root/drivers/pinctrl/meson/pinctrl-amlogic-a4.c
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause)
/*
 * Copyright (c) 2024 Amlogic, Inc. All rights reserved.
 * Author: Xianwei Zhao <xianwei.zhao@amlogic.com>
 */

#include <linux/err.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string_helpers.h>

#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <dt-bindings/pinctrl/amlogic,pinctrl.h>

#include "../core.h"
#include "../pinctrl-utils.h"
#include "../pinconf.h"

#define gpio_chip_to_bank(chip) \
                container_of(chip, struct aml_gpio_bank, gpio_chip)

#define AML_REG_PULLEN          0
#define AML_REG_PULL            1
#define AML_REG_DIR             2
#define AML_REG_OUT             3
#define AML_REG_IN              4
#define AML_REG_DS              5
#define AML_NUM_REG             6

enum aml_pinconf_drv {
        PINCONF_DRV_500UA,
        PINCONF_DRV_2500UA,
        PINCONF_DRV_3000UA,
        PINCONF_DRV_4000UA,
};

struct aml_pio_control {
        u32 gpio_offset;
        u32 reg_offset[AML_NUM_REG];
        u32 bit_offset[AML_NUM_REG];
};

/*
 * partial bank(subordinate) pins mux config use other bank(main) mux registgers
 * m_bank_id:   the main bank which pin_id from 0, but register bit not from bit 0
 * m_bit_offs:  bit offset the main bank mux register
 * sid:         start pin_id of subordinate bank
 * eid:         end pin_id of subordinate bank
 */
struct multi_mux {
        unsigned int m_bank_id;
        unsigned int m_bit_offs;
        unsigned int sid;
        unsigned int eid;
};

struct aml_pctl_data {
        unsigned int number;
        const struct multi_mux *p_mux;
};

struct aml_pmx_func {
        const char      *name;
        const char      **groups;
        unsigned int    ngroups;
};

struct aml_pctl_group {
        const char              *name;
        unsigned int            npins;
        unsigned int            *pins;
        unsigned int            *func;
};

struct aml_gpio_bank {
        struct gpio_chip                gpio_chip;
        struct aml_pio_control          pc;
        u32                             bank_id;
        u32                             mux_bit_offs;
        unsigned int                    pin_base;
        struct regmap                   *reg_mux;
        struct regmap                   *reg_gpio;
        struct regmap                   *reg_ds;
        const struct multi_mux          *p_mux;
};

struct aml_pinctrl {
        struct device                   *dev;
        struct pinctrl_dev              *pctl;
        struct aml_gpio_bank            *banks;
        int                             nbanks;
        struct aml_pmx_func             *functions;
        int                             nfunctions;
        struct aml_pctl_group           *groups;
        int                             ngroups;

        const struct aml_pctl_data      *data;
};

static const unsigned int aml_bit_strides[AML_NUM_REG] = {
        1, 1, 1, 1, 1, 2
};

static const unsigned int aml_def_regoffs[AML_NUM_REG] = {
        3, 4, 2, 1, 0, 7
};

static const char *aml_bank_name[31] = {
"GPIOA", "GPIOB", "GPIOC", "GPIOD", "GPIOE", "GPIOF", "GPIOG",
"GPIOH", "GPIOI", "GPIOJ", "GPIOK", "GPIOL", "GPIOM", "GPION",
"GPIOO", "GPIOP", "GPIOQ", "GPIOR", "GPIOS", "GPIOT", "GPIOU",
"GPIOV", "GPIOW", "GPIOX", "GPIOY", "GPIOZ", "GPIODV", "GPIOAO",
"GPIOCC", "TEST_N", "ANALOG"
};

static const struct multi_mux multi_mux_s7[] = {
        {
                .m_bank_id = AMLOGIC_GPIO_CC,
                .m_bit_offs = 24,
                .sid = (AMLOGIC_GPIO_X << 8) + 16,
                .eid = (AMLOGIC_GPIO_X << 8) + 19,
        },
};

static const struct aml_pctl_data s7_priv_data = {
        .number = ARRAY_SIZE(multi_mux_s7),
        .p_mux = multi_mux_s7,
};

static const struct multi_mux multi_mux_s6[] = {
        {
                .m_bank_id = AMLOGIC_GPIO_CC,
                .m_bit_offs = 24,
                .sid = (AMLOGIC_GPIO_X << 8) + 16,
                .eid = (AMLOGIC_GPIO_X << 8) + 19,
        }, {
                .m_bank_id = AMLOGIC_GPIO_F,
                .m_bit_offs = 4,
                .sid = (AMLOGIC_GPIO_D << 8) + 6,
                .eid = (AMLOGIC_GPIO_D << 8) + 6,
        },
};

static const struct aml_pctl_data s6_priv_data = {
        .number = ARRAY_SIZE(multi_mux_s6),
        .p_mux = multi_mux_s6,
};

static int aml_pmx_calc_reg_and_offset(struct pinctrl_gpio_range *range,
                                       unsigned int pin, unsigned int *reg,
                                       unsigned int *offset)
{
        unsigned int shift;

        shift = ((pin - range->pin_base) << 2) + *offset;
        *reg = (shift / 32) * 4;
        *offset = shift % 32;

        return 0;
}

static int aml_pctl_set_function(struct aml_pinctrl *info,
                                 struct pinctrl_gpio_range *range,
                                 int pin_id, int func)
{
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int shift;
        int reg;
        int i;
        unsigned int offset = bank->mux_bit_offs;
        const struct multi_mux *p_mux;

        /* peculiar mux reg set */
        if (bank->p_mux) {
                p_mux = bank->p_mux;
                if (pin_id >= p_mux->sid && pin_id <= p_mux->eid) {
                        bank = NULL;
                        for (i = 0; i < info->nbanks; i++) {
                                if (info->banks[i].bank_id == p_mux->m_bank_id) {
                                        bank = &info->banks[i];
                                                break;
                                }
                        }

                        if (!bank || !bank->reg_mux)
                                return -EINVAL;

                        shift = (pin_id - p_mux->sid) << 2;
                        reg = (shift / 32) * 4;
                        offset = shift % 32;
                        return regmap_update_bits(bank->reg_mux, reg,
                                        0xf << offset, (func & 0xf) << offset);
                }
        }

        /* normal mux reg set */
        if (!bank->reg_mux)
                return 0;

        aml_pmx_calc_reg_and_offset(range, pin_id, &reg, &offset);
        return regmap_update_bits(bank->reg_mux, reg,
                        0xf << offset, (func & 0xf) << offset);
}

static int aml_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->nfunctions;
}

static const char *aml_pmx_get_fname(struct pinctrl_dev *pctldev,
                                     unsigned int selector)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->functions[selector].name;
}

static int aml_pmx_get_groups(struct pinctrl_dev *pctldev,
                              unsigned int selector,
                              const char * const **grps,
                              unsigned * const ngrps)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        *grps = info->functions[selector].groups;
        *ngrps = info->functions[selector].ngroups;

        return 0;
}

static int aml_pmx_set_mux(struct pinctrl_dev *pctldev, unsigned int fselector,
                           unsigned int group_id)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);
        struct aml_pctl_group *group = &info->groups[group_id];
        struct pinctrl_gpio_range *range;
        int i;

        for (i = 0; i < group->npins; i++) {
                range =  pinctrl_find_gpio_range_from_pin(pctldev, group->pins[i]);
                aml_pctl_set_function(info, range, group->pins[i], group->func[i]);
        }

        return 0;
}

static int aml_pmx_request_gpio(struct pinctrl_dev *pctldev,
                                struct pinctrl_gpio_range *range,
                                unsigned int pin)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return aml_pctl_set_function(info, range, pin, 0);
}

static const struct pinmux_ops aml_pmx_ops = {
        .set_mux                = aml_pmx_set_mux,
        .get_functions_count    = aml_pmx_get_funcs_count,
        .get_function_name      = aml_pmx_get_fname,
        .get_function_groups    = aml_pmx_get_groups,
        .gpio_request_enable    = aml_pmx_request_gpio,
};

static int aml_calc_reg_and_bit(struct pinctrl_gpio_range *range,
                                unsigned int pin,
                                unsigned int reg_type,
                                unsigned int *reg, unsigned int *bit)
{
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);

        *bit = (pin - range->pin_base) * aml_bit_strides[reg_type]
                + bank->pc.bit_offset[reg_type];
        *reg = (bank->pc.reg_offset[reg_type] + (*bit / 32)) * 4;
        *bit &= 0x1f;

        return 0;
}

static int aml_pinconf_get_pull(struct aml_pinctrl *info, unsigned int pin)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit, val;
        int ret, conf;

        aml_calc_reg_and_bit(range, pin, AML_REG_PULLEN, &reg, &bit);

        ret = regmap_read(bank->reg_gpio, reg, &val);
        if (ret)
                return ret;

        if (!(val & BIT(bit))) {
                conf = PIN_CONFIG_BIAS_DISABLE;
        } else {
                aml_calc_reg_and_bit(range, pin, AML_REG_PULL, &reg, &bit);

                ret = regmap_read(bank->reg_gpio, reg, &val);
                if (ret)
                        return ret;

                if (val & BIT(bit))
                        conf = PIN_CONFIG_BIAS_PULL_UP;
                else
                        conf = PIN_CONFIG_BIAS_PULL_DOWN;
        }

        return conf;
}

static int aml_pinconf_get_drive_strength(struct aml_pinctrl *info,
                                          unsigned int pin,
                                          u16 *drive_strength_ua)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit;
        unsigned int val;
        int ret;

        if (!bank->reg_ds)
                return -EOPNOTSUPP;

        aml_calc_reg_and_bit(range, pin, AML_REG_DS, &reg, &bit);
        ret = regmap_read(bank->reg_ds, reg, &val);
        if (ret)
                return ret;

        switch ((val >> bit) & 0x3) {
        case PINCONF_DRV_500UA:
                *drive_strength_ua = 500;
                break;
        case PINCONF_DRV_2500UA:
                *drive_strength_ua = 2500;
                break;
        case PINCONF_DRV_3000UA:
                *drive_strength_ua = 3000;
                break;
        case PINCONF_DRV_4000UA:
                *drive_strength_ua = 4000;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int aml_pinconf_get_gpio_bit(struct aml_pinctrl *info,
                                    unsigned int pin,
                                    unsigned int reg_type)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit, val;
        int ret;

        aml_calc_reg_and_bit(range, pin, reg_type, &reg, &bit);
        ret = regmap_read(bank->reg_gpio, reg, &val);
        if (ret)
                return ret;

        return BIT(bit) & val ? 1 : 0;
}

static int aml_pinconf_get_output(struct aml_pinctrl *info,
                                  unsigned int pin)
{
        int ret = aml_pinconf_get_gpio_bit(info, pin, AML_REG_DIR);

        if (ret < 0)
                return ret;

        return !ret;
}

static int aml_pinconf_get_drive(struct aml_pinctrl *info,
                                 unsigned int pin)
{
        return aml_pinconf_get_gpio_bit(info, pin, AML_REG_OUT);
}

static int aml_pinconf_get(struct pinctrl_dev *pcdev, unsigned int pin,
                           unsigned long *config)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pcdev);
        enum pin_config_param param = pinconf_to_config_param(*config);
        u16 arg;
        int ret;

        switch (param) {
        case PIN_CONFIG_BIAS_DISABLE:
        case PIN_CONFIG_BIAS_PULL_DOWN:
        case PIN_CONFIG_BIAS_PULL_UP:
                if (aml_pinconf_get_pull(info, pin) == param)
                        arg = 1;
                else
                        return -EINVAL;
                break;
        case PIN_CONFIG_DRIVE_STRENGTH_UA:
                ret = aml_pinconf_get_drive_strength(info, pin, &arg);
                if (ret)
                        return ret;
                break;
        case PIN_CONFIG_OUTPUT_ENABLE:
                ret = aml_pinconf_get_output(info, pin);
                if (ret <= 0)
                        return -EINVAL;
                arg = 1;
                break;
        case PIN_CONFIG_LEVEL:
                ret = aml_pinconf_get_output(info, pin);
                if (ret <= 0)
                        return -EINVAL;

                ret = aml_pinconf_get_drive(info, pin);
                if (ret < 0)
                        return -EINVAL;

                arg = ret;
                break;

        default:
                return -ENOTSUPP;
        }

        *config = pinconf_to_config_packed(param, arg);
        dev_dbg(info->dev, "pinconf for pin %u is %lu\n", pin, *config);

        return 0;
}

static int aml_pinconf_disable_bias(struct aml_pinctrl *info,
                                    unsigned int pin)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit = 0;

        aml_calc_reg_and_bit(range, pin, AML_REG_PULLEN, &reg, &bit);

        return regmap_update_bits(bank->reg_gpio, reg, BIT(bit), 0);
}

static int aml_pinconf_enable_bias(struct aml_pinctrl *info, unsigned int pin,
                                   bool pull_up)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit, val = 0;
        int ret;

        aml_calc_reg_and_bit(range, pin, AML_REG_PULL, &reg, &bit);
        if (pull_up)
                val = BIT(bit);

        ret = regmap_update_bits(bank->reg_gpio, reg, BIT(bit), val);
        if (ret)
                return ret;

        aml_calc_reg_and_bit(range, pin, AML_REG_PULLEN, &reg, &bit);
        return regmap_update_bits(bank->reg_gpio, reg, BIT(bit), BIT(bit));
}

static int aml_pinconf_set_drive_strength(struct aml_pinctrl *info,
                                          unsigned int pin,
                                          u16 drive_strength_ua)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit, ds_val;

        if (!bank->reg_ds) {
                dev_err(info->dev, "drive-strength not supported\n");
                return -EOPNOTSUPP;
        }

        aml_calc_reg_and_bit(range, pin, AML_REG_DS, &reg, &bit);

        if (drive_strength_ua <= 500) {
                ds_val = PINCONF_DRV_500UA;
        } else if (drive_strength_ua <= 2500) {
                ds_val = PINCONF_DRV_2500UA;
        } else if (drive_strength_ua <= 3000) {
                ds_val = PINCONF_DRV_3000UA;
        } else if (drive_strength_ua <= 4000) {
                ds_val = PINCONF_DRV_4000UA;
        } else {
                dev_warn_once(info->dev,
                              "pin %u: invalid drive-strength : %d , default to 4mA\n",
                              pin, drive_strength_ua);
                ds_val = PINCONF_DRV_4000UA;
        }

        return regmap_update_bits(bank->reg_ds, reg, 0x3 << bit, ds_val << bit);
}

static int aml_pinconf_set_gpio_bit(struct aml_pinctrl *info,
                                    unsigned int pin,
                                    unsigned int reg_type,
                                    bool arg)
{
        struct pinctrl_gpio_range *range =
                         pinctrl_find_gpio_range_from_pin(info->pctl, pin);
        struct aml_gpio_bank *bank = gpio_chip_to_bank(range->gc);
        unsigned int reg, bit;

        aml_calc_reg_and_bit(range, pin, reg_type, &reg, &bit);
        return regmap_update_bits(bank->reg_gpio, reg, BIT(bit),
                                  arg ? BIT(bit) : 0);
}

static int aml_pinconf_set_output(struct aml_pinctrl *info,
                                  unsigned int pin,
                                  bool out)
{
        return aml_pinconf_set_gpio_bit(info, pin, AML_REG_DIR, !out);
}

static int aml_pinconf_set_drive(struct aml_pinctrl *info,
                                 unsigned int pin,
                                 bool high)
{
        return aml_pinconf_set_gpio_bit(info, pin, AML_REG_OUT, high);
}

static int aml_pinconf_set_output_drive(struct aml_pinctrl *info,
                                        unsigned int pin,
                                        bool high)
{
        int ret;

        ret = aml_pinconf_set_output(info, pin, true);
        if (ret)
                return ret;

        return aml_pinconf_set_drive(info, pin, high);
}

static int aml_pinconf_set(struct pinctrl_dev *pcdev, unsigned int pin,
                           unsigned long *configs, unsigned int num_configs)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pcdev);
        enum pin_config_param param;
        unsigned int arg = 0;
        int i, ret;

        for (i = 0; i < num_configs; i++) {
                param = pinconf_to_config_param(configs[i]);

                switch (param) {
                case PIN_CONFIG_DRIVE_STRENGTH_UA:
                case PIN_CONFIG_OUTPUT_ENABLE:
                case PIN_CONFIG_LEVEL:
                        arg = pinconf_to_config_argument(configs[i]);
                        break;

                default:
                        break;
                }

                switch (param) {
                case PIN_CONFIG_BIAS_DISABLE:
                        ret = aml_pinconf_disable_bias(info, pin);
                        break;
                case PIN_CONFIG_BIAS_PULL_UP:
                        ret = aml_pinconf_enable_bias(info, pin, true);
                        break;
                case PIN_CONFIG_BIAS_PULL_DOWN:
                        ret = aml_pinconf_enable_bias(info, pin, false);
                        break;
                case PIN_CONFIG_DRIVE_STRENGTH_UA:
                        ret = aml_pinconf_set_drive_strength(info, pin, arg);
                        break;
                case PIN_CONFIG_OUTPUT_ENABLE:
                        ret = aml_pinconf_set_output(info, pin, arg);
                        break;
                case PIN_CONFIG_LEVEL:
                        ret = aml_pinconf_set_output_drive(info, pin, arg);
                        break;
                default:
                        ret = -ENOTSUPP;
                }

                if (ret)
                        return ret;
        }

        return 0;
}

static int aml_pinconf_group_set(struct pinctrl_dev *pcdev,
                                 unsigned int num_group,
                                 unsigned long *configs,
                                 unsigned int num_configs)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pcdev);
        int i;

        for (i = 0; i < info->groups[num_group].npins; i++) {
                aml_pinconf_set(pcdev, info->groups[num_group].pins[i], configs,
                                num_configs);
        }

        return 0;
}

static int aml_pinconf_group_get(struct pinctrl_dev *pcdev,
                                 unsigned int group, unsigned long *config)
{
        return -EOPNOTSUPP;
}

static const struct pinconf_ops aml_pinconf_ops = {
        .pin_config_get         = aml_pinconf_get,
        .pin_config_set         = aml_pinconf_set,
        .pin_config_group_get   = aml_pinconf_group_get,
        .pin_config_group_set   = aml_pinconf_group_set,
        .is_generic             = true,
};

static int aml_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->ngroups;
}

static const char *aml_get_group_name(struct pinctrl_dev *pctldev,
                                      unsigned int selector)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        return info->groups[selector].name;
}

static int aml_get_group_pins(struct pinctrl_dev *pctldev,
                              unsigned int selector, const unsigned int **pins,
                              unsigned int *npins)
{
        struct aml_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);

        if (selector >= info->ngroups)
                return -EINVAL;

        *pins = info->groups[selector].pins;
        *npins = info->groups[selector].npins;

        return 0;
}

static void aml_pin_dbg_show(struct pinctrl_dev *pcdev, struct seq_file *s,
                             unsigned int offset)
{
        seq_printf(s, " %s", dev_name(pcdev->dev));
}

static int aml_dt_node_to_map_pinmux(struct pinctrl_dev *pctldev,
                                     struct device_node *np,
                                     struct pinctrl_map **map,
                                     unsigned int *num_maps)
{
        struct device *dev = pctldev->dev;
        unsigned long *configs = NULL;
        unsigned int num_configs = 0;
        struct property *prop;
        unsigned int reserved_maps;
        int reserve;
        int ret;

        prop = of_find_property(np, "pinmux", NULL);
        if (!prop) {
                dev_info(dev, "Missing pinmux property\n");
                return -ENOENT;
        }

        struct device_node *pnode __free(device_node) = of_get_parent(np);
        if (!pnode) {
                dev_info(dev, "Missing function node\n");
                return -EINVAL;
        }

        reserved_maps = 0;
        *map = NULL;
        *num_maps = 0;

        ret = pinconf_generic_parse_dt_config(np, pctldev, &configs,
                                              &num_configs);
        if (ret < 0) {
                dev_err(dev, "%pOF: could not parse node property\n", np);
                return ret;
        }

        reserve = 1;
        if (num_configs)
                reserve++;

        ret = pinctrl_utils_reserve_map(pctldev, map, &reserved_maps,
                                        num_maps, reserve);
        if (ret < 0)
                goto exit;

        ret = pinctrl_utils_add_map_mux(pctldev, map,
                                        &reserved_maps, num_maps, np->name,
                                        pnode->name);
        if (ret < 0)
                goto exit;

        if (num_configs) {
                ret = pinctrl_utils_add_map_configs(pctldev, map, &reserved_maps,
                                                    num_maps, np->name, configs,
                                                    num_configs, PIN_MAP_TYPE_CONFIGS_GROUP);
                if (ret < 0)
                        goto exit;
        }

exit:
        kfree(configs);
        if (ret)
                pinctrl_utils_free_map(pctldev, *map, *num_maps);

        return ret;
}

static const struct pinctrl_ops aml_pctrl_ops = {
        .get_groups_count       = aml_get_groups_count,
        .get_group_name         = aml_get_group_name,
        .get_group_pins         = aml_get_group_pins,
        .dt_node_to_map         = aml_dt_node_to_map_pinmux,
        .dt_free_map            = pinconf_generic_dt_free_map,
        .pin_dbg_show           = aml_pin_dbg_show,
};

static int aml_pctl_parse_functions(struct device_node *np,
                                    struct aml_pinctrl *info, u32 index,
                                    int *grp_index)
{
        struct device *dev = info->dev;
        struct aml_pmx_func *func;
        struct aml_pctl_group *grp;
        int ret, i;

        func = &info->functions[index];
        func->name = np->name;
        func->ngroups = of_get_child_count(np);
        if (func->ngroups == 0)
                return dev_err_probe(dev, -EINVAL, "No groups defined\n");

        func->groups = devm_kcalloc(dev, func->ngroups, sizeof(*func->groups), GFP_KERNEL);
        if (!func->groups)
                return -ENOMEM;

        i = 0;
        for_each_child_of_node_scoped(np, child) {
                func->groups[i++] = child->name;
                grp = &info->groups[*grp_index];
                grp->name = child->name;
                *grp_index += 1;
                ret = pinconf_generic_parse_dt_pinmux(child, dev, &grp->pins,
                                                      &grp->func, &grp->npins);
                if (ret) {
                        dev_err(dev, "function :%s, groups:%s fail\n", func->name, child->name);
                        return ret;
                }
        }
        dev_dbg(dev, "Function[%d\t name:%s,\tgroups:%d]\n", index, func->name, func->ngroups);

        return 0;
}

static u32 aml_bank_pins(struct device_node *np)
{
        struct of_phandle_args of_args;

        if (of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
                                             0, &of_args))
                return 0;

        of_node_put(of_args.np);
        return of_args.args[2];
}

static int aml_bank_number(struct device_node *np)
{
        struct of_phandle_args of_args;

        if (of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
                                             0, &of_args))
                return -EINVAL;

        of_node_put(of_args.np);
        return of_args.args[1] >> 8;
}

static unsigned int aml_count_pins(struct device_node *np)
{
        struct device_node *child;
        unsigned int pins = 0;

        for_each_child_of_node(np, child) {
                if (of_property_read_bool(child, "gpio-controller"))
                        pins += aml_bank_pins(child);
        }

        return pins;
}

/*
 * A pinctrl device contains two types of nodes. The one named GPIO
 * bank which includes gpio-controller property. The other one named
 * function which includes one or more pin groups. The pin group
 * include pinmux property(global index in pinctrl dev, and mux vlaue
 * in mux reg) and pin configuration properties.
 */
static void aml_pctl_dt_child_count(struct aml_pinctrl *info,
                                    struct device_node *np)
{
        struct device_node *child;

        for_each_child_of_node(np, child) {
                if (of_property_read_bool(child, "gpio-controller")) {
                        info->nbanks++;
                } else {
                        info->nfunctions++;
                        info->ngroups += of_get_child_count(child);
                }
        }
}

static struct regmap *aml_map_resource(struct device *dev, unsigned int id,
                                       struct device_node *node, char *name)
{
        struct resource res;
        void __iomem *base;
        int i;

        struct regmap_config aml_regmap_config = {
                .reg_bits = 32,
                .val_bits = 32,
                .reg_stride = 4,
        };

        i = of_property_match_string(node, "reg-names", name);
        if (i < 0)
                return NULL;
        if (of_address_to_resource(node, i, &res))
                return NULL;
        base = devm_ioremap_resource(dev, &res);
        if (IS_ERR(base))
                return ERR_CAST(base);

        aml_regmap_config.max_register = resource_size(&res) - 4;
        aml_regmap_config.name = devm_kasprintf(dev, GFP_KERNEL,
                                                "%s-%s", aml_bank_name[id], name);
        if (!aml_regmap_config.name)
                return ERR_PTR(-ENOMEM);

        return devm_regmap_init_mmio(dev, base, &aml_regmap_config);
}

static inline int aml_gpio_calc_reg_and_bit(struct aml_gpio_bank *bank,
                                            unsigned int reg_type,
                                            unsigned int gpio,
                                            unsigned int *reg,
                                            unsigned int *bit)
{
        *bit = gpio * aml_bit_strides[reg_type] + bank->pc.bit_offset[reg_type];
        *reg = (bank->pc.reg_offset[reg_type] + (*bit / 32)) * 4;
        *bit &= 0x1f;

        return 0;
}

static int aml_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
{
        struct aml_gpio_bank *bank = gpiochip_get_data(chip);
        unsigned int bit, reg, val;
        int ret;

        aml_gpio_calc_reg_and_bit(bank, AML_REG_DIR, gpio, &reg, &bit);

        ret = regmap_read(bank->reg_gpio, reg, &val);
        if (ret)
                return ret;

        return BIT(bit) & val ? GPIO_LINE_DIRECTION_IN : GPIO_LINE_DIRECTION_OUT;
}

static int aml_gpio_direction_input(struct gpio_chip *chip, unsigned int gpio)
{
        struct aml_gpio_bank *bank = gpiochip_get_data(chip);
        unsigned int bit, reg;

        aml_gpio_calc_reg_and_bit(bank, AML_REG_DIR, gpio, &reg, &bit);

        return regmap_update_bits(bank->reg_gpio, reg, BIT(bit), BIT(bit));
}

static int aml_gpio_direction_output(struct gpio_chip *chip, unsigned int gpio,
                                     int value)
{
        struct aml_gpio_bank *bank = gpiochip_get_data(chip);
        unsigned int bit, reg;
        int ret;

        aml_gpio_calc_reg_and_bit(bank, AML_REG_DIR, gpio, &reg, &bit);
        ret = regmap_update_bits(bank->reg_gpio, reg, BIT(bit), 0);
        if (ret < 0)
                return ret;

        aml_gpio_calc_reg_and_bit(bank, AML_REG_OUT, gpio, &reg, &bit);

        return regmap_update_bits(bank->reg_gpio, reg, BIT(bit),
                                  value ? BIT(bit) : 0);
}

static int aml_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
{
        struct aml_gpio_bank *bank = gpiochip_get_data(chip);
        unsigned int bit, reg;

        aml_gpio_calc_reg_and_bit(bank, AML_REG_OUT, gpio, &reg, &bit);

        return regmap_update_bits(bank->reg_gpio, reg, BIT(bit),
                                  value ? BIT(bit) : 0);
}

static int aml_gpio_get(struct gpio_chip *chip, unsigned int gpio)
{
        struct aml_gpio_bank *bank = gpiochip_get_data(chip);
        unsigned int reg, bit, val;

        aml_gpio_calc_reg_and_bit(bank, AML_REG_IN, gpio, &reg, &bit);
        regmap_read(bank->reg_gpio, reg, &val);

        return !!(val & BIT(bit));
}

static const struct gpio_chip aml_gpio_template = {
        .request                = gpiochip_generic_request,
        .free                   = gpiochip_generic_free,
        .set_config             = gpiochip_generic_config,
        .set                    = aml_gpio_set,
        .get                    = aml_gpio_get,
        .direction_input        = aml_gpio_direction_input,
        .direction_output       = aml_gpio_direction_output,
        .get_direction          = aml_gpio_get_direction,
        .can_sleep              = true,
};

static void init_bank_register_bit(struct aml_pinctrl *info,
                                   struct aml_gpio_bank *bank)
{
        const struct aml_pctl_data *data = info->data;
        const struct multi_mux *p_mux;
        int i;

        for (i = 0; i < AML_NUM_REG; i++) {
                bank->pc.reg_offset[i] = aml_def_regoffs[i];
                bank->pc.bit_offset[i] = 0;
        }

        bank->mux_bit_offs = 0;

        if (data) {
                for (i = 0; i < data->number; i++) {
                        p_mux = &data->p_mux[i];
                        if (bank->bank_id == p_mux->m_bank_id) {
                                bank->mux_bit_offs = p_mux->m_bit_offs;
                                break;
                        }
                        if (p_mux->sid >> 8 == bank->bank_id) {
                                bank->p_mux = p_mux;
                                break;
                        }
                }
        }
}

static int aml_gpiolib_register_bank(struct aml_pinctrl *info,
                                     int bank_nr, struct device_node *np)
{
        struct aml_gpio_bank *bank = &info->banks[bank_nr];
        struct device *dev = info->dev;
        int ret = 0;

        ret = aml_bank_number(np);
        if (ret < 0) {
                dev_err(dev, "get num=%d bank identity fail\n", bank_nr);
                return -EINVAL;
        }
        bank->bank_id = ret;

        bank->reg_mux = aml_map_resource(dev, bank->bank_id, np, "mux");
        if (IS_ERR_OR_NULL(bank->reg_mux)) {
                if (bank->bank_id == AMLOGIC_GPIO_TEST_N ||
                    bank->bank_id == AMLOGIC_GPIO_ANALOG)
                        bank->reg_mux = NULL;
                else
                        return dev_err_probe(dev, bank->reg_mux ? PTR_ERR(bank->reg_mux) : -ENOENT,
                                             "mux registers not found\n");
        }

        bank->reg_gpio = aml_map_resource(dev, bank->bank_id, np, "gpio");
        if (IS_ERR_OR_NULL(bank->reg_gpio))
                return dev_err_probe(dev, bank->reg_gpio ? PTR_ERR(bank->reg_gpio) : -ENOENT,
                                     "gpio registers not found\n");

        bank->reg_ds = aml_map_resource(dev, bank->bank_id, np, "ds");
        if (IS_ERR_OR_NULL(bank->reg_ds)) {
                dev_dbg(info->dev, "ds registers not found - skipping\n");
                bank->reg_ds = bank->reg_gpio;
        }

        bank->gpio_chip = aml_gpio_template;
        bank->gpio_chip.base = -1;
        bank->gpio_chip.ngpio = aml_bank_pins(np);
        bank->gpio_chip.fwnode = of_fwnode_handle(np);
        bank->gpio_chip.parent = dev;

        init_bank_register_bit(info, bank);
        bank->gpio_chip.label = aml_bank_name[bank->bank_id];

        bank->pin_base = bank->bank_id << 8;

        return 0;
}

static int aml_pctl_probe_dt(struct platform_device *pdev,
                             struct pinctrl_desc *pctl_desc,
                             struct aml_pinctrl *info)
{
        struct device *dev = &pdev->dev;
        struct pinctrl_pin_desc *pdesc;
        struct device_node *np = dev->of_node;
        int grp_index = 0;
        int i = 0, j = 0, k = 0, bank;
        int ret = 0;

        aml_pctl_dt_child_count(info, np);
        if (!info->nbanks)
                return dev_err_probe(dev, -EINVAL, "you need at least one gpio bank\n");

        dev_dbg(dev, "nbanks = %d\n", info->nbanks);
        dev_dbg(dev, "nfunctions = %d\n", info->nfunctions);
        dev_dbg(dev, "ngroups = %d\n", info->ngroups);

        info->functions = devm_kcalloc(dev, info->nfunctions, sizeof(*info->functions), GFP_KERNEL);

        info->groups = devm_kcalloc(dev, info->ngroups, sizeof(*info->groups), GFP_KERNEL);

        info->banks = devm_kcalloc(dev, info->nbanks, sizeof(*info->banks), GFP_KERNEL);

        if (!info->functions || !info->groups || !info->banks)
                return -ENOMEM;

        info->data = (struct aml_pctl_data *)of_device_get_match_data(dev);

        pctl_desc->npins = aml_count_pins(np);

        pdesc = devm_kcalloc(dev, pctl_desc->npins, sizeof(*pdesc), GFP_KERNEL);
        if (!pdesc)
                return -ENOMEM;

        pctl_desc->pins = pdesc;

        bank = 0;
        for_each_child_of_node_scoped(np, child) {
                if (of_property_read_bool(child, "gpio-controller")) {
                        const char *bank_name = NULL;
                        char **pin_names;

                        ret = aml_gpiolib_register_bank(info, bank, child);
                        if (ret)
                                return ret;

                        k = info->banks[bank].pin_base;
                        bank_name = info->banks[bank].gpio_chip.label;

                        pin_names = devm_kasprintf_strarray(dev, bank_name,
                                                            info->banks[bank].gpio_chip.ngpio);
                        if (IS_ERR(pin_names))
                                return PTR_ERR(pin_names);

                        for (j = 0; j < info->banks[bank].gpio_chip.ngpio; j++, k++) {
                                pdesc->number = k;
                                pdesc->name = pin_names[j];
                                pdesc++;
                        }
                        bank++;
                } else {
                        ret = aml_pctl_parse_functions(child, info,
                                                       i++, &grp_index);
                        if (ret)
                                return ret;
                }
        }

        return 0;
}

static int aml_pctl_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct aml_pinctrl *info;
        struct pinctrl_desc *pctl_desc;
        int ret, i;

        pctl_desc = devm_kzalloc(dev, sizeof(*pctl_desc), GFP_KERNEL);
        if (!pctl_desc)
                return -ENOMEM;

        info = devm_kzalloc(dev, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        info->dev = dev;
        platform_set_drvdata(pdev, info);
        ret = aml_pctl_probe_dt(pdev, pctl_desc, info);
        if (ret)
                return ret;

        pctl_desc->owner        = THIS_MODULE;
        pctl_desc->pctlops      = &aml_pctrl_ops;
        pctl_desc->pmxops       = &aml_pmx_ops;
        pctl_desc->confops      = &aml_pinconf_ops;
        pctl_desc->name         = dev_name(dev);

        info->pctl = devm_pinctrl_register(dev, pctl_desc, info);
        if (IS_ERR(info->pctl))
                return dev_err_probe(dev, PTR_ERR(info->pctl), "Failed pinctrl registration\n");

        for (i = 0; i < info->nbanks; i++) {
                ret  = gpiochip_add_data(&info->banks[i].gpio_chip, &info->banks[i]);
                if (ret)
                        return dev_err_probe(dev, ret, "Failed to add gpiochip(%d)!\n", i);
        }

        return 0;
}

static const struct of_device_id aml_pctl_of_match[] = {
        { .compatible = "amlogic,pinctrl-a4", },
        { .compatible = "amlogic,pinctrl-s7", .data = &s7_priv_data, },
        { .compatible = "amlogic,pinctrl-s6", .data = &s6_priv_data, },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, aml_pctl_of_match);

static struct platform_driver aml_pctl_driver = {
        .driver = {
                .name = "amlogic-pinctrl",
                .of_match_table = aml_pctl_of_match,
        },
        .probe = aml_pctl_probe,
};
module_platform_driver(aml_pctl_driver);

MODULE_AUTHOR("Xianwei Zhao <xianwei.zhao@amlogic.com>");
MODULE_DESCRIPTION("Pin controller and GPIO driver for Amlogic SoC");
MODULE_LICENSE("Dual BSD/GPL");