[PATCH 4/9] gpio: add driver for 74xx-ICs with MMIO access

[Antony Pavlov <antonynpavlov@gmail.com>]

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: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
---
 drivers/gpio/Kconfig          |  14 +++
 drivers/gpio/Makefile         |   1 +
 drivers/gpio/gpio-74xx-mmio.c | 170 ++++++++++++++++++++++++++++++++++
 3 files changed, 185 insertions(+)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 261b6e6662..59cb00ff22 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -21,6 +21,20 @@ config GPIO_74164
 	  shift registers. This driver can be used to provide access
 	  to more gpio outputs.
 
+config GPIO_74XX_MMIO
+	tristate "GPIO driver for 74xx-ICs with MMIO access"
+	depends on OFDEVICE
+	select GPIO_GENERIC
+	help
+	  Say yes here 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)
+
 config GPIO_CLPS711X
 	bool "GPIO support for CLPS711X"
 	depends on ARCH_CLPS711X || COMPILE_TEST
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 77dcf58f64..7ece8621d2 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_GPIOLIB)		+= gpiolib.o
 
 obj-$(CONFIG_GPIO_74164)	+= gpio-74164.o
+obj-$(CONFIG_GPIO_74XX_MMIO)	+= gpio-74xx-mmio.o
 obj-$(CONFIG_MACH_MIPS_ATH79)	+= gpio-ath79.o
 obj-$(CONFIG_GPIO_DAVINCI)	+= gpio-davinci.o
 obj-$(CONFIG_GPIO_CLPS711X)	+= gpio-clps711x.o
diff --git a/drivers/gpio/gpio-74xx-mmio.c b/drivers/gpio/gpio-74xx-mmio.c
new file mode 100644
index 0000000000..2c05d022f1
--- /dev/null
+++ b/drivers/gpio/gpio-74xx-mmio.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 74xx MMIO GPIO driver
+ *
+ *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * Ported to barebox from linux-v5.4-rc6
+ *   Copyright (C) 2019-2021 Antony Pavlov <antonynpavlov@gmail.com>
+ *
+ */
+
+#include <common.h>
+#include <driver.h>
+#include <errno.h>
+#include <gpio.h>
+#include <init.h>
+#include <io.h>
+#include <malloc.h>
+
+#include <linux/err.h>
+#include <linux/basic_mmio_gpio.h>
+
+#define MMIO_74XX_DIR_IN	(0 << 8)
+#define MMIO_74XX_DIR_OUT	(1 << 8)
+#define MMIO_74XX_BIT_CNT(x)	((x) & 0xff)
+
+struct mmio_74xx_gpio_priv {
+	struct bgpio_chip	bgc;
+	unsigned int		flags;
+};
+
+static const struct of_device_id mmio_74xx_gpio_ids[] = {
+	{
+		.compatible	= "ti,741g125",
+		.data		= (const void *)(MMIO_74XX_DIR_IN | 1),
+	},
+	{
+		.compatible	= "ti,742g125",
+		.data		= (const void *)(MMIO_74XX_DIR_IN | 2),
+	},
+	{
+		.compatible	= "ti,74125",
+		.data		= (const void *)(MMIO_74XX_DIR_IN | 4),
+	},
+	{
+		.compatible	= "ti,74365",
+		.data		= (const void *)(MMIO_74XX_DIR_IN | 6),
+	},
+	{
+		.compatible	= "ti,74244",
+		.data		= (const void *)(MMIO_74XX_DIR_IN | 8),
+	},
+	{
+		.compatible	= "ti,741624",
+		.data		= (const void *)(MMIO_74XX_DIR_IN | 16),
+	},
+	{
+		.compatible	= "ti,741g74",
+		.data		= (const void *)(MMIO_74XX_DIR_OUT | 1),
+	},
+	{
+		.compatible	= "ti,7474",
+		.data		= (const void *)(MMIO_74XX_DIR_OUT | 2),
+	},
+	{
+		.compatible	= "ti,74175",
+		.data		= (const void *)(MMIO_74XX_DIR_OUT | 4),
+	},
+	{
+		.compatible	= "ti,74174",
+		.data		= (const void *)(MMIO_74XX_DIR_OUT | 6),
+	},
+	{
+		.compatible	= "ti,74273",
+		.data		= (const void *)(MMIO_74XX_DIR_OUT | 8),
+	},
+	{
+		.compatible	= "ti,7416374",
+		.data		= (const void *)(MMIO_74XX_DIR_OUT | 16),
+	},
+	{ }
+};
+
+static inline
+struct mmio_74xx_gpio_priv *to_mmio_74xx_gpio_priv(struct gpio_chip *gc)
+{
+	struct bgpio_chip *bgc =
+		container_of(gc, struct bgpio_chip, gc);
+
+	return container_of(bgc, struct mmio_74xx_gpio_priv, bgc);
+}
+
+static int mmio_74xx_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	struct mmio_74xx_gpio_priv *priv = to_mmio_74xx_gpio_priv(gc);
+
+	if (priv->flags & MMIO_74XX_DIR_OUT)
+		return GPIOF_DIR_OUT;
+
+	return GPIOF_DIR_IN;
+}
+
+static int mmio_74xx_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+	struct mmio_74xx_gpio_priv *priv = to_mmio_74xx_gpio_priv(gc);
+
+	return (priv->flags & MMIO_74XX_DIR_OUT) ? -ENOTSUPP : 0;
+}
+
+static int mmio_74xx_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+	struct mmio_74xx_gpio_priv *priv = to_mmio_74xx_gpio_priv(gc);
+
+	if (priv->flags & MMIO_74XX_DIR_OUT) {
+		gc->ops->set(gc, gpio, val);
+		return 0;
+	}
+
+	return -ENOTSUPP;
+}
+
+static int mmio_74xx_gpio_probe(struct device_d *dev)
+{
+	struct mmio_74xx_gpio_priv *priv;
+	void __iomem *dat;
+	int err;
+	struct gpio_chip *gc;
+
+	priv = xzalloc(sizeof(*priv));
+
+	err = dev_get_drvdata(dev, (const void **)&priv->flags);
+	if (err)
+		return err;
+
+	dat = dev_request_mem_region(dev, 0);
+	if (IS_ERR(dat))
+		return PTR_ERR(dat);
+
+	err = bgpio_init(&priv->bgc, dev,
+			 DIV_ROUND_UP(MMIO_74XX_BIT_CNT(priv->flags), 8),
+			 dat, NULL, NULL, NULL, NULL, 0);
+	if (err)
+		return err;
+
+	gc = &priv->bgc.gc;
+	gc->ops->direction_input = mmio_74xx_dir_in;
+	gc->ops->direction_output = mmio_74xx_dir_out;
+	gc->ops->get_direction = mmio_74xx_get_direction;
+	gc->ngpio = MMIO_74XX_BIT_CNT(priv->flags);
+
+	dev->priv = priv;
+
+	return gpiochip_add(gc);
+}
+
+static struct driver_d mmio_74xx_gpio_driver = {
+	.name = "74xx-mmio-gpio",
+	.of_compatible	= DRV_OF_COMPAT(mmio_74xx_gpio_ids),
+	.probe = mmio_74xx_gpio_probe,
+};
+
+static int mmio_74xx_gpio_init(void)
+{
+	return platform_driver_register(&mmio_74xx_gpio_driver);
+}
+coredevice_initcall(mmio_74xx_gpio_init);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("74xx MMIO GPIO driver");
-- 
2.31.1


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