root/drivers/pinctrl/realtek/pinctrl-rtd.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Realtek DHC pin controller driver
 *
 * Copyright (c) 2023 Realtek Semiconductor Corp.
 */

#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include "../core.h"
#include "../pinctrl-utils.h"
#include "pinctrl-rtd.h"

struct rtd_pinctrl {
        struct device *dev;
        struct pinctrl_dev *pcdev;
        void __iomem *base;
        struct pinctrl_desc desc;
        const struct rtd_pinctrl_desc *info;
        struct regmap *regmap_pinctrl;
};

/* custom pinconf parameters */
#define RTD_DRIVE_STRENGH_P (PIN_CONFIG_END + 1)
#define RTD_DRIVE_STRENGH_N (PIN_CONFIG_END + 2)
#define RTD_DUTY_CYCLE (PIN_CONFIG_END + 3)

static const struct pinconf_generic_params rtd_custom_bindings[] = {
        {"realtek,drive-strength-p", RTD_DRIVE_STRENGH_P, 0},
        {"realtek,drive-strength-n", RTD_DRIVE_STRENGH_N, 0},
        {"realtek,duty-cycle", RTD_DUTY_CYCLE, 0},
};

static int rtd_pinctrl_get_groups_count(struct pinctrl_dev *pcdev)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);

        return data->info->num_groups;
}

static const char *rtd_pinctrl_get_group_name(struct pinctrl_dev *pcdev,
                                              unsigned int selector)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);

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

static int rtd_pinctrl_get_group_pins(struct pinctrl_dev *pcdev,
                                      unsigned int selector,
                                      const unsigned int **pins,
                                      unsigned int *num_pins)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);

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

        return 0;
}

static void rtd_pinctrl_dbg_show(struct pinctrl_dev *pcdev,
                                 struct seq_file *s,
                                 unsigned int offset)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);
        const struct rtd_pin_desc *mux = &data->info->muxes[offset];
        const struct rtd_pin_mux_desc *func;
        u32 val;
        u32 mask;
        u32 pin_val;
        int is_map;

        if (!mux->name) {
                seq_puts(s, "[not defined]");
                return;
        }
        val = readl_relaxed(data->base + mux->mux_offset);
        mask = mux->mux_mask;
        pin_val = val & mask;

        is_map = 0;
        func = &mux->functions[0];
        seq_puts(s, "function: ");
        while (func->name) {
                if (func->mux_value == pin_val) {
                        is_map = 1;
                        seq_printf(s, "[%s] ", func->name);
                } else {
                        seq_printf(s, "%s ", func->name);
                }
                func++;
        }
        if (!is_map)
                seq_puts(s, "[not defined]");
}

static const struct pinctrl_ops rtd_pinctrl_ops = {
        .dt_node_to_map = pinconf_generic_dt_node_to_map_all,
        .dt_free_map = pinctrl_utils_free_map,
        .get_groups_count = rtd_pinctrl_get_groups_count,
        .get_group_name = rtd_pinctrl_get_group_name,
        .get_group_pins = rtd_pinctrl_get_group_pins,
        .pin_dbg_show = rtd_pinctrl_dbg_show,
};

static int rtd_pinctrl_get_functions_count(struct pinctrl_dev *pcdev)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);

        return data->info->num_functions;
}

static const char *rtd_pinctrl_get_function_name(struct pinctrl_dev *pcdev,
                                                 unsigned int selector)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);

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

static int rtd_pinctrl_get_function_groups(struct pinctrl_dev *pcdev,
                                           unsigned int selector,
                                           const char * const **groups,
                                           unsigned int * const num_groups)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);

        *groups = data->info->functions[selector].groups;
        *num_groups = data->info->functions[selector].num_groups;

        return 0;
}

static const struct rtd_pin_desc *rtd_pinctrl_find_mux(struct rtd_pinctrl *data, unsigned int pin)
{
        if (data->info->muxes[pin].name)
                return &data->info->muxes[pin];

        return NULL;
}

static int rtd_pinctrl_set_one_mux(struct pinctrl_dev *pcdev,
                                   unsigned int pin, const char *func_name)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);
        const struct rtd_pin_desc *mux;
        int ret = 0;
        int i;

        mux = rtd_pinctrl_find_mux(data, pin);
        if (!mux)
                return 0;

        if (!mux->functions) {
                if (!mux->name)
                        dev_err(pcdev->dev, "NULL pin has no functions\n");
                else
                        dev_err(pcdev->dev, "No functions available for pin %s\n", mux->name);
                return -ENOTSUPP;
        }

        for (i = 0; mux->functions[i].name; i++) {
                if (strcmp(mux->functions[i].name, func_name) != 0)
                        continue;
                ret = regmap_update_bits(data->regmap_pinctrl, mux->mux_offset, mux->mux_mask,
                                        mux->functions[i].mux_value);
                return ret;
        }

        if (!mux->name) {
                dev_err(pcdev->dev, "NULL pin provided for function %s\n", func_name);
                return -EINVAL;
        }

        dev_err(pcdev->dev, "No function %s available for pin %s\n", func_name, mux->name);

        return -EINVAL;
}

static int rtd_pinctrl_set_mux(struct pinctrl_dev *pcdev,
                               unsigned int function, unsigned int group)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);
        const unsigned int *pins;
        unsigned int num_pins;
        const char *func_name;
        const char *group_name;
        int i, ret;

        func_name = data->info->functions[function].name;
        group_name = data->info->groups[group].name;

        ret = rtd_pinctrl_get_group_pins(pcdev, group, &pins, &num_pins);
        if (ret) {
                dev_err(pcdev->dev, "Getting pins for group %s failed\n", group_name);
                return ret;
        }

        for (i = 0; i < num_pins; i++) {
                ret = rtd_pinctrl_set_one_mux(pcdev, pins[i], func_name);
                if (ret)
                        return ret;
        }

        return 0;
}

static int rtd_pinctrl_gpio_request_enable(struct pinctrl_dev *pcdev,
                                           struct pinctrl_gpio_range *range,
                                           unsigned int offset)
{
        return rtd_pinctrl_set_one_mux(pcdev, offset, "gpio");
}

static const struct pinmux_ops rtd_pinmux_ops = {
        .get_functions_count = rtd_pinctrl_get_functions_count,
        .get_function_name = rtd_pinctrl_get_function_name,
        .get_function_groups = rtd_pinctrl_get_function_groups,
        .set_mux = rtd_pinctrl_set_mux,
        .gpio_request_enable = rtd_pinctrl_gpio_request_enable,
};

static const struct pinctrl_pin_desc
        *rtd_pinctrl_get_pin_by_number(struct rtd_pinctrl *data, int number)
{
        int i;

        for (i = 0; i < data->info->num_pins; i++) {
                if (data->info->pins[i].number == number)
                        return &data->info->pins[i];
        }

        return NULL;
}

static const struct rtd_pin_config_desc
        *rtd_pinctrl_find_config(struct rtd_pinctrl *data, unsigned int pin)
{
        if (data->info->configs[pin].name)
                return &data->info->configs[pin];

        return NULL;
}

static const struct rtd_pin_sconfig_desc *rtd_pinctrl_find_sconfig(struct rtd_pinctrl *data,
                                                                   unsigned int pin)
{
        int i;
        const struct pinctrl_pin_desc *pin_desc;
        const char *pin_name;

        pin_desc = rtd_pinctrl_get_pin_by_number(data, pin);
        if (!pin_desc)
                return NULL;

        pin_name = pin_desc->name;

        for (i = 0; i < data->info->num_sconfigs; i++) {
                if (strcmp(data->info->sconfigs[i].name, pin_name) == 0)
                        return &data->info->sconfigs[i];
        }

        return NULL;
}

static int rtd_pconf_parse_conf(struct rtd_pinctrl *data,
                                unsigned int pinnr,
                                enum pin_config_param param,
                                enum pin_config_param arg)
{
        const struct rtd_pin_config_desc *config_desc;
        const struct rtd_pin_sconfig_desc *sconfig_desc;
        u8 set_val = 0;
        u16 strength;
        u32 val;
        u32 mask;
        u32 pulsel_off, pulen_off, smt_off, curr_off, pow_off, reg_off, p_off, n_off;
        const char *name = data->info->pins[pinnr].name;
        int ret = 0;

        config_desc = rtd_pinctrl_find_config(data, pinnr);
        if (!config_desc) {
                dev_err(data->dev, "Not support pin config for pin: %s\n", name);
                return -ENOTSUPP;
        }
        switch ((u32)param) {
        case PIN_CONFIG_INPUT_SCHMITT:
        case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
                if (config_desc->smt_offset == NA) {
                        dev_err(data->dev, "Not support input schmitt for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                smt_off = config_desc->base_bit + config_desc->smt_offset;
                reg_off = config_desc->reg_offset;
                set_val = arg;

                mask = BIT(smt_off);
                val = set_val ? BIT(smt_off) : 0;
                break;

        case PIN_CONFIG_DRIVE_PUSH_PULL:
                if (config_desc->pud_en_offset == NA) {
                        dev_err(data->dev, "Not support push pull for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                pulen_off = config_desc->base_bit + config_desc->pud_en_offset;
                reg_off = config_desc->reg_offset;

                mask =  BIT(pulen_off);
                val = 0;
                break;

        case PIN_CONFIG_BIAS_DISABLE:
                if (config_desc->pud_en_offset == NA) {
                        dev_err(data->dev, "Not support bias disable for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                pulen_off = config_desc->base_bit + config_desc->pud_en_offset;
                reg_off = config_desc->reg_offset;

                mask =  BIT(pulen_off);
                val = 0;
                break;

        case PIN_CONFIG_BIAS_PULL_UP:
                if (config_desc->pud_en_offset == NA) {
                        dev_err(data->dev, "Not support bias pull up for pin:%s\n", name);
                        return -ENOTSUPP;
                }
                pulen_off = config_desc->base_bit + config_desc->pud_en_offset;
                pulsel_off = config_desc->base_bit + config_desc->pud_sel_offset;
                reg_off = config_desc->reg_offset;

                mask = BIT(pulen_off) | BIT(pulsel_off);
                val = mask;
                break;

        case PIN_CONFIG_BIAS_PULL_DOWN:
                if (config_desc->pud_en_offset == NA) {
                        dev_err(data->dev, "Not support bias pull down for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                pulen_off = config_desc->base_bit + config_desc->pud_en_offset;
                pulsel_off = config_desc->base_bit + config_desc->pud_sel_offset;
                reg_off = config_desc->reg_offset;

                mask = BIT(pulen_off) | BIT(pulsel_off);
                val = BIT(pulen_off);
                break;

        case PIN_CONFIG_DRIVE_STRENGTH:
                curr_off = config_desc->base_bit + config_desc->curr_offset;
                reg_off = config_desc->reg_offset;
                strength = arg;
                val = 0;
                switch (config_desc->curr_type) {
                case PADDRI_4_8:
                        if (strength == 4)
                                val = 0;
                        else if (strength == 8)
                                val = BIT(curr_off);
                        else
                                return -EINVAL;
                        break;
                case PADDRI_2_4:
                        if (strength == 2)
                                val = 0;
                        else if (strength == 4)
                                val = BIT(curr_off);
                        else
                                return -EINVAL;
                        break;
                case NA:
                        dev_err(data->dev, "Not support drive strength for pin: %s\n", name);
                        return -ENOTSUPP;
                default:
                        return -EINVAL;
                }
                mask = BIT(curr_off);
                break;

        case PIN_CONFIG_POWER_SOURCE:
                if (config_desc->power_offset == NA) {
                        dev_err(data->dev, "Not support power source for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                reg_off = config_desc->reg_offset;
                pow_off = config_desc->base_bit + config_desc->power_offset;
                if (pow_off >= 32) {
                        reg_off += 0x4;
                        pow_off -= 32;
                }
                set_val = arg;
                mask = BIT(pow_off);
                val = set_val ? mask : 0;
                break;

        case RTD_DRIVE_STRENGH_P:
                sconfig_desc = rtd_pinctrl_find_sconfig(data, pinnr);
                if (!sconfig_desc) {
                        dev_err(data->dev, "Not support P driving for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                set_val = arg;
                reg_off = sconfig_desc->reg_offset;
                p_off = sconfig_desc->pdrive_offset;
                if (p_off >= 32) {
                        reg_off += 0x4;
                        p_off -= 32;
                }
                mask = GENMASK(p_off + sconfig_desc->pdrive_maskbits - 1, p_off);
                val = set_val << p_off;
                break;

        case RTD_DRIVE_STRENGH_N:
                sconfig_desc = rtd_pinctrl_find_sconfig(data, pinnr);
                if (!sconfig_desc) {
                        dev_err(data->dev, "Not support N driving for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                set_val = arg;
                reg_off = sconfig_desc->reg_offset;
                n_off = sconfig_desc->ndrive_offset;
                if (n_off >= 32) {
                        reg_off += 0x4;
                        n_off -= 32;
                }
                mask = GENMASK(n_off + sconfig_desc->ndrive_maskbits - 1, n_off);
                val = set_val << n_off;
                break;

        case RTD_DUTY_CYCLE:
                sconfig_desc = rtd_pinctrl_find_sconfig(data, pinnr);
                if (!sconfig_desc || sconfig_desc->dcycle_offset == NA) {
                        dev_err(data->dev, "Not support duty cycle for pin: %s\n", name);
                        return -ENOTSUPP;
                }
                set_val = arg;
                reg_off = config_desc->reg_offset;
                mask = GENMASK(sconfig_desc->dcycle_offset +
                sconfig_desc->dcycle_maskbits - 1, sconfig_desc->dcycle_offset);
                val = set_val << sconfig_desc->dcycle_offset;
                break;

        default:
                dev_err(data->dev, "unsupported pinconf: %d\n", (u32)param);
                return -EINVAL;
        }

        ret = regmap_update_bits(data->regmap_pinctrl, reg_off, mask, val);
        if (ret)
                dev_err(data->dev, "could not update pinconf(%d) for pin(%s)\n", (u32)param, name);

        return ret;
}

static int rtd_pin_config_get(struct pinctrl_dev *pcdev, unsigned int pinnr,
                              unsigned long *config)
{
        unsigned int param = pinconf_to_config_param(*config);
        unsigned int arg = 0;

        switch (param) {
        default:
                return -ENOTSUPP;
        }

        *config = pinconf_to_config_packed(param, arg);
        return 0;
}

static int rtd_pin_config_set(struct pinctrl_dev *pcdev, unsigned int pinnr,
                              unsigned long *configs, unsigned int num_configs)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);
        int i;
        int ret = 0;

        for (i = 0; i < num_configs; i++) {
                ret = rtd_pconf_parse_conf(data, pinnr,
                                           pinconf_to_config_param(configs[i]),
                                           pinconf_to_config_argument(configs[i]));
                if (ret < 0)
                        return ret;
        }

        return 0;
}

static int rtd_pin_config_group_set(struct pinctrl_dev *pcdev, unsigned int group,
                                    unsigned long *configs, unsigned int num_configs)
{
        struct rtd_pinctrl *data = pinctrl_dev_get_drvdata(pcdev);
        const unsigned int *pins;
        unsigned int num_pins;
        const char *group_name;
        int i, ret;

        group_name = data->info->groups[group].name;

        ret = rtd_pinctrl_get_group_pins(pcdev, group, &pins, &num_pins);
        if (ret) {
                dev_err(pcdev->dev, "Getting pins for group %s failed\n", group_name);
                return ret;
        }

        for (i = 0; i < num_pins; i++) {
                ret = rtd_pin_config_set(pcdev, pins[i], configs, num_configs);
                if (ret)
                        return ret;
        }

        return 0;
}

static const struct pinconf_ops rtd_pinconf_ops = {
        .is_generic = true,
        .pin_config_get = rtd_pin_config_get,
        .pin_config_set = rtd_pin_config_set,
        .pin_config_group_set = rtd_pin_config_group_set,
};

static const struct regmap_config rtd_pinctrl_regmap_config = {
        .reg_bits = 32,
        .val_bits = 32,
        .reg_stride = 4,
        .use_relaxed_mmio = true,
};

int rtd_pinctrl_probe(struct platform_device *pdev, const struct rtd_pinctrl_desc *desc)
{
        struct rtd_pinctrl *data;
        int ret;

        data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->base = of_iomap(pdev->dev.of_node, 0);
        if (!data->base)
                return -ENOMEM;

        data->dev = &pdev->dev;
        data->info = desc;
        data->desc.name = dev_name(&pdev->dev);
        data->desc.pins = data->info->pins;
        data->desc.npins = data->info->num_pins;
        data->desc.pctlops = &rtd_pinctrl_ops;
        data->desc.pmxops = &rtd_pinmux_ops;
        data->desc.confops = &rtd_pinconf_ops;
        data->desc.custom_params = rtd_custom_bindings;
        data->desc.num_custom_params = ARRAY_SIZE(rtd_custom_bindings);
        data->desc.owner = THIS_MODULE;
        data->regmap_pinctrl = devm_regmap_init_mmio(data->dev, data->base,
                                                     &rtd_pinctrl_regmap_config);

        if (IS_ERR(data->regmap_pinctrl)) {
                dev_err(data->dev, "failed to init regmap: %ld\n",
                        PTR_ERR(data->regmap_pinctrl));
                ret = PTR_ERR(data->regmap_pinctrl);
                goto unmap;
        }

        data->pcdev = pinctrl_register(&data->desc, &pdev->dev, data);
        if (IS_ERR(data->pcdev)) {
                ret = PTR_ERR(data->pcdev);
                goto unmap;
        }

        platform_set_drvdata(pdev, data);

        dev_dbg(&pdev->dev, "probed\n");

        return 0;

unmap:
        iounmap(data->base);
        return ret;
}
EXPORT_SYMBOL(rtd_pinctrl_probe);

MODULE_DESCRIPTION("Realtek DHC SoC pinctrl driver");
MODULE_LICENSE("GPL v2");