1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * 74xx MMIO GPIO driver
  4 *
  5 *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
  6 */
  7
  8#include <linux/bits.h>
  9#include <linux/err.h>
 10#include <linux/gpio/driver.h>
 11#include <linux/mod_devicetable.h>
 12#include <linux/module.h>
 13#include <linux/platform_device.h>
 14#include <linux/property.h>
 15
 16#define MMIO_74XX_DIR_IN	BIT(8)
 17#define MMIO_74XX_DIR_OUT	BIT(9)
 18#define MMIO_74XX_BIT_CNT(x)	((x) & GENMASK(7, 0))
 19
 20struct mmio_74xx_gpio_priv {
 21	struct gpio_chip	gc;
 22	unsigned		flags;
 23};
 24
 25static const struct of_device_id mmio_74xx_gpio_ids[] = {
 26	{
 27		.compatible	= "ti,741g125",
 28		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
 29	},
 30	{
 31		.compatible	= "ti,742g125",
 32		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
 33	},
 34	{
 35		.compatible	= "ti,74125",
 36		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
 37	},
 38	{
 39		.compatible	= "ti,74365",
 40		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
 41	},
 42	{
 43		.compatible	= "ti,74244",
 44		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
 45	},
 46	{
 47		.compatible	= "ti,741624",
 48		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
 49	},
 50	{
 51		.compatible	= "ti,741g74",
 52		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
 53	},
 54	{
 55		.compatible	= "ti,7474",
 56		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
 57	},
 58	{
 59		.compatible	= "ti,74175",
 60		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
 61	},
 62	{
 63		.compatible	= "ti,74174",
 64		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
 65	},
 66	{
 67		.compatible	= "ti,74273",
 68		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
 69	},
 70	{
 71		.compatible	= "ti,7416374",
 72		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
 73	},
 74	{ }
 75};
 76MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
 77
 78static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
 79{
 80	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
 81
 82	if (priv->flags & MMIO_74XX_DIR_OUT)
 83		return GPIO_LINE_DIRECTION_OUT;
 84
 85	return  GPIO_LINE_DIRECTION_IN;
 86}
 87
 88static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
 89{
 90	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
 91
 92	if (priv->flags & MMIO_74XX_DIR_IN)
 93		return 0;
 94
 95	return -ENOTSUPP;
 96}
 97
 98static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
 99{
100	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
101
102	if (priv->flags & MMIO_74XX_DIR_OUT) {
103		gc->set(gc, gpio, val);
104		return 0;
105	}
106
107	return -ENOTSUPP;
108}
109
110static int mmio_74xx_gpio_probe(struct platform_device *pdev)
111{
112	struct mmio_74xx_gpio_priv *priv;
113	void __iomem *dat;
114	int err;
115
116	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
117	if (!priv)
118		return -ENOMEM;
119
120	priv->flags = (uintptr_t)device_get_match_data(&pdev->dev);
121
122	dat = devm_platform_ioremap_resource(pdev, 0);
123	if (IS_ERR(dat))
124		return PTR_ERR(dat);
125
126	err = bgpio_init(&priv->gc, &pdev->dev,
127			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
128			 dat, NULL, NULL, NULL, NULL, 0);
129	if (err)
130		return err;
131
132	priv->gc.direction_input = mmio_74xx_dir_in;
133	priv->gc.direction_output = mmio_74xx_dir_out;
134	priv->gc.get_direction = mmio_74xx_get_direction;
135	priv->gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
136	priv->gc.owner = THIS_MODULE;
137
138	return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
139}
140
141static struct platform_driver mmio_74xx_gpio_driver = {
142	.driver	= {
143		.name		= "74xx-mmio-gpio",
144		.of_match_table	= mmio_74xx_gpio_ids,
145	},
146	.probe	= mmio_74xx_gpio_probe,
147};
148module_platform_driver(mmio_74xx_gpio_driver);
149
150MODULE_LICENSE("GPL");
151MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
152MODULE_DESCRIPTION("74xx MMIO GPIO driver");