pinctrl-lantiq.c

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/*
 *  linux/drivers/pinctrl/pinctrl-lantiq.c
 *  based on linux/drivers/pinctrl/pinctrl-pxa3xx.c
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  publishhed by the Free Software Foundation.
 *
 *  Copyright (C) 2012 John Crispin <[email protected]>
 */

#include <linux/module.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/of.h>

#include "pinctrl-lantiq.h"

static int ltq_get_group_count(struct pinctrl_dev *pctrldev)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
    return info->num_grps;
}

static const char *ltq_get_group_name(struct pinctrl_dev *pctrldev,
                     unsigned selector)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
    if (selector >= info->num_grps)
        return NULL;
    return info->grps[selector].name;
}

static int ltq_get_group_pins(struct pinctrl_dev *pctrldev,
                 unsigned selector,
                 const unsigned **pins,
                 unsigned *num_pins)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
    if (selector >= info->num_grps)
        return -EINVAL;
    *pins = info->grps[selector].pins;
    *num_pins = info->grps[selector].npins;
    return 0;
}

void ltq_pinctrl_dt_free_map(struct pinctrl_dev *pctldev,
                struct pinctrl_map *map, unsigned num_maps)
{
    int i;

    for (i = 0; i < num_maps; i++)
        if (map[i].type == PIN_MAP_TYPE_CONFIGS_PIN)
            kfree(map[i].data.configs.configs);
    kfree(map);
}

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

static int ltq_pinctrl_dt_subnode_to_map(struct pinctrl_dev *pctldev,
                struct device_node *np,
                struct pinctrl_map **map)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctldev);
    unsigned long configs[3];
    unsigned num_configs = 0;
    struct property *prop;
    const char *group, *pin;
    const char *function;
    int ret, i;

    ret = of_property_read_string(np, "lantiq,function", &function);
    if (!ret) {
        of_property_for_each_string(np, "lantiq,groups", prop, group) {
            (*map)->type = PIN_MAP_TYPE_MUX_GROUP;
            (*map)->name = function;
            (*map)->data.mux.group = group;
            (*map)->data.mux.function = function;
            (*map)++;
        }
        if (of_find_property(np, "lantiq,pins", NULL))
            dev_err(pctldev->dev,
                "%s mixes pins and groups settings\n",
                np->name);
        return 0;
    }

    for (i = 0; i < info->num_params; i++) {
        u32 val;
        int ret = of_property_read_u32(np,
                info->params[i].property, &val);
        if (!ret)
            configs[num_configs++] =
                LTQ_PINCONF_PACK(info->params[i].param,
                val);
    }

    if (!num_configs)
        return -EINVAL;

    of_property_for_each_string(np, "lantiq,pins", prop, pin) {
        (*map)->data.configs.configs = kmemdup(configs,
                    num_configs * sizeof(unsigned long),
                    GFP_KERNEL);
        (*map)->type = PIN_MAP_TYPE_CONFIGS_PIN;
        (*map)->name = pin;
        (*map)->data.configs.group_or_pin = pin;
        (*map)->data.configs.num_configs = num_configs;
        (*map)++;
    }
    return 0;
}

static int ltq_pinctrl_dt_subnode_size(struct device_node *np)
{
    int ret;

    ret = of_property_count_strings(np, "lantiq,groups");
    if (ret < 0)
        ret = of_property_count_strings(np, "lantiq,pins");
    return ret;
}

int ltq_pinctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
                struct device_node *np_config,
                struct pinctrl_map **map,
                unsigned *num_maps)
{
    struct pinctrl_map *tmp;
    struct device_node *np;
    int ret;

    *num_maps = 0;
    for_each_child_of_node(np_config, np)
        *num_maps += ltq_pinctrl_dt_subnode_size(np);
    *map = kzalloc(*num_maps * sizeof(struct pinctrl_map), GFP_KERNEL);
    if (!*map)
        return -ENOMEM;
    tmp = *map;

    for_each_child_of_node(np_config, np) {
        ret = ltq_pinctrl_dt_subnode_to_map(pctldev, np, &tmp);
        if (ret < 0) {
            ltq_pinctrl_dt_free_map(pctldev, *map, *num_maps);
            return ret;
        }
    }
    return 0;
}

static struct pinctrl_ops ltq_pctrl_ops = {
    .get_groups_count   = ltq_get_group_count,
    .get_group_name     = ltq_get_group_name,
    .get_group_pins     = ltq_get_group_pins,
    .pin_dbg_show       = ltq_pinctrl_pin_dbg_show,
    .dt_node_to_map     = ltq_pinctrl_dt_node_to_map,
    .dt_free_map        = ltq_pinctrl_dt_free_map,
};

static int ltq_pmx_func_count(struct pinctrl_dev *pctrldev)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);

    return info->num_funcs;
}

static const char *ltq_pmx_func_name(struct pinctrl_dev *pctrldev,
                     unsigned selector)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);

    if (selector >= info->num_funcs)
        return NULL;

    return info->funcs[selector].name;
}

static int ltq_pmx_get_groups(struct pinctrl_dev *pctrldev,
                unsigned func,
                const char * const **groups,
                unsigned * const num_groups)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);

    *groups = info->funcs[func].groups;
    *num_groups = info->funcs[func].num_groups;

    return 0;
}

/* Return function number. If failure, return negative value. */
static int match_mux(const struct ltq_mfp_pin *mfp, unsigned mux)
{
    int i;
    for (i = 0; i < LTQ_MAX_MUX; i++) {
        if (mfp->func[i] == mux)
            break;
    }
    if (i >= LTQ_MAX_MUX)
        return -EINVAL;
    return i;
}

/* dont assume .mfp is linearly mapped. find the mfp with the correct .pin */
static int match_mfp(const struct ltq_pinmux_info *info, int pin)
{
    int i;
    for (i = 0; i < info->num_mfp; i++) {
        if (info->mfp[i].pin == pin)
            return i;
    }
    return -1;
}

/* check whether current pin configuration is valid. Negative for failure */
static int match_group_mux(const struct ltq_pin_group *grp,
               const struct ltq_pinmux_info *info,
               unsigned mux)
{
    int i, pin, ret = 0;
    for (i = 0; i < grp->npins; i++) {
        pin = match_mfp(info, grp->pins[i]);
        if (pin < 0) {
            dev_err(info->dev, "could not find mfp for pin %d\n",
                grp->pins[i]);
            return -EINVAL;
        }
        ret = match_mux(&info->mfp[pin], mux);
        if (ret < 0) {
            dev_err(info->dev, "Can't find mux %d on pin%d\n",
                mux, pin);
            break;
        }
    }
    return ret;
}

static int ltq_pmx_enable(struct pinctrl_dev *pctrldev,
                unsigned func,
                unsigned group)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
    const struct ltq_pin_group *pin_grp = &info->grps[group];
    int i, pin, pin_func, ret;

    if (!pin_grp->npins ||
        (match_group_mux(pin_grp, info, pin_grp->mux) < 0)) {
        dev_err(info->dev, "Failed to set the pin group: %s\n",
            info->grps[group].name);
        return -EINVAL;
    }
    for (i = 0; i < pin_grp->npins; i++) {
        pin = match_mfp(info, pin_grp->pins[i]);
        if (pin < 0) {
            dev_err(info->dev, "could not find mfp for pin %d\n",
                pin_grp->pins[i]);
            return -EINVAL;
        }
        pin_func = match_mux(&info->mfp[pin], pin_grp->mux);
        ret = info->apply_mux(pctrldev, pin, pin_func);
        if (ret) {
            dev_err(info->dev,
                "failed to apply mux %d for pin %d\n",
                pin_func, pin);
            return ret;
        }
    }
    return 0;
}

static void ltq_pmx_disable(struct pinctrl_dev *pctrldev,
                unsigned func,
                unsigned group)
{
    /*
     * Nothing to do here. However, pinconf_check_ops() requires this
     * callback to be defined.
     */
}

static int ltq_pmx_gpio_request_enable(struct pinctrl_dev *pctrldev,
                struct pinctrl_gpio_range *range,
                unsigned pin)
{
    struct ltq_pinmux_info *info = pinctrl_dev_get_drvdata(pctrldev);
    int mfp = match_mfp(info, pin + (range->id * 32));
    int pin_func;

    if (mfp < 0) {
        dev_err(info->dev, "could not find mfp for pin %d\n", pin);
        return -EINVAL;
    }

    pin_func = match_mux(&info->mfp[mfp], 0);
    if (pin_func < 0) {
        dev_err(info->dev, "No GPIO function on pin%d\n", mfp);
        return -EINVAL;
    }

    return info->apply_mux(pctrldev, mfp, pin_func);
}

static struct pinmux_ops ltq_pmx_ops = {
    .get_functions_count    = ltq_pmx_func_count,
    .get_function_name  = ltq_pmx_func_name,
    .get_function_groups    = ltq_pmx_get_groups,
    .enable         = ltq_pmx_enable,
    .disable        = ltq_pmx_disable,
    .gpio_request_enable    = ltq_pmx_gpio_request_enable,
};

/*
 * allow different socs to register with the generic part of the lanti
 * pinctrl code
 */
int ltq_pinctrl_register(struct platform_device *pdev,
                struct ltq_pinmux_info *info)
{
    struct pinctrl_desc *desc;

    if (!info)
        return -EINVAL;
    desc = info->desc;
    desc->pctlops = &ltq_pctrl_ops;
    desc->pmxops = &ltq_pmx_ops;
    info->dev = &pdev->dev;

    info->pctrl = pinctrl_register(desc, &pdev->dev, info);
    if (!info->pctrl) {
        dev_err(&pdev->dev, "failed to register LTQ pinmux driver\n");
        return -EINVAL;
    }
    platform_set_drvdata(pdev, info);
    return 0;
}