diff options
Diffstat (limited to 'drivers/gpio/gpio-menz127.c')
| -rw-r--r-- | drivers/gpio/gpio-menz127.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-menz127.c b/drivers/gpio/gpio-menz127.c new file mode 100644 index 000000000000..52b13c6ae496 --- /dev/null +++ b/drivers/gpio/gpio-menz127.c @@ -0,0 +1,227 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * MEN 16Z127 GPIO driver + * + * Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de) + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/mcb.h> +#include <linux/bitops.h> +#include <linux/gpio/driver.h> +#include <linux/gpio/generic.h> + +#define MEN_Z127_CTRL 0x00 +#define MEN_Z127_PSR 0x04 +#define MEN_Z127_IRQR 0x08 +#define MEN_Z127_GPIODR 0x0c +#define MEN_Z127_IER1 0x10 +#define MEN_Z127_IER2 0x14 +#define MEN_Z127_DBER 0x18 +#define MEN_Z127_ODER 0x1C +#define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80) + +/* MEN Z127 supported model ids*/ +#define MEN_Z127_ID 0x7f +#define MEN_Z034_ID 0x22 +#define MEN_Z037_ID 0x25 + +#define MEN_Z127_DB_MIN_US 50 +/* 16 bit compare register. Each bit represents 50us */ +#define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US) +#define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \ + (db <= MEN_Z127_DB_MAX_US)) + +struct men_z127_gpio { + struct gpio_generic_chip chip; + void __iomem *reg_base; + struct resource *mem; +}; + +static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio, + unsigned debounce) +{ + struct men_z127_gpio *priv = gpiochip_get_data(gc); + struct device *dev = gc->parent; + unsigned int rnd; + u32 db_en, db_cnt; + + if (!MEN_Z127_DB_IN_RANGE(debounce)) { + dev_err(dev, "debounce value %u out of range", debounce); + return -EINVAL; + } + + if (debounce > 0) { + /* round up or down depending on MSB-1 */ + rnd = fls(debounce) - 1; + + if (rnd && (debounce & BIT(rnd - 1))) + debounce = roundup(debounce, MEN_Z127_DB_MIN_US); + else + debounce = rounddown(debounce, MEN_Z127_DB_MIN_US); + + if (debounce > MEN_Z127_DB_MAX_US) + debounce = MEN_Z127_DB_MAX_US; + + /* 50us per register unit */ + debounce /= 50; + } + + guard(gpio_generic_lock)(&priv->chip); + + db_en = readl(priv->reg_base + MEN_Z127_DBER); + + if (debounce == 0) { + db_en &= ~BIT(gpio); + db_cnt = 0; + } else { + db_en |= BIT(gpio); + db_cnt = debounce; + } + + writel(db_en, priv->reg_base + MEN_Z127_DBER); + writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio)); + + return 0; +} + +static int men_z127_set_single_ended(struct gpio_chip *gc, + unsigned offset, + enum pin_config_param param) +{ + struct men_z127_gpio *priv = gpiochip_get_data(gc); + u32 od_en; + + guard(gpio_generic_lock)(&priv->chip); + + od_en = readl(priv->reg_base + MEN_Z127_ODER); + + if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN) + od_en |= BIT(offset); + else + /* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */ + od_en &= ~BIT(offset); + + writel(od_en, priv->reg_base + MEN_Z127_ODER); + + return 0; +} + +static int men_z127_set_config(struct gpio_chip *gc, unsigned offset, + unsigned long config) +{ + enum pin_config_param param = pinconf_to_config_param(config); + + switch (param) { + case PIN_CONFIG_DRIVE_OPEN_DRAIN: + case PIN_CONFIG_DRIVE_PUSH_PULL: + return men_z127_set_single_ended(gc, offset, param); + + case PIN_CONFIG_INPUT_DEBOUNCE: + return men_z127_debounce(gc, offset, + pinconf_to_config_argument(config)); + + default: + break; + } + + return -ENOTSUPP; +} + +static void men_z127_release_mem(void *data) +{ + struct resource *res = data; + + mcb_release_mem(res); +} + +static int men_z127_probe(struct mcb_device *mdev, + const struct mcb_device_id *id) +{ + struct gpio_generic_chip_config config; + struct men_z127_gpio *men_z127_gpio; + struct device *dev = &mdev->dev; + int ret; + unsigned long sz; + + men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio), + GFP_KERNEL); + if (!men_z127_gpio) + return -ENOMEM; + + men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev)); + if (IS_ERR(men_z127_gpio->mem)) + return dev_err_probe(dev, PTR_ERR(men_z127_gpio->mem), + "failed to request device memory"); + + ret = devm_add_action_or_reset(dev, men_z127_release_mem, + men_z127_gpio->mem); + if (ret) + return ret; + + men_z127_gpio->reg_base = devm_ioremap(dev, men_z127_gpio->mem->start, + resource_size(men_z127_gpio->mem)); + if (men_z127_gpio->reg_base == NULL) + return -ENXIO; + + mcb_set_drvdata(mdev, men_z127_gpio); + + switch (mdev->id) { + case MEN_Z127_ID: + sz = 4; + break; + case MEN_Z034_ID: + case MEN_Z037_ID: + sz = 1; + break; + default: + return dev_err_probe(&mdev->dev, -EINVAL, "no size found for id %d", mdev->id); + } + + config = (struct gpio_generic_chip_config) { + .dev = &mdev->dev, + .sz = sz, + .dat = men_z127_gpio->reg_base + MEN_Z127_PSR, + .set = men_z127_gpio->reg_base + MEN_Z127_CTRL, + .dirout = men_z127_gpio->reg_base + MEN_Z127_GPIODR, + }; + + ret = gpio_generic_chip_init(&men_z127_gpio->chip, &config); + if (ret) + return ret; + + men_z127_gpio->chip.gc.set_config = men_z127_set_config; + + ret = devm_gpiochip_add_data(dev, &men_z127_gpio->chip.gc, men_z127_gpio); + if (ret) + return dev_err_probe(dev, ret, + "failed to register MEN 16Z127 GPIO controller"); + + return 0; +} + +static const struct mcb_device_id men_z127_ids[] = { + { .device = MEN_Z127_ID }, + { .device = MEN_Z034_ID }, + { .device = MEN_Z037_ID }, + { } +}; +MODULE_DEVICE_TABLE(mcb, men_z127_ids); + +static struct mcb_driver men_z127_driver = { + .driver = { + .name = "z127-gpio", + }, + .probe = men_z127_probe, + .id_table = men_z127_ids, +}; +module_mcb_driver(men_z127_driver); + +MODULE_AUTHOR("Andreas Werner <andreas.werner@men.de>"); +MODULE_DESCRIPTION("MEN GPIO Controller"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("mcb:16z127"); +MODULE_IMPORT_NS("MCB"); |