// SPDX-License-Identifier: GPL-2.0-only
/*
 * Core driver for the generic pin config portions of the pin control subsystem
 *
 * Copyright (C) 2011 ST-Ericsson SA
 * Written on behalf of Linaro for ST-Ericsson
 *
 * Author: Linus Walleij <linus.walleij@linaro.org>
 */

#define pr_fmt(fmt) "generic pinconfig core: " fmt

#include <linux/array_size.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>

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

#ifdef CONFIG_DEBUG_FS
static const struct pin_config_item conf_items[] = {
        PCONFDUMP(PIN_CONFIG_BIAS_BUS_HOLD, "input bias bus hold", NULL, false),
        PCONFDUMP(PIN_CONFIG_BIAS_DISABLE, "input bias disabled", NULL, false),
        PCONFDUMP(PIN_CONFIG_BIAS_HIGH_IMPEDANCE, "input bias high impedance", NULL, false),
        PCONFDUMP(PIN_CONFIG_BIAS_PULL_DOWN, "input bias pull down", "ohms", true),
        PCONFDUMP(PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
                                "input bias pull to pin specific state", "ohms", true),
        PCONFDUMP(PIN_CONFIG_BIAS_PULL_UP, "input bias pull up", "ohms", true),
        PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_DRAIN, "output drive open drain", NULL, false),
        PCONFDUMP(PIN_CONFIG_DRIVE_OPEN_SOURCE, "output drive open source", NULL, false),
        PCONFDUMP(PIN_CONFIG_DRIVE_PUSH_PULL, "output drive push pull", NULL, false),
        PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH, "output drive strength", "mA", true),
        PCONFDUMP(PIN_CONFIG_DRIVE_STRENGTH_UA, "output drive strength", "uA", true),
        PCONFDUMP(PIN_CONFIG_INPUT_DEBOUNCE, "input debounce", "usec", true),
        PCONFDUMP(PIN_CONFIG_INPUT_ENABLE, "input enabled", NULL, false),
        PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT, "input schmitt trigger", NULL, false),
        PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_UV, "input schmitt threshold", "uV", true),
        PCONFDUMP(PIN_CONFIG_INPUT_SCHMITT_ENABLE, "input schmitt enabled", NULL, false),
        PCONFDUMP(PIN_CONFIG_MODE_LOW_POWER, "pin low power", "mode", true),
        PCONFDUMP(PIN_CONFIG_OUTPUT_ENABLE, "output enabled", NULL, false),
        PCONFDUMP(PIN_CONFIG_LEVEL, "pin output", "level", true),
        PCONFDUMP(PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, "output impedance", "ohms", true),
        PCONFDUMP(PIN_CONFIG_POWER_SOURCE, "pin power source", "selector", true),
        PCONFDUMP(PIN_CONFIG_SLEEP_HARDWARE_STATE, "sleep hardware state", NULL, false),
        PCONFDUMP(PIN_CONFIG_SLEW_RATE, "slew rate", NULL, true),
        PCONFDUMP(PIN_CONFIG_SKEW_DELAY, "skew delay", NULL, true),
        PCONFDUMP(PIN_CONFIG_SKEW_DELAY_INPUT_PS, "input skew delay", "ps", true),
        PCONFDUMP(PIN_CONFIG_SKEW_DELAY_OUTPUT_PS, "output skew delay", "ps", true),
};

static void pinconf_generic_dump_one(struct pinctrl_dev *pctldev,
                                     struct seq_file *s, const char *gname,
                                     unsigned int pin,
                                     const struct pin_config_item *items,
                                     int nitems, int *print_sep)
{
        int i;

        for (i = 0; i < nitems; i++) {
                const struct pin_config_item *item = &items[i];
                unsigned long config;
                int ret;

                /* We want to check out this parameter */
                config = pinconf_to_config_packed(item->param, 0);
                if (gname)
                        ret = pin_config_group_get(dev_name(pctldev->dev),
                                                   gname, &config);
                else
                        ret = pin_config_get_for_pin(pctldev, pin, &config);
                /* These are legal errors */
                if (ret == -EINVAL || ret == -ENOTSUPP)
                        continue;
                if (ret) {
                        seq_printf(s, "ERROR READING CONFIG SETTING %d ", i);
                        continue;
                }
                /* comma between multiple configs */
                if (*print_sep)
                        seq_puts(s, ", ");
                *print_sep = 1;
                seq_puts(s, item->display);
                /* Print unit if available */
                if (item->has_arg) {
                        u32 val = pinconf_to_config_argument(config);

                        if (item->format)
                                seq_printf(s, " (%u %s)", val, item->format);
                        else
                                seq_printf(s, " (0x%x)", val);

                        if (item->values && item->num_values) {
                                if (val < item->num_values)
                                        seq_printf(s, " \"%s\"", item->values[val]);
                                else
                                        seq_puts(s, " \"(unknown)\"");
                        }
                }
        }
}

/**
 * pinconf_generic_dump_pins - Print information about pin or group of pins
 * @pctldev:    Pincontrol device
 * @s:          File to print to
 * @gname:      Group name specifying pins
 * @pin:        Pin number specifying pin
 *
 * Print the pinconf configuration for the requested pin(s) to @s. Pins can be
 * specified either by pin using @pin or by group using @gname. Only one needs
 * to be specified the other can be NULL/0.
 */
void pinconf_generic_dump_pins(struct pinctrl_dev *pctldev, struct seq_file *s,
                               const char *gname, unsigned int pin)
{
        const struct pinconf_ops *ops = pctldev->desc->confops;
        int print_sep = 0;

        if (!ops->is_generic)
                return;

        /* generic parameters */
        pinconf_generic_dump_one(pctldev, s, gname, pin, conf_items,
                                 ARRAY_SIZE(conf_items), &print_sep);
        /* driver-specific parameters */
        if (pctldev->desc->num_custom_params &&
            pctldev->desc->custom_conf_items)
                pinconf_generic_dump_one(pctldev, s, gname, pin,
                                         pctldev->desc->custom_conf_items,
                                         pctldev->desc->num_custom_params,
                                         &print_sep);
}

void pinconf_generic_dump_config(struct pinctrl_dev *pctldev,
                                 struct seq_file *s, unsigned long config)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(conf_items); i++) {
                if (pinconf_to_config_param(config) != conf_items[i].param)
                        continue;
                seq_printf(s, "%s: 0x%x", conf_items[i].display,
                           pinconf_to_config_argument(config));
        }

        if (!pctldev->desc->num_custom_params ||
            !pctldev->desc->custom_conf_items)
                return;

        for (i = 0; i < pctldev->desc->num_custom_params; i++) {
                if (pinconf_to_config_param(config) !=
                    pctldev->desc->custom_conf_items[i].param)
                        continue;
                seq_printf(s, "%s: 0x%x",
                                pctldev->desc->custom_conf_items[i].display,
                                pinconf_to_config_argument(config));
        }
}
EXPORT_SYMBOL_GPL(pinconf_generic_dump_config);
#endif

#ifdef CONFIG_OF
static const struct pinconf_generic_params dt_params[] = {
        { "bias-bus-hold", PIN_CONFIG_BIAS_BUS_HOLD, 0 },
        { "bias-disable", PIN_CONFIG_BIAS_DISABLE, 0 },
        { "bias-high-impedance", PIN_CONFIG_BIAS_HIGH_IMPEDANCE, 0 },
        { "bias-pull-up", PIN_CONFIG_BIAS_PULL_UP, 1 },
        { "bias-pull-pin-default", PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, 1 },
        { "bias-pull-down", PIN_CONFIG_BIAS_PULL_DOWN, 1 },
        { "drive-open-drain", PIN_CONFIG_DRIVE_OPEN_DRAIN, 0 },
        { "drive-open-source", PIN_CONFIG_DRIVE_OPEN_SOURCE, 0 },
        { "drive-push-pull", PIN_CONFIG_DRIVE_PUSH_PULL, 0 },
        { "drive-strength", PIN_CONFIG_DRIVE_STRENGTH, 0 },
        { "drive-strength-microamp", PIN_CONFIG_DRIVE_STRENGTH_UA, 0 },
        { "input-debounce", PIN_CONFIG_INPUT_DEBOUNCE, 0 },
        { "input-disable", PIN_CONFIG_INPUT_ENABLE, 0 },
        { "input-enable", PIN_CONFIG_INPUT_ENABLE, 1 },
        { "input-schmitt", PIN_CONFIG_INPUT_SCHMITT, 0 },
        { "input-schmitt-disable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 0 },
        { "input-schmitt-enable", PIN_CONFIG_INPUT_SCHMITT_ENABLE, 1 },
        { "input-schmitt-microvolts", PIN_CONFIG_INPUT_SCHMITT_UV, 0 },
        { "low-power-disable", PIN_CONFIG_MODE_LOW_POWER, 0 },
        { "low-power-enable", PIN_CONFIG_MODE_LOW_POWER, 1 },
        { "output-disable", PIN_CONFIG_OUTPUT_ENABLE, 0 },
        { "output-enable", PIN_CONFIG_OUTPUT_ENABLE, 1 },
        { "output-high", PIN_CONFIG_LEVEL, 1, },
        { "output-impedance-ohms", PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, 0 },
        { "output-low", PIN_CONFIG_LEVEL, 0, },
        { "power-source", PIN_CONFIG_POWER_SOURCE, 0 },
        { "sleep-hardware-state", PIN_CONFIG_SLEEP_HARDWARE_STATE, 0 },
        { "slew-rate", PIN_CONFIG_SLEW_RATE, 0 },
        { "skew-delay", PIN_CONFIG_SKEW_DELAY, 0 },
        { "skew-delay-input-ps", PIN_CONFIG_SKEW_DELAY_INPUT_PS, 0 },
        { "skew-delay-output-ps", PIN_CONFIG_SKEW_DELAY_OUTPUT_PS, 0 },
};

/**
 * parse_dt_cfg() - Parse DT pinconf parameters
 * @np: DT node
 * @params:     Array of describing generic parameters
 * @count:      Number of entries in @params
 * @cfg:        Array of parsed config options
 * @ncfg:       Number of entries in @cfg
 *
 * Parse the config options described in @params from @np and puts the result
 * in @cfg. @cfg does not need to be empty, entries are added beginning at
 * @ncfg. @ncfg is updated to reflect the number of entries after parsing. @cfg
 * needs to have enough memory allocated to hold all possible entries.
 */
static int parse_dt_cfg(struct device_node *np,
                        const struct pinconf_generic_params *params,
                        unsigned int count, unsigned long *cfg,
                        unsigned int *ncfg)
{
        int i;

        for (i = 0; i < count; i++) {
                u32 val;
                int ret;
                const struct pinconf_generic_params *par = &params[i];

                if (par->values && par->num_values) {
                        ret = fwnode_property_match_property_string(of_fwnode_handle(np),
                                                                    par->property,
                                                                    par->values, par->num_values);
                        if (ret == -ENOENT)
                                return ret;
                        if (ret >= 0) {
                                val = ret;
                                ret = 0;
                        }
                } else {
                        ret = of_property_read_u32(np, par->property, &val);
                }

                /* property not found */
                if (ret == -EINVAL)
                        continue;

                /* use default value, when no value is specified */
                if (ret)
                        val = par->default_value;

                pr_debug("found %s with value %u\n", par->property, val);
                cfg[*ncfg] = pinconf_to_config_packed(par->param, val);
                (*ncfg)++;
        }

        return 0;
}

/**
 * pinconf_generic_parse_dt_pinmux()
 * parse the pinmux properties into generic pin mux values.
 * @np: node containing the pinmux properties
 * @dev: pincontrol core device
 * @pid: array with pin identity entries
 * @pmux: array with pin mux value entries
 * @npins: number of pins
 *
 * pinmux property: mux value [0,7]bits and pin identity [8,31]bits.
 */
int pinconf_generic_parse_dt_pinmux(struct device_node *np, struct device *dev,
                                    unsigned int **pid, unsigned int **pmux,
                                    unsigned int *npins)
{
        unsigned int *pid_t;
        unsigned int *pmux_t;
        struct property *prop;
        unsigned int npins_t, i;
        u32 value;
        int ret;

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

        if (!pid || !pmux || !npins) {
                dev_err(dev, "parameters error\n");
                return -EINVAL;
        }

        npins_t = prop->length / sizeof(u32);
        pid_t = devm_kcalloc(dev, npins_t, sizeof(*pid_t), GFP_KERNEL);
        pmux_t = devm_kcalloc(dev, npins_t, sizeof(*pmux_t), GFP_KERNEL);
        if (!pid_t || !pmux_t) {
                dev_err(dev, "kalloc memory fail\n");
                return -ENOMEM;
        }
        for (i = 0; i < npins_t; i++) {
                ret = of_property_read_u32_index(np, "pinmux", i, &value);
                if (ret) {
                        dev_err(dev, "get pinmux value fail\n");
                        goto exit;
                }
                pmux_t[i] = value & 0xff;
                pid_t[i] = (value >> 8) & 0xffffff;
        }
        *pid = pid_t;
        *pmux = pmux_t;
        *npins = npins_t;

        return 0;
exit:
        devm_kfree(dev, pid_t);
        devm_kfree(dev, pmux_t);
        return ret;
}
EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_pinmux);

/**
 * pinconf_generic_parse_dt_config()
 * parse the config properties into generic pinconfig values.
 * @np: node containing the pinconfig properties
 * @pctldev: pincontrol device
 * @configs: array with nconfigs entries containing the generic pinconf values
 *           must be freed when no longer necessary.
 * @nconfigs: number of configurations
 */
int pinconf_generic_parse_dt_config(struct device_node *np,
                                    struct pinctrl_dev *pctldev,
                                    unsigned long **configs,
                                    unsigned int *nconfigs)
{
        unsigned long *cfg;
        unsigned int max_cfg, ncfg = 0;
        int ret;

        if (!np)
                return -EINVAL;

        /* allocate a temporary array big enough to hold one of each option */
        max_cfg = ARRAY_SIZE(dt_params);
        if (pctldev)
                max_cfg += pctldev->desc->num_custom_params;
        cfg = kcalloc(max_cfg, sizeof(*cfg), GFP_KERNEL);
        if (!cfg)
                return -ENOMEM;

        ret = parse_dt_cfg(np, dt_params, ARRAY_SIZE(dt_params), cfg, &ncfg);
        if (ret)
                goto out;
        if (pctldev && pctldev->desc->num_custom_params &&
                pctldev->desc->custom_params) {
                ret = parse_dt_cfg(np, pctldev->desc->custom_params,
                                   pctldev->desc->num_custom_params, cfg, &ncfg);
                if (ret)
                        goto out;
        }

        /* no configs found at all */
        if (ncfg == 0) {
                *configs = NULL;
                *nconfigs = 0;
                goto out;
        }

        /*
         * Now limit the number of configs to the real number of
         * found properties.
         */
        *configs = kmemdup(cfg, ncfg * sizeof(unsigned long), GFP_KERNEL);
        if (!*configs) {
                ret = -ENOMEM;
                goto out;
        }

        *nconfigs = ncfg;

out:
        kfree(cfg);
        return ret;
}
EXPORT_SYMBOL_GPL(pinconf_generic_parse_dt_config);

int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
                struct device_node *np, struct pinctrl_map **map,
                unsigned int *reserved_maps, unsigned int *num_maps,
                enum pinctrl_map_type type)
{
        int ret;
        const char *function;
        struct device *dev = pctldev->dev;
        unsigned long *configs = NULL;
        unsigned int num_configs = 0;
        unsigned int reserve, strings_count;
        struct property *prop;
        const char *group;
        const char *subnode_target_type = "pins";

        ret = of_property_count_strings(np, "pins");
        if (ret < 0) {
                ret = of_property_count_strings(np, "groups");
                if (ret < 0)
                        /* skip this node; may contain config child nodes */
                        return 0;
                if (type == PIN_MAP_TYPE_INVALID)
                        type = PIN_MAP_TYPE_CONFIGS_GROUP;
                subnode_target_type = "groups";
        } else {
                if (type == PIN_MAP_TYPE_INVALID)
                        type = PIN_MAP_TYPE_CONFIGS_PIN;
        }
        strings_count = ret;

        ret = of_property_read_string(np, "function", &function);
        if (ret < 0) {
                /* EINVAL=missing, which is fine since it's optional */
                if (ret != -EINVAL)
                        dev_err(dev, "%pOF: could not parse property function\n",
                                np);
                function = NULL;
        }

        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 = 0;
        if (function != NULL)
                reserve++;
        if (num_configs)
                reserve++;

        reserve *= strings_count;

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

        of_property_for_each_string(np, subnode_target_type, prop, group) {
                if (function) {
                        ret = pinctrl_utils_add_map_mux(pctldev, map,
                                        reserved_maps, num_maps, group,
                                        function);
                        if (ret < 0)
                                goto exit;
                }

                if (num_configs) {
                        ret = pinctrl_utils_add_map_configs(pctldev, map,
                                        reserved_maps, num_maps, group, configs,
                                        num_configs, type);
                        if (ret < 0)
                                goto exit;
                }
        }
        ret = 0;

exit:
        kfree(configs);
        return ret;
}
EXPORT_SYMBOL_GPL(pinconf_generic_dt_subnode_to_map);

int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
                struct device_node *np_config, struct pinctrl_map **map,
                unsigned int *num_maps, enum pinctrl_map_type type)
{
        unsigned int reserved_maps;
        int ret;

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

        ret = pinconf_generic_dt_subnode_to_map(pctldev, np_config, map,
                                                &reserved_maps, num_maps, type);
        if (ret < 0)
                goto exit;

        for_each_available_child_of_node_scoped(np_config, np) {
                ret = pinconf_generic_dt_subnode_to_map(pctldev, np, map,
                                        &reserved_maps, num_maps, type);
                if (ret < 0)
                        goto exit;
        }
        return 0;

exit:
        pinctrl_utils_free_map(pctldev, *map, *num_maps);
        return ret;
}
EXPORT_SYMBOL_GPL(pinconf_generic_dt_node_to_map);

void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
                                 struct pinctrl_map *map,
                                 unsigned int num_maps)
{
        pinctrl_utils_free_map(pctldev, map, num_maps);
}
EXPORT_SYMBOL_GPL(pinconf_generic_dt_free_map);

#endif