path: root/drivers/pinctrl/pinctrl-samsung.c

/*
 * pin-controller/pin-mux/pin-config/gpio-driver for Samsung's SoC's.
 *
 * Copyright (c) 2012 Samsung Electronics Co., Ltd.
 *		http://www.samsung.com
 * Copyright (c) 2012 Linaro Ltd
 *		http://www.linaro.org
 *
 * Author: Thomas Abraham <thomas.ab@samsung.com>
 *
 * 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.
 *
 * This driver implements the Samsung pinctrl driver. It supports setting up of
 * pinmux and pinconf configurations. The gpiolib interface is also included.
 * External interrupt (gpio and wakeup) support are not included in this driver
 * but provides extensions to which platform specific implementation of the gpio
 * and wakeup interrupts can be hooked to.
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/irqdomain.h>

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

#define GROUP_SUFFIX		"-grp"
#define GSUFFIX_LEN		sizeof(GROUP_SUFFIX)
#define FUNCTION_SUFFIX		"-mux"
#define FSUFFIX_LEN		sizeof(FUNCTION_SUFFIX)

/* list of all possible config options supported */
static struct pin_config {
	char		*prop_cfg;
	unsigned int	cfg_type;
} pcfgs[] = {
	{ "samsung,pin-pud", PINCFG_TYPE_PUD },
	{ "samsung,pin-drv", PINCFG_TYPE_DRV },
	{ "samsung,pin-con-pdn", PINCFG_TYPE_CON_PDN },
	{ "samsung,pin-pud-pdn", PINCFG_TYPE_PUD_PDN },
};

static unsigned int pin_base;

static inline struct samsung_pin_bank *gc_to_pin_bank(struct gpio_chip *gc)
{
	return container_of(gc, struct samsung_pin_bank, gpio_chip);
}

/* check if the selector is a valid pin group selector */
static int samsung_get_group_count(struct pinctrl_dev *pctldev)
{
	struct samsung_pinctrl_drv_data *drvdata;

	drvdata = pinctrl_dev_get_drvdata(pctldev);
	return drvdata->nr_groups;
}

/* return the name of the group selected by the group selector */
static const char *samsung_get_group_name(struct pinctrl_dev *pctldev,
						unsigned selector)
{
	struct samsung_pinctrl_drv_data *drvdata;

	drvdata = pinctrl_dev_get_drvdata(pctldev);
	return drvdata->pin_groups[selector].name;
}

/* return the pin numbers associated with the specified group */
static int samsung_get_group_pins(struct pinctrl_dev *pctldev,
		unsigned selector, const unsigned **pins, unsigned *num_pins)
{
	struct samsung_pinctrl_drv_data *drvdata;

	drvdata = pinctrl_dev_get_drvdata(pctldev);
	*pins = drvdata->pin_groups[selector].pins;
	*num_pins = drvdata->pin_groups[selector].num_pins;
	return 0;
}

/* create pinctrl_map entries by parsing device tree nodes */
static int samsung_dt_node_to_map(struct pinctrl_dev *pctldev,
			struct device_node *np, struct pinctrl_map **maps,
			unsigned *nmaps)
{
	struct device *dev = pctldev->dev;
	struct pinctrl_map *map;
	unsigned long *cfg = NULL;
	char *gname, *fname;
	int cfg_cnt = 0, map_cnt = 0, idx = 0;

	/* count the number of config options specfied in the node */
	for (idx = 0; idx < ARRAY_SIZE(pcfgs); idx++) {
		if (of_find_property(np, pcfgs[idx].prop_cfg, NULL))
			cfg_cnt++;
	}

	/*
	 * Find out the number of map entries to create. All the config options
	 * can be accomadated into a single config map entry.
	 */
	if (cfg_cnt)
		map_cnt = 1;
	if (of_find_property(np, "samsung,pin-function", NULL))
		map_cnt++;
	if (!map_cnt) {
		dev_err(dev, "node %s does not have either config or function "
				"configurations\n", np->name);
		return -EINVAL;
	}

	/* Allocate memory for pin-map entries */
	map = kzalloc(sizeof(*map) * map_cnt, GFP_KERNEL);
	if (!map) {
		dev_err(dev, "could not alloc memory for pin-maps\n");
		return -ENOMEM;
	}
	*nmaps = 0;

	/*
	 * Allocate memory for pin group name. The pin group name is derived
	 * from the node name from which these map entries are be created.
	 */
	gname = kzalloc(strlen(np->name) + GSUFFIX_LEN, GFP_KERNEL);
	if (!gname) {
		dev_err(dev, "failed to alloc memory for group name\n");
		goto free_map;
	}
	sprintf(gname, "%s%s", np->name, GROUP_SUFFIX);

	/*
	 * don't have config options? then skip over to creating function
	 * map entries.
	 */
	if (!cfg_cnt)
		goto skip_cfgs;

	/* Allocate memory for config entries */
	cfg = kzalloc(sizeof(*cfg) * cfg_cnt, GFP_KERNEL);
	if (!cfg) {
		dev_err(dev, "failed to alloc memory for configs\n");
		goto free_gname;
	}

	/* Prepare a list of config settings */
	for (idx = 0, cfg_cnt = 0; idx < ARRAY_SIZE(pcfgs); idx++) {
		u32 value;
		if (!of_property_read_u32(np, pcfgs[idx].prop_cfg, &value))
			cfg