 80	} else {
 81		db_en |= BIT(gpio);
 82		db_cnt = debounce;
 83	}
 84
 85	writel(db_en, priv->reg_base + MEN_Z127_DBER);
 86	writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio));
 87
 88	return 0;
 89}
 90
 91static int men_z127_set_single_ended(struct gpio_chip *gc,
 92				     unsigned offset,
 93				     enum pin_config_param param)
 94{
 95	struct men_z127_gpio *priv = gpiochip_get_data(gc);
 96	u32 od_en;
 97
 98	guard(gpio_generic_lock)(&priv->chip);
 99
100	od_en = readl(priv->reg_base + MEN_Z127_ODER);
101
102	if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)
103		od_en |= BIT(offset);
104	else
105		/* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */
106		od_en &= ~BIT(offset);
107
108	writel(od_en, priv->reg_base + MEN_Z127_ODER);
109
110	return 0;
111}
112
113static int men_z127_set_config(struct gpio_chip *gc, unsigned offset,
114			       unsigned long config)
115{
116	enum pin_config_param param = pinconf_to_config_param(config);
117
118	switch (param) {
119	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
120	case PIN_CONFIG_DRIVE_PUSH_PULL:
121		return men_z127_set_single_ended(gc, offset, param);
122
123	case PIN_CONFIG_INPUT_DEBOUNCE:
124		return men_z127_debounce(gc, offset,
125			pinconf_to_config_argument(config));
126
127	default:
128		break;
129	}
130
131	return -ENOTSUPP;
132}
133
134static void men_z127_release_mem(void *data)
135{
136	struct resource *res = data;
137
138	mcb_release_mem(res);
139}
140
141static int men_z127_probe(struct mcb_device *mdev,
142			  const struct mcb_device_id *id)
143{
144	struct gpio_generic_chip_config config;
145	struct men_z127_gpio *men_z127_gpio;
146	struct device *dev = &mdev->dev;
147	int ret;
148	unsigned long sz;
149
150	men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio),
151				     GFP_KERNEL);
152	if (!men_z127_gpio)
153		return -ENOMEM;
154
155	men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev));
156	if (IS_ERR(men_z127_gpio->mem))
157		return dev_err_probe(dev, PTR_ERR(men_z127_gpio->mem),
158				     "failed to request device memory");
159
160	ret = devm_add_action_or_reset(dev, men_z127_release_mem,
161				       men_z127_gpio->mem);
162	if (ret)
163		return ret;
164
165	men_z127_gpio->reg_base = devm_ioremap(dev, men_z127_gpio->mem->start,
166					resource_size(men_z127_gpio->mem));
167	if (men_z127_gpio->reg_base == NULL)
168		return -ENXIO;
169
170	mcb_set_drvdata(mdev, men_z127_gpio);
171
172	switch (mdev->id) {
173	case MEN_Z127_ID:
174		sz = 4;
175		break;
176	case MEN_Z034_ID:
177	case MEN_Z037_ID:
178		sz = 1;
179		break;
180	default:
181		return dev_err_probe(&mdev->dev, -EINVAL, "no size found for id %d", mdev->id);
182	}
183
184	config = (struct gpio_generic_chip_config) {
185		.dev = &mdev->dev,
186		.sz = sz,
187		.dat = men_z127_gpio->reg_base + MEN_Z127_PSR,
188		.set = men_z127_gpio->reg_base + MEN_Z127_CTRL,
189		.dirout = men_z127_gpio->reg_base + MEN_Z127_GPIODR,
190	};
191
192	ret = gpio_generic_chip_init(&men_z127_gpio->chip, &config);
193	if (ret)
194		return ret;
195
196	men_z127_gpio->chip.gc.set_config = men_z127_set_config;
197
198	ret = devm_gpiochip_add_data(dev, &men_z127_gpio->chip.gc, men_z127_gpio);
199	if (ret)
200		return dev_err_probe(dev, ret,
201			"failed to register MEN 16Z127 GPIO controller");
202
203	return 0;
204}
205
206static const struct mcb_device_id men_z127_ids[] = {
207	{ .device = MEN_Z127_ID },
208	{ .device = MEN_Z034_ID },
209	{ .device = MEN_Z037_ID },
210	{ }
211};
212MODULE_DEVICE_TABLE(mcb, men_z127_ids);
213
214static struct mcb_driver men_z127_driver = {
215	.driver = {
216		.name = "z127-gpio",
217	},
218	.probe = men_z127_probe,
219	.id_table = men_z127_ids,
220};
221module_mcb_driver(men_z127_driver);
222
223MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");
224MODULE_DESCRIPTION("MEN GPIO Controller");
225MODULE_LICENSE("GPL v2");
226MODULE_ALIAS("mcb:16z127");
227MODULE_IMPORT_NS("MCB");