[linux.git] / drivers / gpio / gpio-amdpt.c

/*
 * AMD Promontory GPIO driver
 *
 * Copyright (C) 2015 ASMedia Technology Inc.
 * Author: YD Tseng <[email protected]>
 *
 * 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.
 */

#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;
	struct resource *res_mem;
	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;

	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res_mem) {
		dev_err(&pdev->dev, "Failed to get MMIO resource for PT GPIO.\n");
		return -EINVAL;
	}
	pt_gpio->reg_base = devm_ioremap_resource(dev, res_mem);
	if (IS_ERR(pt_gpio->reg_base)) {
		dev_err(&pdev->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(&pdev->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          = pdev->dev.of_node;
#endif
	ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);
	if (ret) {
		dev_err(&pdev->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(&pdev->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 <[email protected]>");
MODULE_DESCRIPTION("AMD Promontory GPIO Driver");
Commit	Line	Data
6057d40f YT	1	/*
	2	* AMD Promontory GPIO driver
	3	*
	4	* Copyright (C) 2015 ASMedia Technology Inc.
	5	* Author: YD Tseng <[email protected]>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*/
	11
	12	#include <linux/kernel.h>
	13	#include <linux/module.h>
	14	#include <linux/gpio/driver.h>
	15	#include <linux/spinlock.h>
	16	#include <linux/acpi.h>
	17	#include <linux/platform_device.h>
	18
	19	#define PT_TOTAL_GPIO 8
	20
	21	/* PCI-E MMIO register offsets */
	22	#define PT_DIRECTION_REG 0x00
	23	#define PT_INPUTDATA_REG 0x04
	24	#define PT_OUTPUTDATA_REG 0x08
	25	#define PT_CLOCKRATE_REG 0x0C
	26	#define PT_SYNC_REG 0x28
	27
	28	struct pt_gpio_chip {
	29	struct gpio_chip gc;
	30	void __iomem *reg_base;
6057d40f YT	31	};
6057d40f YT	32
6057d40f YT	33	static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)
6057d40f YT	34	{
fb722887	35	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
6057d40f YT	36	unsigned long flags;
	37	u32 using_pins;
	38
58383c78	39	dev_dbg(gc->parent, "pt_gpio_request offset=%x\n", offset);
6057d40f	40
574b782e	41	spin_lock_irqsave(&gc->bgpio_lock, flags);
6057d40f YT	42
	43	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	44	if (using_pins & BIT(offset)) {
58383c78 LW	45	dev_warn(gc->parent, "PT GPIO pin %x reconfigured\n",
58383c78 LW	46	offset);
574b782e	47	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
6057d40f YT	48	return -EINVAL;
	49	}
	50
	51	writel(using_pins \| BIT(offset), pt_gpio->reg_base + PT_SYNC_REG);
	52
574b782e	53	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
6057d40f YT	54
	55	return 0;
	56	}
	57
	58	static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)
	59	{
fb722887	60	struct pt_gpio_chip *pt_gpio = gpiochip_get_data(gc);
6057d40f YT	61	unsigned long flags;
	62	u32 using_pins;
	63
574b782e	64	spin_lock_irqsave(&gc->bgpio_lock, flags);
6057d40f YT	65
	66	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);
	67	using_pins &= ~BIT(offset);
	68	writel(using_pins, pt_gpio->reg_base + PT_SYNC_REG);
	69
574b782e	70	spin_unlock_irqrestore(&gc->bgpio_lock, flags);
6057d40f	71
58383c78	72	dev_dbg(gc->parent, "pt_gpio_free offset=%x\n", offset);
6057d40f YT	73	}
6057d40f YT	74
6057d40f YT	75	static int pt_gpio_probe(struct platform_device *pdev)
	76	{
	77	struct device *dev = &pdev->dev;
	78	struct acpi_device *acpi_dev;
	79	acpi_handle handle = ACPI_HANDLE(dev);
	80	struct pt_gpio_chip *pt_gpio;
	81	struct resource *res_mem;
	82	int ret = 0;
	83
	84	if (acpi_bus_get_device(handle, &acpi_dev)) {
	85	dev_err(dev, "PT GPIO device node not found\n");
	86	return -ENODEV;
	87	}
	88
	89	pt_gpio = devm_kzalloc(dev, sizeof(struct pt_gpio_chip), GFP_KERNEL);
	90	if (!pt_gpio)
	91	return -ENOMEM;
	92
	93	res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	94	if (!res_mem) {
	95	dev_err(&pdev->dev, "Failed to get MMIO resource for PT GPIO.\n");
	96	return -EINVAL;
	97	}
	98	pt_gpio->reg_base = devm_ioremap_resource(dev, res_mem);
	99	if (IS_ERR(pt_gpio->reg_base)) {
	100	dev_err(&pdev->dev, "Failed to map MMIO resource for PT GPIO.\n");
	101	return PTR_ERR(pt_gpio->reg_base);
	102	}
	103
574b782e AL	104	ret = bgpio_init(&pt_gpio->gc, dev, 4,
	105	pt_gpio->reg_base + PT_INPUTDATA_REG,
	106	pt_gpio->reg_base + PT_OUTPUTDATA_REG, NULL,
	107	pt_gpio->reg_base + PT_DIRECTION_REG, NULL,
	108	BGPIOF_READ_OUTPUT_REG_SET);
	109	if (ret) {
	110	dev_err(&pdev->dev, "bgpio_init failed\n");
	111	return ret;
	112	}
6057d40f	113
6057d40f	114	pt_gpio->gc.owner = THIS_MODULE;
6057d40f YT	115	pt_gpio->gc.request = pt_gpio_request;
6057d40f YT	116	pt_gpio->gc.free = pt_gpio_free;
6057d40f YT	117	pt_gpio->gc.ngpio = PT_TOTAL_GPIO;
	118	#if defined(CONFIG_OF_GPIO)
	119	pt_gpio->gc.of_node = pdev->dev.of_node;
	120	#endif
fb722887	121	ret = gpiochip_add_data(&pt_gpio->gc, pt_gpio);
6057d40f YT	122	if (ret) {
	123	dev_err(&pdev->dev, "Failed to register GPIO lib\n");
	124	return ret;
	125	}
	126
	127	platform_set_drvdata(pdev, pt_gpio);
	128
	129	/* initialize register setting */
	130	writel(0, pt_gpio->reg_base + PT_SYNC_REG);
	131	writel(0, pt_gpio->reg_base + PT_CLOCKRATE_REG);
	132
	133	dev_dbg(&pdev->dev, "PT GPIO driver loaded\n");
	134	return ret;
	135	}
	136
	137	static int pt_gpio_remove(struct platform_device *pdev)
	138	{
	139	struct pt_gpio_chip *pt_gpio = platform_get_drvdata(pdev);
	140
	141	gpiochip_remove(&pt_gpio->gc);
	142
	143	return 0;
	144	}
	145
	146	static const struct acpi_device_id pt_gpio_acpi_match[] = {
	147	{ "AMDF030", 0 },
ca27379f	148	{ "AMDIF030", 0 },
6057d40f YT	149	{ },
	150	};
	151	MODULE_DEVICE_TABLE(acpi, pt_gpio_acpi_match);
	152
	153	static struct platform_driver pt_gpio_driver = {
	154	.driver = {
	155	.name = "pt-gpio",
	156	.acpi_match_table = ACPI_PTR(pt_gpio_acpi_match),
	157	},
	158	.probe = pt_gpio_probe,
	159	.remove = pt_gpio_remove,
	160	};
	161
	162	module_platform_driver(pt_gpio_driver);
	163
	164	MODULE_LICENSE("GPL");
	165	MODULE_AUTHOR("YD Tseng <[email protected]>");
	166	MODULE_DESCRIPTION("AMD Promontory GPIO Driver");