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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * MEN 16Z127 GPIO driver4 *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 16#define MEN_Z127_CTRL 0x0017#define MEN_Z127_PSR 0x0418#define MEN_Z127_IRQR 0x0819#define MEN_Z127_GPIODR 0x0c20#define MEN_Z127_IER1 0x1021#define MEN_Z127_IER2 0x1422#define MEN_Z127_DBER 0x1823#define MEN_Z127_ODER 0x1C24#define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80)25 26#define MEN_Z127_DB_MIN_US 5027/* 16 bit compare register. Each bit represents 50us */28#define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US)29#define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \30 (db <= MEN_Z127_DB_MAX_US))31 32struct men_z127_gpio {33 struct gpio_chip gc;34 void __iomem *reg_base;35 struct resource *mem;36};37 38static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio,39 unsigned debounce)40{41 struct men_z127_gpio *priv = gpiochip_get_data(gc);42 struct device *dev = gc->parent;43 unsigned int rnd;44 u32 db_en, db_cnt;45 46 if (!MEN_Z127_DB_IN_RANGE(debounce)) {47 dev_err(dev, "debounce value %u out of range", debounce);48 return -EINVAL;49 }50 51 if (debounce > 0) {52 /* round up or down depending on MSB-1 */53 rnd = fls(debounce) - 1;54 55 if (rnd && (debounce & BIT(rnd - 1)))56 debounce = roundup(debounce, MEN_Z127_DB_MIN_US);57 else58 debounce = rounddown(debounce, MEN_Z127_DB_MIN_US);59 60 if (debounce > MEN_Z127_DB_MAX_US)61 debounce = MEN_Z127_DB_MAX_US;62 63 /* 50us per register unit */64 debounce /= 50;65 }66 67 raw_spin_lock(&gc->bgpio_lock);68 69 db_en = readl(priv->reg_base + MEN_Z127_DBER);70 71 if (debounce == 0) {72 db_en &= ~BIT(gpio);73 db_cnt = 0;74 } else {75 db_en |= BIT(gpio);76 db_cnt = debounce;77 }78 79 writel(db_en, priv->reg_base + MEN_Z127_DBER);80 writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio));81 82 raw_spin_unlock(&gc->bgpio_lock);83 84 return 0;85}86 87static int men_z127_set_single_ended(struct gpio_chip *gc,88 unsigned offset,89 enum pin_config_param param)90{91 struct men_z127_gpio *priv = gpiochip_get_data(gc);92 u32 od_en;93 94 raw_spin_lock(&gc->bgpio_lock);95 od_en = readl(priv->reg_base + MEN_Z127_ODER);96 97 if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN)98 od_en |= BIT(offset);99 else100 /* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */101 od_en &= ~BIT(offset);102 103 writel(od_en, priv->reg_base + MEN_Z127_ODER);104 raw_spin_unlock(&gc->bgpio_lock);105 106 return 0;107}108 109static int men_z127_set_config(struct gpio_chip *gc, unsigned offset,110 unsigned long config)111{112 enum pin_config_param param = pinconf_to_config_param(config);113 114 switch (param) {115 case PIN_CONFIG_DRIVE_OPEN_DRAIN:116 case PIN_CONFIG_DRIVE_PUSH_PULL:117 return men_z127_set_single_ended(gc, offset, param);118 119 case PIN_CONFIG_INPUT_DEBOUNCE:120 return men_z127_debounce(gc, offset,121 pinconf_to_config_argument(config));122 123 default:124 break;125 }126 127 return -ENOTSUPP;128}129 130static int men_z127_probe(struct mcb_device *mdev,131 const struct mcb_device_id *id)132{133 struct men_z127_gpio *men_z127_gpio;134 struct device *dev = &mdev->dev;135 int ret;136 137 men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio),138 GFP_KERNEL);139 if (!men_z127_gpio)140 return -ENOMEM;141 142 men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev));143 if (IS_ERR(men_z127_gpio->mem)) {144 dev_err(dev, "failed to request device memory");145 return PTR_ERR(men_z127_gpio->mem);146 }147 148 men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start,149 resource_size(men_z127_gpio->mem));150 if (men_z127_gpio->reg_base == NULL) {151 ret = -ENXIO;152 goto err_release;153 }154 155 mcb_set_drvdata(mdev, men_z127_gpio);156 157 ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4,158 men_z127_gpio->reg_base + MEN_Z127_PSR,159 men_z127_gpio->reg_base + MEN_Z127_CTRL,160 NULL,161 men_z127_gpio->reg_base + MEN_Z127_GPIODR,162 NULL, 0);163 if (ret)164 goto err_unmap;165 166 men_z127_gpio->gc.set_config = men_z127_set_config;167 168 ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio);169 if (ret) {170 dev_err(dev, "failed to register MEN 16Z127 GPIO controller");171 goto err_unmap;172 }173 174 dev_info(dev, "MEN 16Z127 GPIO driver registered");175 176 return 0;177 178err_unmap:179 iounmap(men_z127_gpio->reg_base);180err_release:181 mcb_release_mem(men_z127_gpio->mem);182 return ret;183}184 185static void men_z127_remove(struct mcb_device *mdev)186{187 struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev);188 189 gpiochip_remove(&men_z127_gpio->gc);190 iounmap(men_z127_gpio->reg_base);191 mcb_release_mem(men_z127_gpio->mem);192}193 194static const struct mcb_device_id men_z127_ids[] = {195 { .device = 0x7f },196 { }197};198MODULE_DEVICE_TABLE(mcb, men_z127_ids);199 200static struct mcb_driver men_z127_driver = {201 .driver = {202 .name = "z127-gpio",203 },204 .probe = men_z127_probe,205 .remove = men_z127_remove,206 .id_table = men_z127_ids,207};208module_mcb_driver(men_z127_driver);209 210MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>");211MODULE_DESCRIPTION("MEN 16z127 GPIO Controller");212MODULE_LICENSE("GPL v2");213MODULE_ALIAS("mcb:16z127");214MODULE_IMPORT_NS(MCB);215