Commit 6057d40f authored by YD Tseng's avatar YD Tseng Committed by Linus Walleij
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gpio: driver for AMD Promontory 



This patch adds a new GPIO driver for AMD Promontory chip.

This GPIO controller is enumerated by ACPI and the ACPI compliant
hardware ID is AMDF030.

Change history:

v2: 1. fix coding style
    2. registers renaming
v3: 1. change include file
    2. fix coding style
    3. remove module_init/exit, add module_platform_driver
    4. remove MODULE_ALIAS
v4: 1. change TOTAL_GPIO_PINS to PT_TOTAL_GPIO
    2. remove PCI dependency in Kconfig
    3. fix subject line

Signed-off-by: default avatarYD Tseng <Yd_Tseng@asmedia.com.tw>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
parent 83ea24fd

drivers/gpio/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -119,6 +119,13 @@ config GPIO_ALTERA 


	  If driver is built as a module it will be called gpio-altera.



config GPIO_AMDPT

	tristate "AMD Promontory GPIO support"

	depends on ACPI

	help

	  driver for GPIO functionality on Promontory IOHub

	  Require ACPI ASL code to enumerate as a platform device.



config GPIO_BCM_KONA

	bool "Broadcom Kona GPIO"

	depends on OF_GPIO && (ARCH_BCM_MOBILE || COMPILE_TEST)

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o 
obj-$(CONFIG_GPIO_ADP5588)	+= gpio-adp5588.o

obj-$(CONFIG_GPIO_ALTERA)  	+= gpio-altera.o

obj-$(CONFIG_GPIO_AMD8111)	+= gpio-amd8111.o

obj-$(CONFIG_GPIO_AMDPT)	+= gpio-amdpt.o

obj-$(CONFIG_GPIO_ARIZONA)	+= gpio-arizona.o

obj-$(CONFIG_ATH79)		+= gpio-ath79.o

obj-$(CONFIG_GPIO_BCM_KONA)	+= gpio-bcm-kona.o

drivers/gpio/gpio-amdpt.c

0 → 100644
+261 −0
Original line number Diff line number Diff line 
/*

 * AMD Promontory GPIO driver

 *

 * Copyright (C) 2015 ASMedia Technology Inc.

 * Author: YD Tseng <yd_tseng@asmedia.com.tw>

 *

 * 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;

	spinlock_t               lock;

};



#define to_pt_gpio(c)	container_of(c, struct pt_gpio_chip, gc)



static int pt_gpio_request(struct gpio_chip *gc, unsigned offset)

{

	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);

	unsigned long flags;

	u32 using_pins;



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



	spin_lock_irqsave(&pt_gpio->lock, flags);



	using_pins = readl(pt_gpio->reg_base + PT_SYNC_REG);

	if (using_pins & BIT(offset)) {

		dev_warn(gc->dev, "PT GPIO pin %x reconfigured\n",

			offset);

		spin_unlock_irqrestore(&pt_gpio->lock, flags);

		return -EINVAL;

	}



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



	spin_unlock_irqrestore(&pt_gpio->lock, flags);



	return 0;

}



static void pt_gpio_free(struct gpio_chip *gc, unsigned offset)

{

	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);

	unsigned long flags;

	u32 using_pins;



	spin_lock_irqsave(&pt_gpio->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(&pt_gpio->lock, flags);



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

}



static void pt_gpio_set_value(struct gpio_chip *gc, unsigned offset, int value)

{

	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);

	unsigned long flags;

	u32 data;



	dev_dbg(gc->dev, "pt_gpio_set_value offset=%x, value=%x\n",

		offset, value);



	spin_lock_irqsave(&pt_gpio->lock, flags);



	data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);

	data &= ~BIT(offset);

	if (value)

		data |= BIT(offset);

	writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG);



	spin_unlock_irqrestore(&pt_gpio->lock, flags);

}



static int pt_gpio_get_value(struct gpio_chip *gc, unsigned offset)

{

	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);

	unsigned long flags;

	u32 data;



	spin_lock_irqsave(&pt_gpio->lock, flags);



	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);



	/* configure as output */

	if (data & BIT(offset))

		data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);

	else	/* configure as input */

		data = readl(pt_gpio->reg_base + PT_INPUTDATA_REG);



	spin_unlock_irqrestore(&pt_gpio->lock, flags);



	data >>= offset;

	data &= 1;



	dev_dbg(gc->dev, "pt_gpio_get_value offset=%x, value=%x\n",

		offset, data);



	return data;

}



static int pt_gpio_direction_input(struct gpio_chip *gc, unsigned offset)

{

	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);

	unsigned long flags;

	u32 data;



	dev_dbg(gc->dev, "pt_gpio_dirction_input offset=%x\n", offset);



	spin_lock_irqsave(&pt_gpio->lock, flags);



	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);

	data &= ~BIT(offset);

	writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);



	spin_unlock_irqrestore(&pt_gpio->lock, flags);



	return 0;

}



static int pt_gpio_direction_output(struct gpio_chip *gc,

					unsigned offset, int value)

{

	struct pt_gpio_chip *pt_gpio = to_pt_gpio(gc);

	unsigned long flags;

	u32 data;



	dev_dbg(gc->dev, "pt_gpio_direction_output offset=%x, value=%x\n",

		offset, value);



	spin_lock_irqsave(&pt_gpio->lock, flags);



	data = readl(pt_gpio->reg_base + PT_OUTPUTDATA_REG);

	if (value)

		data |= BIT(offset);

	else

		data &= ~BIT(offset);

	writel(data, pt_gpio->reg_base + PT_OUTPUTDATA_REG);



	data = readl(pt_gpio->reg_base + PT_DIRECTION_REG);

	data |= BIT(offset);

	writel(data, pt_gpio->reg_base + PT_DIRECTION_REG);



	spin_unlock_irqrestore(&pt_gpio->lock, flags);



	return 0;

}



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);

	}



	spin_lock_init(&pt_gpio->lock);



	pt_gpio->gc.label            = pdev->name;

	pt_gpio->gc.owner            = THIS_MODULE;

	pt_gpio->gc.dev              = dev;

	pt_gpio->gc.request          = pt_gpio_request;

	pt_gpio->gc.free             = pt_gpio_free;

	pt_gpio->gc.direction_input  = pt_gpio_direction_input;

	pt_gpio->gc.direction_output = pt_gpio_direction_output;

	pt_gpio->gc.get              = pt_gpio_get_value;

	pt_gpio->gc.set              = pt_gpio_set_value;

	pt_gpio->gc.base             = -1;

	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(&pt_gpio->gc);

	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 },

	{ },

};

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");

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