Re: [PATCH v8 13/14] gpio: Add support for Airoha EN7523 GPIO controller

[Andy Shevchenko <andy.shevchenko@xxxxxxxxx>]

On Tue, Dec 21, 2021 at 12:02 AM Felix Fietkau <nbd@xxxxxxxx> wrote:
>
> From: John Crispin <john@xxxxxxxxxxx>
>
> Airoha's GPIO controller on their ARM EN7523 SoCs consists of two banks of 32
> GPIOs. Each instance in DT is for a single bank.

FWIW,
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

A couple of minor comments and one about headers below.

> Signed-off-by: John Crispin <john@xxxxxxxxxxx>
> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx>
> ---
>  drivers/gpio/Kconfig       |   9 +++
>  drivers/gpio/Makefile      |   1 +
>  drivers/gpio/gpio-en7523.c | 134 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 144 insertions(+)
>  create mode 100644 drivers/gpio/gpio-en7523.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 072ed610f9c6..e4a34272504f 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -247,6 +247,15 @@ config GPIO_EM
>         help
>           Say yes here to support GPIO on Renesas Emma Mobile SoCs.
>
> +config GPIO_EN7523
> +       tristate "Airoha GPIO support"
> +       depends on ARCH_AIROHA
> +       default ARCH_AIROHA
> +       select GPIO_GENERIC
> +       select GPIOLIB_IRQCHIP
> +       help
> +         Say yes here to support the GPIO controller on Airoha EN7523.

Checkpatch nowadays wants a better description. Also add a paragraph
at the end, like many other drivers do, what the module would be if
selected as M.

>  config GPIO_EP93XX
>         def_bool y
>         depends on ARCH_EP93XX
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 71ee9fc2ff83..d2269ee0948e 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -56,6 +56,7 @@ obj-$(CONFIG_GPIO_DLN2)                       += gpio-dln2.o
>  obj-$(CONFIG_GPIO_DWAPB)               += gpio-dwapb.o
>  obj-$(CONFIG_GPIO_EIC_SPRD)            += gpio-eic-sprd.o
>  obj-$(CONFIG_GPIO_EM)                  += gpio-em.o
> +obj-$(CONFIG_GPIO_EN7523)              += gpio-en7523.o
>  obj-$(CONFIG_GPIO_EP93XX)              += gpio-ep93xx.o
>  obj-$(CONFIG_GPIO_EXAR)                        += gpio-exar.o
>  obj-$(CONFIG_GPIO_F7188X)              += gpio-f7188x.o
> diff --git a/drivers/gpio/gpio-en7523.c b/drivers/gpio/gpio-en7523.c
> new file mode 100644
> index 000000000000..67631396cd93
> --- /dev/null
> +++ b/drivers/gpio/gpio-en7523.c
> @@ -0,0 +1,134 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +
> +#include <linux/gpio/driver.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>

Missed headers
types.h for _iomem, etc.
io.h for I/O accessors.
bits.h for BIT(), etc.

> +#define AIROHA_GPIO_MAX                32
> +
> +/**
> + * airoha_gpio_ctrl - Airoha GPIO driver data
> + * @gc: Associated gpio_chip instance.
> + * @data: The data register.
> + * @dir0: The direction register for the lower 16 pins.
> + * @dir1: The direction register for the higher 16 pins.
> + * @output: The output enable register.
> + */
> +struct airoha_gpio_ctrl {
> +       struct gpio_chip gc;
> +       void __iomem *data;
> +       void __iomem *dir[2];
> +       void __iomem *output;
> +};
> +
> +static struct airoha_gpio_ctrl *gc_to_ctrl(struct gpio_chip *gc)
> +{
> +       return container_of(gc, struct airoha_gpio_ctrl, gc);
> +}
> +
> +static int airoha_dir_set(struct gpio_chip *gc, unsigned int gpio,
> +                         int val, int out)
> +{
> +       struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
> +       u32 dir = ioread32(ctrl->dir[gpio / 16]);
> +       u32 output = ioread32(ctrl->output);
> +       u32 mask = BIT((gpio % 16) * 2);
> +
> +       if (out) {
> +               dir |= mask;
> +               output |= BIT(gpio);
> +       } else {
> +               dir &= ~mask;
> +               output &= ~BIT(gpio);
> +       }
> +
> +       iowrite32(dir, ctrl->dir[gpio / 16]);
> +
> +       if (out)
> +               gc->set(gc, gpio, val);
> +
> +       iowrite32(output, ctrl->output);
> +
> +       return 0;
> +}
> +
> +static int airoha_dir_out(struct gpio_chip *gc, unsigned int gpio,
> +                         int val)
> +{
> +       return airoha_dir_set(gc, gpio, val, 1);
> +}
> +
> +static int airoha_dir_in(struct gpio_chip *gc, unsigned int gpio)
> +{
> +       return airoha_dir_set(gc, gpio, 0, 0);
> +}
> +
> +static int airoha_get_dir(struct gpio_chip *gc, unsigned int gpio)
> +{
> +       struct airoha_gpio_ctrl *ctrl = gc_to_ctrl(gc);
> +       u32 dir = ioread32(ctrl->dir[gpio / 16]);
> +       u32 mask = BIT((gpio % 16) * 2);
> +
> +       return (dir & mask) ? GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN;
> +}

> +static const struct of_device_id airoha_gpio_of_match[] = {
> +       { .compatible = "airoha,en7523-gpio" },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, airoha_gpio_of_match);

Move this below, closer to its user.

> +static int airoha_gpio_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct airoha_gpio_ctrl *ctrl;
> +       int err;
> +
> +       ctrl = devm_kzalloc(dev, sizeof(*ctrl), GFP_KERNEL);
> +       if (!ctrl)
> +               return -ENOMEM;
> +
> +       ctrl->data = devm_platform_ioremap_resource(pdev, 0);
> +       if (IS_ERR(ctrl->data))
> +               return PTR_ERR(ctrl->data);
> +
> +       ctrl->dir[0] = devm_platform_ioremap_resource(pdev, 1);
> +       if (IS_ERR(ctrl->dir[0]))
> +               return PTR_ERR(ctrl->dir[0]);
> +
> +       ctrl->dir[1] = devm_platform_ioremap_resource(pdev, 2);
> +       if (IS_ERR(ctrl->dir[1]))
> +               return PTR_ERR(ctrl->dir[1]);
> +
> +       ctrl->output = devm_platform_ioremap_resource(pdev, 3);
> +       if (IS_ERR(ctrl->output))
> +               return PTR_ERR(ctrl->output);
> +
> +       err = bgpio_init(&ctrl->gc, dev, 4, ctrl->data, NULL,
> +                        NULL, NULL, NULL, 0);
> +       if (err)
> +               return dev_err_probe(dev, err, "unable to init generic GPIO");
> +
> +       ctrl->gc.ngpio = AIROHA_GPIO_MAX;
> +       ctrl->gc.owner = THIS_MODULE;
> +       ctrl->gc.direction_output = airoha_dir_out;
> +       ctrl->gc.direction_input = airoha_dir_in;
> +       ctrl->gc.get_direction = airoha_get_dir;
> +
> +       return devm_gpiochip_add_data(dev, &ctrl->gc, ctrl);
> +}
> +
> +static struct platform_driver airoha_gpio_driver = {
> +       .driver = {
> +               .name = "airoha-gpio",
> +               .of_match_table = airoha_gpio_of_match,
> +       },
> +       .probe = airoha_gpio_probe,
> +};
> +module_platform_driver(airoha_gpio_driver);
> +
> +MODULE_DESCRIPTION("Airoha GPIO support");
> +MODULE_AUTHOR("John Crispin <john@xxxxxxxxxxx>");
> +MODULE_LICENSE("GPL v2");
> --
> 2.34.1
>


-- 
With Best Regards,
Andy Shevchenko