/*
 * Allwinner A1X SoCs pinctrl driver.
 *
 * Copyright (C) 2012 Maxime Ripard
 *
 * Maxime Ripard <maxime.ripard@free-electrons.com>
 *
 * 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/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinconf-generic.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

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

static struct sunxi_pinctrl_group *
sunxi_pinctrl_find_group_by_name(struct sunxi_pinctrl *pctl, const char *group)
{
	int i;

	for (i = 0; i < pctl->ngroups; i++) {
		struct sunxi_pinctrl_group *grp = pctl->groups + i;

		if (!strcmp(grp->name, group))
			return grp;
	}

	return NULL;
}

static struct sunxi_pinctrl_function *
sunxi_pinctrl_find_function_by_name(struct sunxi_pinctrl *pctl,
				    const char *name)
{
	struct sunxi_pinctrl_function *func = pctl->functions;
	int i;

	for (i = 0; i < pctl->nfunctions; i++) {
		if (!func[i].name)
			break;

		if (!strcmp(func[i].name, name))
			return func + i;
	}

	return NULL;
}

static struct sunxi_desc_function *
sunxi_pinctrl_desc_find_function_by_name(struct sunxi_pinctrl *pctl,
					 const char *pin_name,
					 const char *func_name)
{
	int i;

	for (i = 0; i < pctl->desc->npins; i++) {
		const struct sunxi_desc_pin *pin = pctl->desc->pins + i;

		if (!strcmp(pin->pin.name, pin_name)) {
			struct sunxi_desc_function *func = pin->functions;

			while (func->name) {
				if (!strcmp(func->name, func_name))
					return func;

				func++;
			}
		}
	}

	return NULL;
}

static int sunxi_pctrl_get_groups_count(struct pinctrl_dev *pctldev)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	return pctl->ngroups;
}

static const char *sunxi_pctrl_get_group_name(struct pinctrl_dev *pctldev,
					      unsigned group)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	return pctl->groups[group].name;
}

static int sunxi_pctrl_get_group_pins(struct pinctrl_dev *pctldev,
				      unsigned group,
				      const unsigned **pins,
				      unsigned *num_pins)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	*pins = (unsigned *)&pctl->groups[group].pin;
	*num_pins = 1;

	return 0;
}

static int sunxi_pctrl_dt_node_to_map(struct pinctrl_dev *pctldev,
				      struct device_node *node,
				      struct pinctrl_map **map,
				      unsigned *num_maps)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
	unsigned long *pinconfig;
	struct property *prop;
	const char *function;
	const char *group;
	int ret, nmaps, i = 0;
	u32 val;

	*map = NULL;
	*num_maps = 0;

	ret = of_property_read_string(node, "allwinner,function", &function);
	if (ret) {
		dev_err(pctl->dev,
			"missing allwinner,function property in node %s\n",
			node->name);
		return -EINVAL;
	}

	nmaps = of_property_count_strings(node, "allwinner,pins") * 2;
	if (nmaps < 0) {
		dev_err(pctl->dev,
			"missing allwinner,pins property in node %s\n",
			node->name);
		return -EINVAL;
	}

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

	of_property_for_each_string(node, "allwinner,pins", prop, group) {
		struct sunxi_pinctrl_group *grp =
			sunxi_pinctrl_find_group_by_name(pctl, group);
		int j = 0, configlen = 0;

		if (!grp) {
			dev_err(pctl->dev, "unknown pin %s", group);
			continue;
		}

		if (!sunxi_pinctrl_desc_find_function_by_name(pctl,
							      grp->name,
							      function)) {
			dev_err(pctl->dev, "unsupported function %s on pin %s",
				function, group);
			continue;
		}

		(*map)[i].type = PIN_MAP_TYPE_MUX_GROUP;
		(*map)[i].data.mux.group = group;
		(*map)[i].data.mux.function = function;

		i++;

		(*map)[i].type = PIN_MAP_TYPE_CONFIGS_GROUP;
		(*map)[i].data.configs.group_or_pin = group;

		if (of_find_property(node, "allwinner,drive", NULL))
			configlen++;
		if (of_find_property(node, "allwinner,pull", NULL))
			configlen++;

		pinconfig = kzalloc(configlen * sizeof(*pinconfig), GFP_KERNEL);

		if (!of_property_read_u32(node, "allwinner,drive", &val)) {
			u16 strength = (val + 1) * 10;
			pinconfig[j++] =
				pinconf_to_config_packed(PIN_CONFIG_DRIVE_STRENGTH,
							 strength);
		}

		if (!of_property_read_u32(node, "allwinner,pull", &val)) {
			enum pin_config_param pull = PIN_CONFIG_END;
			if (val == 1)
				pull = PIN_CONFIG_BIAS_PULL_UP;
			else if (val == 2)
				pull = PIN_CONFIG_BIAS_PULL_DOWN;
			pinconfig[j++] = pinconf_to_config_packed(pull, 0);
		}

		(*map)[i].data.configs.configs = pinconfig;
		(*map)[i].data.configs.num_configs = configlen;

		i++;
	}

	*num_maps = nmaps;

	return 0;
}

static void sunxi_pctrl_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_GROUP)
			kfree(map[i].data.configs.configs);
	}

	kfree(map);
}

static struct pinctrl_ops sunxi_pctrl_ops = {
	.dt_node_to_map		= sunxi_pctrl_dt_node_to_map,
	.dt_free_map		= sunxi_pctrl_dt_free_map,
	.get_groups_count	= sunxi_pctrl_get_groups_count,
	.get_group_name		= sunxi_pctrl_get_group_name,
	.get_group_pins		= sunxi_pctrl_get_group_pins,
};

static int sunxi_pconf_group_get(struct pinctrl_dev *pctldev,
				 unsigned group,
				 unsigned long *config)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	*config = pctl->groups[group].config;

	return 0;
}

static int sunxi_pconf_group_set(struct pinctrl_dev *pctldev,
				 unsigned group,
				 unsigned long config)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
	struct sunxi_pinctrl_group *g = &pctl->groups[group];
	u32 val, mask;
	u16 strength;
	u8 dlevel;

	switch (pinconf_to_config_param(config)) {
	case PIN_CONFIG_DRIVE_STRENGTH:
		strength = pinconf_to_config_argument(config);
		if (strength > 40)
			return -EINVAL;
		/*
		 * We convert from mA to what the register expects:
		 *   0: 10mA
		 *   1: 20mA
		 *   2: 30mA
		 *   3: 40mA
		 */
		dlevel = strength / 10 - 1;
		val = readl(pctl->membase + sunxi_dlevel_reg(g->pin));
	        mask = DLEVEL_PINS_MASK << sunxi_dlevel_offset(g->pin);
		writel((val & ~mask) | dlevel << sunxi_dlevel_offset(g->pin),
			pctl->membase + sunxi_dlevel_reg(g->pin));
		break;
	case PIN_CONFIG_BIAS_PULL_UP:
		val = readl(pctl->membase + sunxi_pull_reg(g->pin));
		mask = PULL_PINS_MASK << sunxi_pull_offset(g->pin);
		writel((val & ~mask) | 1 << sunxi_pull_offset(g->pin),
			pctl->membase + sunxi_pull_reg(g->pin));
		break;
	case PIN_CONFIG_BIAS_PULL_DOWN:
		val = readl(pctl->membase + sunxi_pull_reg(g->pin));
		mask = PULL_PINS_MASK << sunxi_pull_offset(g->pin);
		writel((val & ~mask) | 2 << sunxi_pull_offset(g->pin),
			pctl->membase + sunxi_pull_reg(g->pin));
		break;
	default:
		break;
	}

	/* cache the config value */
	g->config = config;

	return 0;
}

static struct pinconf_ops sunxi_pconf_ops = {
	.pin_config_group_get	= sunxi_pconf_group_get,
	.pin_config_group_set	= sunxi_pconf_group_set,
};

static int sunxi_pmx_get_funcs_cnt(struct pinctrl_dev *pctldev)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	return pctl->nfunctions;
}

static const char *sunxi_pmx_get_func_name(struct pinctrl_dev *pctldev,
					   unsigned function)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	return pctl->functions[function].name;
}

static int sunxi_pmx_get_func_groups(struct pinctrl_dev *pctldev,
				     unsigned function,
				     const char * const **groups,
				     unsigned * const num_groups)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	*groups = pctl->functions[function].groups;
	*num_groups = pctl->functions[function].ngroups;

	return 0;
}

static void sunxi_pmx_set(struct pinctrl_dev *pctldev,
				 unsigned pin,
				 u8 config)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);

	u32 val = readl(pctl->membase + sunxi_mux_reg(pin));
	u32 mask = MUX_PINS_MASK << sunxi_mux_offset(pin);
	writel((val & ~mask) | config << sunxi_mux_offset(pin),
		pctl->membase + sunxi_mux_reg(pin));
}

static int sunxi_pmx_enable(struct pinctrl_dev *pctldev,
			    unsigned function,
			    unsigned group)
{
	struct sunxi_pinctrl *pctl = pinctrl_dev_get_drvdata(pctldev);
	struct sunxi_pinctrl_group *g = pctl->groups + group;
	struct sunxi_pinctrl_function *func = pctl->functions + function;
	struct sunxi_desc_function *desc =
		sunxi_pinctrl_desc_find_function_by_name(pctl,
							 g->name,
							 func->name);

	if (!desc)
		return -EINVAL;

	sunxi_pmx_set(pctldev, g->pin, desc->muxval);

	return 0;
}

static struct pinmux_ops sunxi_pmx_ops = {
	.get_functions_count	= sunxi_pmx_get_funcs_cnt,
	.get_function_name	= sunxi_pmx_get_func_name,
	.get_function_groups	= sunxi_pmx_get_func_groups,
	.enable			= sunxi_pmx_enable,
};

static struct pinctrl_desc sunxi_pctrl_desc = {
	.confops	= &sunxi_pconf_ops,
	.pctlops	= &sunxi_pctrl_ops,
	.pmxops		= &sunxi_pmx_ops,
};

static struct of_device_id sunxi_pinctrl_match[] = {
	{}
};
MODULE_DEVICE_TABLE(of, sunxi_pinctrl_match);

static int sunxi_pinctrl_add_function(struct sunxi_pinctrl *pctl,
					const char *name)
{
	struct sunxi_pinctrl_function *func = pctl->functions;

	while (func->name) {
		/* function already there */
		if (strcmp(func->name, name) == 0) {
			func->ngroups++;
			return -EEXIST;
		}
		func++;
	}

	func->name = name;
	func->ngroups = 1;

	pctl->nfunctions++;

	return 0;
}

static int sunxi_pinctrl_build_state(struct platform_device *pdev)
{
	struct sunxi_pinctrl *pctl = platform_get_drvdata(pdev);
	int i;

	pctl->ngroups = pctl->desc->npins;

	/* Allocate groups */
	pctl->groups = devm_kzalloc(&pdev->dev,
				    pctl->ngroups * sizeof(*pctl->groups),
				    GFP_KERNEL);
	if (!pctl->groups)
		return -ENOMEM;

	for (i = 0; i < pctl->desc->npins; i++) {
		const struct sunxi_desc_pin *pin = pctl->desc->pins + i;
		struct sunxi_pinctrl_group *group = pctl->groups + i;

		group->name = pin->pin.name;
		group->pin = pin->pin.number;
	}

	/*
	 * We suppose that we won't have any more functions than pins,
	 * we'll reallocate that later anyway
	 */
	pctl->functions = devm_kzalloc(&pdev->dev,
				pctl->desc->npins * sizeof(*pctl->functions),
				GFP_KERNEL);
	if (!pctl->functions)
		return -ENOMEM;

	/* Count functions and their associated groups */
	for (i = 0; i < pctl->desc->npins; i++) {
		const struct sunxi_desc_pin *pin = pctl->desc->pins + i;
		struct sunxi_desc_function *func = pin->functions;

		while (func->name) {
			sunxi_pinctrl_add_function(pctl, func->name);
			func++;
		}
	}

	pctl->functions = krealloc(pctl->functions,
				pctl->nfunctions * sizeof(*pctl->functions),
				GFP_KERNEL);

	for (i = 0; i < pctl->desc->npins; i++) {
		const struct sunxi_desc_pin *pin = pctl->desc->pins + i;
		struct sunxi_desc_function *func = pin->functions;

		while (func->name) {
			struct sunxi_pinctrl_function *func_item;
			const char **func_grp;

			func_item = sunxi_pinctrl_find_function_by_name(pctl,
									func->name);
			if (!func_item)
				return -EINVAL;

			if (!func_item->groups) {
				func_item->groups =
					devm_kzalloc(&pdev->dev,
						     func_item->ngroups * sizeof(*func_item->groups),
						     GFP_KERNEL);
				if (!func_item->groups)
					return -ENOMEM;
			}

			func_grp = func_item->groups;
			while (*func_grp)
				func_grp++;

			*func_grp = pin->pin.name;
			func++;
		}
	}

	return 0;
}

static int sunxi_pinctrl_probe(struct platform_device *pdev)
{
	struct device_node *node = pdev->dev.of_node;
	const struct of_device_id *device;
	struct pinctrl_pin_desc *pins;
	struct sunxi_pinctrl *pctl;
	int i, ret;

	pctl = devm_kzalloc(&pdev->dev, sizeof(*pctl), GFP_KERNEL);
	if (!pctl)
		return -ENOMEM;
	platform_set_drvdata(pdev, pctl);

	pctl->membase = of_iomap(node, 0);
	if (!pctl->membase)
		return -ENOMEM;

	device = of_match_device(sunxi_pinctrl_match, &pdev->dev);
	if (!device)
		return -ENODEV;

	pctl->desc = (struct sunxi_pinctrl_desc *)device->data;

	ret = sunxi_pinctrl_build_state(pdev);
	if (ret) {
		dev_err(&pdev->dev, "dt probe failed: %d\n", ret);
		return ret;
	}

	pins = devm_kzalloc(&pdev->dev,
			    pctl->desc->npins * sizeof(*pins),
			    GFP_KERNEL);
	if (!pins)
		return -ENOMEM;

	for (i = 0; i < pctl->desc->npins; i++)
		pins[i] = pctl->desc->pins[i].pin;

	sunxi_pctrl_desc.name = dev_name(&pdev->dev);
	sunxi_pctrl_desc.owner = THIS_MODULE;
	sunxi_pctrl_desc.pins = pins;
	sunxi_pctrl_desc.npins = pctl->desc->npins;
	pctl->dev = &pdev->dev;
	pctl->pctl_dev = pinctrl_register(&sunxi_pctrl_desc,
					  &pdev->dev, pctl);
	if (!pctl->pctl_dev) {
		dev_err(&pdev->dev, "couldn't register pinctrl driver\n");
		return -EINVAL;
	}

	dev_info(&pdev->dev, "initialized sunXi pin control driver\n");

	return 0;
}

static struct platform_driver sunxi_pinctrl_driver = {
	.probe = sunxi_pinctrl_probe,
	.driver = {
		.name = "sunxi-pinctrl",
		.owner = THIS_MODULE,
		.of_match_table = sunxi_pinctrl_match,
	},
};
module_platform_driver(sunxi_pinctrl_driver);

MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com");
MODULE_DESCRIPTION("Allwinner A1X pinctrl driver");
MODULE_LICENSE("GPL");