/*
 * Driver for the ST Microelectronics SPEAr pinmux
 *
 * Copyright (C) 2012 ST Microelectronics
 * Viresh Kumar <vireshk@kernel.org>
 *
 * Inspired from:
 * - U300 Pinctl drivers
 * - Tegra Pinctl drivers
 *
 * This file is licensed under the terms of the GNU General Public
 * License version 2. This program is licensed "as is" without any
 * warranty of any kind, whether express or implied.
 */

#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/slab.h>

#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>

#include "pinctrl-spear.h"

#define DRIVER_NAME "spear-pinmux"

static void muxregs_endisable(struct spear_pmx *pmx,
                struct spear_muxreg *muxregs, u8 count, bool enable)
{
        struct spear_muxreg *muxreg;
        u32 val, temp, j;

        for (j = 0; j < count; j++) {
                muxreg = &muxregs[j];

                val = pmx_readl(pmx, muxreg->reg);
                val &= ~muxreg->mask;

                if (enable)
                        temp = muxreg->val;
                else
                        temp = ~muxreg->val;

                val |= muxreg->mask & temp;
                pmx_writel(pmx, val, muxreg->reg);
        }
}

static int set_mode(struct spear_pmx *pmx, int mode)
{
        struct spear_pmx_mode *pmx_mode = NULL;
        int i;
        u32 val;

        if (!pmx->machdata->pmx_modes || !pmx->machdata->npmx_modes)
                return -EINVAL;

        for (i = 0; i < pmx->machdata->npmx_modes; i++) {
                if (pmx->machdata->pmx_modes[i]->mode == (1 << mode)) {
                        pmx_mode = pmx->machdata->pmx_modes[i];
                        break;
                }
        }

        if (!pmx_mode)
                return -EINVAL;

        val = pmx_readl(pmx, pmx_mode->reg);
        val &= ~pmx_mode->mask;
        val |= pmx_mode->val;
        pmx_writel(pmx, val, pmx_mode->reg);

        pmx->machdata->mode = pmx_mode->mode;
        dev_info(pmx->dev, "Configured Mode: %s with id: %x\n\n",
                        pmx_mode->name ? pmx_mode->name : "no_name",
                        pmx_mode->reg);

        return 0;
}

void pmx_init_gpio_pingroup_addr(struct spear_gpio_pingroup *gpio_pingroup,
                                 unsigned count, u16 reg)
{
        int i, j;

        for (i = 0; i < count; i++)
                for (j = 0; j < gpio_pingroup[i].nmuxregs; j++)
                        gpio_pingroup[i].muxregs[j].reg = reg;
}

void pmx_init_addr(struct spear_pinctrl_machdata *machdata, u16 reg)
{
        struct spear_pingroup *pgroup;
        struct spear_modemux *modemux;
        int i, j, group;

        for (group = 0; group < machdata->ngroups; group++) {
                pgroup = machdata->groups[group];

                for (i = 0; i < pgroup->nmodemuxs; i++) {
                        modemux = &pgroup->modemuxs[i];

                        for (j = 0; j < modemux->nmuxregs; j++)
                                if (modemux->muxregs[j].reg == 0xFFFF)
                                        modemux->muxregs[j].reg = reg;
                }
        }
}

static int spear_pinctrl_get_groups_cnt(struct pinctrl_dev *pctldev)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pmx->machdata->ngroups;
}

static const char *spear_pinctrl_get_group_name(struct pinctrl_dev *pctldev,
                unsigned group)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pmx->machdata->groups[group]->name;
}

static int spear_pinctrl_get_group_pins(struct pinctrl_dev *pctldev,
                unsigned group, const unsigned **pins, unsigned *num_pins)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);

        *pins = pmx->machdata->groups[group]->pins;
        *num_pins = pmx->machdata->groups[group]->npins;

        return 0;
}

static void spear_pinctrl_pin_dbg_show(struct pinctrl_dev *pctldev,
                struct seq_file *s, unsigned offset)
{
        seq_printf(s, " " DRIVER_NAME);
}

static int spear_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
                                        struct device_node *np_config,
                                        struct pinctrl_map **map,
                                        unsigned *num_maps)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
        struct property *prop;
        const char *function, *group;
        int ret, index = 0, count = 0;

        /* calculate number of maps required */
        for_each_child_of_node_scoped(np_config, np) {
                ret = of_property_read_string(np, "st,function", &function);
                if (ret < 0)
                        return ret;

                ret = of_property_count_strings(np, "st,pins");
                if (ret < 0)
                        return ret;

                count += ret;
        }

        if (!count) {
                dev_err(pmx->dev, "No child nodes passed via DT\n");
                return -ENODEV;
        }

        *map = kzalloc_objs(**map, count);
        if (!*map)
                return -ENOMEM;

        for_each_child_of_node_scoped(np_config, np) {
                of_property_read_string(np, "st,function", &function);
                of_property_for_each_string(np, "st,pins", prop, group) {
                        (*map)[index].type = PIN_MAP_TYPE_MUX_GROUP;
                        (*map)[index].data.mux.group = group;
                        (*map)[index].data.mux.function = function;
                        index++;
                }
        }

        *num_maps = count;

        return 0;
}

static void spear_pinctrl_dt_free_map(struct pinctrl_dev *pctldev,
                                      struct pinctrl_map *map,
                                      unsigned num_maps)
{
        kfree(map);
}

static const struct pinctrl_ops spear_pinctrl_ops = {
        .get_groups_count = spear_pinctrl_get_groups_cnt,
        .get_group_name = spear_pinctrl_get_group_name,
        .get_group_pins = spear_pinctrl_get_group_pins,
        .pin_dbg_show = spear_pinctrl_pin_dbg_show,
        .dt_node_to_map = spear_pinctrl_dt_node_to_map,
        .dt_free_map = spear_pinctrl_dt_free_map,
};

static int spear_pinctrl_get_funcs_count(struct pinctrl_dev *pctldev)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pmx->machdata->nfunctions;
}

static const char *spear_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
                unsigned function)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);

        return pmx->machdata->functions[function]->name;
}

static int spear_pinctrl_get_func_groups(struct pinctrl_dev *pctldev,
                unsigned function, const char *const **groups,
                unsigned * const ngroups)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);

        *groups = pmx->machdata->functions[function]->groups;
        *ngroups = pmx->machdata->functions[function]->ngroups;

        return 0;
}

static int spear_pinctrl_endisable(struct pinctrl_dev *pctldev,
                unsigned function, unsigned group, bool enable)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
        const struct spear_pingroup *pgroup;
        const struct spear_modemux *modemux;
        int i;
        bool found = false;

        pgroup = pmx->machdata->groups[group];

        for (i = 0; i < pgroup->nmodemuxs; i++) {
                modemux = &pgroup->modemuxs[i];

                /* SoC have any modes */
                if (pmx->machdata->modes_supported) {
                        if (!(pmx->machdata->mode & modemux->modes))
                                continue;
                }

                found = true;
                muxregs_endisable(pmx, modemux->muxregs, modemux->nmuxregs,
                                enable);
        }

        if (!found) {
                dev_err(pmx->dev, "pinmux group: %s not supported\n",
                                pgroup->name);
                return -ENODEV;
        }

        return 0;
}

static int spear_pinctrl_set_mux(struct pinctrl_dev *pctldev, unsigned function,
                unsigned group)
{
        return spear_pinctrl_endisable(pctldev, function, group, true);
}

/* gpio with pinmux */
static struct spear_gpio_pingroup *get_gpio_pingroup(struct spear_pmx *pmx,
                unsigned pin)
{
        struct spear_gpio_pingroup *gpio_pingroup;
        int i, j;

        if (!pmx->machdata->gpio_pingroups)
                return NULL;

        for (i = 0; i < pmx->machdata->ngpio_pingroups; i++) {
                gpio_pingroup = &pmx->machdata->gpio_pingroups[i];

                for (j = 0; j < gpio_pingroup->npins; j++) {
                        if (gpio_pingroup->pins[j] == pin)
                                return gpio_pingroup;
                }
        }

        return NULL;
}

static int gpio_request_endisable(struct pinctrl_dev *pctldev,
                struct pinctrl_gpio_range *range, unsigned offset, bool enable)
{
        struct spear_pmx *pmx = pinctrl_dev_get_drvdata(pctldev);
        struct spear_pinctrl_machdata *machdata = pmx->machdata;
        struct spear_gpio_pingroup *gpio_pingroup;

        /*
         * Some SoC have configuration options applicable to group of pins,
         * rather than a single pin.
         */
        gpio_pingroup = get_gpio_pingroup(pmx, offset);
        if (gpio_pingroup)
                muxregs_endisable(pmx, gpio_pingroup->muxregs,
                                gpio_pingroup->nmuxregs, enable);

        /*
         * SoC may need some extra configurations, or configurations for single
         * pin
         */
        if (machdata->gpio_request_endisable)
                machdata->gpio_request_endisable(pmx, offset, enable);

        return 0;
}

static int gpio_request_enable(struct pinctrl_dev *pctldev,
                struct pinctrl_gpio_range *range, unsigned offset)
{
        return gpio_request_endisable(pctldev, range, offset, true);
}

static void gpio_disable_free(struct pinctrl_dev *pctldev,
                struct pinctrl_gpio_range *range, unsigned offset)
{
        gpio_request_endisable(pctldev, range, offset, false);
}

static const struct pinmux_ops spear_pinmux_ops = {
        .get_functions_count = spear_pinctrl_get_funcs_count,
        .get_function_name = spear_pinctrl_get_func_name,
        .get_function_groups = spear_pinctrl_get_func_groups,
        .set_mux = spear_pinctrl_set_mux,
        .gpio_request_enable = gpio_request_enable,
        .gpio_disable_free = gpio_disable_free,
};

static struct pinctrl_desc spear_pinctrl_desc = {
        .name = DRIVER_NAME,
        .pctlops = &spear_pinctrl_ops,
        .pmxops = &spear_pinmux_ops,
        .owner = THIS_MODULE,
};

int spear_pinctrl_probe(struct platform_device *pdev,
                        struct spear_pinctrl_machdata *machdata)
{
        struct device_node *np = pdev->dev.of_node;
        struct spear_pmx *pmx;

        if (!machdata)
                return -ENODEV;

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

        pmx->regmap = device_node_to_regmap(np);
        if (IS_ERR(pmx->regmap)) {
                dev_err(&pdev->dev, "Init regmap failed (%pe).\n",
                        pmx->regmap);
                return PTR_ERR(pmx->regmap);
        }

        pmx->dev = &pdev->dev;
        pmx->machdata = machdata;

        /* configure mode, if supported by SoC */
        if (machdata->modes_supported) {
                int mode = 0;

                if (of_property_read_u32(np, "st,pinmux-mode", &mode)) {
                        dev_err(&pdev->dev, "OF: pinmux mode not passed\n");
                        return -EINVAL;
                }

                if (set_mode(pmx, mode)) {
                        dev_err(&pdev->dev, "OF: Couldn't configure mode: %x\n",
                                        mode);
                        return -EINVAL;
                }
        }

        platform_set_drvdata(pdev, pmx);

        spear_pinctrl_desc.pins = machdata->pins;
        spear_pinctrl_desc.npins = machdata->npins;

        pmx->pctl = devm_pinctrl_register(&pdev->dev, &spear_pinctrl_desc, pmx);
        if (IS_ERR(pmx->pctl)) {
                dev_err(&pdev->dev, "Couldn't register pinctrl driver\n");
                return PTR_ERR(pmx->pctl);
        }

        return 0;
}