// SPDX-License-Identifier: GPL-2.0-only
/*
 * Pinconf driver for TI DA850/OMAP-L138/AM18XX pullup/pulldown groups
 *
 * Copyright (C) 2016  David Lechner
 */

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/platform_device.h>

#define DA850_PUPD_ENA          0x00
#define DA850_PUPD_SEL          0x04

struct da850_pupd_data {
        void __iomem *base;
        struct pinctrl_desc desc;
        struct pinctrl_dev *pinctrl;
};

static const char * const da850_pupd_group_names[] = {
        "cp0", "cp1", "cp2", "cp3", "cp4", "cp5", "cp6", "cp7",
        "cp8", "cp9", "cp10", "cp11", "cp12", "cp13", "cp14", "cp15",
        "cp16", "cp17", "cp18", "cp19", "cp20", "cp21", "cp22", "cp23",
        "cp24", "cp25", "cp26", "cp27", "cp28", "cp29", "cp30", "cp31",
};

static int da850_pupd_get_groups_count(struct pinctrl_dev *pctldev)
{
        return ARRAY_SIZE(da850_pupd_group_names);
}

static const char *da850_pupd_get_group_name(struct pinctrl_dev *pctldev,
                                             unsigned int selector)
{
        return da850_pupd_group_names[selector];
}

static int da850_pupd_get_group_pins(struct pinctrl_dev *pctldev,
                                     unsigned int selector,
                                     const unsigned int **pins,
                                     unsigned int *num_pins)
{
        *num_pins = 0;

        return 0;
}

static const struct pinctrl_ops da850_pupd_pctlops = {
        .get_groups_count       = da850_pupd_get_groups_count,
        .get_group_name         = da850_pupd_get_group_name,
        .get_group_pins         = da850_pupd_get_group_pins,
        .dt_node_to_map         = pinconf_generic_dt_node_to_map_group,
        .dt_free_map            = pinconf_generic_dt_free_map,
};

static int da850_pupd_pin_config_group_get(struct pinctrl_dev *pctldev,
                                           unsigned int selector,
                                           unsigned long *config)
{
        struct da850_pupd_data *data = pinctrl_dev_get_drvdata(pctldev);
        enum pin_config_param param = pinconf_to_config_param(*config);
        u32 val;
        u16 arg;

        val = readl(data->base + DA850_PUPD_ENA);
        arg = !!(~val & BIT(selector));

        switch (param) {
        case PIN_CONFIG_BIAS_DISABLE:
                break;
        case PIN_CONFIG_BIAS_PULL_UP:
        case PIN_CONFIG_BIAS_PULL_DOWN:
                if (arg) {
                        /* bias is disabled */
                        arg = 0;
                        break;
                }
                val = readl(data->base + DA850_PUPD_SEL);
                if (param == PIN_CONFIG_BIAS_PULL_DOWN)
                        val = ~val;
                arg = !!(val & BIT(selector));
                break;
        default:
                return -EINVAL;
        }

        *config = pinconf_to_config_packed(param, arg);

        return 0;
}

static int da850_pupd_pin_config_group_set(struct pinctrl_dev *pctldev,
                                           unsigned int selector,
                                           unsigned long *configs,
                                           unsigned int num_configs)
{
        struct da850_pupd_data *data = pinctrl_dev_get_drvdata(pctldev);
        u32 ena, sel;
        enum pin_config_param param;
        int i;

        ena = readl(data->base + DA850_PUPD_ENA);
        sel = readl(data->base + DA850_PUPD_SEL);

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

                switch (param) {
                case PIN_CONFIG_BIAS_DISABLE:
                        ena &= ~BIT(selector);
                        break;
                case PIN_CONFIG_BIAS_PULL_UP:
                        ena |= BIT(selector);
                        sel |= BIT(selector);
                        break;
                case PIN_CONFIG_BIAS_PULL_DOWN:
                        ena |= BIT(selector);
                        sel &= ~BIT(selector);
                        break;
                default:
                        return -EINVAL;
                }
        }

        writel(sel, data->base + DA850_PUPD_SEL);
        writel(ena, data->base + DA850_PUPD_ENA);

        return 0;
}

static const struct pinconf_ops da850_pupd_confops = {
        .is_generic             = true,
        .pin_config_group_get   = da850_pupd_pin_config_group_get,
        .pin_config_group_set   = da850_pupd_pin_config_group_set,
};

static int da850_pupd_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct da850_pupd_data *data;

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

        data->base = devm_platform_ioremap_resource(pdev, 0);
        if (IS_ERR(data->base)) {
                dev_err(dev, "Could not map resource\n");
                return PTR_ERR(data->base);
        }

        data->desc.name = dev_name(dev);
        data->desc.pctlops = &da850_pupd_pctlops;
        data->desc.confops = &da850_pupd_confops;
        data->desc.owner = THIS_MODULE;

        data->pinctrl = devm_pinctrl_register(dev, &data->desc, data);
        if (IS_ERR(data->pinctrl)) {
                dev_err(dev, "Failed to register pinctrl\n");
                return PTR_ERR(data->pinctrl);
        }

        platform_set_drvdata(pdev, data);

        return 0;
}

static const struct of_device_id da850_pupd_of_match[] = {
        { .compatible = "ti,da850-pupd" },
        { }
};
MODULE_DEVICE_TABLE(of, da850_pupd_of_match);

static struct platform_driver da850_pupd_driver = {
        .driver = {
                .name           = "ti-da850-pupd",
                .of_match_table = da850_pupd_of_match,
        },
        .probe  = da850_pupd_probe,
};
module_platform_driver(da850_pupd_driver);

MODULE_AUTHOR("David Lechner <david@lechnology.com>");
MODULE_DESCRIPTION("TI DA850/OMAP-L138/AM18XX pullup/pulldown configuration");
MODULE_LICENSE("GPL");