[mirror_ubuntu-hirsute-kernel.git] / drivers / gpio / gpio-amdpt.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * AMD Promontory GPIO driver
 *
 * Copyright (C) 2015 ASMedia Technology Inc.
 * Author: YD Tseng <yd_tseng@asmedia.com.tw>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/spinlock.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>

#define PT_TOTAL_GPIO 8

/* PCI-E MMIO register offsets */
#define PT_DIRECTION_REG   0x00
#define PT_INPUTDATA_REG   0x04
#define PT_OUTPUTDATA_REG  0x08
#define PT_CLOCKRATE_REG   0x0C
#define PT_SYNC_REG        0x28

struct pt_gpio_chip {
	struct gpio_chip         gc;
	void __iomem             *reg_base;
};

static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
{
	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
	unsigned long flags;
	u32 using_pins;

	dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);

	spin_lock_irqsave(&gc->bgpio_lock, flags);

	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	if (using_pins & BIT(offset)) {
		dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",
			 offset);
		spin_unlock_irqrestore(&gc->bgpio_lock, flags);
		return -EINVAL;
	}

	writel(using_pins | BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);

	spin_unlock_irqrestore(&gc->bgpio_lock, flags);

	return 0;
}

static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
{
	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
	unsigned long flags;
	u32 using_pins;

	spin_lock_irqsave(&gc->bgpio_lock, flags);

	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	using_pins &= ~BIT(offset);
	writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);

	spin_unlock_irqrestore(&gc->bgpio_lock, flags);

	dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset);
}

static int pt_gpio_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct acpi_device *acpi_dev;
	acpi_handle handle = ACPI_HANDLE(dev);
	struct pt_gpio_chip *pt_gpio;
	int ret = 0;

	if (acpi_bus_get_device(handle, &acpi_dev)) {
		dev_err(dev, "PT GPIO device node not found\n");
		return -ENODEV;
	}

	pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);
	if (!pt_gpio)
		return -ENOMEM;

	pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(pt_gpio->reg_base)) {
		dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n");
		return PTR_ERR(pt_gpio->reg_base);
	}

	ret = bgpio_init(&pt_gpio->gc, dev, 4,
			 pt_gpio->reg_base + PT_INPUTDATA_REG,
			 pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL,
			 pt_gpio->reg_base + PT_DIRECTION_REG, NULL,
			 BGPIOF_READ_OUTPUT_REG_SET);
	if (ret) {
		dev_err(dev, "bgpio_init failed\n");
		return ret;
	}

	pt_gpio->gc.owner            = THIS_MODULE;
	pt_gpio->gc.request          = pt_gpio_request;
	pt_gpio->gc.free             = pt_gpio_free;
	pt_gpio->gc.ngpio            = PT_TOTAL_GPIO;
#if defined(CONFIG_OF_GPIO)
	pt_gpio->gc.of_node          = dev->of_node;
#endif
	ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);
	if (ret) {
		dev_err(dev, "Failed to register GPIO lib\n");
		return ret;
	}

	platform_set_drvdata(pdev, pt_gpio);

	/* initialize register setting */
	writel(0, pt_gpio->reg_base + PT_SYNC_REG);
	writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);

	dev_dbg(dev, "PT GPIO driver loaded\n");
	return ret;
}

static int pt_gpio_remove(struct platform_device *pdev)
{
	struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);

	gpiochip_remove(&pt_gpio->gc);

	return 0;
}

static const struct acpi_device_id pt_gpio_acpi_match[] = {
	{ "AMDF030", 0 },
	{ "AMDIF030", 0 },
	{ },
};
MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);

static struct platform_driver pt_gpio_driver = {
	.driver = {
		.name = "pt-gpio",
		.acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),
	},
	.probe = pt_gpio_probe,
	.remove = pt_gpio_remove,
};

module_platform_driver(pt_gpio_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");
MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
Commit	Line	Data
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
6057d40f YT	2	/*
	3	* AMD Promontory GPIO driver
	4	*
	5	* Copyright (C) 2015 ASMedia Technology Inc.
	6	* Author: YD Tseng <yd_tseng@asmedia.com.tw>
6057d40f YT	7	*/
	8
	9	#include <linux/kernel.h>
	10	#include <linux/module.h>
	11	#include <linux/gpio/driver.h>
	12	#include <linux/spinlock.h>
	13	#include <linux/acpi.h>
	14	#include <linux/platform_device.h>
	15
	16	#define PT_TOTAL_GPIO 8
	17
	18	/* PCI-E MMIO register offsets */
	19	#define PT_DIRECTION_REG 0x00
	20	#define PT_INPUTDATA_REG 0x04
	21	#define PT_OUTPUTDATA_REG 0x08
	22	#define PT_CLOCKRATE_REG 0x0C
	23	#define PT_SYNC_REG 0x28
	24
	25	struct pt_gpio_chip {
	26	struct gpio_chip gc;
	27	void __iomem *reg_base;
6057d40f YT	28	};
6057d40f YT	29
6057d40f YT	30	static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
6057d40f YT	31	{
fb722887	32	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
6057d40f YT	33	unsigned long flags;
	34	u32 using_pins;
	35
58383c78	36	dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);
6057d40f	37
574b782e	38	spin_lock_irqsave(&gc->bgpio_lock, flags);
6057d40f YT	39
	40	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	41	if (using_pins & BIT(offset)) {
58383c78 LW	42	dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",
58383c78 LW	43	offset);
574b782e	44	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
6057d40f YT	45	return -EINVAL;
	46	}
	47
	48	writel(using_pins \| BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);
	49
574b782e	50	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
6057d40f YT	51
	52	return 0;
	53	}
	54
	55	static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
	56	{
fb722887	57	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
6057d40f YT	58	unsigned long flags;
	59	u32 using_pins;
	60
574b782e	61	spin_lock_irqsave(&gc->bgpio_lock, flags);
6057d40f YT	62
	63	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	64	using_pins &= ~BIT(offset);
	65	writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);
	66
574b782e	67	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
6057d40f	68
58383c78	69	dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset);
6057d40f YT	70	}
6057d40f YT	71
6057d40f YT	72	static int pt_gpio_probe(struct platform_device *pdev)
	73	{
	74	struct device *dev = &pdev->dev;
	75	struct acpi_device *acpi_dev;
	76	acpi_handle handle = ACPI_HANDLE(dev);
	77	struct pt_gpio_chip *pt_gpio;
6057d40f YT	78	int ret = 0;
	79
	80	if (acpi_bus_get_device(handle, &acpi_dev)) {
	81	dev_err(dev, "PT GPIO device node not found\n");
	82	return -ENODEV;
	83	}
	84
	85	pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);
	86	if (!pt_gpio)
	87	return -ENOMEM;
	88
bb17a27a	89	pt_gpio->reg_base = devm_platform_ioremap_resource(pdev, 0);
6057d40f	90	if (IS_ERR(pt_gpio->reg_base)) {
2b3fee36	91	dev_err(dev, "Failed to map MMIO resource for PT GPIO.\n");
6057d40f YT	92	return PTR_ERR(pt_gpio->reg_base);
	93	}
	94
574b782e AL	95	ret = bgpio_init(&pt_gpio->gc, dev, 4,
	96	pt_gpio->reg_base + PT_INPUTDATA_REG,
	97	pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL,
	98	pt_gpio->reg_base + PT_DIRECTION_REG, NULL,
	99	BGPIOF_READ_OUTPUT_REG_SET);
	100	if (ret) {
2b3fee36	101	dev_err(dev, "bgpio_init failed\n");
574b782e AL	102	return ret;
574b782e AL	103	}
6057d40f	104
6057d40f	105	pt_gpio->gc.owner = THIS_MODULE;
6057d40f YT	106	pt_gpio->gc.request = pt_gpio_request;
6057d40f YT	107	pt_gpio->gc.free = pt_gpio_free;
6057d40f YT	108	pt_gpio->gc.ngpio = PT_TOTAL_GPIO;
6057d40f YT	109	#if defined(CONFIG_OF_GPIO)
2b3fee36	110	pt_gpio->gc.of_node = dev->of_node;
6057d40f	111	#endif
fb722887	112	ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);
6057d40f	113	if (ret) {
2b3fee36	114	dev_err(dev, "Failed to register GPIO lib\n");
6057d40f YT	115	return ret;
	116	}
	117
	118	platform_set_drvdata(pdev, pt_gpio);
	119
	120	/* initialize register setting */
	121	writel(0, pt_gpio->reg_base + PT_SYNC_REG);
	122	writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);
	123
2b3fee36	124	dev_dbg(dev, "PT GPIO driver loaded\n");
6057d40f YT	125	return ret;
	126	}
	127
	128	static int pt_gpio_remove(struct platform_device *pdev)
	129	{
	130	struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);
	131
	132	gpiochip_remove(&pt_gpio->gc);
	133
	134	return 0;
	135	}
	136
	137	static const struct acpi_device_id pt_gpio_acpi_match[] = {
	138	{ "AMDF030", 0 },
ca27379f	139	{ "AMDIF030", 0 },
6057d40f YT	140	{ },
	141	};
	142	MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);
	143
	144	static struct platform_driver pt_gpio_driver = {
	145	.driver = {
	146	.name = "pt-gpio",
	147	.acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),
	148	},
	149	.probe = pt_gpio_probe,
	150	.remove = pt_gpio_remove,
	151	};
	152
	153	module_platform_driver(pt_gpio_driver);
	154
	155	MODULE_LICENSE("GPL");
	156	MODULE_AUTHOR("YD Tseng <yd_tseng@asmedia.com.tw>");
	157	MODULE_DESCRIPTION("AMD Promontory GPIO Driver");