/*
 * Copyright 2012 Freescale Semiconductor, Inc.
 *
 * The code contained herein is licensed under the GNU General Public
 * License. You may obtain a copy of the GNU General Public License
 * Version 2 or later at the following locations:
 *
 * http://www.opensource.org/licenses/gpl-license.html
 * http://www.gnu.org/copyleft/gpl.html
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include "../core.h"
#include "pinctrl-mxs.h"

#define SUFFIX_LEN      4

struct mxs_pinctrl_data {
        struct device *dev;
        struct pinctrl_dev *pctl;
        void __iomem *base;
        struct mxs_pinctrl_soc_data *soc;
};

static int mxs_get_groups_count(struct pinctrl_dev *pctldev)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        return d->soc->ngroups;
}

static const char *mxs_get_group_name(struct pinctrl_dev *pctldev,
                                      unsigned group)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        return d->soc->groups[group].name;
}

static int mxs_get_group_pins(struct pinctrl_dev *pctldev, unsigned group,
                              const unsigned **pins, unsigned *num_pins)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        *pins = d->soc->groups[group].pins;
        *num_pins = d->soc->groups[group].npins;

        return 0;
}

static void mxs_pin_dbg_show(struct pinctrl_dev *pctldev, struct seq_file *s,
                             unsigned offset)
{
        seq_printf(s, " %s", dev_name(pctldev->dev));
}

static int mxs_dt_node_to_map(struct pinctrl_dev *pctldev,
                              struct device_node *np,
                              struct pinctrl_map **map, unsigned *num_maps)
{
        struct pinctrl_map *new_map;
        char *group = NULL;
        unsigned new_num = 1;
        unsigned long config = 0;
        unsigned long *pconfig;
        int length = strlen(np->name) + SUFFIX_LEN;
        bool purecfg = false;
        u32 val, reg;
        int ret, i = 0;

        /* Check for pin config node which has no 'reg' property */
        if (of_property_read_u32(np, "reg", &reg))
                purecfg = true;

        ret = of_property_read_u32(np, "fsl,drive-strength", &val);
        if (!ret)
                config = val | MA_PRESENT;
        ret = of_property_read_u32(np, "fsl,voltage", &val);
        if (!ret)
                config |= val << VOL_SHIFT | VOL_PRESENT;
        ret = of_property_read_u32(np, "fsl,pull-up", &val);
        if (!ret)
                config |= val << PULL_SHIFT | PULL_PRESENT;

        /* Check for group node which has both mux and config settings */
        if (!purecfg && config)
                new_num = 2;

        new_map = kzalloc(sizeof(*new_map) * new_num, GFP_KERNEL);
        if (!new_map)
                return -ENOMEM;

        if (!purecfg) {
                new_map[i].type = PIN_MAP_TYPE_MUX_GROUP;
                new_map[i].data.mux.function = np->name;

                /* Compose group name */
                group = kzalloc(length, GFP_KERNEL);
                if (!group) {
                        ret = -ENOMEM;
                        goto free;
                }
                snprintf(group, length, "%s.%d", np->name, reg);
                new_map[i].data.mux.group = group;
                i++;
        }

        if (config) {
                pconfig = kmemdup(&config, sizeof(config), GFP_KERNEL);
                if (!pconfig) {
                        ret = -ENOMEM;
                        goto free_group;
                }

                new_map[i].type = PIN_MAP_TYPE_CONFIGS_GROUP;
                new_map[i].data.configs.group_or_pin = purecfg ? np->name :
                                                                 group;
                new_map[i].data.configs.configs = pconfig;
                new_map[i].data.configs.num_configs = 1;
        }

        *map = new_map;
        *num_maps = new_num;

        return 0;

free_group:
        if (!purecfg)
                kfree(group);
free:
        kfree(new_map);
        return ret;
}

static void mxs_dt_free_map(struct pinctrl_dev *pctldev,
                            struct pinctrl_map *map, unsigned num_maps)
{
        u32 i;

        for (i = 0; i < num_maps; i++) {
                if (map[i].type == PIN_MAP_TYPE_MUX_GROUP)
                        kfree(map[i].data.mux.group);
                if (map[i].type == PIN_MAP_TYPE_CONFIGS_GROUP)
                        kfree(map[i].data.configs.configs);
        }

        kfree(map);
}

static const struct pinctrl_ops mxs_pinctrl_ops = {
        .get_groups_count = mxs_get_groups_count,
        .get_group_name = mxs_get_group_name,
        .get_group_pins = mxs_get_group_pins,
        .pin_dbg_show = mxs_pin_dbg_show,
        .dt_node_to_map = mxs_dt_node_to_map,
        .dt_free_map = mxs_dt_free_map,
};

static int mxs_pinctrl_get_funcs_count(struct pinctrl_dev *pctldev)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        return d->soc->nfunctions;
}

static const char *mxs_pinctrl_get_func_name(struct pinctrl_dev *pctldev,
                                             unsigned function)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        return d->soc->functions[function].name;
}

static int mxs_pinctrl_get_func_groups(struct pinctrl_dev *pctldev,
                                       unsigned group,
                                       const char * const **groups,
                                       unsigned * const num_groups)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        *groups = d->soc->functions[group].groups;
        *num_groups = d->soc->functions[group].ngroups;

        return 0;
}

static int mxs_pinctrl_set_mux(struct pinctrl_dev *pctldev, unsigned selector,
                               unsigned group)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);
        struct mxs_group *g = &d->soc->groups[group];
        void __iomem *reg;
        u8 bank, shift;
        u16 pin;
        u32 i;

        for (i = 0; i < g->npins; i++) {
                bank = PINID_TO_BANK(g->pins[i]);
                pin = PINID_TO_PIN(g->pins[i]);
                reg = d->base + d->soc->regs->muxsel;
                reg += bank * 0x20 + pin / 16 * 0x10;
                shift = pin % 16 * 2;

                writel(0x3 << shift, reg + CLR);
                writel(g->muxsel[i] << shift, reg + SET);
        }

        return 0;
}

static const struct pinmux_ops mxs_pinmux_ops = {
        .get_functions_count = mxs_pinctrl_get_funcs_count,
        .get_function_name = mxs_pinctrl_get_func_name,
        .get_function_groups = mxs_pinctrl_get_func_groups,
        .set_mux = mxs_pinctrl_set_mux,
};

static int mxs_pinconf_get(struct pinctrl_dev *pctldev,
                           unsigned pin, unsigned long *config)
{
        return -ENOTSUPP;
}

static int mxs_pinconf_set(struct pinctrl_dev *pctldev,
                           unsigned pin, unsigned long *configs,
                           unsigned num_configs)
{
        return -ENOTSUPP;
}

static int mxs_pinconf_group_get(struct pinctrl_dev *pctldev,
                                 unsigned group, unsigned long *config)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);

        *config = d->soc->groups[group].config;

        return 0;
}

static int mxs_pinconf_group_set(struct pinctrl_dev *pctldev,
                                 unsigned group, unsigned long *configs,
                                 unsigned num_configs)
{
        struct mxs_pinctrl_data *d = pinctrl_dev_get_drvdata(pctldev);
        struct mxs_group *g = &d->soc->groups[group];
        void __iomem *reg;
        u8 ma, vol, pull, bank, shift;
        u16 pin;
        u32 i;
        int n;
        unsigned long config;

        for (n = 0; n < num_configs; n++) {
                config = configs[n];

                ma = CONFIG_TO_MA(config);
                vol = CONFIG_TO_VOL(config);
                pull = CONFIG_TO_PULL(config);

                for (i = 0; i < g->npins; i++) {
                        bank = PINID_TO_BANK(g->pins[i]);
                        pin = PINID_TO_PIN(g->pins[i]);

                        /* drive */
                        reg = d->base + d->soc->regs->drive;
                        reg += bank * 0x40 + pin / 8 * 0x10;

                        /* mA */
                        if (config & MA_PRESENT) {
                                shift = pin % 8 * 4;
                                writel(0x3 << shift, reg + CLR);
                                writel(ma << shift, reg + SET);
                        }

                        /* vol */
                        if (config & VOL_PRESENT) {
                                shift = pin % 8 * 4 + 2;
                                if (vol)
                                        writel(1 << shift, reg + SET);
                                else
                                        writel(1 << shift, reg + CLR);
                        }

                        /* pull */
                        if (config & PULL_PRESENT) {
                                reg = d->base + d->soc->regs->pull;
                                reg += bank * 0x10;
                                shift = pin;
                                if (pull)
                                        writel(1 << shift, reg + SET);
                                else
                                        writel(1 << shift, reg + CLR);
                        }
                }

                /* cache the config value for mxs_pinconf_group_get() */
                g->config = config;

        } /* for each config */

        return 0;
}

static void mxs_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                                 struct seq_file *s, unsigned pin)
{
        /* Not support */
}

static void mxs_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
                                       struct seq_file *s, unsigned group)
{
        unsigned long config;

        if (!mxs_pinconf_group_get(pctldev, group, &config))
                seq_printf(s, "0x%lx", config);
}

static const struct pinconf_ops mxs_pinconf_ops = {
        .pin_config_get = mxs_pinconf_get,
        .pin_config_set = mxs_pinconf_set,
        .pin_config_group_get = mxs_pinconf_group_get,
        .pin_config_group_set = mxs_pinconf_group_set,
        .pin_config_dbg_show = mxs_pinconf_dbg_show,
        .pin_config_group_dbg_show = mxs_pinconf_group_dbg_show,
};

static struct pinctrl_desc mxs_pinctrl_desc = {
        .pctlops = &mxs_pinctrl_ops,
        .pmxops = &mxs_pinmux_ops,
        .confops = &mxs_pinconf_ops,
        .owner = THIS_MODULE,
};

static int mxs_pinctrl_parse_group(struct platform_device *pdev,
                                   struct device_node *np, int idx,
                                   const char **out_name)
{
        struct mxs_pinctrl_data *d = platform_get_drvdata(pdev);
        struct mxs_group *g = &d->soc->groups[idx];
        struct property *prop;
        const char *propname = "fsl,pinmux-ids";
        char *group;
        int length = strlen(np->name) + SUFFIX_LEN;
        u32 val, i;

        group = devm_kzalloc(&pdev->dev, length, GFP_KERNEL);
        if (!group)
                return -ENOMEM;
        if (of_property_read_u32(np, "reg", &val))
                snprintf(group, length, "%s", np->name);
        else
                snprintf(group, length, "%s.%d", np->name, val);
        g->name = group;

        prop = of_find_property(np, propname, &length);
        if (!prop)
                return -EINVAL;
        g->npins = length / sizeof(u32);

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

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

        of_property_read_u32_array(np, propname, g->pins, g->npins);
        for (i = 0; i < g->npins; i++) {
                g->muxsel[i] = MUXID_TO_MUXSEL(g->pins[i]);
                g->pins[i] = MUXID_TO_PINID(g->pins[i]);
        }

        if (out_name)
                *out_name = g->name;

        return 0;
}

static int mxs_pinctrl_probe_dt(struct platform_device *pdev,
                                struct mxs_pinctrl_data *d)
{
        struct mxs_pinctrl_soc_data *soc = d->soc;
        struct device_node *np = pdev->dev.of_node;
        struct device_node *child;
        struct mxs_function *f;
        const char *gpio_compat = "fsl,mxs-gpio";
        const char *fn, *fnull = "";
        int i = 0, idxf = 0, idxg = 0;
        int ret;
        u32 val;

        child = of_get_next_child(np, NULL);
        if (!child) {
                dev_err(&pdev->dev, "no group is defined\n");
                return -ENOENT;
        }

        /* Count total functions and groups */
        fn = fnull;
        for_each_child_of_node(np, child) {
                if (of_device_is_compatible(child, gpio_compat))
                        continue;
                soc->ngroups++;
                /* Skip pure pinconf node */
                if (of_property_read_u32(child, "reg", &val))
                        continue;
                if (strcmp(fn, child->name)) {
                        fn = child->name;
                        soc->nfunctions++;
                }
        }

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

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

        /* Count groups for each function */
        fn = fnull;
        f = &soc->functions[idxf];
        for_each_child_of_node(np, child) {
                if (of_device_is_compatible(child, gpio_compat))
                        continue;
                if (of_property_read_u32(child, "reg", &val))
                        continue;
                if (strcmp(fn, child->name)) {
                        struct device_node *child2;

                        /*
                         * This reference is dropped by
                         * of_get_next_child(np, * child)
                         */
                        of_node_get(child);

                        /*
                         * The logic parsing the functions from dt currently
                         * doesn't handle if functions with the same name are
                         * not grouped together. Only the first contiguous
                         * cluster is usable for each function name. This is a
                         * bug that is not trivial to fix, but at least warn
                         * about it.
                         */
                        for (child2 = of_get_next_child(np, child);
                             child2 != NULL;
                             child2 = of_get_next_child(np, child2)) {
                                if (!strcmp(child2->name, fn))
                                        dev_warn(&pdev->dev,
                                                 "function nodes must be grouped by name (failed for: %s)",
                                                 fn);
                        }

                        f = &soc->functions[idxf++];
                        f->name = fn = child->name;
                }
                f->ngroups++;
        }

        /* Get groups for each function */
        idxf = 0;
        fn = fnull;
        for_each_child_of_node(np, child) {
                if (of_device_is_compatible(child, gpio_compat))
                        continue;
                if (of_property_read_u32(child, "reg", &val)) {
                        ret = mxs_pinctrl_parse_group(pdev, child,
                                                      idxg++, NULL);
                        if (ret)
                                return ret;
                        continue;
                }

                if (strcmp(fn, child->name)) {
                        f = &soc->functions[idxf++];
                        f->groups = devm_kzalloc(&pdev->dev, f->ngroups *
                                                 sizeof(*f->groups),
                                                 GFP_KERNEL);
                        if (!f->groups)
                                return -ENOMEM;
                        fn = child->name;
                        i = 0;
                }
                ret = mxs_pinctrl_parse_group(pdev, child, idxg++,
                                              &f->groups[i++]);
                if (ret)
                        return ret;
        }

        return 0;
}

int mxs_pinctrl_probe(struct platform_device *pdev,
                      struct mxs_pinctrl_soc_data *soc)
{
        struct device_node *np = pdev->dev.of_node;
        struct mxs_pinctrl_data *d;
        int ret;

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

        d->dev = &pdev->dev;
        d->soc = soc;

        d->base = of_iomap(np, 0);
        if (!d->base)
                return -EADDRNOTAVAIL;

        mxs_pinctrl_desc.pins = d->soc->pins;
        mxs_pinctrl_desc.npins = d->soc->npins;
        mxs_pinctrl_desc.name = dev_name(&pdev->dev);

        platform_set_drvdata(pdev, d);

        ret = mxs_pinctrl_probe_dt(pdev, d);
        if (ret) {
                dev_err(&pdev->dev, "dt probe failed: %d\n", ret);
                goto err;
        }

        d->pctl = pinctrl_register(&mxs_pinctrl_desc, &pdev->dev, d);
        if (IS_ERR(d->pctl)) {
                dev_err(&pdev->dev, "Couldn't register MXS pinctrl driver\n");
                ret = PTR_ERR(d->pctl);
                goto err;
        }

        return 0;

err:
        iounmap(d->base);
        return ret;
}
EXPORT_SYMBOL_GPL(mxs_pinctrl_probe);