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Message-ID: <3ae71f5c-2737-b313-31f5-5de9eedcf6cd@xen0n.name>
Date:   Wed, 16 Nov 2022 16:35:43 +0800
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Subject: Re: [PATCH v3 1/2] gpio: loongson: add dts/acpi gpio support
Content-Language: en-US
To:     Yinbo Zhu <zhuyinbo@loongson.cn>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <brgl@bgdev.pl>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Jiaxun Yang <jiaxun.yang@flygoat.com>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        Juxin Gao <gaojuxin@loongson.cn>,
        Bibo Mao <maobibo@loongson.cn>,
        Yanteng Si <siyanteng@loongson.cn>, linux-gpio@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        loongarch@lists.linux.dev, linux-mips@vger.kernel.org,
        Arnaud Patard <apatard@mandriva.com>,
        Huacai Chen <chenhuacai@kernel.org>
Cc:     lvjianmin <lvjianmin@loongson.cn>,
        zhanghongchen <zhanghongchen@loongson.cn>,
        Liu Peibao <liupeibao@loongson.cn>
References: <20221116065335.8823-1-zhuyinbo@loongson.cn>
From:   WANG Xuerui <kernel@xen0n.name>
In-Reply-To: <20221116065335.8823-1-zhuyinbo@loongson.cn>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

On 2022/11/16 14:53, Yinbo Zhu wrote:
> The latest Loongson series platform use dts or acpi framework to
> register gpio device resources, such as the Loongson-2 series
> SoC of LOONGARCH architecture. In order to support dts, acpi and
> compatibility with previous platform device resources in driver,
> this patch was added.

"LoongArch", not "LOONGARCH". The latter sounds too similar to a mass 
replace from the all-caps MIPS.

But again the commit message is overly verbose IMO, and contains minor 
grammatical mistakes that don't hamper understanding but are a nuisance 
nevertheless. I think the following could be enough:

"Subject: gpio: loongson: Add DTS and ACPI support"

"Latest Loongson platforms such as the Loongson-2 SoC series describe 
GPIO device resources with DTS or ACPI. Add such support to the existing 
platform device driver."

> 
> Signed-off-by: lvjianmin <lvjianmin@loongson.cn>

He's canonically "Jianmin Lv <...>" in the Git history.

> Signed-off-by: zhanghongchen <zhanghongchen@loongson.cn>

Please use proper spelling, either "Zhang Hongchen" or "Hongchen Zhang". 
I think every people with a loongson.cn address is using the latter form 
i.e. the Western order of "Firstname Lastname" except the "Liu Peibao" 
below, but ask the person themselves for honoring their own preference.

> Signed-off-by: Liu Peibao <liupeibao@loongson.cn>
> Signed-off-by: Juxin Gao <gaojuxin@loongson.cn>
> Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
> ---
> Change in v3:
> 		1. Move the gpio platform data struct from arch/ into include/linux/
> 		   platform_data/.
> 		2. Replace platform_gpio_data with loongson_gpio_platform_data in .c.
> 		3. Add maintainer in MAINTAINERS file for include/linux/platform_data/
> 		   gpio-loongson.h and gpio-loongson.c
> Change in v2:
> 		1. Fixup of_loongson_gpio_get_props and remove the parse logic about
> 	           "loongson,conf_offset", "loongson,out_offset", "loongson,in_offset",
> 		   "loongson,gpio_base", "loongson,support_irq" then kernel driver will
> 		   initial them that depend compatible except "loongson,gpio_base".
> 
>   MAINTAINERS                                 |   8 +
>   drivers/gpio/Kconfig                        |   6 +-
>   drivers/gpio/gpio-loongson.c                | 424 ++++++++++++++++----
>   include/linux/platform_data/gpio-loongson.h |  22 +
>   4 files changed, 385 insertions(+), 75 deletions(-)
>   create mode 100644 include/linux/platform_data/gpio-loongson.h
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5114db9c8f32..bbd7a0d946eb 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -12051,6 +12051,14 @@ S:	Maintained
>   F:	Documentation/devicetree/bindings/hwinfo/loongson,ls2k-chipid.yaml
>   F:	drivers/soc/loongson/loongson2_guts.c
>   
> +LOONGSON SERIES GPIO DRIVER

Drop "series" here and everywhere else.

> +M:	Huacai Chen <chenhuacai@kernel.org>
> +M:	Yinbo Zhu <zhuyinbo@loongson.cn>
> +L:	linux-gpio@vger.kernel.org
> +S:	Maintained
> +F:	drivers/gpio/gpio-loongson.c
> +F:	include/linux/platform_data/gpio-loongson.h
> +
>   LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI)
>   M:	Sathya Prakash <sathya.prakash@broadcom.com>
>   M:	Sreekanth Reddy <sreekanth.reddy@broadcom.com>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index a01af1180616..fb8f0075a8ae 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -376,10 +376,10 @@ config GPIO_LOGICVC
>   	  programmable logic block.
>   
>   config GPIO_LOONGSON
> -	bool "Loongson-2/3 GPIO support"
> -	depends on CPU_LOONGSON2EF || CPU_LOONGSON64
> +	bool "Loongson series GPIO support"
> +	depends on CPU_LOONGSON2EF || CPU_LOONGSON64 || LOONGARCH
>   	help
> -	  Driver for GPIO functionality on Loongson-2F/3A/3B processors.
> +	  Driver for GPIO functionality on Loongson seires processors.
>   
>   config GPIO_LPC18XX
>   	tristate "NXP LPC18XX/43XX GPIO support"
> diff --git a/drivers/gpio/gpio-loongson.c b/drivers/gpio/gpio-loongson.c
> index a42145873cc9..1e553db03cf8 100644
> --- a/drivers/gpio/gpio-loongson.c
> +++ b/drivers/gpio/gpio-loongson.c
> @@ -1,13 +1,15 @@
>   // SPDX-License-Identifier: GPL-2.0-or-later
>   /*
> - *  Loongson-2F/3A/3B GPIO Support
> + *  Loongson Series GPIO Support
>    *
> - *  Copyright (c) 2008 Richard Liu,  STMicroelectronics	 <richard.liu@st.com>
> + *  Copyright (c) 2008 Richard Liu, STMicroelectronics <richard.liu@st.com>
>    *  Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>
>    *  Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>
>    *  Copyright (c) 2014 Huacai Chen <chenhc@lemote.com>
> + *  Copyright (c) 2022-2023 Yinbo Zhu <zhuyinbo@loongson.cn>

Is it 2023 already?

And do the people listed in the S-o-b tags need a mention here? Or is it 
more appropriate to remove some of them or demote to tags like 
Co-developed-by?

>    */
>   
> +#include <linux/acpi.h>
>   #include <linux/kernel.h>
>   #include <linux/init.h>
>   #include <linux/module.h>
> @@ -16,120 +18,398 @@
>   #include <linux/gpio/driver.h>
>   #include <linux/platform_device.h>
>   #include <linux/bitops.h>
> +#include <linux/platform_data/gpio-loongson.h>
>   #include <asm/types.h>
> -#include <loongson.h>
> -
> -#define STLS2F_N_GPIO		4
> -#define STLS3A_N_GPIO		16
> -
> -#ifdef CONFIG_CPU_LOONGSON64
> -#define LOONGSON_N_GPIO	STLS3A_N_GPIO
> +#if defined(CONFIG_LOONGARCH)
> +#include <asm/loongson.h>
> +#elif defined(CONFIG_CPU_LOONGSON2EF)
> +#include <asm/mach-loongson2ef/loongson.h>
>   #else
> -#define LOONGSON_N_GPIO	STLS2F_N_GPIO
> +#include <asm/mach-loongson64/loongson.h>
>   #endif
>   
> -/*
> - * Offset into the register where we read lines, we write them from offset 0.
> - * This offset is the only thing that stand between us and using
> - * GPIO_GENERIC.
> - */
> -#define LOONGSON_GPIO_IN_OFFSET	16
> +#define LOONGSON_GPIO_IN(x)		(x->base + x->in_offset)
> +#define LOONGSON_GPIO_OUT(x)		(x->base + x->out_offset)
> +#define LOONGSON_GPIO_OEN(x)		(x->base + x->conf_offset)
> +
> +#define LOONGSON_GPIO_IN_BYTE(x, gpio)	(x->base +\
> +					x->in_offset + gpio)
> +#define LOONGSON_GPIO_OUT_BYTE(x, gpio)	(x->base +\
> +					x->out_offset + gpio)
> +#define LOONGSON_GPIO_OEN_BYTE(x, gpio)	(x->base +\
> +					x->conf_offset + gpio)
> +
> +struct loongson_gpio_chip {
> +	struct gpio_chip	chip;
> +	spinlock_t		lock;
> +	void __iomem		*base;
> +	int			conf_offset;
> +	int			out_offset;
> +	int			in_offset;
> +	u16			*gsi_idx_map;
> +	u16			mapsize;
> +	bool			support_irq;
> +};
> +
> +static int loongson_gpio_request(
> +			struct gpio_chip *chip, unsigned int pin)
> +{
> +	if (pin >= chip->ngpio)
> +		return -EINVAL;
> +	else

Drop the "else" because the true branch is an early return i.e. diverging.

> +		return 0;
> +}
> +
> +static inline void __set_direction(struct loongson_gpio_chip *lgpio,
> +			unsigned int pin, int input)
> +{
> +	u64 qval;
> +	u8  bval;
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,ls2k-gpio")) {
> +		qval = readq(LOONGSON_GPIO_OEN(lgpio));
> +		if (input)
> +			qval |= 1ULL << pin;
> +		else
> +			qval &= ~(1ULL << pin);
> +		writeq(qval, LOONGSON_GPIO_OEN(lgpio));
> +		return;
> +	}
>   
> -static DEFINE_SPINLOCK(gpio_lock);
> +	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
> +			!strncmp(lgpio->chip.label, "LOON0002", 8)) {
> +		if (input)
> +			bval = 1;
> +		else
> +			bval = 0;

bval = input ? 1 : 0;

> +		writeb(bval, LOONGSON_GPIO_OEN_BYTE(lgpio, pin));
> +		return;
> +	}
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
> +		if (input)
> +			LOONGSON_GPIOIE |= BIT(pin);
> +		else
> +			LOONGSON_GPIOIE &= ~BIT(pin);
> +		return;
> +	}
> +}
>   
> -static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
> +static void __set_level(struct loongson_gpio_chip *lgpio, unsigned int pin,
> +			int high)
>   {
> -	u32 val;
> +	u64 qval;
> +	u8 bval;
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,ls2k-gpio")) {
> +		qval = readq(LOONGSON_GPIO_OUT(lgpio));
> +		if (high)
> +			qval |= 1ULL << pin;
> +		else
> +			qval &= ~(1ULL << pin);
> +		writeq(qval, LOONGSON_GPIO_OUT(lgpio));
> +		return;
> +	}
>   
> -	spin_lock(&gpio_lock);
> -	val = LOONGSON_GPIODATA;
> -	spin_unlock(&gpio_lock);
> +	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
> +			!strncmp(lgpio->chip.label, "LOON0002", 8)) {
> +		if (high)
> +			bval = 1;
> +		else
> +			bval = 0;

bval = high ? 1 : 0;

> +		writeb(bval, LOONGSON_GPIO_OUT_BYTE(lgpio, pin));
> +		return;
> +	}
>   
> -	return !!(val & BIT(gpio + LOONGSON_GPIO_IN_OFFSET));
> +	if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
> +		if (LOONGSON_GPIODATA)
> +			LOONGSON_GPIODATA |= BIT(pin);
> +		else
> +			LOONGSON_GPIODATA &= ~BIT(pin);
> +		return;
> +	}
>   }
>   
> -static void loongson_gpio_set_value(struct gpio_chip *chip,
> -		unsigned gpio, int value)
> +static int loongson_gpio_direction_input(
> +				struct gpio_chip *chip, unsigned int pin)
>   {
> -	u32 val;
> +	unsigned long flags;
> +	struct loongson_gpio_chip *lgpio =
> +		container_of(chip, struct loongson_gpio_chip, chip);
>   
> -	spin_lock(&gpio_lock);
> -	val = LOONGSON_GPIODATA;
> -	if (value)
> -		val |= BIT(gpio);
> -	else
> -		val &= ~BIT(gpio);
> -	LOONGSON_GPIODATA = val;
> -	spin_unlock(&gpio_lock);
> +	spin_lock_irqsave(&lgpio->lock, flags);
> +	__set_direction(lgpio, pin, 1);
> +	spin_unlock_irqrestore(&lgpio->lock, flags);
> +
> +	return 0;
>   }
>   
> -static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
> +static int loongson_gpio_direction_output(
> +				struct gpio_chip *chip, unsigned int pin,
> +				int value)
>   {
> -	u32 temp;
> +	struct loongson_gpio_chip *lgpio =
> +		container_of(chip, struct loongson_gpio_chip, chip);
> +	unsigned long flags;
>   
> -	spin_lock(&gpio_lock);
> -	temp = LOONGSON_GPIOIE;
> -	temp |= BIT(gpio);
> -	LOONGSON_GPIOIE = temp;
> -	spin_unlock(&gpio_lock);
> +	spin_lock_irqsave(&lgpio->lock, flags);
> +	__set_level(lgpio, pin, value);
> +	__set_direction(lgpio, pin, 0);
> +	spin_unlock_irqrestore(&lgpio->lock, flags);
>   
>   	return 0;
>   }
>   
> -static int loongson_gpio_direction_output(struct gpio_chip *chip,
> -		unsigned gpio, int level)
> +static int loongson_gpio_get(struct gpio_chip *chip, unsigned int pin)
> +{
> +	u64 qval;
> +	u8  bval;
> +	int val;
> +	struct loongson_gpio_chip *lgpio =
> +		container_of(chip, struct loongson_gpio_chip, chip);
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,ls2k-gpio")) {
> +		qval = readq(LOONGSON_GPIO_IN(lgpio));
> +		return ((qval & (1ULL << pin)) != 0);
> +	}
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
> +			!strncmp(lgpio->chip.label, "LOON0002", 8)) {
> +		bval = readb(LOONGSON_GPIO_IN_BYTE(lgpio, pin));
> +		return (bval & 1);
> +	}
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
> +		val = LOONGSON_GPIODATA;
> +		return !!(val & BIT(pin + lgpio->in_offset));
> +	}
> +
> +	return -ENXIO;
> +}
> +
> +static void loongson_gpio_set(struct gpio_chip *chip, unsigned int pin,
> +			int value)
>   {
> -	u32 temp;
> +	unsigned long flags;
> +	struct loongson_gpio_chip *lgpio =
> +		container_of(chip, struct loongson_gpio_chip, chip);
>   
> -	loongson_gpio_set_value(chip, gpio, level);
> -	spin_lock(&gpio_lock);
> -	temp = LOONGSON_GPIOIE;
> -	temp &= ~BIT(gpio);
> -	LOONGSON_GPIOIE = temp;
> -	spin_unlock(&gpio_lock);
> +	spin_lock_irqsave(&lgpio->lock, flags);
> +	__set_level(lgpio, pin, value);
> +	spin_unlock_irqrestore(&lgpio->lock, flags);
> +}
> +
> +static int loongson_gpio_to_irq(
> +			struct gpio_chip *chip, unsigned int offset)
> +{
> +	struct platform_device *pdev =
> +		container_of(chip->parent, struct platform_device, dev);
> +	struct loongson_gpio_chip *lgpio =
> +		container_of(chip, struct loongson_gpio_chip, chip);
> +
> +	if (offset >= chip->ngpio)
> +		return -EINVAL;
> +
> +	if ((lgpio->gsi_idx_map != NULL) && (offset < lgpio->mapsize))
> +		offset = lgpio->gsi_idx_map[offset];
> +
> +	return platform_get_irq(pdev, offset);
> +}
> +
> +static int loongson_gpio_init(
> +			struct device *dev, struct loongson_gpio_chip *lgpio,
> +			struct device_node *np, void __iomem *base)
> +{
> +	lgpio->chip.request = loongson_gpio_request;
> +	lgpio->chip.direction_input = loongson_gpio_direction_input;
> +	lgpio->chip.get = loongson_gpio_get;
> +	lgpio->chip.direction_output = loongson_gpio_direction_output;
> +	lgpio->chip.set = loongson_gpio_set;
> +	lgpio->chip.can_sleep = 0;
> +	lgpio->chip.of_node = np;
> +	lgpio->chip.parent = dev;
> +	spin_lock_init(&lgpio->lock);
> +	lgpio->base = (void __iomem *)base;
> +
> +	if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
> +			!strncmp(lgpio->chip.label, "LOON0002", 8) ||
> +			!strcmp(lgpio->chip.label, "loongson,ls2k-gpio"))

Aren't these 3 device IDs the only models we support/have right now? If 
so I think the check could safely be dropped.

> +		lgpio->chip.to_irq = loongson_gpio_to_irq;
> +
> +	gpiochip_add(&lgpio->chip);
>   
>   	return 0;
>   }
>   
> +static void of_loongson_gpio_get_props(struct device_node *np,
> +				  struct loongson_gpio_chip *lgpio)
> +{
> +	const char *name;
> +
> +	of_property_read_u32(np, "ngpios", (u32 *)&lgpio->chip.ngpio);
> +
> +	of_property_read_string(np, "compatible", &name);
> +	lgpio->chip.label = kstrdup(name, GFP_KERNEL);
> +
> +	if (!strcmp(name, "loongson,ls2k-gpio")) {
> +		lgpio->support_irq = true;
> +		lgpio->conf_offset = 0x0;
> +		lgpio->out_offset = 0x10;
> +		lgpio->in_offset = 0x20;
> +		return;
> +	}
> +
> +	if (!strcmp(name, "loongson,ls7a-gpio")) {
> +		lgpio->support_irq = true;
> +		lgpio->conf_offset = 0x800;
> +		lgpio->out_offset = 0x900;
> +		lgpio->in_offset = 0xa00;

Aren't configurations like these usually described in the DT? Are you 
trying to maintain compatibility with the pre-existing DT structure that 
is missing such data?

> +		return;
> +	}
> +}
> +
> +static void acpi_loongson_gpio_get_props(struct platform_device *pdev,
> +				  struct loongson_gpio_chip *lgpio)
> +{
> +
> +	struct device *dev = &pdev->dev;
> +	int rval;
> +
> +	device_property_read_u32(dev, "ngpios", (u32 *)&lgpio->chip.ngpio);
> +	device_property_read_u32(dev, "gpio_base", (u32 *)&lgpio->chip.base);
> +	device_property_read_u32(dev, "conf_offset",
> +					(u32 *)&lgpio->conf_offset);
> +	device_property_read_u32(dev, "out_offset",
> +					(u32 *)&lgpio->out_offset);
> +	device_property_read_u32(dev, "in_offset", (u32 *)&lgpio->in_offset);
> +
> +	rval = device_property_read_u16_array(dev, "gsi_idx_map", NULL, 0);
> +	if (rval > 0) {
> +		lgpio->gsi_idx_map =
> +			kmalloc_array(rval, sizeof(*lgpio->gsi_idx_map),
> +					GFP_KERNEL);
> +		if (unlikely(!lgpio->gsi_idx_map)) {
> +			dev_err(dev, "Alloc gsi_idx_map fail!\n");
> +		} else {
> +			lgpio->mapsize = rval;
> +			device_property_read_u16_array(dev, "gsi_idx_map",
> +					lgpio->gsi_idx_map, lgpio->mapsize);
> +		}
> +	}
> +
> +	lgpio->chip.label = kstrdup(pdev->name, GFP_KERNEL);
> +}
> +
> +static void platform_loongson_gpio_get_props(struct platform_device *pdev,
> +				  struct loongson_gpio_chip *lgpio)
> +{
> +	struct loongson_gpio_platform_data *gpio_data =
> +		(struct loongson_gpio_platform_data *)pdev->dev.platform_data;
> +
> +	lgpio->chip.ngpio = gpio_data->ngpio;
> +	lgpio->chip.base = gpio_data->gpio_base;
> +	lgpio->conf_offset = gpio_data->gpio_conf;
> +	lgpio->out_offset = gpio_data->gpio_out;
> +	lgpio->in_offset = gpio_data->gpio_in;
> +	lgpio->chip.label = kstrdup(gpio_data->label, GFP_KERNEL);
> +}
> +
>   static int loongson_gpio_probe(struct platform_device *pdev)
>   {
> -	struct gpio_chip *gc;
> +	struct resource *iores;
> +	void __iomem *base;
> +	struct loongson_gpio_chip *lgpio;
> +	struct device_node *np = pdev->dev.of_node;
>   	struct device *dev = &pdev->dev;
> +	int ret = 0;
>   
> -	gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
> -	if (!gc)
> +	lgpio = kzalloc(sizeof(struct loongson_gpio_chip), GFP_KERNEL);
> +	if (!lgpio)
>   		return -ENOMEM;
>   
> -	gc->label = "loongson-gpio-chip";
> -	gc->base = 0;
> -	gc->ngpio = LOONGSON_N_GPIO;
> -	gc->get = loongson_gpio_get_value;
> -	gc->set = loongson_gpio_set_value;
> -	gc->direction_input = loongson_gpio_direction_input;
> -	gc->direction_output = loongson_gpio_direction_output;
> +	if (np)
> +		of_loongson_gpio_get_props(np, lgpio);
> +	else if (ACPI_COMPANION(&pdev->dev))
> +		acpi_loongson_gpio_get_props(pdev, lgpio);
> +	else
> +		platform_loongson_gpio_get_props(pdev, lgpio);
> +
> +	iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!iores) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	if (!request_mem_region(iores->start, resource_size(iores),
> +				pdev->name)) {
> +		ret = -EBUSY;
> +		goto out;
> +	}
> +
> +	base = ioremap(iores->start, resource_size(iores));
> +	if (!base) {
> +		ret = -ENOMEM;
> +		goto out;
> +	}
> +
> +	platform_set_drvdata(pdev, lgpio);
> +
> +	loongson_gpio_init(dev, lgpio, np, base);
> +
> +	return 0;
> +out:
> +	pr_err("%s: %s: missing mandatory property\n", __func__, np->name);

I suggest checking out <linux/dev_printk.h> and use dev_* printk's 
everywhere you have a `dev` at hand (which is the case here).

> +	return ret;
> +}
> +
> +static int loongson_gpio_remove(struct platform_device *pdev)
> +{
> +	struct loongson_gpio_chip *lgpio = platform_get_drvdata(pdev);
> +	struct resource		*mem;
> +
> +	platform_set_drvdata(pdev, NULL);
>   
> -	return gpiochip_add_data(gc, NULL);
> +	gpiochip_remove(&lgpio->chip);
> +	iounmap(lgpio->base);
> +	kfree(lgpio->gsi_idx_map);
> +	kfree(lgpio);
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	release_mem_region(mem->start, resource_size(mem));
> +
> +	return 0;
>   }
>   
> +static const struct of_device_id loongson_gpio_dt_ids[] = {
> +	{ .compatible = "loongson,ls2k-gpio"},
> +	{ .compatible = "loongson,ls7a-gpio"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, loongson_gpio_dt_ids);
> +
> +static const struct acpi_device_id loongson_gpio_acpi_match[] = {
> +	{"LOON0002"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(acpi, loongson_gpio_acpi_match);
> +
>   static struct platform_driver loongson_gpio_driver = {
>   	.driver = {
>   		.name = "loongson-gpio",
> +		.owner = THIS_MODULE,
> +		.of_match_table = loongson_gpio_dt_ids,
> +		.acpi_match_table = ACPI_PTR(loongson_gpio_acpi_match),
>   	},
>   	.probe = loongson_gpio_probe,
> +	.remove = loongson_gpio_remove,
>   };
>   
>   static int __init loongson_gpio_setup(void)
>   {
> -	struct platform_device *pdev;
> -	int ret;
> -
> -	ret = platform_driver_register(&loongson_gpio_driver);
> -	if (ret) {
> -		pr_err("error registering loongson GPIO driver\n"); > -		return ret;
> -	}
> -
> -	pdev = platform_device_register_simple("loongson-gpio", -1, NULL, 0);
> -	return PTR_ERR_OR_ZERO(pdev);
> +	return platform_driver_register(&loongson_gpio_driver);
>   }
>   postcore_initcall(loongson_gpio_setup);
> +
> +static void __exit loongson_gpio_exit(void)
> +{
> +	platform_driver_unregister(&loongson_gpio_driver);
> +}
> diff --git a/include/linux/platform_data/gpio-loongson.h b/include/linux/platform_data/gpio-loongson.h
> new file mode 100644
> index 000000000000..f102d2650576
> --- /dev/null
> +++ b/include/linux/platform_data/gpio-loongson.h
> @@ -0,0 +1,22 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Author: Yinbo Zhu <zhuyinbo@loongson.cn>
> + * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
> + */
> +
> +#ifndef __LOONGSON_GPIO_PLATFORM_H
> +#define __LOONGSON_GPIO_PLATFORM_H
> +
> +/* ============== Data structrues =============== */

This comment could be removed as the code here is very trivial hence 
self-commentary.

But again, please check out Arnd's review comment; still I think this 
might not be necessary at all because the legacy users already have to 
modify many other things elsewhere before they can rebase on the more 
recent upstream versions.

> +
> +struct loongson_gpio_platform_data {
> +	u32 gpio_conf;
> +	u32 gpio_out;
> +	u32 gpio_in;
> +	u32 support_irq;
> +	char *label;
> +	int gpio_base;
> +	int ngpio;
> +};
> +
> +#endif

-- 
WANG "xen0n" Xuerui

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