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214 lines
4.9 KiB
214 lines
4.9 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* MEN 16Z127 GPIO driver |
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* |
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* Copyright (C) 2016 MEN Mikroelektronik GmbH (www.men.de) |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/io.h> |
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#include <linux/err.h> |
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#include <linux/mcb.h> |
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#include <linux/bitops.h> |
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#include <linux/gpio/driver.h> |
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#define MEN_Z127_CTRL 0x00 |
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#define MEN_Z127_PSR 0x04 |
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#define MEN_Z127_IRQR 0x08 |
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#define MEN_Z127_GPIODR 0x0c |
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#define MEN_Z127_IER1 0x10 |
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#define MEN_Z127_IER2 0x14 |
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#define MEN_Z127_DBER 0x18 |
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#define MEN_Z127_ODER 0x1C |
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#define GPIO_TO_DBCNT_REG(gpio) ((gpio * 4) + 0x80) |
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#define MEN_Z127_DB_MIN_US 50 |
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/* 16 bit compare register. Each bit represents 50us */ |
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#define MEN_Z127_DB_MAX_US (0xffff * MEN_Z127_DB_MIN_US) |
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#define MEN_Z127_DB_IN_RANGE(db) ((db >= MEN_Z127_DB_MIN_US) && \ |
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(db <= MEN_Z127_DB_MAX_US)) |
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struct men_z127_gpio { |
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struct gpio_chip gc; |
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void __iomem *reg_base; |
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struct resource *mem; |
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}; |
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static int men_z127_debounce(struct gpio_chip *gc, unsigned gpio, |
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unsigned debounce) |
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{ |
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struct men_z127_gpio *priv = gpiochip_get_data(gc); |
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struct device *dev = gc->parent; |
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unsigned int rnd; |
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u32 db_en, db_cnt; |
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if (!MEN_Z127_DB_IN_RANGE(debounce)) { |
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dev_err(dev, "debounce value %u out of range", debounce); |
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return -EINVAL; |
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} |
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if (debounce > 0) { |
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/* round up or down depending on MSB-1 */ |
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rnd = fls(debounce) - 1; |
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if (rnd && (debounce & BIT(rnd - 1))) |
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debounce = roundup(debounce, MEN_Z127_DB_MIN_US); |
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else |
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debounce = rounddown(debounce, MEN_Z127_DB_MIN_US); |
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if (debounce > MEN_Z127_DB_MAX_US) |
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debounce = MEN_Z127_DB_MAX_US; |
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/* 50us per register unit */ |
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debounce /= 50; |
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} |
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spin_lock(&gc->bgpio_lock); |
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db_en = readl(priv->reg_base + MEN_Z127_DBER); |
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if (debounce == 0) { |
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db_en &= ~BIT(gpio); |
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db_cnt = 0; |
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} else { |
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db_en |= BIT(gpio); |
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db_cnt = debounce; |
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} |
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writel(db_en, priv->reg_base + MEN_Z127_DBER); |
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writel(db_cnt, priv->reg_base + GPIO_TO_DBCNT_REG(gpio)); |
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spin_unlock(&gc->bgpio_lock); |
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return 0; |
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} |
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static int men_z127_set_single_ended(struct gpio_chip *gc, |
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unsigned offset, |
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enum pin_config_param param) |
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{ |
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struct men_z127_gpio *priv = gpiochip_get_data(gc); |
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u32 od_en; |
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spin_lock(&gc->bgpio_lock); |
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od_en = readl(priv->reg_base + MEN_Z127_ODER); |
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if (param == PIN_CONFIG_DRIVE_OPEN_DRAIN) |
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od_en |= BIT(offset); |
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else |
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/* Implicitly PIN_CONFIG_DRIVE_PUSH_PULL */ |
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od_en &= ~BIT(offset); |
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writel(od_en, priv->reg_base + MEN_Z127_ODER); |
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spin_unlock(&gc->bgpio_lock); |
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return 0; |
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} |
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static int men_z127_set_config(struct gpio_chip *gc, unsigned offset, |
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unsigned long config) |
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{ |
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enum pin_config_param param = pinconf_to_config_param(config); |
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switch (param) { |
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case PIN_CONFIG_DRIVE_OPEN_DRAIN: |
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case PIN_CONFIG_DRIVE_PUSH_PULL: |
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return men_z127_set_single_ended(gc, offset, param); |
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case PIN_CONFIG_INPUT_DEBOUNCE: |
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return men_z127_debounce(gc, offset, |
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pinconf_to_config_argument(config)); |
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default: |
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break; |
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} |
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return -ENOTSUPP; |
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} |
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static int men_z127_probe(struct mcb_device *mdev, |
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const struct mcb_device_id *id) |
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{ |
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struct men_z127_gpio *men_z127_gpio; |
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struct device *dev = &mdev->dev; |
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int ret; |
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men_z127_gpio = devm_kzalloc(dev, sizeof(struct men_z127_gpio), |
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GFP_KERNEL); |
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if (!men_z127_gpio) |
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return -ENOMEM; |
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men_z127_gpio->mem = mcb_request_mem(mdev, dev_name(dev)); |
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if (IS_ERR(men_z127_gpio->mem)) { |
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dev_err(dev, "failed to request device memory"); |
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return PTR_ERR(men_z127_gpio->mem); |
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} |
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men_z127_gpio->reg_base = ioremap(men_z127_gpio->mem->start, |
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resource_size(men_z127_gpio->mem)); |
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if (men_z127_gpio->reg_base == NULL) { |
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ret = -ENXIO; |
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goto err_release; |
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} |
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mcb_set_drvdata(mdev, men_z127_gpio); |
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ret = bgpio_init(&men_z127_gpio->gc, &mdev->dev, 4, |
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men_z127_gpio->reg_base + MEN_Z127_PSR, |
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men_z127_gpio->reg_base + MEN_Z127_CTRL, |
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NULL, |
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men_z127_gpio->reg_base + MEN_Z127_GPIODR, |
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NULL, 0); |
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if (ret) |
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goto err_unmap; |
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men_z127_gpio->gc.set_config = men_z127_set_config; |
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ret = gpiochip_add_data(&men_z127_gpio->gc, men_z127_gpio); |
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if (ret) { |
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dev_err(dev, "failed to register MEN 16Z127 GPIO controller"); |
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goto err_unmap; |
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} |
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dev_info(dev, "MEN 16Z127 GPIO driver registered"); |
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return 0; |
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err_unmap: |
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iounmap(men_z127_gpio->reg_base); |
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err_release: |
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mcb_release_mem(men_z127_gpio->mem); |
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return ret; |
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} |
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static void men_z127_remove(struct mcb_device *mdev) |
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{ |
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struct men_z127_gpio *men_z127_gpio = mcb_get_drvdata(mdev); |
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gpiochip_remove(&men_z127_gpio->gc); |
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iounmap(men_z127_gpio->reg_base); |
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mcb_release_mem(men_z127_gpio->mem); |
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} |
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static const struct mcb_device_id men_z127_ids[] = { |
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{ .device = 0x7f }, |
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{ } |
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}; |
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MODULE_DEVICE_TABLE(mcb, men_z127_ids); |
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static struct mcb_driver men_z127_driver = { |
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.driver = { |
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.name = "z127-gpio", |
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}, |
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.probe = men_z127_probe, |
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.remove = men_z127_remove, |
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.id_table = men_z127_ids, |
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}; |
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module_mcb_driver(men_z127_driver); |
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MODULE_AUTHOR("Andreas Werner <[email protected]>"); |
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MODULE_DESCRIPTION("MEN 16z127 GPIO Controller"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("mcb:16z127"); |
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MODULE_IMPORT_NS(MCB);
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