pinctrl-spear.c

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/*
 * Driver for the ST Microelectronics SPEAr pinmux
 *
 * Copyright (C) 2012 ST Microelectronics
 * Viresh Kumar <[email protected]>
 *
 * 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/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include "pinctrl-spear.h"

#define DRIVER_NAME "spear-pinmux"

static inline u32 pmx_readl(struct spear_pmx *pmx, u32 reg)
{
    return readl_relaxed(pmx->vbase + reg);
}

static inline void pmx_writel(struct spear_pmx *pmx, u32 val, u32 reg)
{
    writel_relaxed(val, pmx->vbase + 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 __devinit 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);
}

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 device_node *np;
    struct property *prop;
    const char *function, *group;
    int ret, index = 0, count = 0;

    /* calculate number of maps required */
    for_each_child_of_node(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(sizeof(**map) * count, GFP_KERNEL);
    if (!*map)
        return -ENOMEM;

    for_each_child_of_node(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;
}

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

static 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;
    struct spear_muxreg *muxreg;
    u32 val, temp;
    int i, j;
    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;
        for (j = 0; j < modemux->nmuxregs; j++) {
            muxreg = &modemux->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);
        }
    }

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

    return 0;
}

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

static void spear_pinctrl_disable(struct pinctrl_dev *pctldev,
        unsigned function, unsigned group)
{
    spear_pinctrl_endisable(pctldev, function, group, false);
}

static 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,
    .enable = spear_pinctrl_enable,
    .disable = spear_pinctrl_disable,
};

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

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

    if (!machdata)
        return -ENODEV;

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res)
        return -EINVAL;

    pmx = devm_kzalloc(&pdev->dev, sizeof(*pmx), GFP_KERNEL);
    if (!pmx) {
        dev_err(&pdev->dev, "Can't alloc spear_pmx\n");
        return -ENOMEM;
    }

    pmx->vbase = devm_ioremap(&pdev->dev, res->start, resource_size(res));
    if (!pmx->vbase) {
        dev_err(&pdev->dev, "Couldn't ioremap at index 0\n");
        return -ENODEV;
    }

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

    return 0;
}

int __devexit spear_pinctrl_remove(struct platform_device *pdev)
{
    struct spear_pmx *pmx = platform_get_drvdata(pdev);

    pinctrl_unregister(pmx->pctl);

    return 0;
}