// SPDX-License-Identifier: GPL-2.0
/*
 * System Control and Power Interface (SCMI) Protocol based pinctrl driver
 *
 * Copyright (C) 2024 EPAM
 * Copyright 2024 NXP
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of.h>
#include <linux/scmi_protocol.h>
#include <linux/slab.h>
#include <linux/types.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 "pinctrl-utils.h"
#include "core.h"
#include "pinconf.h"

#define DRV_NAME "scmi-pinctrl"

/* Define num configs, if not large than 4 use stack, else use kcalloc() */
#define SCMI_NUM_CONFIGS        4

static const struct scmi_pinctrl_proto_ops *pinctrl_ops;

struct scmi_pinctrl {
        struct device *dev;
        struct scmi_protocol_handle *ph;
        struct pinctrl_dev *pctldev;
        struct pinctrl_desc pctl_desc;
        struct pinfunction *functions;
        unsigned int nr_functions;
};

static int pinctrl_scmi_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pinctrl_ops->count_get(pmx->ph, GROUP_TYPE);
}

static const char *pinctrl_scmi_get_group_name(struct pinctrl_dev *pctldev,
                                               unsigned int selector)
{
        int ret;
        const char *name;
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        ret = pinctrl_ops->name_get(pmx->ph, selector, GROUP_TYPE, &name);
        if (ret) {
                dev_err(pmx->dev, "get name failed with err %d", ret);
                return NULL;
        }

        return name;
}

static int pinctrl_scmi_get_group_pins(struct pinctrl_dev *pctldev,
                                       unsigned int selector,
                                       const unsigned int **pins,
                                       unsigned int *num_pins)
{
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pinctrl_ops->group_pins_get(pmx->ph, selector, pins, num_pins);
}

static const struct pinctrl_ops pinctrl_scmi_pinctrl_ops = {
        .get_groups_count = pinctrl_scmi_get_groups_count,
        .get_group_name = pinctrl_scmi_get_group_name,
        .get_group_pins = pinctrl_scmi_get_group_pins,
#ifdef CONFIG_OF
        .dt_node_to_map = pinconf_generic_dt_node_to_map_all,
        .dt_free_map = pinconf_generic_dt_free_map,
#endif
};

static int pinctrl_scmi_get_functions_count(struct pinctrl_dev *pctldev)
{
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pinctrl_ops->count_get(pmx->ph, FUNCTION_TYPE);
}

static const char *pinctrl_scmi_get_function_name(struct pinctrl_dev *pctldev,
                                                  unsigned int selector)
{
        int ret;
        const char *name;
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        ret = pinctrl_ops->name_get(pmx->ph, selector, FUNCTION_TYPE, &name);
        if (ret) {
                dev_err(pmx->dev, "get name failed with err %d", ret);
                return NULL;
        }

        return name;
}

static int pinctrl_scmi_get_function_groups(struct pinctrl_dev *pctldev,
                                            unsigned int selector,
                                            const char * const **p_groups,
                                            unsigned int * const p_num_groups)
{
        struct pinfunction *func;
        const unsigned int *group_ids;
        unsigned int num_groups;
        const char **groups;
        int ret, i;
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        if (!p_groups || !p_num_groups)
                return -EINVAL;

        if (selector >= pmx->nr_functions)
                return -EINVAL;

        func = &pmx->functions[selector];
        if (func->ngroups)
                goto done;

        ret = pinctrl_ops->function_groups_get(pmx->ph, selector, &num_groups,
                                               &group_ids);
        if (ret) {
                dev_err(pmx->dev, "Unable to get function groups, err %d", ret);
                return ret;
        }
        if (!num_groups)
                return -EINVAL;

        groups = kcalloc(num_groups, sizeof(*groups), GFP_KERNEL);
        if (!groups)
                return -ENOMEM;

        for (i = 0; i < num_groups; i++) {
                groups[i] = pinctrl_scmi_get_group_name(pctldev, group_ids[i]);
                if (!groups[i]) {
                        ret = -EINVAL;
                        goto err_free;
                }
        }

        func->ngroups = num_groups;
        func->groups = groups;
done:
        *p_groups = func->groups;
        *p_num_groups = func->ngroups;

        return 0;

err_free:
        kfree(groups);

        return ret;
}

static int pinctrl_scmi_func_set_mux(struct pinctrl_dev *pctldev,
                                     unsigned int selector, unsigned int group)
{
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pinctrl_ops->mux_set(pmx->ph, selector, group);
}

static int pinctrl_scmi_request(struct pinctrl_dev *pctldev,
                                unsigned int offset)
{
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pinctrl_ops->pin_request(pmx->ph, offset);
}

static int pinctrl_scmi_free(struct pinctrl_dev *pctldev, unsigned int offset)
{
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pinctrl_ops->pin_free(pmx->ph, offset);
}

static const struct pinmux_ops pinctrl_scmi_pinmux_ops = {
        .request = pinctrl_scmi_request,
        .free = pinctrl_scmi_free,
        .get_functions_count = pinctrl_scmi_get_functions_count,
        .get_function_name = pinctrl_scmi_get_function_name,
        .get_function_groups = pinctrl_scmi_get_function_groups,
        .set_mux = pinctrl_scmi_func_set_mux,
};

static int pinctrl_scmi_map_pinconf_type(enum pin_config_param param,
                                         enum scmi_pinctrl_conf_type *type)
{
        u32 arg = param;

        switch (arg) {
        case PIN_CONFIG_BIAS_BUS_HOLD:
                *type = SCMI_PIN_BIAS_BUS_HOLD;
                break;
        case PIN_CONFIG_BIAS_DISABLE:
                *type = SCMI_PIN_BIAS_DISABLE;
                break;
        case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
                *type = SCMI_PIN_BIAS_HIGH_IMPEDANCE;
                break;
        case PIN_CONFIG_BIAS_PULL_DOWN:
                *type = SCMI_PIN_BIAS_PULL_DOWN;
                break;
        case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
                *type = SCMI_PIN_BIAS_PULL_DEFAULT;
                break;
        case PIN_CONFIG_BIAS_PULL_UP:
                *type = SCMI_PIN_BIAS_PULL_UP;
                break;
        case PIN_CONFIG_DRIVE_OPEN_DRAIN:
                *type = SCMI_PIN_DRIVE_OPEN_DRAIN;
                break;
        case PIN_CONFIG_DRIVE_OPEN_SOURCE:
                *type = SCMI_PIN_DRIVE_OPEN_SOURCE;
                break;
        case PIN_CONFIG_DRIVE_PUSH_PULL:
                *type = SCMI_PIN_DRIVE_PUSH_PULL;
                break;
        case PIN_CONFIG_DRIVE_STRENGTH:
                *type = SCMI_PIN_DRIVE_STRENGTH;
                break;
        case PIN_CONFIG_DRIVE_STRENGTH_UA:
                *type = SCMI_PIN_DRIVE_STRENGTH;
                break;
        case PIN_CONFIG_INPUT_DEBOUNCE:
                *type = SCMI_PIN_INPUT_DEBOUNCE;
                break;
        case PIN_CONFIG_INPUT_ENABLE:
                *type = SCMI_PIN_INPUT_MODE;
                break;
        case PIN_CONFIG_INPUT_SCHMITT:
                *type = SCMI_PIN_INPUT_SCHMITT;
                break;
        case PIN_CONFIG_INPUT_SCHMITT_ENABLE:
                *type = SCMI_PIN_INPUT_MODE;
                break;
        case PIN_CONFIG_MODE_LOW_POWER:
                *type = SCMI_PIN_LOW_POWER_MODE;
                break;
        case PIN_CONFIG_LEVEL:
                *type = SCMI_PIN_OUTPUT_VALUE;
                break;
        case PIN_CONFIG_OUTPUT_ENABLE:
                *type = SCMI_PIN_OUTPUT_MODE;
                break;
        case PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS:
                *type = SCMI_PIN_OUTPUT_VALUE;
                break;
        case PIN_CONFIG_POWER_SOURCE:
                *type = SCMI_PIN_POWER_SOURCE;
                break;
        case PIN_CONFIG_SLEW_RATE:
                *type = SCMI_PIN_SLEW_RATE;
                break;
        case SCMI_PIN_OEM_START ... SCMI_PIN_OEM_END:
                *type = arg;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int pinctrl_scmi_pinconf_get(struct pinctrl_dev *pctldev,
                                    unsigned int pin, unsigned long *config)
{
        int ret;
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param config_type;
        enum scmi_pinctrl_conf_type type;
        u32 config_value;

        if (!config)
                return -EINVAL;

        config_type = pinconf_to_config_param(*config);

        ret = pinctrl_scmi_map_pinconf_type(config_type, &type);
        if (ret)
                return ret;

        ret = pinctrl_ops->settings_get_one(pmx->ph, pin, PIN_TYPE, type,
                                            &config_value);
        /* Convert SCMI error code to PINCTRL expected error code */
        if (ret == -EOPNOTSUPP)
                return -ENOTSUPP;
        if (ret)
                return ret;

        *config = pinconf_to_config_packed(config_type, config_value);

        return 0;
}

static int
pinctrl_scmi_alloc_configs(struct pinctrl_dev *pctldev, u32 num_configs,
                           u32 **p_config_value,
                           enum scmi_pinctrl_conf_type **p_config_type)
{
        if (num_configs <= SCMI_NUM_CONFIGS)
                return 0;

        *p_config_value = kcalloc(num_configs, sizeof(**p_config_value), GFP_KERNEL);
        if (!*p_config_value)
                return -ENOMEM;

        *p_config_type = kzalloc_objs(**p_config_type, num_configs);
        if (!*p_config_type) {
                kfree(*p_config_value);
                return -ENOMEM;
        }

        return 0;
}

static void
pinctrl_scmi_free_configs(struct pinctrl_dev *pctldev, u32 num_configs,
                          u32 **p_config_value,
                          enum scmi_pinctrl_conf_type **p_config_type)
{
        if (num_configs <= SCMI_NUM_CONFIGS)
                return;

        kfree(*p_config_value);
        kfree(*p_config_type);
}

static int pinctrl_scmi_pinconf_set(struct pinctrl_dev *pctldev,
                                    unsigned int pin,
                                    unsigned long *configs,
                                    unsigned int num_configs)
{
        int i, ret;
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
        enum scmi_pinctrl_conf_type config_type[SCMI_NUM_CONFIGS];
        u32 config_value[SCMI_NUM_CONFIGS];
        enum scmi_pinctrl_conf_type *p_config_type = config_type;
        u32 *p_config_value = config_value;
        enum pin_config_param param;

        if (!configs || !num_configs)
                return -EINVAL;

        ret = pinctrl_scmi_alloc_configs(pctldev, num_configs, &p_config_type,
                                         &p_config_value);
        if (ret)
                return ret;

        for (i = 0; i < num_configs; i++) {
                param = pinconf_to_config_param(configs[i]);
                ret = pinctrl_scmi_map_pinconf_type(param, &p_config_type[i]);
                if (ret) {
                        dev_err(pmx->dev, "Error map pinconf_type %d\n", ret);
                        goto free_config;
                }
                p_config_value[i] = pinconf_to_config_argument(configs[i]);
        }

        ret = pinctrl_ops->settings_conf(pmx->ph, pin, PIN_TYPE, num_configs,
                                         p_config_type,  p_config_value);
        if (ret)
                dev_err(pmx->dev, "Error parsing config %d\n", ret);

free_config:
        pinctrl_scmi_free_configs(pctldev, num_configs, &p_config_type,
                                  &p_config_value);
        return ret;
}

static int pinctrl_scmi_pinconf_group_set(struct pinctrl_dev *pctldev,
                                          unsigned int group,
                                          unsigned long *configs,
                                          unsigned int num_configs)
{
        int i, ret;
        struct scmi_pinctrl *pmx =  pinctrl_dev_get_drvdata(pctldev);
        enum scmi_pinctrl_conf_type config_type[SCMI_NUM_CONFIGS];
        u32 config_value[SCMI_NUM_CONFIGS];
        enum scmi_pinctrl_conf_type *p_config_type = config_type;
        u32 *p_config_value = config_value;
        enum pin_config_param param;

        if (!configs || !num_configs)
                return -EINVAL;

        ret = pinctrl_scmi_alloc_configs(pctldev, num_configs, &p_config_type,
                                         &p_config_value);
        if (ret)
                return ret;

        for (i = 0; i < num_configs; i++) {
                param = pinconf_to_config_param(configs[i]);
                ret = pinctrl_scmi_map_pinconf_type(param, &p_config_type[i]);
                if (ret) {
                        dev_err(pmx->dev, "Error map pinconf_type %d\n", ret);
                        goto free_config;
                }

                p_config_value[i] = pinconf_to_config_argument(configs[i]);
        }

        ret = pinctrl_ops->settings_conf(pmx->ph, group, GROUP_TYPE,
                                         num_configs, p_config_type,
                                         p_config_value);
        if (ret)
                dev_err(pmx->dev, "Error parsing config %d", ret);

free_config:
        pinctrl_scmi_free_configs(pctldev, num_configs, &p_config_type,
                                  &p_config_value);
        return ret;
};

static int pinctrl_scmi_pinconf_group_get(struct pinctrl_dev *pctldev,
                                          unsigned int group,
                                          unsigned long *config)
{
        int ret;
        struct scmi_pinctrl *pmx = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param config_type;
        enum scmi_pinctrl_conf_type type;
        u32 config_value;

        if (!config)
                return -EINVAL;

        config_type = pinconf_to_config_param(*config);
        ret = pinctrl_scmi_map_pinconf_type(config_type, &type);
        if (ret) {
                dev_err(pmx->dev, "Error map pinconf_type %d\n", ret);
                return ret;
        }

        ret = pinctrl_ops->settings_get_one(pmx->ph, group, GROUP_TYPE, type,
                                            &config_value);
        /* Convert SCMI error code to PINCTRL expected error code */
        if (ret == -EOPNOTSUPP)
                return -ENOTSUPP;
        if (ret)
                return ret;

        *config = pinconf_to_config_packed(config_type, config_value);

        return 0;
}

static const struct pinconf_ops pinctrl_scmi_pinconf_ops = {
        .is_generic = true,
        .pin_config_get = pinctrl_scmi_pinconf_get,
        .pin_config_set = pinctrl_scmi_pinconf_set,
        .pin_config_group_set = pinctrl_scmi_pinconf_group_set,
        .pin_config_group_get = pinctrl_scmi_pinconf_group_get,
        .pin_config_config_dbg_show = pinconf_generic_dump_config,
};

static int pinctrl_scmi_get_pins(struct scmi_pinctrl *pmx,
                                 struct pinctrl_desc *desc)
{
        struct pinctrl_pin_desc *pins;
        unsigned int npins;
        int ret, i;

        npins = pinctrl_ops->count_get(pmx->ph, PIN_TYPE);
        /*
         * npins will never be zero, the scmi pinctrl driver has bailed out
         * if npins is zero.
         */
        pins = devm_kmalloc_array(pmx->dev, npins, sizeof(*pins), GFP_KERNEL);
        if (!pins)
                return -ENOMEM;

        for (i = 0; i < npins; i++) {
                pins[i].number = i;
                /*
                 * The memory for name is handled by the scmi firmware driver,
                 * no need free here
                 */
                ret = pinctrl_ops->name_get(pmx->ph, i, PIN_TYPE, &pins[i].name);
                if (ret)
                        return dev_err_probe(pmx->dev, ret,
                                             "Can't get name for pin %d", i);
        }

        desc->npins = npins;
        desc->pins = pins;
        dev_dbg(pmx->dev, "got pins %u", npins);

        return 0;
}

static const char * const scmi_pinctrl_blocklist[] = {
        "fsl,imx94",
        "fsl,imx95",
        "fsl,imx952",
        NULL
};

static int scmi_pinctrl_probe(struct scmi_device *sdev)
{
        int ret;
        struct device *dev = &sdev->dev;
        struct scmi_pinctrl *pmx;
        const struct scmi_handle *handle;
        struct scmi_protocol_handle *ph;

        if (!sdev->handle)
                return -EINVAL;

        if (of_machine_compatible_match(scmi_pinctrl_blocklist))
                return -ENODEV;

        handle = sdev->handle;

        pinctrl_ops = handle->devm_protocol_get(sdev, SCMI_PROTOCOL_PINCTRL, &ph);
        if (IS_ERR(pinctrl_ops))
                return PTR_ERR(pinctrl_ops);

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

        pmx->ph = ph;

        pmx->dev = dev;
        pmx->pctl_desc.name = DRV_NAME;
        pmx->pctl_desc.owner = THIS_MODULE;
        pmx->pctl_desc.pctlops = &pinctrl_scmi_pinctrl_ops;
        pmx->pctl_desc.pmxops = &pinctrl_scmi_pinmux_ops;
        pmx->pctl_desc.confops = &pinctrl_scmi_pinconf_ops;

        ret = pinctrl_scmi_get_pins(pmx, &pmx->pctl_desc);
        if (ret)
                return ret;

        ret = devm_pinctrl_register_and_init(dev, &pmx->pctl_desc, pmx,
                                             &pmx->pctldev);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to register pinctrl\n");

        pmx->nr_functions = pinctrl_scmi_get_functions_count(pmx->pctldev);
        pmx->functions = devm_kcalloc(dev, pmx->nr_functions,
                                      sizeof(*pmx->functions), GFP_KERNEL);
        if (!pmx->functions)
                return -ENOMEM;

        return pinctrl_enable(pmx->pctldev);
}

static const struct scmi_device_id scmi_id_table[] = {
        { SCMI_PROTOCOL_PINCTRL, "pinctrl" },
        { }
};
MODULE_DEVICE_TABLE(scmi, scmi_id_table);

static struct scmi_driver scmi_pinctrl_driver = {
        .name = DRV_NAME,
        .probe = scmi_pinctrl_probe,
        .id_table = scmi_id_table,
};
module_scmi_driver(scmi_pinctrl_driver);

MODULE_AUTHOR("Oleksii Moisieiev <oleksii_moisieiev@epam.com>");
MODULE_AUTHOR("Peng Fan <peng.fan@nxp.com>");
MODULE_DESCRIPTION("ARM SCMI pin controller driver");
MODULE_LICENSE("GPL");