/*
 * 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 <linus.walleij@linaro.org>
 *
 * 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 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);
}

/**
 * pin_config_get() - get the configuration of a single pin parameter
 * @dev_name: name of the pin controller device for this pin
 * @name: name of the pin to get the config for
 * @config: the config pointed to by this argument will be filled in with the
 *      current pin state, it can be used directly by drivers as a numeral, or
 *      it can be dereferenced to any struct.
 */
int pin_config_get(const char *dev_name, const char *name,
                          unsigned long *config)
{
        struct pinctrl_dev *pctldev;
        int pin;

        pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
        if (!pctldev)
                return -EINVAL;

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

        return pin_config_get_for_pin(pctldev, pin, config);
}
EXPORT_SYMBOL(pin_config_get);

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;
}

/**
 * pin_config_set() - set the configuration of a single pin parameter
 * @dev_name: name of pin controller device for this pin
 * @name: name of the pin to set the config for
 * @config: the config in this argument will contain the desired pin state, it
 *      can be used directly by drivers as a numeral, or it can be dereferenced
 *      to any struct.
 */
int pin_config_set(const char *dev_name, const char *name,
                   unsigned long config)
{
        struct pinctrl_dev *pctldev;
        int pin;

        pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
        if (!pctldev)
                return -EINVAL;

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

        return pin_config_set_for_pin(pctldev, pin, config);
}
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;

        pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
        if (!pctldev)
                return -EINVAL;
        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");
                return -EINVAL;
        }

        selector = pinctrl_get_group_selector(pctldev, pin_group);
        if (selector < 0)
                return selector;

        return ops->pin_config_group_get(pctldev, selector, config);
}
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;

        pctldev = get_pinctrl_dev_from_dev(NULL, dev_name);
        if (!pctldev)
                return -EINVAL;
        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");
                return -EINVAL;
        }

        selector = pinctrl_get_group_selector(pctldev, pin_group);
        if (selector < 0)
                return selector;

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

        /*
         * 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)
                        return ret;
        }

        /*
         * If the controller cannot handle entire groups, we configure each pin
         * individually.
         */
        if (!ops->pin_config_set)
                return 0;

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

        return 0;
}
EXPORT_SYMBOL(pin_config_group_set);

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)
                return -EINVAL;
        /* We have to be able to config the pins in SOME way */
        if (!ops->pin_config_set && !ops->pin_config_group_set)
                return -EINVAL;
        return 0;
}

#ifdef CONFIG_DEBUG_FS

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

        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;
        unsigned i, pin;

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

        /* 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");
        }

        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;

        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 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): pinmux setting array\n");

        while (pctlops->list_groups(pctldev, selector) >= 0) {
                const char *gname = pctlops->get_group_name(pctldev, selector);

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