pinctrl-imx.c

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/*
 * Core driver for the imx pin controller
 *
 * Copyright (C) 2012 Freescale Semiconductor, Inc.
 * Copyright (C) 2012 Linaro Ltd.
 *
 * Author: Dong Aisheng <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 */

#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/slab.h>

#include "core.h"
#include "pinctrl-imx.h"

#define IMX_PMX_DUMP(info, p, m, c, n)          \
{                           \
    int i, j;                   \
    printk(KERN_DEBUG "Format: Pin Mux Config\n");  \
    for (i = 0; i < n; i++) {           \
        j = p[i];               \
        printk(KERN_DEBUG "%s %d 0x%lx\n",  \
            info->pins[j].name,     \
            m[i], c[i]);            \
    }                       \
}

/* The bits in CONFIG cell defined in binding doc*/
#define IMX_NO_PAD_CTL  0x80000000  /* no pin config need */
#define IMX_PAD_SION 0x40000000     /* set SION */

struct imx_pinctrl {
    struct device *dev;
    struct pinctrl_dev *pctl;
    void __iomem *base;
    const struct imx_pinctrl_soc_info *info;
};

static const struct imx_pin_reg *imx_find_pin_reg(
                const struct imx_pinctrl_soc_info *info,
                unsigned pin, bool is_mux, unsigned mux)
{
    const struct imx_pin_reg *pin_reg = NULL;
    int i;

    for (i = 0; i < info->npin_regs; i++) {
        pin_reg = &info->pin_regs[i];
        if (pin_reg->pid != pin)
            continue;
        if (!is_mux)
            break;
        else if (pin_reg->mux_mode == (mux & IMX_MUX_MASK))
            break;
    }

    if (!pin_reg) {
        dev_err(info->dev, "Pin(%s): unable to find pin reg map\n",
            info->pins[pin].name);
        return NULL;
    }

    return pin_reg;
}

static const inline struct imx_pin_group *imx_pinctrl_find_group_by_name(
                const struct imx_pinctrl_soc_info *info,
                const char *name)
{
    const struct imx_pin_group *grp = NULL;
    int i;

    for (i = 0; i < info->ngroups; i++) {
        if (!strcmp(info->groups[i].name, name)) {
            grp = &info->groups[i];
            break;
        }
    }

    return grp;
}

static int imx_get_groups_count(struct pinctrl_dev *pctldev)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;

    return info->ngroups;
}

static const char *imx_get_group_name(struct pinctrl_dev *pctldev,
                       unsigned selector)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;

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

static int imx_get_group_pins(struct pinctrl_dev *pctldev, unsigned selector,
                   const unsigned **pins,
                   unsigned *npins)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;

    if (selector >= info->ngroups)
        return -EINVAL;

    *pins = info->groups[selector].pins;
    *npins = info->groups[selector].npins;

    return 0;
}

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

static int imx_dt_node_to_map(struct pinctrl_dev *pctldev,
            struct device_node *np,
            struct pinctrl_map **map, unsigned *num_maps)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;
    const struct imx_pin_group *grp;
    struct pinctrl_map *new_map;
    struct device_node *parent;
    int map_num = 1;
    int i, j;

    /*
     * first find the group of this node and check if we need create
     * config maps for pins
     */
    grp = imx_pinctrl_find_group_by_name(info, np->name);
    if (!grp) {
        dev_err(info->dev, "unable to find group for node %s\n",
            np->name);
        return -EINVAL;
    }

    for (i = 0; i < grp->npins; i++) {
        if (!(grp->configs[i] & IMX_NO_PAD_CTL))
            map_num++;
    }

    new_map = kmalloc(sizeof(struct pinctrl_map) * map_num, GFP_KERNEL);
    if (!new_map)
        return -ENOMEM;

    *map = new_map;
    *num_maps = map_num;

    /* create mux map */
    parent = of_get_parent(np);
    if (!parent) {
        kfree(new_map);
        return -EINVAL;
    }
    new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;
    new_map[0].data.mux.function = parent->name;
    new_map[0].data.mux.group = np->name;
    of_node_put(parent);

    /* create config map */
    new_map++;
    for (i = j = 0; i < grp->npins; i++) {
        if (!(grp->configs[i] & IMX_NO_PAD_CTL)) {
            new_map[j].type = PIN_MAP_TYPE_CONFIGS_PIN;
            new_map[j].data.configs.group_or_pin =
                    pin_get_name(pctldev, grp->pins[i]);
            new_map[j].data.configs.configs = &grp->configs[i];
            new_map[j].data.configs.num_configs = 1;
            j++;
        }
    }

    dev_dbg(pctldev->dev, "maps: function %s group %s num %d\n",
        (*map)->data.mux.function, (*map)->data.mux.group, map_num);

    return 0;
}

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

static struct pinctrl_ops imx_pctrl_ops = {
    .get_groups_count = imx_get_groups_count,
    .get_group_name = imx_get_group_name,
    .get_group_pins = imx_get_group_pins,
    .pin_dbg_show = imx_pin_dbg_show,
    .dt_node_to_map = imx_dt_node_to_map,
    .dt_free_map = imx_dt_free_map,

};

static int imx_pmx_enable(struct pinctrl_dev *pctldev, unsigned selector,
               unsigned group)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;
    const struct imx_pin_reg *pin_reg;
    const unsigned *pins, *mux;
    unsigned int npins, pin_id;
    int i;

    /*
     * Configure the mux mode for each pin in the group for a specific
     * function.
     */
    pins = info->groups[group].pins;
    npins = info->groups[group].npins;
    mux = info->groups[group].mux_mode;

    WARN_ON(!pins || !npins || !mux);

    dev_dbg(ipctl->dev, "enable function %s group %s\n",
        info->functions[selector].name, info->groups[group].name);

    for (i = 0; i < npins; i++) {
        pin_id = pins[i];

        pin_reg = imx_find_pin_reg(info, pin_id, 1, mux[i]);
        if (!pin_reg)
            return -EINVAL;

        if (!pin_reg->mux_reg) {
            dev_err(ipctl->dev, "Pin(%s) does not support mux function\n",
                info->pins[pin_id].name);
            return -EINVAL;
        }

        writel(mux[i], ipctl->base + pin_reg->mux_reg);
        dev_dbg(ipctl->dev, "write: offset 0x%x val 0x%x\n",
            pin_reg->mux_reg, mux[i]);

        /* some pins also need select input setting, set it if found */
        if (pin_reg->input_reg) {
            writel(pin_reg->input_val, ipctl->base + pin_reg->input_reg);
            dev_dbg(ipctl->dev,
                "==>select_input: offset 0x%x val 0x%x\n",
                pin_reg->input_reg, pin_reg->input_val);
        }
    }

    return 0;
}

static int imx_pmx_get_funcs_count(struct pinctrl_dev *pctldev)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;

    return info->nfunctions;
}

static const char *imx_pmx_get_func_name(struct pinctrl_dev *pctldev,
                      unsigned selector)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;

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

static int imx_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
                   const char * const **groups,
                   unsigned * const num_groups)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;

    *groups = info->functions[selector].groups;
    *num_groups = info->functions[selector].num_groups;

    return 0;
}

static struct pinmux_ops imx_pmx_ops = {
    .get_functions_count = imx_pmx_get_funcs_count,
    .get_function_name = imx_pmx_get_func_name,
    .get_function_groups = imx_pmx_get_groups,
    .enable = imx_pmx_enable,
};

static int imx_pinconf_get(struct pinctrl_dev *pctldev,
                 unsigned pin_id, unsigned long *config)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;
    const struct imx_pin_reg *pin_reg;

    pin_reg = imx_find_pin_reg(info, pin_id, 0, 0);
    if (!pin_reg)
        return -EINVAL;

    if (!pin_reg->conf_reg) {
        dev_err(info->dev, "Pin(%s) does not support config function\n",
            info->pins[pin_id].name);
        return -EINVAL;
    }

    *config = readl(ipctl->base + pin_reg->conf_reg);

    return 0;
}

static int imx_pinconf_set(struct pinctrl_dev *pctldev,
                 unsigned pin_id, unsigned long config)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;
    const struct imx_pin_reg *pin_reg;

    pin_reg = imx_find_pin_reg(info, pin_id, 0, 0);
    if (!pin_reg)
        return -EINVAL;

    if (!pin_reg->conf_reg) {
        dev_err(info->dev, "Pin(%s) does not support config function\n",
            info->pins[pin_id].name);
        return -EINVAL;
    }

    dev_dbg(ipctl->dev, "pinconf set pin %s\n",
        info->pins[pin_id].name);

    writel(config, ipctl->base + pin_reg->conf_reg);
    dev_dbg(ipctl->dev, "write: offset 0x%x val 0x%lx\n",
        pin_reg->conf_reg, config);

    return 0;
}

static void imx_pinconf_dbg_show(struct pinctrl_dev *pctldev,
                   struct seq_file *s, unsigned pin_id)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;
    const struct imx_pin_reg *pin_reg;
    unsigned long config;

    pin_reg = imx_find_pin_reg(info, pin_id, 0, 0);
    if (!pin_reg || !pin_reg->conf_reg) {
        seq_printf(s, "N/A");
        return;
    }

    config = readl(ipctl->base + pin_reg->conf_reg);
    seq_printf(s, "0x%lx", config);
}

static void imx_pinconf_group_dbg_show(struct pinctrl_dev *pctldev,
                     struct seq_file *s, unsigned group)
{
    struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
    const struct imx_pinctrl_soc_info *info = ipctl->info;
    struct imx_pin_group *grp;
    unsigned long config;
    const char *name;
    int i, ret;

    if (group > info->ngroups)
        return;

    seq_printf(s, "\n");
    grp = &info->groups[group];
    for (i = 0; i < grp->npins; i++) {
        name = pin_get_name(pctldev, grp->pins[i]);
        ret = imx_pinconf_get(pctldev, grp->pins[i], &config);
        if (ret)
            return;
        seq_printf(s, "%s: 0x%lx", name, config);
    }
}

struct pinconf_ops imx_pinconf_ops = {
    .pin_config_get = imx_pinconf_get,
    .pin_config_set = imx_pinconf_set,
    .pin_config_dbg_show = imx_pinconf_dbg_show,
    .pin_config_group_dbg_show = imx_pinconf_group_dbg_show,
};

static struct pinctrl_desc imx_pinctrl_desc = {
    .pctlops = &imx_pctrl_ops,
    .pmxops = &imx_pmx_ops,
    .confops = &imx_pinconf_ops,
    .owner = THIS_MODULE,
};

/* decode pin id and mux from pin function id got from device tree*/
static int imx_pinctrl_get_pin_id_and_mux(const struct imx_pinctrl_soc_info *info,
                unsigned int pin_func_id, unsigned int *pin_id,
                unsigned int *mux)
{
    if (pin_func_id > info->npin_regs)
        return -EINVAL;

    *pin_id = info->pin_regs[pin_func_id].pid;
    *mux = info->pin_regs[pin_func_id].mux_mode;

    return 0;
}

static int __devinit imx_pinctrl_parse_groups(struct device_node *np,
                struct imx_pin_group *grp,
                struct imx_pinctrl_soc_info *info,
                u32 index)
{
    unsigned int pin_func_id;
    int ret, size;
    const __be32 *list;
    int i, j;
    u32 config;

    dev_dbg(info->dev, "group(%d): %s\n", index, np->name);

    /* Initialise group */
    grp->name = np->name;

    /*
     * the binding format is fsl,pins = <PIN_FUNC_ID CONFIG ...>,
     * do sanity check and calculate pins number
     */
    list = of_get_property(np, "fsl,pins", &size);
    /* we do not check return since it's safe node passed down */
    size /= sizeof(*list);
    if (!size || size % 2) {
        dev_err(info->dev, "wrong pins number or pins and configs should be pairs\n");
        return -EINVAL;
    }

    grp->npins = size / 2;
    grp->pins = devm_kzalloc(info->dev, grp->npins * sizeof(unsigned int),
                GFP_KERNEL);
    grp->mux_mode = devm_kzalloc(info->dev, grp->npins * sizeof(unsigned int),
                GFP_KERNEL);
    grp->configs = devm_kzalloc(info->dev, grp->npins * sizeof(unsigned long),
                GFP_KERNEL);
    for (i = 0, j = 0; i < size; i += 2, j++) {
        pin_func_id = be32_to_cpu(*list++);
        ret = imx_pinctrl_get_pin_id_and_mux(info, pin_func_id,
                    &grp->pins[j], &grp->mux_mode[j]);
        if (ret) {
            dev_err(info->dev, "get invalid pin function id\n");
            return -EINVAL;
        }
        /* SION bit is in mux register */
        config = be32_to_cpu(*list++);
        if (config & IMX_PAD_SION)
            grp->mux_mode[j] |= IOMUXC_CONFIG_SION;
        grp->configs[j] = config & ~IMX_PAD_SION;
    }

#ifdef DEBUG
    IMX_PMX_DUMP(info, grp->pins, grp->mux_mode, grp->configs, grp->npins);
#endif

    return 0;
}

static int __devinit imx_pinctrl_parse_functions(struct device_node *np,
            struct imx_pinctrl_soc_info *info, u32 index)
{
    struct device_node *child;
    struct imx_pmx_func *func;
    struct imx_pin_group *grp;
    int ret;
    static u32 grp_index;
    u32 i = 0;

    dev_dbg(info->dev, "parse function(%d): %s\n", index, np->name);

    func = &info->functions[index];

    /* Initialise function */
    func->name = np->name;
    func->num_groups = of_get_child_count(np);
    if (func->num_groups <= 0) {
        dev_err(info->dev, "no groups defined\n");
        return -EINVAL;
    }
    func->groups = devm_kzalloc(info->dev,
            func->num_groups * sizeof(char *), GFP_KERNEL);

    for_each_child_of_node(np, child) {
        func->groups[i] = child->name;
        grp = &info->groups[grp_index++];
        ret = imx_pinctrl_parse_groups(child, grp, info, i++);
        if (ret)
            return ret;
    }

    return 0;
}

static int __devinit imx_pinctrl_probe_dt(struct platform_device *pdev,
                struct imx_pinctrl_soc_info *info)
{
    struct device_node *np = pdev->dev.of_node;
    struct device_node *child;
    int ret;
    u32 nfuncs = 0;
    u32 i = 0;

    if (!np)
        return -ENODEV;

    nfuncs = of_get_child_count(np);
    if (nfuncs <= 0) {
        dev_err(&pdev->dev, "no functions defined\n");
        return -EINVAL;
    }

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

    info->ngroups = 0;
    for_each_child_of_node(np, child)
        info->ngroups += of_get_child_count(child);
    info->groups = devm_kzalloc(&pdev->dev, info->ngroups * sizeof(struct imx_pin_group),
                    GFP_KERNEL);
    if (!info->groups)
        return -ENOMEM;

    for_each_child_of_node(np, child) {
        ret = imx_pinctrl_parse_functions(child, info, i++);
        if (ret) {
            dev_err(&pdev->dev, "failed to parse function\n");
            return ret;
        }
    }

    return 0;
}

int __devinit imx_pinctrl_probe(struct platform_device *pdev,
                struct imx_pinctrl_soc_info *info)
{
    struct imx_pinctrl *ipctl;
    struct resource *res;
    int ret;

    if (!info || !info->pins || !info->npins
          || !info->pin_regs || !info->npin_regs) {
        dev_err(&pdev->dev, "wrong pinctrl info\n");
        return -EINVAL;
    }
    info->dev = &pdev->dev;

    /* Create state holders etc for this driver */
    ipctl = devm_kzalloc(&pdev->dev, sizeof(*ipctl), GFP_KERNEL);
    if (!ipctl)
        return -ENOMEM;

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

    ipctl->base = devm_request_and_ioremap(&pdev->dev, res);
    if (!ipctl->base)
        return -EBUSY;

    imx_pinctrl_desc.name = dev_name(&pdev->dev);
    imx_pinctrl_desc.pins = info->pins;
    imx_pinctrl_desc.npins = info->npins;

    ret = imx_pinctrl_probe_dt(pdev, info);
    if (ret) {
        dev_err(&pdev->dev, "fail to probe dt properties\n");
        return ret;
    }

    ipctl->info = info;
    ipctl->dev = info->dev;
    platform_set_drvdata(pdev, ipctl);
    ipctl->pctl = pinctrl_register(&imx_pinctrl_desc, &pdev->dev, ipctl);
    if (!ipctl->pctl) {
        dev_err(&pdev->dev, "could not register IMX pinctrl driver\n");
        return -EINVAL;
    }

    dev_info(&pdev->dev, "initialized IMX pinctrl driver\n");

    return 0;
}

int __devexit imx_pinctrl_remove(struct platform_device *pdev)
{
    struct imx_pinctrl *ipctl = platform_get_drvdata(pdev);

    pinctrl_unregister(ipctl->pctl);

    return 0;
}