[v7,5/9] gpio/rockchip: add driver for rockchip gpio

This patch add support for rockchip gpio controller, which is supported
in pinctrl driver in the past.

With this patch, the pinctrl-rockchip driver will drop gpio related
codes and populate platform driver to gpio-rockchip.

Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
---
v7:
 - include gpio/driver.h instead of gpio.h, suggested by Walleij
 - use gpio align id instead of gpio bank name
v6:
 - reorder patches suggested by heiko

 drivers/gpio/Kconfig         |   8 +
 drivers/gpio/Makefile        |   1 +
 drivers/gpio/gpio-rockchip.c | 626 +++++++++++++++++++++++++++++++++++
 3 files changed, 635 insertions(+)
 create mode 100644 drivers/gpio/gpio-rockchip.c

On Mon, Jul 26, 2021 at 3:35 AM Jianqun Xu <jay.xu@rock-chips.com> wrote:
>
> This patch add support for rockchip gpio controller, which is supported
> in pinctrl driver in the past.
>
> With this patch, the pinctrl-rockchip driver will drop gpio related
> codes and populate platform driver to gpio-rockchip.
>
> Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
> ---
> v7:
>  - include gpio/driver.h instead of gpio.h, suggested by Walleij
>  - use gpio align id instead of gpio bank name
> v6:
>  - reorder patches suggested by heiko
>
>  drivers/gpio/Kconfig         |   8 +
>  drivers/gpio/Makefile        |   1 +
>  drivers/gpio/gpio-rockchip.c | 626 +++++++++++++++++++++++++++++++++++
>  3 files changed, 635 insertions(+)
>  create mode 100644 drivers/gpio/gpio-rockchip.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 1dd0ec6727fd..764ef6b14678 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -520,6 +520,14 @@ config GPIO_REG
>           A 32-bit single register GPIO fixed in/out implementation.  This
>           can be used to represent any register as a set of GPIO signals.
>
> +config GPIO_ROCKCHIP
> +       tristate "Rockchip GPIO support"
> +       depends on ARCH_ROCKCHIP || COMPILE_TEST
> +       select GPIOLIB_IRQCHIP
> +       default ARCH_ROCKCHIP
> +       help
> +         Say yes here to support GPIO on Rockchip SoCs.
> +
>  config GPIO_SAMA5D2_PIOBU
>         tristate "SAMA5D2 PIOBU GPIO support"
>         depends on MFD_SYSCON
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index d7c81e1611a4..81e95a0db25b 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -127,6 +127,7 @@ obj-$(CONFIG_GPIO_RDA)                      += gpio-rda.o
>  obj-$(CONFIG_GPIO_RDC321X)             += gpio-rdc321x.o
>  obj-$(CONFIG_GPIO_REALTEK_OTTO)                += gpio-realtek-otto.o
>  obj-$(CONFIG_GPIO_REG)                 += gpio-reg.o
> +obj-$(CONFIG_GPIO_ROCKCHIP)    += gpio-rockchip.o
>  obj-$(CONFIG_ARCH_SA1100)              += gpio-sa1100.o
>  obj-$(CONFIG_GPIO_SAMA5D2_PIOBU)       += gpio-sama5d2-piobu.o
>  obj-$(CONFIG_GPIO_SCH311X)             += gpio-sch311x.o
> diff --git a/drivers/gpio/gpio-rockchip.c b/drivers/gpio/gpio-rockchip.c
> new file mode 100644
> index 000000000000..b455fcf7efda
> --- /dev/null
> +++ b/drivers/gpio/gpio-rockchip.c
> @@ -0,0 +1,626 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2013 MundoReader S.L.
> + * Author: Heiko Stuebner <heiko@sntech.de>
> + *
> + * Copyright (c) 2021 Rockchip Electronics Co. Ltd.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_irq.h>
> +#include <linux/regmap.h>

Doesn't look like you're actually using regmap.

> +
> +#include "../pinctrl/core.h"
> +#include "../pinctrl/pinctrl-rockchip.h"
> +
> +/* GPIO control registers */
> +#define GPIO_SWPORT_DR         0x00
> +#define GPIO_SWPORT_DDR                0x04
> +#define GPIO_INTEN             0x30
> +#define GPIO_INTMASK           0x34
> +#define GPIO_INTTYPE_LEVEL     0x38
> +#define GPIO_INT_POLARITY      0x3c
> +#define GPIO_INT_STATUS                0x40
> +#define GPIO_INT_RAWSTATUS     0x44
> +#define GPIO_DEBOUNCE          0x48
> +#define GPIO_PORTS_EOI         0x4c
> +#define GPIO_EXT_PORT          0x50
> +#define GPIO_LS_SYNC           0x60
> +
> +static int rockchip_gpio_get_direction(struct gpio_chip *chip,
> +                                      unsigned int offset)
> +{
> +       struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
> +       u32 data;
> +
> +       data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
> +       if (data & BIT(offset))
> +               return GPIO_LINE_DIRECTION_OUT;
> +
> +       return GPIO_LINE_DIRECTION_IN;
> +}
> +
> +static int rockchip_gpio_set_direction(struct gpio_chip *chip,
> +                                      unsigned int offset, bool input)
> +{
> +       struct rockchip_pin_bank *bank = gpiochip_get_data(chip);
> +       unsigned long flags;
> +       u32 data;
> +
> +       raw_spin_lock_irqsave(&bank->slock, flags);
> +
> +       data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
> +       /* set bit to 1 for output, 0 for input */
> +       if (!input)
> +               data |= BIT(offset);
> +       else
> +               data &= ~BIT(offset);
> +       writel_relaxed(data, bank->reg_base + GPIO_SWPORT_DDR);
> +
> +       raw_spin_unlock_irqrestore(&bank->slock, flags);
> +
> +       return 0;
> +}
> +
> +static void rockchip_gpio_set(struct gpio_chip *gc, unsigned int offset,
> +                             int value)
> +{
> +       struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
> +       void __iomem *reg = bank->reg_base + GPIO_SWPORT_DR;
> +       unsigned long flags;
> +       u32 data;
> +
> +       raw_spin_lock_irqsave(&bank->slock, flags);
> +
> +       data = readl(reg);
> +       data &= ~BIT(offset);
> +       if (value)
> +               data |= BIT(offset);
> +       writel(data, reg);
> +
> +       raw_spin_unlock_irqrestore(&bank->slock, flags);
> +}
> +
> +static int rockchip_gpio_get(struct gpio_chip *gc, unsigned int offset)
> +{
> +       struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
> +       u32 data;
> +
> +       data = readl(bank->reg_base + GPIO_EXT_PORT);
> +       data >>= offset;
> +       data &= 1;
> +       return data;
> +}
> +
> +static void rockchip_gpio_set_debounce(struct gpio_chip *gc,
> +                                      unsigned int offset, bool enable)
> +{
> +       struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
> +       void __iomem *reg = bank->reg_base + GPIO_DEBOUNCE;
> +       unsigned long flags;
> +       u32 data;
> +
> +       raw_spin_lock_irqsave(&bank->slock, flags);
> +
> +       data = readl(reg);
> +       if (enable)
> +               data |= BIT(offset);
> +       else
> +               data &= ~BIT(offset);
> +       writel(data, reg);
> +
> +       raw_spin_unlock_irqrestore(&bank->slock, flags);
> +}
> +
> +static int rockchip_gpio_direction_input(struct gpio_chip *gc,
> +                                        unsigned int offset)
> +{
> +       return rockchip_gpio_set_direction(gc, offset, true);
> +}
> +
> +static int rockchip_gpio_direction_output(struct gpio_chip *gc,
> +                                         unsigned int offset, int value)
> +{
> +       rockchip_gpio_set(gc, offset, value);
> +
> +       return rockchip_gpio_set_direction(gc, offset, false);
> +}
> +
> +/*
> + * gpiolib set_config callback function. The setting of the pin
> + * mux function as 'gpio output' will be handled by the pinctrl subsystem
> + * interface.
> + */
> +static int rockchip_gpio_set_config(struct gpio_chip *gc, unsigned int offset,
> +                                 unsigned long config)
> +{
> +       enum pin_config_param param = pinconf_to_config_param(config);
> +
> +       switch (param) {
> +       case PIN_CONFIG_INPUT_DEBOUNCE:
> +               rockchip_gpio_set_debounce(gc, offset, true);
> +               /*
> +                * Rockchip's gpio could only support up to one period
> +                * of the debounce clock(pclk), which is far away from
> +                * satisftying the requirement, as pclk is usually near
> +                * 100MHz shared by all peripherals. So the fact is it
> +                * has crippled debounce capability could only be useful
> +                * to prevent any spurious glitches from waking up the system
> +                * if the gpio is conguired as wakeup interrupt source. Let's
> +                * still return -ENOTSUPP as before, to make sure the caller
> +                * of gpiod_set_debounce won't change its behaviour.
> +                */
> +               return -ENOTSUPP;
> +       default:
> +               return -ENOTSUPP;
> +       }
> +}
> +
> +/*
> + * gpiolib gpio_to_irq callback function. Creates a mapping between a GPIO pin
> + * and a virtual IRQ, if not already present.
> + */
> +static int rockchip_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
> +{
> +       struct rockchip_pin_bank *bank = gpiochip_get_data(gc);
> +       unsigned int virq;
> +
> +       if (!bank->domain)
> +               return -ENXIO;
> +
> +       virq = irq_create_mapping(bank->domain, offset);
> +
> +       return (virq) ? : -ENXIO;
> +}
> +
> +static const struct gpio_chip rockchip_gpiolib_chip = {
> +       .request = gpiochip_generic_request,
> +       .free = gpiochip_generic_free,
> +       .set = rockchip_gpio_set,
> +       .get = rockchip_gpio_get,
> +       .get_direction  = rockchip_gpio_get_direction,
> +       .direction_input = rockchip_gpio_direction_input,
> +       .direction_output = rockchip_gpio_direction_output,
> +       .set_config = rockchip_gpio_set_config,
> +       .to_irq = rockchip_gpio_to_irq,
> +       .owner = THIS_MODULE,
> +};
> +
> +static void rockchip_irq_demux(struct irq_desc *desc)
> +{
> +       struct irq_chip *chip = irq_desc_get_chip(desc);
> +       struct rockchip_pin_bank *bank = irq_desc_get_handler_data(desc);
> +       u32 pend;
> +
> +       dev_dbg(bank->dev, "got irq for bank %s\n", bank->name);
> +
> +       chained_irq_enter(chip, desc);
> +
> +       pend = readl_relaxed(bank->reg_base + GPIO_INT_STATUS);
> +
> +       while (pend) {
> +               unsigned int irq, virq;
> +
> +               irq = __ffs(pend);
> +               pend &= ~BIT(irq);
> +               virq = irq_find_mapping(bank->domain, irq);
> +
> +               if (!virq) {
> +                       dev_err(bank->dev, "unmapped irq %d\n", irq);
> +                       continue;
> +               }
> +
> +               dev_dbg(bank->dev, "handling irq %d\n", irq);
> +
> +               /*
> +                * Triggering IRQ on both rising and falling edge
> +                * needs manual intervention.
> +                */
> +               if (bank->toggle_edge_mode & BIT(irq)) {
> +                       u32 data, data_old, polarity;
> +                       unsigned long flags;
> +
> +                       data = readl_relaxed(bank->reg_base + GPIO_EXT_PORT);
> +                       do {
> +                               raw_spin_lock_irqsave(&bank->slock, flags);
> +
> +                               polarity = readl_relaxed(bank->reg_base +
> +                                                        GPIO_INT_POLARITY);
> +                               if (data & BIT(irq))
> +                                       polarity &= ~BIT(irq);
> +                               else
> +                                       polarity |= BIT(irq);
> +                               writel(polarity,
> +                                      bank->reg_base + GPIO_INT_POLARITY);
> +
> +                               raw_spin_unlock_irqrestore(&bank->slock, flags);
> +
> +                               data_old = data;
> +                               data = readl_relaxed(bank->reg_base +
> +                                                    GPIO_EXT_PORT);
> +                       } while ((data & BIT(irq)) != (data_old & BIT(irq)));
> +               }
> +
> +               generic_handle_irq(virq);
> +       }
> +
> +       chained_irq_exit(chip, desc);
> +}
> +
> +static int rockchip_irq_set_type(struct irq_data *d, unsigned int type)
> +{
> +       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +       struct rockchip_pin_bank *bank = gc->private;
> +       u32 mask = BIT(d->hwirq);
> +       u32 polarity;
> +       u32 level;
> +       u32 data;
> +       unsigned long flags;
> +
> +       raw_spin_lock_irqsave(&bank->slock, flags);
> +
> +       data = readl_relaxed(bank->reg_base + GPIO_SWPORT_DDR);
> +       data &= ~mask;
> +       writel_relaxed(data, bank->reg_base + GPIO_SWPORT_DDR);
> +
> +       raw_spin_unlock_irqrestore(&bank->slock, flags);
> +
> +       if (type & IRQ_TYPE_EDGE_BOTH)
> +               irq_set_handler_locked(d, handle_edge_irq);
> +       else
> +               irq_set_handler_locked(d, handle_level_irq);
> +
> +       raw_spin_lock_irqsave(&bank->slock, flags);
> +       irq_gc_lock(gc);
> +
> +       level = readl_relaxed(gc->reg_base + GPIO_INTTYPE_LEVEL);
> +       polarity = readl_relaxed(gc->reg_base + GPIO_INT_POLARITY);
> +
> +       switch (type) {
> +       case IRQ_TYPE_EDGE_BOTH:
> +               bank->toggle_edge_mode |= mask;
> +               level |= mask;
> +
> +               /*
> +                * Determine gpio state. If 1 next interrupt should be falling
> +                * otherwise rising.
> +                */
> +               data = readl(bank->reg_base + GPIO_EXT_PORT);
> +               if (data & mask)
> +                       polarity &= ~mask;
> +               else
> +                       polarity |= mask;
> +               break;
> +       case IRQ_TYPE_EDGE_RISING:
> +               bank->toggle_edge_mode &= ~mask;
> +               level |= mask;
> +               polarity |= mask;
> +               break;
> +       case IRQ_TYPE_EDGE_FALLING:
> +               bank->toggle_edge_mode &= ~mask;
> +               level |= mask;
> +               polarity &= ~mask;
> +               break;
> +       case IRQ_TYPE_LEVEL_HIGH:
> +               bank->toggle_edge_mode &= ~mask;
> +               level &= ~mask;
> +               polarity |= mask;
> +               break;
> +       case IRQ_TYPE_LEVEL_LOW:
> +               bank->toggle_edge_mode &= ~mask;
> +               level &= ~mask;
> +               polarity &= ~mask;
> +               break;
> +       default:
> +               irq_gc_unlock(gc);
> +               raw_spin_unlock_irqrestore(&bank->slock, flags);
> +               clk_disable(bank->clk);
> +               return -EINVAL;
> +       }
> +
> +       writel_relaxed(level, gc->reg_base + GPIO_INTTYPE_LEVEL);
> +       writel_relaxed(polarity, gc->reg_base + GPIO_INT_POLARITY);
> +
> +       irq_gc_unlock(gc);
> +       raw_spin_unlock_irqrestore(&bank->slock, flags);
> +
> +       return 0;
> +}
> +
> +static void rockchip_irq_suspend(struct irq_data *d)
> +{
> +       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +       struct rockchip_pin_bank *bank = gc->private;
> +
> +       bank->saved_masks = irq_reg_readl(gc, GPIO_INTMASK);
> +       irq_reg_writel(gc, ~gc->wake_active, GPIO_INTMASK);
> +}
> +
> +static void rockchip_irq_resume(struct irq_data *d)
> +{
> +       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +       struct rockchip_pin_bank *bank = gc->private;
> +
> +       irq_reg_writel(gc, bank->saved_masks, GPIO_INTMASK);
> +}
> +
> +static void rockchip_irq_enable(struct irq_data *d)
> +{
> +       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +       struct rockchip_pin_bank *bank = gc->private;
> +
> +       irq_gc_mask_clr_bit(d);
> +}
> +
> +static void rockchip_irq_disable(struct irq_data *d)
> +{
> +       struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
> +       struct rockchip_pin_bank *bank = gc->private;
> +
> +       irq_gc_mask_set_bit(d);
> +       clk_disable(bank->clk);
> +}
> +
> +static int rockchip_interrupts_register(struct rockchip_pin_bank *bank)
> +{
> +       unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
> +       struct irq_chip_generic *gc;
> +       int ret;
> +
> +       bank->domain = irq_domain_add_linear(bank->of_node, 32,
> +                                       &irq_generic_chip_ops, NULL);
> +       if (!bank->domain) {
> +               dev_warn(bank->dev, "could not init irq domain for bank %s\n",
> +                        bank->name);
> +               return -EINVAL;
> +       }
> +
> +       ret = irq_alloc_domain_generic_chips(bank->domain, 32, 1,
> +                                            "rockchip_gpio_irq",
> +                                            handle_level_irq,
> +                                            clr, 0, 0);
> +       if (ret) {
> +               dev_err(bank->dev, "could not alloc generic chips for bank %s\n",
> +                       bank->name);
> +               irq_domain_remove(bank->domain);
> +               return -EINVAL;
> +       }
> +
> +       gc = irq_get_domain_generic_chip(bank->domain, 0);
> +       gc->reg_base = bank->reg_base;
> +       gc->private = bank;
> +       gc->chip_types[0].regs.mask = GPIO_INTMASK;
> +       gc->chip_types[0].regs.ack = GPIO_PORTS_EOI;
> +       gc->chip_types[0].chip.irq_ack = irq_gc_ack_set_bit;
> +       gc->chip_types[0].chip.irq_mask = irq_gc_mask_set_bit;
> +       gc->chip_types[0].chip.irq_unmask = irq_gc_mask_clr_bit;
> +       gc->chip_types[0].chip.irq_enable = rockchip_irq_enable;
> +       gc->chip_types[0].chip.irq_disable = rockchip_irq_disable;
> +       gc->chip_types[0].chip.irq_set_wake = irq_gc_set_wake;
> +       gc->chip_types[0].chip.irq_suspend = rockchip_irq_suspend;
> +       gc->chip_types[0].chip.irq_resume = rockchip_irq_resume;
> +       gc->chip_types[0].chip.irq_set_type = rockchip_irq_set_type;
> +       gc->wake_enabled = IRQ_MSK(bank->nr_pins);
> +
> +       /*
> +        * Linux assumes that all interrupts start out disabled/masked.
> +        * Our driver only uses the concept of masked and always keeps
> +        * things enabled, so for us that's all masked and all enabled.
> +        */
> +       writel_relaxed(0xffffffff, bank->reg_base + GPIO_INTMASK);
> +       writel_relaxed(0xffffffff, bank->reg_base + GPIO_PORTS_EOI);
> +       writel_relaxed(0xffffffff, bank->reg_base + GPIO_INTEN);
> +       gc->mask_cache = 0xffffffff;
> +
> +       irq_set_chained_handler_and_data(bank->irq,
> +                                        rockchip_irq_demux, bank);
> +
> +       return 0;
> +}
> +
> +static int rockchip_gpiolib_register(struct rockchip_pin_bank *bank)
> +{
> +       struct gpio_chip *gc;
> +       int ret;
> +
> +       bank->gpio_chip = rockchip_gpiolib_chip;
> +
> +       gc = &bank->gpio_chip;
> +       gc->base = bank->pin_base;
> +       gc->ngpio = bank->nr_pins;
> +       gc->label = bank->name;
> +       gc->parent = bank->dev;
> +#ifdef CONFIG_OF_GPIO
> +       gc->of_node = of_node_get(bank->of_node);
> +#endif
> +
> +       ret = gpiochip_add_data(gc, bank);
> +       if (ret) {
> +               dev_err(bank->dev, "failed to add gpiochip %s, %d\n",
> +                       gc->label, ret);
> +               return ret;
> +       }
> +
> +       /*
> +        * For DeviceTree-supported systems, the gpio core checks the
> +        * pinctrl's device node for the "gpio-ranges" property.
> +        * If it is present, it takes care of adding the pin ranges
> +        * for the driver. In this case the driver can skip ahead.
> +        *
> +        * In order to remain compatible with older, existing DeviceTree
> +        * files which don't set the "gpio-ranges" property or systems that
> +        * utilize ACPI the driver has to call gpiochip_add_pin_range().
> +        */
> +       if (!of_property_read_bool(bank->of_node, "gpio-ranges")) {
> +               struct device_node *pctlnp = of_get_parent(bank->of_node);
> +               struct pinctrl_dev *pctldev = NULL;
> +
> +               if (!pctlnp)
> +                       return -ENODATA;
> +
> +               pctldev = of_pinctrl_get(pctlnp);
> +               if (!pctldev)
> +                       return -ENODEV;
> +
> +               ret = gpiochip_add_pin_range(gc, dev_name(pctldev->dev), 0,
> +                                            gc->base, gc->ngpio);
> +               if (ret) {
> +                       dev_err(bank->dev, "Failed to add pin range\n");
> +                       goto fail;
> +               }
> +       }
> +
> +       ret = rockchip_interrupts_register(bank);
> +       if (ret) {
> +               dev_err(bank->dev, "failed to register interrupt, %d\n", ret);
> +               goto fail;
> +       }
> +
> +       return 0;
> +
> +fail:
> +       gpiochip_remove(&bank->gpio_chip);
> +
> +       return ret;
> +}
> +
> +static int rockchip_get_bank_data(struct rockchip_pin_bank *bank)
> +{
> +       struct resource res;
> +
> +       if (of_address_to_resource(bank->of_node, 0, &res)) {
> +               dev_err(bank->dev, "cannot find IO resource for bank\n");
> +               return -ENOENT;
> +       }
> +
> +       bank->reg_base = devm_ioremap_resource(bank->dev, &res);
> +       if (IS_ERR(bank->reg_base))
> +               return PTR_ERR(bank->reg_base);
> +
> +       bank->irq = irq_of_parse_and_map(bank->of_node, 0);
> +
> +       bank->clk = of_clk_get(bank->of_node, 0);
> +       if (!IS_ERR(bank->clk))
> +               return clk_prepare_enable(bank->clk);
> +
> +       bank->clk = NULL;
> +       return 0;
> +}
> +
> +static struct rockchip_pin_bank *
> +rockchip_gpio_find_bank(struct pinctrl_dev *pctldev, int id)
> +{
> +       struct rockchip_pinctrl *info;
> +       struct rockchip_pin_bank *bank;
> +       int i, found = 0;
> +
> +       info = pinctrl_dev_get_drvdata(pctldev);
> +       bank = info->ctrl->pin_banks;
> +       for (i = 0; i < info->ctrl->nr_banks; i++, bank++) {
> +               if (bank->bank_num == id) {
> +                       found = 1;
> +                       break;
> +               }
> +       }
> +
> +       return found ? bank : NULL;
> +}
> +
> +static int rockchip_gpio_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct device_node *np = dev->of_node;
> +       struct device_node *pctlnp = of_get_parent(np);
> +       struct pinctrl_dev *pctldev = NULL;
> +       struct rockchip_pin_bank *bank = NULL;
> +       static int gpio;
> +       int id, ret;
> +
> +       if (!np || !pctlnp)
> +               return -ENODEV;
> +
> +       pctldev = of_pinctrl_get(pctlnp);
> +       if (!pctldev)
> +               return -EPROBE_DEFER;
> +
> +       id = of_alias_get_id(np, "gpio");
> +       if (id < 0)
> +               id = gpio++;
> +
> +       bank = rockchip_gpio_find_bank(pctldev, id);
> +       if (!bank)
> +               return -EINVAL;
> +
> +       bank->dev = dev;
> +       bank->of_node = np;
> +
> +       raw_spin_lock_init(&bank->slock);
> +
> +       ret = rockchip_get_bank_data(bank);
> +       if (ret)
> +               return ret;
> +
> +       ret = rockchip_gpiolib_register(bank);
> +       if (ret) {
> +               clk_disable_unprepare(bank->clk);
> +               return ret;
> +       }
> +
> +       platform_set_drvdata(pdev, bank);
> +       dev_info(dev, "probed %pOF\n", np);
> +
> +       return 0;
> +}
> +
> +static int rockchip_gpio_remove(struct platform_device *pdev)
> +{
> +       struct rockchip_pin_bank *bank = platform_get_drvdata(pdev);
> +
> +       clk_disable_unprepare(bank->clk);
> +       gpiochip_remove(&bank->gpio_chip);

All release functions for devres will be called after the remove()
callback so you can use the devm variant for adding the chip. In fact
- I would prefer the clk_disable_unprepare() to be called in a
callback registered with devm_add_action_or_reset() which will also
simplify the error handling in probe.

> +
> +       return 0;
> +}
> +
> +static const struct of_device_id rockchip_gpio_match[] = {
> +       { .compatible = "rockchip,gpio-bank", },
> +       { .compatible = "rockchip,rk3188-gpio-bank0" },
> +       { },
> +};
> +
> +static struct platform_driver rockchip_gpio_driver = {
> +       .probe          = rockchip_gpio_probe,
> +       .remove         = rockchip_gpio_remove,
> +       .driver         = {
> +               .name   = "rockchip-gpio",
> +               .of_match_table = rockchip_gpio_match,
> +       },
> +};
> +
> +static int __init rockchip_gpio_init(void)
> +{
> +       return platform_driver_register(&rockchip_gpio_driver);
> +}
> +postcore_initcall(rockchip_gpio_init);

Mind to add a comment why this is needed?

> +
> +static void __exit rockchip_gpio_exit(void)
> +{
> +       platform_driver_unregister(&rockchip_gpio_driver);
> +}
> +module_exit(rockchip_gpio_exit);
> +
> +MODULE_DESCRIPTION("Rockchip gpio driver");
> +MODULE_ALIAS("platform:rockchip-gpio");
> +MODULE_LICENSE("GPL v2");
> +MODULE_DEVICE_TABLE(of, rockchip_gpio_match);
> --
> 2.25.1
>
>
>