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GPIO: Add driver for 74xx-ICs with MMIO access
This patch adds driver to support GPIO functionality for 74xx-compatible ICs with MMIO access. Compatible models include: 1 bit: 741G125 (Input), 741G74 (Output) 2 bits: 742G125 (Input), 7474 (Output) 4 bits: 74125 (Input), 74175 (Output) 6 bits: 74365 (Input), 74174 (Output) 8 bits: 74244 (Input), 74273 (Output) 16 bits: 741624 (Input), 7416374 (Output) Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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‎drivers/gpio/Kconfig

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@@ -112,6 +112,20 @@ config GPIO_MAX730X
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comment "Memory mapped GPIO drivers:"
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config GPIO_74XX_MMIO
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tristate "GPIO driver for 74xx-ICs with MMIO access"
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depends on OF_GPIO
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select GPIO_GENERIC
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help
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Say yes here to support GPIO functionality for 74xx-compatible ICs
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with MMIO access. Compatible models include:
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1 bit: 741G125 (Input), 741G74 (Output)
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2 bits: 742G125 (Input), 7474 (Output)
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4 bits: 74125 (Input), 74175 (Output)
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6 bits: 74365 (Input), 74174 (Output)
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8 bits: 74244 (Input), 74273 (Output)
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16 bits: 741624 (Input), 7416374 (Output)
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config GPIO_CLPS711X
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tristate "CLPS711X GPIO support"
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depends on ARCH_CLPS711X || COMPILE_TEST

‎drivers/gpio/Makefile

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@@ -13,6 +13,7 @@ obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o
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obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o
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obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o
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obj-$(CONFIG_GPIO_74XX_MMIO) += gpio-74xx-mmio.o
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obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o
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obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o
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obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o

‎drivers/gpio/gpio-74xx-mmio.c

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/*
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* 74xx MMIO GPIO driver
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*
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* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/err.h>
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#include <linux/gpio.h>
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#include <linux/module.h>
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#include <linux/of_device.h>
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#include <linux/basic_mmio_gpio.h>
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#include <linux/platform_device.h>
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#define MMIO_74XX_DIR_IN (0 << 8)
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#define MMIO_74XX_DIR_OUT (1 << 8)
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#define MMIO_74XX_BIT_CNT(x) ((x) & 0xff)
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struct mmio_74xx_gpio_priv {
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struct bgpio_chip bgc;
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unsigned flags;
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};
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static const struct of_device_id mmio_74xx_gpio_ids[] = {
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{
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.compatible = "ti,741g125",
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.data = (const void *)(MMIO_74XX_DIR_IN | 1),
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},
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{
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.compatible = "ti,742g125",
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.data = (const void *)(MMIO_74XX_DIR_IN | 2),
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},
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{
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.compatible = "ti,74125",
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.data = (const void *)(MMIO_74XX_DIR_IN | 4),
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},
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{
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.compatible = "ti,74365",
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.data = (const void *)(MMIO_74XX_DIR_IN | 6),
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},
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{
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.compatible = "ti,74244",
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.data = (const void *)(MMIO_74XX_DIR_IN | 8),
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},
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{
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.compatible = "ti,741624",
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.data = (const void *)(MMIO_74XX_DIR_IN | 16),
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},
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{
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.compatible = "ti,741g74",
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.data = (const void *)(MMIO_74XX_DIR_OUT | 1),
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},
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{
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.compatible = "ti,7474",
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.data = (const void *)(MMIO_74XX_DIR_OUT | 2),
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},
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{
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.compatible = "ti,74175",
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.data = (const void *)(MMIO_74XX_DIR_OUT | 4),
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},
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{
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.compatible = "ti,74174",
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.data = (const void *)(MMIO_74XX_DIR_OUT | 6),
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},
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{
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.compatible = "ti,74273",
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.data = (const void *)(MMIO_74XX_DIR_OUT | 8),
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},
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{
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.compatible = "ti,7416374",
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.data = (const void *)(MMIO_74XX_DIR_OUT | 16),
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},
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{ }
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};
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MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
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static inline struct mmio_74xx_gpio_priv *to_74xx_gpio(struct gpio_chip *gc)
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{
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struct bgpio_chip *bgc = to_bgpio_chip(gc);
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return container_of(bgc, struct mmio_74xx_gpio_priv, bgc);
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}
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static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
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{
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struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
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return (priv->flags & MMIO_74XX_DIR_OUT) ? GPIOF_DIR_OUT : GPIOF_DIR_IN;
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}
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static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
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{
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struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
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return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
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}
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static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
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{
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struct mmio_74xx_gpio_priv *priv = to_74xx_gpio(gc);
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if (priv->flags & MMIO_74XX_DIR_OUT) {
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gc->set(gc, gpio, val);
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return 0;
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}
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return -ENOTSUPP;
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}
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static int mmio_74xx_gpio_probe(struct platform_device *pdev)
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{
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const struct of_device_id *of_id =
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of_match_device(mmio_74xx_gpio_ids, &pdev->dev);
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struct mmio_74xx_gpio_priv *priv;
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struct resource *res;
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void __iomem *dat;
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int err;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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dat = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(dat))
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return PTR_ERR(dat);
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priv->flags = (unsigned)of_id->data;
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err = bgpio_init(&priv->bgc, &pdev->dev,
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DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
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dat, NULL, NULL, NULL, NULL, 0);
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if (err)
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return err;
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priv->bgc.gc.direction_input = mmio_74xx_dir_in;
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priv->bgc.gc.direction_output = mmio_74xx_dir_out;
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priv->bgc.gc.get_direction = mmio_74xx_get_direction;
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priv->bgc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
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priv->bgc.gc.owner = THIS_MODULE;
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platform_set_drvdata(pdev, priv);
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return gpiochip_add(&priv->bgc.gc);
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}
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static int mmio_74xx_gpio_remove(struct platform_device *pdev)
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{
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struct mmio_74xx_gpio_priv *priv = platform_get_drvdata(pdev);
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return bgpio_remove(&priv->bgc);
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}
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static struct platform_driver mmio_74xx_gpio_driver = {
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.driver = {
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.name = "74xx-mmio-gpio",
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.of_match_table = mmio_74xx_gpio_ids,
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},
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.probe = mmio_74xx_gpio_probe,
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.remove = mmio_74xx_gpio_remove,
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};
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module_platform_driver(mmio_74xx_gpio_driver);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
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MODULE_DESCRIPTION("74xx MMIO GPIO driver");

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