Re: [PATCH] gpio: loongson: add firmware offset parse support
From: Bartosz Golaszewski
Date: Sat Jul 29 2023 - 09:49:12 EST
On Tue, Jul 11, 2023 at 11:23 AM Yinbo Zhu <zhuyinbo@xxxxxxxxxxx> wrote:
>
> Some platforms contain multiple GPIO chips that with different offset
> addresses, if using acpi_device_id or of_device_id's data domain to
> initialize GPIO chip and different compatibles need to be added, but
> this addition is unnecessary because these GPIO chips are compatible
> with each other. Therefore, this driver adds support for parsing the
> necessary offset elements of GPIO chips from firmware to fix such
> issue.
>
The commit message is hard to parse, it took me a long while trying to
figure out what it's saying. Why not: "Loongson GPIO controllers come
in multiple variants that are compatible except for certain register
offset values. Add support for device properties allowing to specify
them in ACPI or DT."
> Signed-off-by: Yinbo Zhu <zhuyinbo@xxxxxxxxxxx>
> ---
> drivers/gpio/gpio-loongson-64bit.c | 71 +++++++++++++++++++++++++++---
> 1 file changed, 64 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpio/gpio-loongson-64bit.c b/drivers/gpio/gpio-loongson-64bit.c
> index 06213bbfabdd..7f92cb6205b2 100644
> --- a/drivers/gpio/gpio-loongson-64bit.c
> +++ b/drivers/gpio/gpio-loongson-64bit.c
> @@ -26,6 +26,7 @@ struct loongson_gpio_chip_data {
> unsigned int conf_offset;
> unsigned int out_offset;
> unsigned int in_offset;
> + unsigned int inten_offset;
> };
>
> struct loongson_gpio_chip {
> @@ -117,7 +118,17 @@ static void loongson_gpio_set(struct gpio_chip *chip, unsigned int pin, int valu
>
> static int loongson_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
> {
> + unsigned int u;
> struct platform_device *pdev = to_platform_device(chip->parent);
> + struct loongson_gpio_chip *lgpio = to_loongson_gpio_chip(chip);
> +
> + if (lgpio->chip_data->mode == BIT_CTRL_MODE) {
> + u = readl(lgpio->reg_base + lgpio->chip_data->inten_offset + offset / 32 * 4);
> + u |= BIT(offset % 32);
> + writel(u, lgpio->reg_base + lgpio->chip_data->inten_offset + offset / 32 * 4);
> + } else {
> + writeb(1, lgpio->reg_base + lgpio->chip_data->inten_offset + offset);
> + }
>
> return platform_get_irq(pdev, offset);
> }
> @@ -127,11 +138,30 @@ static int loongson_gpio_init(struct device *dev, struct loongson_gpio_chip *lgp
> {
> int ret;
> u32 ngpios;
> + unsigned int io_width;
>
> lgpio->reg_base = reg_base;
> + if (device_property_read_u32(dev, "ngpios", &ngpios) || !ngpios)
> + return -EINVAL;
> +
> + ret = DIV_ROUND_UP(ngpios, 8);
> + switch (ret) {
> + case 1 ... 2:
> + io_width = ret;
> + break;
> + case 3 ... 4:
> + io_width = 0x4;
> + break;
> + case 5 ... 8:
> + io_width = 0x8;
> + break;
> + default:
> + dev_err(dev, "unsupported io width\n");
> + return -EINVAL;
> + }
>
> if (lgpio->chip_data->mode == BIT_CTRL_MODE) {
> - ret = bgpio_init(&lgpio->chip, dev, 8,
> + ret = bgpio_init(&lgpio->chip, dev, io_width,
> lgpio->reg_base + lgpio->chip_data->in_offset,
> lgpio->reg_base + lgpio->chip_data->out_offset,
> NULL, NULL,
> @@ -151,16 +181,35 @@ static int loongson_gpio_init(struct device *dev, struct loongson_gpio_chip *lgp
> spin_lock_init(&lgpio->lock);
> }
>
> - device_property_read_u32(dev, "ngpios", &ngpios);
> -
> - lgpio->chip.can_sleep = 0;
> lgpio->chip.ngpio = ngpios;
> - lgpio->chip.label = lgpio->chip_data->label;
> - lgpio->chip.to_irq = loongson_gpio_to_irq;
> + lgpio->chip.can_sleep = 0;
> + if (lgpio->chip_data->label)
> + lgpio->chip.label = lgpio->chip_data->label;
> + else
> + lgpio->chip.label = kstrdup(to_platform_device(dev)->name, GFP_KERNEL);
> +
> + if (lgpio->chip_data->inten_offset)
> + lgpio->chip.to_irq = loongson_gpio_to_irq;
>
> return devm_gpiochip_add_data(dev, &lgpio->chip, lgpio);
> }
>
> +static int loongson_gpio_get_props(struct device *dev,
> + struct loongson_gpio_chip *lgpio)
> +{
> + const struct loongson_gpio_chip_data *d = lgpio->chip_data;
> +
> + if (device_property_read_u32(dev, "loongson,gpio-conf-offset", (u32 *)&d->conf_offset)
> + || device_property_read_u32(dev, "loongson,gpio-in-offset", (u32 *)&d->in_offset)
> + || device_property_read_u32(dev, "loongson,gpio-out-offset", (u32 *)&d->out_offset)
> + || device_property_read_u32(dev, "loongson,gpio-ctrl-mode", (u32 *)&d->mode))
These need to be first specified in DT bindings. Please do it in a
separate patch.
Bart
> + return -EINVAL;
> +
> + device_property_read_u32(dev, "loongson,gpio-inten-offset", (u32 *)&d->inten_offset);
> +
> + return 0;
> +}
> +
> static int loongson_gpio_probe(struct platform_device *pdev)
> {
> void __iomem *reg_base;
> @@ -172,7 +221,12 @@ static int loongson_gpio_probe(struct platform_device *pdev)
> if (!lgpio)
> return -ENOMEM;
>
> - lgpio->chip_data = device_get_match_data(dev);
> + lgpio->chip_data = devm_kzalloc(dev, sizeof(*lgpio->chip_data), GFP_KERNEL);
> + if (!lgpio->chip_data)
> + return -ENOMEM;
> +
> + if (loongson_gpio_get_props(dev, lgpio))
> + lgpio->chip_data = device_get_match_data(dev);
>
> reg_base = devm_platform_ioremap_resource(pdev, 0);
> if (IS_ERR(reg_base))
> @@ -215,6 +269,9 @@ static const struct acpi_device_id loongson_gpio_acpi_match[] = {
> .id = "LOON0002",
> .driver_data = (kernel_ulong_t)&loongson_gpio_ls7a_data,
> },
> + {
> + .id = "LOON0007",
> + },
> {}
> };
> MODULE_DEVICE_TABLE(acpi, loongson_gpio_acpi_match);
> --
> 2.31.1
>