[linux-2.6-block.git] / drivers / of / of_mtd.c

/*
 * Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
 *
 * OF helpers for mtd.
 *
 * This file is released under the GPLv2
 *
 */
#include <linux/kernel.h>
#include <linux/of_mtd.h>
#include <linux/mtd/nand.h>
#include <linux/export.h>

/**
 * It maps 'enum nand_ecc_modes_t' found in include/linux/mtd/nand.h
 * into the device tree binding of 'nand-ecc', so that MTD
 * device driver can get nand ecc from device tree.
 */
static const char *nand_ecc_modes[] = {
	[NAND_ECC_NONE]		= "none",
	[NAND_ECC_SOFT]		= "soft",
	[NAND_ECC_HW]		= "hw",
	[NAND_ECC_HW_SYNDROME]	= "hw_syndrome",
	[NAND_ECC_HW_OOB_FIRST]	= "hw_oob_first",
	[NAND_ECC_SOFT_BCH]	= "soft_bch",
};

/**
 * of_get_nand_ecc_mode - Get nand ecc mode for given device_node
 * @np:	Pointer to the given device_node
 *
 * The function gets ecc mode string from property 'nand-ecc-mode',
 * and return its index in nand_ecc_modes table, or errno in error case.
 */
int of_get_nand_ecc_mode(struct device_node *np)
{
	const char *pm;
	int err, i;

	err = of_property_read_string(np, "nand-ecc-mode", &pm);
	if (err < 0)
		return err;

	for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
		if (!strcasecmp(pm, nand_ecc_modes[i]))
			return i;

	return -ENODEV;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode);

/**
 * of_get_nand_ecc_step_size - Get ECC step size associated to
 * the required ECC strength (see below).
 * @np:	Pointer to the given device_node
 *
 * return the ECC step size, or errno in error case.
 */
int of_get_nand_ecc_step_size(struct device_node *np)
{
	int ret;
	u32 val;

	ret = of_property_read_u32(np, "nand-ecc-step-size", &val);
	return ret ? ret : val;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_step_size);

/**
 * of_get_nand_ecc_strength - Get required ECC strength over the
 * correspnding step size as defined by 'nand-ecc-size'
 * @np:	Pointer to the given device_node
 *
 * return the ECC strength, or errno in error case.
 */
int of_get_nand_ecc_strength(struct device_node *np)
{
	int ret;
	u32 val;

	ret = of_property_read_u32(np, "nand-ecc-strength", &val);
	return ret ? ret : val;
}
EXPORT_SYMBOL_GPL(of_get_nand_ecc_strength);

/**
 * of_get_nand_bus_width - Get nand bus witdh for given device_node
 * @np:	Pointer to the given device_node
 *
 * return bus width option, or errno in error case.
 */
int of_get_nand_bus_width(struct device_node *np)
{
	u32 val;

	if (of_property_read_u32(np, "nand-bus-width", &val))
		return 8;

	switch(val) {
	case 8:
	case 16:
		return val;
	default:
		return -EIO;
	}
}
EXPORT_SYMBOL_GPL(of_get_nand_bus_width);

/**
 * of_get_nand_on_flash_bbt - Get nand on flash bbt for given device_node
 * @np:	Pointer to the given device_node
 *
 * return true if present false other wise
 */
bool of_get_nand_on_flash_bbt(struct device_node *np)
{
	return of_property_read_bool(np, "nand-on-flash-bbt");
}
EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt);
Commit	Line	Data
770d7c39 JCPV	1	/*
	2	* Copyright 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
	3	*
	4	* OF helpers for mtd.
	5	*
	6	* This file is released under the GPLv2
	7	*
	8	*/
	9	#include <linux/kernel.h>
	10	#include <linux/of_mtd.h>
	11	#include <linux/mtd/nand.h>
	12	#include <linux/export.h>
	13
	14	/**
	15	* It maps 'enum nand_ecc_modes_t' found in include/linux/mtd/nand.h
	16	* into the device tree binding of 'nand-ecc', so that MTD
	17	* device driver can get nand ecc from device tree.
	18	*/
	19	static const char *nand_ecc_modes[] = {
	20	[NAND_ECC_NONE] = "none",
	21	[NAND_ECC_SOFT] = "soft",
	22	[NAND_ECC_HW] = "hw",
	23	[NAND_ECC_HW_SYNDROME] = "hw_syndrome",
	24	[NAND_ECC_HW_OOB_FIRST] = "hw_oob_first",
	25	[NAND_ECC_SOFT_BCH] = "soft_bch",
	26	};
	27
	28	/**
	29	* of_get_nand_ecc_mode - Get nand ecc mode for given device_node
	30	* @np: Pointer to the given device_node
	31	*
	32	* The function gets ecc mode string from property 'nand-ecc-mode',
	33	* and return its index in nand_ecc_modes table, or errno in error case.
	34	*/
e95d8aaf	35	int of_get_nand_ecc_mode(struct device_node *np)
770d7c39 JCPV	36	{
	37	const char *pm;
	38	int err, i;
	39
	40	err = of_property_read_string(np, "nand-ecc-mode", &pm);
	41	if (err < 0)
	42	return err;
	43
	44	for (i = 0; i < ARRAY_SIZE(nand_ecc_modes); i++)
	45	if (!strcasecmp(pm, nand_ecc_modes[i]))
	46	return i;
	47
	48	return -ENODEV;
	49	}
	50	EXPORT_SYMBOL_GPL(of_get_nand_ecc_mode);
	51
6d9434eb EG	52	/**
	53	* of_get_nand_ecc_step_size - Get ECC step size associated to
	54	* the required ECC strength (see below).
	55	* @np: Pointer to the given device_node
	56	*
	57	* return the ECC step size, or errno in error case.
	58	*/
	59	int of_get_nand_ecc_step_size(struct device_node *np)
	60	{
	61	int ret;
	62	u32 val;
	63
	64	ret = of_property_read_u32(np, "nand-ecc-step-size", &val);
	65	return ret ? ret : val;
	66	}
	67	EXPORT_SYMBOL_GPL(of_get_nand_ecc_step_size);
	68
	69	/**
	70	* of_get_nand_ecc_strength - Get required ECC strength over the
	71	* correspnding step size as defined by 'nand-ecc-size'
	72	* @np: Pointer to the given device_node
	73	*
	74	* return the ECC strength, or errno in error case.
	75	*/
	76	int of_get_nand_ecc_strength(struct device_node *np)
	77	{
	78	int ret;
	79	u32 val;
	80
	81	ret = of_property_read_u32(np, "nand-ecc-strength", &val);
	82	return ret ? ret : val;
	83	}
	84	EXPORT_SYMBOL_GPL(of_get_nand_ecc_strength);
	85
770d7c39 JCPV	86	/**
	87	* of_get_nand_bus_width - Get nand bus witdh for given device_node
	88	* @np: Pointer to the given device_node
	89	*
	90	* return bus width option, or errno in error case.
	91	*/
	92	int of_get_nand_bus_width(struct device_node *np)
	93	{
	94	u32 val;
	95
	96	if (of_property_read_u32(np, "nand-bus-width", &val))
	97	return 8;
	98
	99	switch(val) {
	100	case 8:
	101	case 16:
	102	return val;
	103	default:
	104	return -EIO;
	105	}
	106	}
	107	EXPORT_SYMBOL_GPL(of_get_nand_bus_width);
	108
	109	/**
	110	* of_get_nand_on_flash_bbt - Get nand on flash bbt for given device_node
	111	* @np: Pointer to the given device_node
	112	*
	113	* return true if present false other wise
	114	*/
	115	bool of_get_nand_on_flash_bbt(struct device_node *np)
	116	{
	117	return of_property_read_bool(np, "nand-on-flash-bbt");
	118	}
	119	EXPORT_SYMBOL_GPL(of_get_nand_on_flash_bbt);