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SubjectRe: [PATCH v4 1/2] gpio: loongson: add dts and acpi support
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在 2022/11/17 下午5:39, Bartosz Golaszewski 写道:
> On Thu, Nov 17, 2022 at 4:59 AM Yinbo Zhu <zhuyinbo@loongson.cn> wrote:
>>
>> 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: Jianmin Lv <lvjianmin@loongson.cn>
>> Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>
>> 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 v4:
>> 1. Fixup name spelling about Signed-off-by.
>> 2. Drop "series" here and everywhere else.
>> 3. Fixup the copyright in driver.
>> 4. Drop the "else" in loongson_gpio_request.
>> 5. Use trinocular operation replace the related logic.
>> 6. Remove lable judgement in context about "lgpio->chip.to_irq =
>> loongson_gpio_to_irq"
>> 7. Use dev_err replace pr_err in probe.
>> 8. Make legacy platform_data should be left out of this patch.
>> 9. Remove the mips config in gpio Kconfig.
>> 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 | 403 ++++++++++++++++++++++++++++-------
>> 3 files changed, 338 insertions(+), 79 deletions(-)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 5114db9c8f32..838b920efcef 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 GPIO DRIVER
>> +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..b4423c058b1d 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 LOONGARCH || COMPILE_TEST
>> 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..b9b191a541c0 100644
>> --- a/drivers/gpio/gpio-loongson.c
>> +++ b/drivers/gpio/gpio-loongson.c
>> @@ -1,13 +1,11 @@
>> -// SPDX-License-Identifier: GPL-2.0-or-later
>> +// SPDX-License-Identifier: GPL-2.0+
>> /*
>> - * Loongson-2F/3A/3B GPIO Support
>> + * Loongson GPIO Support
>> *
>> - * 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>
>
> Why are you removing other people's copyright notices?
I will add a new file.
>
>> + * Copyright (C) 2022 Loongson Technology Corporation Limited
>> */
>>
>> +#include <linux/acpi.h>
>> #include <linux/kernel.h>
>> #include <linux/init.h>
>> #include <linux/module.h>
>> @@ -17,119 +15,372 @@
>> #include <linux/platform_device.h>
>> #include <linux/bitops.h>
>> #include <asm/types.h>
>> -#include <loongson.h>
>> +#include <asm/loongson.h>
>>
>> -#define STLS2F_N_GPIO 4
>> -#define STLS3A_N_GPIO 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)
>>
>> -#ifdef CONFIG_CPU_LOONGSON64
>> -#define LOONGSON_N_GPIO STLS3A_N_GPIO
>> -#else
>> -#define LOONGSON_N_GPIO STLS2F_N_GPIO
>> -#endif
>> +#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)
>>
>> -/*
>> - * 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
>> +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;
>> +};
>>
>> -static DEFINE_SPINLOCK(gpio_lock);
>> +static int loongson_gpio_request(
>> + struct gpio_chip *chip, unsigned int pin)
>> +{
>> + if (pin >= chip->ngpio)
>> + return -EINVAL;
>> +
>> + return 0;
>> +}
>>
>> -static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
>> +static inline void __set_direction(struct loongson_gpio_chip *lgpio,
>> + unsigned int pin, int input)
>> {
>> - u32 val;
>> + 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;
>> + }
>>
>> - 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)) {
>
> This is ugly - can you instead use chip data associated with the
> relevant compatible to store whatever custom info you need? See the
> data field in struct of_device_id and acpi_device_id. Same elsewhere,
> I really dislike this label parsing everywhere.
okay, I got it.
>
>> + bval = input ? 1 : 0;
>> + writeb(bval, LOONGSON_GPIO_OEN_BYTE(lgpio, pin));
>> + return;
>> + }
>>
>> - return !!(val & BIT(gpio + LOONGSON_GPIO_IN_OFFSET));
>> + if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
>> + if (input)
>> + LOONGSON_GPIOIE |= BIT(pin);
>> + else
>> + LOONGSON_GPIOIE &= ~BIT(pin);
>> + return;
>> + }
>> }
>>
>> -static void loongson_gpio_set_value(struct gpio_chip *chip,
>> - unsigned gpio, int value)
>> +static void __set_level(struct loongson_gpio_chip *lgpio, unsigned int pin,
>> + int high)
>> {
>> - u32 val;
>> + u64 qval;
>> + u8 bval;
>>
>> - spin_lock(&gpio_lock);
>> - val = LOONGSON_GPIODATA;
>> - if (value)
>> - val |= BIT(gpio);
>> - else
>> - val &= ~BIT(gpio);
>> - LOONGSON_GPIODATA = val;
>> - spin_unlock(&gpio_lock);
>> + 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;
>> + }
>> +
>> + if (!strcmp(lgpio->chip.label, "loongson,ls7a-gpio") ||
>> + !strncmp(lgpio->chip.label, "LOON0002", 8)) {
>> + bval = high ? 1 : 0;
>> + writeb(bval, LOONGSON_GPIO_OUT_BYTE(lgpio, pin));
>> + return;
>> + }
>> +
>> + if (!strcmp(lgpio->chip.label, "loongson,platform-gpio")) {
>> + if (LOONGSON_GPIODATA)
>> + LOONGSON_GPIODATA |= BIT(pin);
>> + else
>> + LOONGSON_GPIODATA &= ~BIT(pin);
>> + return;
>> + }
>> }
>>
>> -static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
>> +static int loongson_gpio_direction_input(
>> + struct gpio_chip *chip, unsigned int pin)
>> {
>> - u32 temp;
>> + unsigned long flags;
>> + struct loongson_gpio_chip *lgpio =
>> + container_of(chip, struct loongson_gpio_chip, chip);
>>
>> - spin_lock(&gpio_lock);
>> - temp = LOONGSON_GPIOIE;
>> - temp |= BIT(gpio);
>> - LOONGSON_GPIOIE = temp;
>> - 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_output(struct gpio_chip *chip,
>> - unsigned gpio, int level)
>> +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;
>>
>> - 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);
>> + __set_direction(lgpio, pin, 0);
>> + spin_unlock_irqrestore(&lgpio->lock, flags);
>>
>> return 0;
>> }
>>
>> +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)
>> +{
>> + unsigned long flags;
>> + struct loongson_gpio_chip *lgpio =
>> + container_of(chip, struct loongson_gpio_chip, chip);
>> +
>> + 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;
>> + 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->conf_offset = 0x0;
>> + lgpio->out_offset = 0x10;
>> + lgpio->in_offset = 0x20;
>> + return;
>> + }
>> +
>> + if (!strcmp(name, "loongson,ls7a-gpio")) {
>> + lgpio->conf_offset = 0x800;
>> + lgpio->out_offset = 0x900;
>> + lgpio->in_offset = 0xa00;
>> + 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)
>> +{
>> +}
>
> Drop it, if you don't use it.
okay, I got it.
>
>> +
>> 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);
>
> Why stop using devres? Same elsewhere.
okay, I had use it devres.
>
>> + 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);
>
> I would prefer if you used generic device properties - like you
> already do for acpi. They work for OF too thanks to the fwnode
> abstraction.
Some of these attributes I tried to define in the dts, but they are not
generic, so I put them in xxx_ device_ id data field.
>
>> +
>> + 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;
>> + }
>
> Are you aware of the gpio-regmap interface? It seems to me that this
> code could benefit from using it. There are already some good examples
> in the tree.
I tried to use regmap, but I found that my driver needs to access 64 bit
registers, and regmap cannot cover it.
>
>> +
>> + platform_set_drvdata(pdev, lgpio);
>> +
>> + loongson_gpio_init(dev, lgpio, np, base);
>> +
>> + return 0;
>> +out:
>> + dev_err(dev, "missing mandatory property\n");
>> +
>
> So if request_mem_region() or ioremap() fails, we're printing this
> error message? Doesn't seem right.
>
>> + return ret;
>> +}
>> +
>> +static int loongson_gpio_remove(struct platform_device *pdev)
>> +{
>> + struct loongson_gpio_chip *lgpio = platform_get_drvdata(pdev);
>> + struct resource *mem;
>>
>> - return gpiochip_add_data(gc, NULL);
>> + platform_set_drvdata(pdev, 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));
>> +
>
> This entire function can be dropped if you used devres.
>
>> + 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);
>> +}
>
> This module cannot be unloaded so you can drop this. The __exit macro
> will make the compiler drop it anyway.
okay I got it.
>
> Bart
>
>> +
>> +MODULE_DESCRIPTION("Loongson gpio driver");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.31.1
>>

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