gpio-74xx-mmio.c

  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/gpio/generic.h>
 12#include <linux/mod_devicetable.h>
 13#include <linux/module.h>
 14#include <linux/platform_device.h>
 15#include <linux/property.h>
 16
 17#define MMIO_74XX_DIR_IN	BIT(8)
 18#define MMIO_74XX_DIR_OUT	BIT(9)
 19#define MMIO_74XX_BIT_CNT(x)	((x) & GENMASK(7, 0))
 20
 21struct mmio_74xx_gpio_priv {
 22	struct gpio_generic_chip gen_gc;
 23	unsigned int flags;
 24};
 25
 26static const struct of_device_id mmio_74xx_gpio_ids[] = {
 27	{
 28		.compatible	= "ti,741g125",
 29		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
 30	},
 31	{
 32		.compatible	= "ti,742g125",
 33		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
 34	},
 35	{
 36		.compatible	= "ti,74125",
 37		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
 38	},
 39	{
 40		.compatible	= "ti,74365",
 41		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
 42	},
 43	{
 44		.compatible	= "ti,74244",
 45		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
 46	},
 47	{
 48		.compatible	= "ti,741624",
 49		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
 50	},
 51	{
 52		.compatible	= "ti,741g74",
 53		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
 54	},
 55	{
 56		.compatible	= "ti,7474",
 57		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
 58	},
 59	{
 60		.compatible	= "ti,74175",
 61		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
 62	},
 63	{
 64		.compatible	= "ti,74174",
 65		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
 66	},
 67	{
 68		.compatible	= "ti,74273",
 69		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
 70	},
 71	{
 72		.compatible	= "ti,7416374",
 73		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
 74	},
 75	{ }
 76};
 77MODULE_DEVICE_TABLE(of, mmio_74xx_gpio_ids);
 78
 79static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned offset)
 80{
 81	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
 82
 83	if (priv->flags & MMIO_74XX_DIR_OUT)
 84		return GPIO_LINE_DIRECTION_OUT;
 85
 86	return  GPIO_LINE_DIRECTION_IN;
 87}
 88
 89static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
 90{
 91	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
 92
 93	if (priv->flags & MMIO_74XX_DIR_IN)
 94		return 0;
 95
 96	return -ENOTSUPP;
 97}
 98
 99static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
100{
101	struct mmio_74xx_gpio_priv *priv = gpiochip_get_data(gc);
102
103	if (priv->flags & MMIO_74XX_DIR_OUT)
104		return gpio_generic_chip_set(&priv->gen_gc, gpio, val);
105
106	return -ENOTSUPP;
107}
108
109static int mmio_74xx_gpio_probe(struct platform_device *pdev)
110{
111	struct gpio_generic_chip_config config = { };
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	config.dev = &pdev->dev;
127	config.sz = DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8);
128	config.dat = dat;
129
130	err = gpio_generic_chip_init(&priv->gen_gc, &config);
131	if (err)
132		return err;
133
134	priv->gen_gc.gc.direction_input = mmio_74xx_dir_in;
135	priv->gen_gc.gc.direction_output = mmio_74xx_dir_out;
136	priv->gen_gc.gc.get_direction = mmio_74xx_get_direction;
137	priv->gen_gc.gc.ngpio = MMIO_74XX_BIT_CNT(priv->flags);
138	priv->gen_gc.gc.owner = THIS_MODULE;
139
140	return devm_gpiochip_add_data(&pdev->dev, &priv->gen_gc.gc, priv);
141}
142
143static struct platform_driver mmio_74xx_gpio_driver = {
144	.driver	= {
145		.name		= "74xx-mmio-gpio",
146		.of_match_table	= mmio_74xx_gpio_ids,
147	},
148	.probe	= mmio_74xx_gpio_probe,
149};
150module_platform_driver(mmio_74xx_gpio_driver);
151
152MODULE_LICENSE("GPL");
153MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
154MODULE_DESCRIPTION("74xx MMIO GPIO driver");