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Commit 29cbf458 authored by Feng Kan's avatar Feng Kan Committed by Linus Walleij
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gpio: Add APM X-Gene SoC GPIO controller support



Add APM X-Gene SoC gpio controller driver.

Signed-off-by: default avatarFeng Kan <fkan@apm.com>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent e8126753
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+9 −0
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@@ -334,6 +334,15 @@ config GPIO_TZ1090_PDC
	help
	  Say yes here to support Toumaz Xenif TZ1090 PDC GPIOs.

config GPIO_XGENE
	bool "APM X-Gene GPIO controller support"
	depends on ARM64 && OF_GPIO
	help
	  This driver is to support the GPIO block within the APM X-Gene SoC
	  platform's generic flash controller. The GPIO pins are muxed with
	  the generic flash controller's address and data pins. Say yes
	  here to enable the GFC GPIO functionality.

config GPIO_XILINX
	bool "Xilinx GPIO support"
	depends on PPC_OF || MICROBLAZE || ARCH_ZYNQ
+1 −0
Original line number Diff line number Diff line
@@ -101,6 +101,7 @@ obj-$(CONFIG_GPIO_VX855) += gpio-vx855.o
obj-$(CONFIG_GPIO_WM831X)	+= gpio-wm831x.o
obj-$(CONFIG_GPIO_WM8350)	+= gpio-wm8350.o
obj-$(CONFIG_GPIO_WM8994)	+= gpio-wm8994.o
obj-$(CONFIG_GPIO_XGENE)	+= gpio-xgene.o
obj-$(CONFIG_GPIO_XILINX)	+= gpio-xilinx.o
obj-$(CONFIG_GPIO_XTENSA)	+= gpio-xtensa.o
obj-$(CONFIG_GPIO_ZEVIO)	+= gpio-zevio.o
+250 −0
Original line number Diff line number Diff line
/*
 * AppliedMicro X-Gene SoC GPIO Driver
 *
 * Copyright (c) 2014, Applied Micro Circuits Corporation
 * Author: Feng Kan <fkan@apm.com>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/types.h>
#include <linux/bitops.h>

#define GPIO_SET_DR_OFFSET	0x0C
#define GPIO_DATA_OFFSET	0x14
#define GPIO_BANK_STRIDE	0x0C

#define XGENE_GPIOS_PER_BANK	16
#define XGENE_MAX_GPIO_BANKS	3
#define XGENE_MAX_GPIOS		(XGENE_GPIOS_PER_BANK * XGENE_MAX_GPIO_BANKS)

#define GPIO_BIT_OFFSET(x)	(x % XGENE_GPIOS_PER_BANK)
#define GPIO_BANK_OFFSET(x)	((x / XGENE_GPIOS_PER_BANK) * GPIO_BANK_STRIDE)

struct xgene_gpio;

struct xgene_gpio {
	struct gpio_chip	chip;
	void __iomem		*base;
	spinlock_t		lock;
#ifdef CONFIG_PM
	u32			set_dr_val[XGENE_MAX_GPIO_BANKS];
#endif
};

static inline struct xgene_gpio *to_xgene_gpio(struct gpio_chip *chip)
{
	return container_of(chip, struct xgene_gpio, chip);
}

static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
	struct xgene_gpio *chip = to_xgene_gpio(gc);
	unsigned long bank_offset;
	u32 bit_offset;

	bank_offset = GPIO_DATA_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);
	return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
}

static void __xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
	struct xgene_gpio *chip = to_xgene_gpio(gc);
	unsigned long bank_offset;
	u32 setval, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset) + XGENE_GPIOS_PER_BANK;

	setval = ioread32(chip->base + bank_offset);
	if (val)
		setval |= BIT(bit_offset);
	else
		setval &= ~BIT(bit_offset);
	iowrite32(setval, chip->base + bank_offset);
}

static void xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
	struct xgene_gpio *chip = to_xgene_gpio(gc);
	unsigned long flags;

	spin_lock_irqsave(&chip->lock, flags);
	__xgene_gpio_set(gc, offset, val);
	spin_unlock_irqrestore(&chip->lock, flags);
}

static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
{
	struct xgene_gpio *chip = to_xgene_gpio(gc);
	unsigned long flags, bank_offset;
	u32 dirval, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);

	spin_lock_irqsave(&chip->lock, flags);

	dirval = ioread32(chip->base + bank_offset);
	dirval |= BIT(bit_offset);
	iowrite32(dirval, chip->base + bank_offset);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

static int xgene_gpio_dir_out(struct gpio_chip *gc,
					unsigned int offset, int val)
{
	struct xgene_gpio *chip = to_xgene_gpio(gc);
	unsigned long flags, bank_offset;
	u32 dirval, bit_offset;

	bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
	bit_offset = GPIO_BIT_OFFSET(offset);

	spin_lock_irqsave(&chip->lock, flags);

	dirval = ioread32(chip->base + bank_offset);
	dirval &= ~BIT(bit_offset);
	iowrite32(dirval, chip->base + bank_offset);
	__xgene_gpio_set(gc, offset, val);

	spin_unlock_irqrestore(&chip->lock, flags);

	return 0;
}

#ifdef CONFIG_PM
static int xgene_gpio_suspend(struct device *dev)
{
	struct xgene_gpio *gpio = dev_get_drvdata(dev);
	unsigned long bank_offset;
	unsigned int bank;

	for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
		bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
		gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset);
	}
	return 0;
}

static int xgene_gpio_resume(struct device *dev)
{
	struct xgene_gpio *gpio = dev_get_drvdata(dev);
	unsigned long bank_offset;
	unsigned int bank;

	for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
		bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
		iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset);
	}
	return 0;
}

static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);
#define XGENE_GPIO_PM_OPS	(&xgene_gpio_pm)
#else
#define XGENE_GPIO_PM_OPS	NULL
#endif

static int xgene_gpio_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct xgene_gpio *gpio;
	int err = 0;

	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
	if (!gpio) {
		err = -ENOMEM;
		goto err;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	gpio->base = devm_ioremap_nocache(&pdev->dev, res->start,
							resource_size(res));
	if (IS_ERR(gpio->base)) {
		err = PTR_ERR(gpio->base);
		goto err;
	}

	gpio->chip.ngpio = XGENE_MAX_GPIOS;

	gpio->chip.dev = &pdev->dev;
	gpio->chip.direction_input = xgene_gpio_dir_in;
	gpio->chip.direction_output = xgene_gpio_dir_out;
	gpio->chip.get = xgene_gpio_get;
	gpio->chip.set = xgene_gpio_set;
	gpio->chip.label = dev_name(&pdev->dev);
	gpio->chip.base = -1;

	platform_set_drvdata(pdev, gpio);

	err = gpiochip_add(&gpio->chip);
	if (err) {
		dev_err(&pdev->dev,
			"failed to register gpiochip.\n");
		goto err;
	}

	dev_info(&pdev->dev, "X-Gene GPIO driver registered.\n");
	return 0;
err:
	dev_err(&pdev->dev, "X-Gene GPIO driver registration failed.\n");
	return err;
}

static int xgene_gpio_remove(struct platform_device *pdev)
{
	struct xgene_gpio *gpio = platform_get_drvdata(pdev);
	int ret = 0;

	ret = gpiochip_remove(&gpio->chip);
	if (ret)
		dev_err(&pdev->dev, "unable to remove gpio_chip.\n");
	return ret;
}

#ifdef CONFIG_OF
static const struct of_device_id xgene_gpio_of_match[] = {
	{ .compatible = "apm,xgene-gpio", },
	{},
};
MODULE_DEVICE_TABLE(of, xgene_gpio_of_match);
#endif

static struct platform_driver xgene_gpio_driver = {
	.driver = {
		.name = "xgene-gpio",
		.owner = THIS_MODULE,
		.of_match_table = xgene_gpio_of_match,
		.pm     = XGENE_GPIO_PM_OPS,
	},
	.probe = xgene_gpio_probe,
	.remove = xgene_gpio_remove,
};

module_platform_driver(xgene_gpio_driver);

MODULE_AUTHOR("Feng Kan <fkan@apm.com>");
MODULE_DESCRIPTION("APM X-Gene GPIO driver");
MODULE_LICENSE("GPL");