pinconf.c

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/*
 * Core driver for the pin config portions of the pin control subsystem
 *
 * Copyright (C) 2011 ST-Ericsson SA
 * Written on behalf of Linaro for ST-Ericsson
 *
 * Author: Linus Walleij <[email protected]>
 *
 * License terms: GNU General Public License (GPL) version 2
 */
#define pr_fmt(fmt) "pinconfig core: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf.h>
#include "core.h"
#include "pinconf.h"

int pinconf_check_ops(struct pinctrl_dev *pctldev)
{
    const struct pinconf_ops *ops = pctldev->desc->confops;

    /* We must be able to read out pin status */
    if (!ops->pin_config_get && !ops->pin_config_group_get) {
        dev_err(pctldev->dev,
            "pinconf must be able to read out pin status\n");
        return -EINVAL;
    }
    /* We have to be able to config the pins in SOME way */
    if (!ops->pin_config_set && !ops->pin_config_group_set) {
        dev_err(pctldev->dev,
            "pinconf has to be able to set a pins config\n");
        return -EINVAL;
    }
    return 0;
}

int pinconf_validate_map(struct pinctrl_map const *map, int i)
{
    if (!map->data.configs.group_or_pin) {
        pr_err("failed to register map %s (%d): no group/pin given\n",
               map->name, i);
        return -EINVAL;
    }

    if (!map->data.configs.num_configs ||
            !map->data.configs.configs) {
        pr_err("failed to register map %s (%d): no configs given\n",
               map->name, i);
        return -EINVAL;
    }

    return 0;
}

int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
               unsigned long *config)
{
    const struct pinconf_ops *ops = pctldev->desc->confops;

    if (!ops || !ops->pin_config_get) {
        dev_err(pctldev->dev, "cannot get pin configuration, missing "
            "pin_config_get() function in driver\n");
        return -EINVAL;
    }

    return ops->pin_config_get(pctldev, pin, config);
}

int pin_config_get(const char *dev_name, const char *name,
              unsigned long *config)
{
    struct pinctrl_dev *pctldev;
    int pin;

    mutex_lock(&pinctrl_mutex);

    pctldev = get_pinctrl_dev_from_devname(dev_name);
    if (!pctldev) {
        pin = -EINVAL;
        goto unlock;
    }

    pin = pin_get_from_name(pctldev, name);
    if (pin < 0)
        goto unlock;

    pin = pin_config_get_for_pin(pctldev, pin, config);

unlock:
    mutex_unlock(&pinctrl_mutex);
    return pin;
}
EXPORT_SYMBOL(pin_config_get);

static int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
               unsigned long config)
{
    const struct pinconf_ops *ops = pctldev->desc->confops;
    int ret;

    if (!ops || !ops->pin_config_set) {
        dev_err(pctldev->dev, "cannot configure pin, missing "
            "config function in driver\n");
        return -EINVAL;
    }

    ret = ops->pin_config_set(pctldev, pin, config);
    if (ret) {
        dev_err(pctldev->dev,
            "unable to set pin configuration on pin %d\n", pin);
        return ret;
    }

    return 0;
}

int pin_config_set(const char *dev_name, const char *name,
           unsigned long config)
{
    struct pinctrl_dev *pctldev;
    int pin, ret;

    mutex_lock(&pinctrl_mutex);

    pctldev = get_pinctrl_dev_from_devname(dev_name);
    if (!pctldev) {
        ret = -EINVAL;
        goto unlock;
    }

    pin = pin_get_from_name(pctldev, name);
    if (pin < 0) {
        ret = pin;
        goto unlock;
    }

    ret = pin_config_set_for_pin(pctldev, pin, config);

unlock:
    mutex_unlock(&pinctrl_mutex);
    return ret;
}
EXPORT_SYMBOL(pin_config_set);

int pin_config_group_get(const char *dev_name, const char *pin_group,
             unsigned long *config)
{
    struct pinctrl_dev *pctldev;
    const struct pinconf_ops *ops;
    int selector, ret;

    mutex_lock(&pinctrl_mutex);

    pctldev = get_pinctrl_dev_from_devname(dev_name);
    if (!pctldev) {
        ret = -EINVAL;
        goto unlock;
    }
    ops = pctldev->desc->confops;

    if (!ops || !ops->pin_config_group_get) {
        dev_err(pctldev->dev, "cannot get configuration for pin "
            "group, missing group config get function in "
            "driver\n");
        ret = -EINVAL;
        goto unlock;
    }

    selector = pinctrl_get_group_selector(pctldev, pin_group);
    if (selector < 0) {
        ret = selector;
        goto unlock;
    }

    ret = ops->pin_config_group_get(pctldev, selector, config);

unlock:
    mutex_unlock(&pinctrl_mutex);
    return ret;
}
EXPORT_SYMBOL(pin_config_group_get);

int pin_config_group_set(const char *dev_name, const char *pin_group,
             unsigned long config)
{
    struct pinctrl_dev *pctldev;
    const struct pinconf_ops *ops;
    const struct pinctrl_ops *pctlops;
    int selector;
    const unsigned *pins;
    unsigned num_pins;
    int ret;
    int i;

    mutex_lock(&pinctrl_mutex);

    pctldev = get_pinctrl_dev_from_devname(dev_name);
    if (!pctldev) {
        ret = -EINVAL;
        goto unlock;
    }
    ops = pctldev->desc->confops;
    pctlops = pctldev->desc->pctlops;

    if (!ops || (!ops->pin_config_group_set && !ops->pin_config_set)) {
        dev_err(pctldev->dev, "cannot configure pin group, missing "
            "config function in driver\n");
        ret = -EINVAL;
        goto unlock;
    }

    selector = pinctrl_get_group_selector(pctldev, pin_group);
    if (selector < 0) {
        ret = selector;
        goto unlock;
    }

    ret = pctlops->get_group_pins(pctldev, selector, &pins, &num_pins);
    if (ret) {
        dev_err(pctldev->dev, "cannot configure pin group, error "
            "getting pins\n");
        goto unlock;
    }

    /*
     * If the pin controller supports handling entire groups we use that
     * capability.
     */
    if (ops->pin_config_group_set) {
        ret = ops->pin_config_group_set(pctldev, selector, config);
        /*
         * If the pin controller prefer that a certain group be handled
         * pin-by-pin as well, it returns -EAGAIN.
         */
        if (ret != -EAGAIN)
            goto unlock;
    }

    /*
     * If the controller cannot handle entire groups, we configure each pin
     * individually.
     */
    if (!ops->pin_config_set) {
        ret = 0;
        goto unlock;
    }

    for (i = 0; i < num_pins; i++) {
        ret = ops->pin_config_set(pctldev, pins[i], config);
        if (ret < 0)
            goto unlock;
    }

    ret = 0;

unlock:
    mutex_unlock(&pinctrl_mutex);

    return ret;
}
EXPORT_SYMBOL(pin_config_group_set);

int pinconf_map_to_setting(struct pinctrl_map const *map,
              struct pinctrl_setting *setting)
{
    struct pinctrl_dev *pctldev = setting->pctldev;
    int pin;

    switch (setting->type) {
    case PIN_MAP_TYPE_CONFIGS_PIN:
        pin = pin_get_from_name(pctldev,
                    map->data.configs.group_or_pin);
        if (pin < 0) {
            dev_err(pctldev->dev, "could not map pin config for \"%s\"",
                map->data.configs.group_or_pin);
            return pin;
        }
        setting->data.configs.group_or_pin = pin;
        break;
    case PIN_MAP_TYPE_CONFIGS_GROUP:
        pin = pinctrl_get_group_selector(pctldev,
                     map->data.configs.group_or_pin);
        if (pin < 0) {
            dev_err(pctldev->dev, "could not map group config for \"%s\"",
                map->data.configs.group_or_pin);
            return pin;
        }
        setting->data.configs.group_or_pin = pin;
        break;
    default:
        return -EINVAL;
    }

    setting->data.configs.num_configs = map->data.configs.num_configs;
    setting->data.configs.configs = map->data.configs.configs;

    return 0;
}

void pinconf_free_setting(struct pinctrl_setting const *setting)
{
}

int pinconf_apply_setting(struct pinctrl_setting const *setting)
{
    struct pinctrl_dev *pctldev = setting->pctldev;
    const struct pinconf_ops *ops = pctldev->desc->confops;
    int i, ret;

    if (!ops) {
        dev_err(pctldev->dev, "missing confops\n");
        return -EINVAL;
    }

    switch (setting->type) {
    case PIN_MAP_TYPE_CONFIGS_PIN:
        if (!ops->pin_config_set) {
            dev_err(pctldev->dev, "missing pin_config_set op\n");
            return -EINVAL;
        }
        for (i = 0; i < setting->data.configs.num_configs; i++) {
            ret = ops->pin_config_set(pctldev,
                    setting->data.configs.group_or_pin,
                    setting->data.configs.configs[i]);
            if (ret < 0) {
                dev_err(pctldev->dev,
                    "pin_config_set op failed for pin %d config %08lx\n",
                    setting->data.configs.group_or_pin,
                    setting->data.configs.configs[i]);
                return ret;
            }
        }
        break;
    case PIN_MAP_TYPE_CONFIGS_GROUP:
        if (!ops->pin_config_group_set) {
            dev_err(pctldev->dev,
                "missing pin_config_group_set op\n");
            return -EINVAL;
        }
        for (i = 0; i < setting->data.configs.num_configs; i++) {
            ret = ops->pin_config_group_set(pctldev,
                    setting->data.configs.group_or_pin,
                    setting->data.configs.configs[i]);
            if (ret < 0) {
                dev_err(pctldev->dev,
                    "pin_config_group_set op failed for group %d config %08lx\n",
                    setting->data.configs.group_or_pin,
                    setting->data.configs.configs[i]);
                return ret;
            }
        }
        break;
    default:
        return -EINVAL;
    }

    return 0;
}

#ifdef CONFIG_DEBUG_FS

void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
{
    struct pinctrl_dev *pctldev;
    const struct pinconf_ops *confops;
    int i;

    pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
    if (pctldev)
        confops = pctldev->desc->confops;
    else
        confops = NULL;

    switch (map->type) {
    case PIN_MAP_TYPE_CONFIGS_PIN:
        seq_printf(s, "pin ");
        break;
    case PIN_MAP_TYPE_CONFIGS_GROUP:
        seq_printf(s, "group ");
        break;
    default:
        break;
    }

    seq_printf(s, "%s\n", map->data.configs.group_or_pin);

    for (i = 0; i < map->data.configs.num_configs; i++) {
        seq_printf(s, "config ");
        if (confops && confops->pin_config_config_dbg_show)
            confops->pin_config_config_dbg_show(pctldev, s,
                        map->data.configs.configs[i]);
        else
            seq_printf(s, "%08lx", map->data.configs.configs[i]);
        seq_printf(s, "\n");
    }
}

void pinconf_show_setting(struct seq_file *s,
              struct pinctrl_setting const *setting)
{
    struct pinctrl_dev *pctldev = setting->pctldev;
    const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
    const struct pinconf_ops *confops = pctldev->desc->confops;
    struct pin_desc *desc;
    int i;

    switch (setting->type) {
    case PIN_MAP_TYPE_CONFIGS_PIN:
        desc = pin_desc_get(setting->pctldev,
                    setting->data.configs.group_or_pin);
        seq_printf(s, "pin %s (%d)",
               desc->name ? desc->name : "unnamed",
               setting->data.configs.group_or_pin);
        break;
    case PIN_MAP_TYPE_CONFIGS_GROUP:
        seq_printf(s, "group %s (%d)",
               pctlops->get_group_name(pctldev,
                    setting->data.configs.group_or_pin),
               setting->data.configs.group_or_pin);
        break;
    default:
        break;
    }

    /*
     * FIXME: We should really get the pin controler to dump the config
     * values, so they can be decoded to something meaningful.
     */
    for (i = 0; i < setting->data.configs.num_configs; i++) {
        seq_printf(s, " ");
        if (confops && confops->pin_config_config_dbg_show)
            confops->pin_config_config_dbg_show(pctldev, s,
                setting->data.configs.configs[i]);
        else
            seq_printf(s, "%08lx",
                   setting->data.configs.configs[i]);
    }

    seq_printf(s, "\n");
}

static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
                 struct seq_file *s, int pin)
{
    const struct pinconf_ops *ops = pctldev->desc->confops;

    /* no-op when not using generic pin config */
    pinconf_generic_dump_pin(pctldev, s, pin);
    if (ops && ops->pin_config_dbg_show)
        ops->pin_config_dbg_show(pctldev, s, pin);
}

static int pinconf_pins_show(struct seq_file *s, void *what)
{
    struct pinctrl_dev *pctldev = s->private;
    const struct pinconf_ops *ops = pctldev->desc->confops;
    unsigned i, pin;

    if (!ops || !ops->pin_config_get)
        return 0;

    seq_puts(s, "Pin config settings per pin\n");
    seq_puts(s, "Format: pin (name): configs\n");

    mutex_lock(&pinctrl_mutex);

    /* The pin number can be retrived from the pin controller descriptor */
    for (i = 0; i < pctldev->desc->npins; i++) {
        struct pin_desc *desc;

        pin = pctldev->desc->pins[i].number;
        desc = pin_desc_get(pctldev, pin);
        /* Skip if we cannot search the pin */
        if (desc == NULL)
            continue;

        seq_printf(s, "pin %d (%s):", pin,
               desc->name ? desc->name : "unnamed");

        pinconf_dump_pin(pctldev, s, pin);

        seq_printf(s, "\n");
    }

    mutex_unlock(&pinctrl_mutex);

    return 0;
}

static void pinconf_dump_group(struct pinctrl_dev *pctldev,
                   struct seq_file *s, unsigned selector,
                   const char *gname)
{
    const struct pinconf_ops *ops = pctldev->desc->confops;

    /* no-op when not using generic pin config */
    pinconf_generic_dump_group(pctldev, s, gname);
    if (ops && ops->pin_config_group_dbg_show)
        ops->pin_config_group_dbg_show(pctldev, s, selector);
}

static int pinconf_groups_show(struct seq_file *s, void *what)
{
    struct pinctrl_dev *pctldev = s->private;
    const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
    const struct pinconf_ops *ops = pctldev->desc->confops;
    unsigned ngroups = pctlops->get_groups_count(pctldev);
    unsigned selector = 0;

    if (!ops || !ops->pin_config_group_get)
        return 0;

    seq_puts(s, "Pin config settings per pin group\n");
    seq_puts(s, "Format: group (name): configs\n");

    while (selector < ngroups) {
        const char *gname = pctlops->get_group_name(pctldev, selector);

        seq_printf(s, "%u (%s):", selector, gname);
        pinconf_dump_group(pctldev, s, selector, gname);
        seq_printf(s, "\n");

        selector++;
    }

    return 0;
}

static int pinconf_pins_open(struct inode *inode, struct file *file)
{
    return single_open(file, pinconf_pins_show, inode->i_private);
}

static int pinconf_groups_open(struct inode *inode, struct file *file)
{
    return single_open(file, pinconf_groups_show, inode->i_private);
}

static const struct file_operations pinconf_pins_ops = {
    .open       = pinconf_pins_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};

static const struct file_operations pinconf_groups_ops = {
    .open       = pinconf_groups_open,
    .read       = seq_read,
    .llseek     = seq_lseek,
    .release    = single_release,
};

void pinconf_init_device_debugfs(struct dentry *devroot,
             struct pinctrl_dev *pctldev)
{
    debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
                devroot, pctldev, &pinconf_pins_ops);
    debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
                devroot, pctldev, &pinconf_groups_ops);
}

#endif