[deliverable/linux.git] / drivers / mtd / maps / lantiq-flash.c

/*
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License version 2 as published
 *  by the Free Software Foundation.
 *
 *  Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
 *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
 */

#include <linux/err.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/map.h>
#include <linux/mtd/partitions.h>
#include <linux/mtd/cfi.h>
#include <linux/platform_device.h>
#include <linux/mtd/physmap.h>
#include <linux/of.h>

#include <lantiq_soc.h>

/*
 * The NOR flash is connected to the same external bus unit (EBU) as PCI.
 * To make PCI work we need to enable the endianness swapping for the address
 * written to the EBU. This endianness swapping works for PCI correctly but
 * fails for attached NOR devices. To workaround this we need to use a complex
 * map. The workaround involves swapping all addresses whilst probing the chip.
 * Once probing is complete we stop swapping the addresses but swizzle the
 * unlock addresses to ensure that access to the NOR device works correctly.
 */

enum {
	LTQ_NOR_PROBING,
	LTQ_NOR_NORMAL
};

struct ltq_mtd {
	struct resource *res;
	struct mtd_info *mtd;
	struct map_info *map;
};

static const char ltq_map_name[] = "ltq_nor";
static const char *ltq_probe_types[] = {
					"cmdlinepart", "ofpart", NULL };

static map_word
ltq_read16(struct map_info *map, unsigned long adr)
{
	unsigned long flags;
	map_word temp;

	if (map->map_priv_1 == LTQ_NOR_PROBING)
		adr ^= 2;
	spin_lock_irqsave(&ebu_lock, flags);
	temp.x[0] = *(u16 *)(map->virt + adr);
	spin_unlock_irqrestore(&ebu_lock, flags);
	return temp;
}

static void
ltq_write16(struct map_info *map, map_word d, unsigned long adr)
{
	unsigned long flags;

	if (map->map_priv_1 == LTQ_NOR_PROBING)
		adr ^= 2;
	spin_lock_irqsave(&ebu_lock, flags);
	*(u16 *)(map->virt + adr) = d.x[0];
	spin_unlock_irqrestore(&ebu_lock, flags);
}

/*
 * The following 2 functions copy data between iomem and a cached memory
 * section. As memcpy() makes use of pre-fetching we cannot use it here.
 * The normal alternative of using memcpy_{to,from}io also makes use of
 * memcpy() on MIPS so it is not applicable either. We are therefore stuck
 * with having to use our own loop.
 */
static void
ltq_copy_from(struct map_info *map, void *to,
	unsigned long from, ssize_t len)
{
	unsigned char *f = (unsigned char *)map->virt + from;
	unsigned char *t = (unsigned char *)to;
	unsigned long flags;

	spin_lock_irqsave(&ebu_lock, flags);
	while (len--)
		*t++ = *f++;
	spin_unlock_irqrestore(&ebu_lock, flags);
}

static void
ltq_copy_to(struct map_info *map, unsigned long to,
	const void *from, ssize_t len)
{
	unsigned char *f = (unsigned char *)from;
	unsigned char *t = (unsigned char *)map->virt + to;
	unsigned long flags;

	spin_lock_irqsave(&ebu_lock, flags);
	while (len--)
		*t++ = *f++;
	spin_unlock_irqrestore(&ebu_lock, flags);
}

static int
ltq_mtd_probe(struct platform_device *pdev)
{
	struct mtd_part_parser_data ppdata;
	struct ltq_mtd *ltq_mtd;
	struct cfi_private *cfi;
	int err;

	if (of_machine_is_compatible("lantiq,falcon") &&
			(ltq_boot_select() != BS_FLASH)) {
		dev_err(&pdev->dev, "invalid bootstrap options\n");
		return -ENODEV;
	}

	ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
	platform_set_drvdata(pdev, ltq_mtd);

	ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!ltq_mtd->res) {
		dev_err(&pdev->dev, "failed to get memory resource\n");
		err = -ENOENT;
		goto err_out;
	}

	ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
	ltq_mtd->map->phys = ltq_mtd->res->start;
	ltq_mtd->map->size = resource_size(ltq_mtd->res);
	ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
	if (IS_ERR(ltq_mtd->map->virt)) {
		err = PTR_ERR(ltq_mtd->map->virt);
		goto err_out;
	}

	ltq_mtd->map->name = ltq_map_name;
	ltq_mtd->map->bankwidth = 2;
	ltq_mtd->map->read = ltq_read16;
	ltq_mtd->map->write = ltq_write16;
	ltq_mtd->map->copy_from = ltq_copy_from;
	ltq_mtd->map->copy_to = ltq_copy_to;

	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;

	if (!ltq_mtd->mtd) {
		dev_err(&pdev->dev, "probing failed\n");
		err = -ENXIO;
		goto err_free;
	}

	ltq_mtd->mtd->owner = THIS_MODULE;

	cfi = ltq_mtd->map->fldrv_priv;
	cfi->addr_unlock1 ^= 1;
	cfi->addr_unlock2 ^= 1;

	ppdata.of_node = pdev->dev.of_node;
	err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types,
					&ppdata, NULL, 0);
	if (err) {
		dev_err(&pdev->dev, "failed to add partitions\n");
		goto err_destroy;
	}

	return 0;

err_destroy:
	map_destroy(ltq_mtd->mtd);
err_free:
	kfree(ltq_mtd->map);
err_out:
	kfree(ltq_mtd);
	return err;
}

static int
ltq_mtd_remove(struct platform_device *pdev)
{
	struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);

	if (ltq_mtd) {
		if (ltq_mtd->mtd) {
			mtd_device_unregister(ltq_mtd->mtd);
			map_destroy(ltq_mtd->mtd);
		}
		kfree(ltq_mtd->map);
		kfree(ltq_mtd);
	}
	return 0;
}

static const struct of_device_id ltq_mtd_match[] = {
	{ .compatible = "lantiq,nor" },
	{},
};
MODULE_DEVICE_TABLE(of, ltq_mtd_match);

static struct platform_driver ltq_mtd_driver = {
	.probe = ltq_mtd_probe,
	.remove = ltq_mtd_remove,
	.driver = {
		.name = "ltq-nor",
		.owner = THIS_MODULE,
		.of_match_table = ltq_mtd_match,
	},
};

module_platform_driver(ltq_mtd_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
MODULE_DESCRIPTION("Lantiq SoC NOR");
Commit	Line	Data
3c544739 JC	1	/*
	2	* This program is free software; you can redistribute it and/or modify it
	3	* under the terms of the GNU General Public License version 2 as published
	4	* by the Free Software Foundation.
	5	*
	6	* Copyright (C) 2004 Liu Peng Infineon IFAP DC COM CPE
	7	* Copyright (C) 2010 John Crispin <blogic@openwrt.org>
	8	*/
	9
b0de774c	10	#include <linux/err.h>
3c544739 JC	11	#include <linux/module.h>
	12	#include <linux/types.h>
	13	#include <linux/kernel.h>
	14	#include <linux/io.h>
	15	#include <linux/slab.h>
	16	#include <linux/init.h>
	17	#include <linux/mtd/mtd.h>
	18	#include <linux/mtd/map.h>
	19	#include <linux/mtd/partitions.h>
	20	#include <linux/mtd/cfi.h>
	21	#include <linux/platform_device.h>
	22	#include <linux/mtd/physmap.h>
fa09eded	23	#include <linux/of.h>
3c544739 JC	24
3c544739 JC	25	#include <lantiq_soc.h>
3c544739 JC	26
	27	/*
	28	* The NOR flash is connected to the same external bus unit (EBU) as PCI.
	29	* To make PCI work we need to enable the endianness swapping for the address
	30	* written to the EBU. This endianness swapping works for PCI correctly but
	31	* fails for attached NOR devices. To workaround this we need to use a complex
	32	* map. The workaround involves swapping all addresses whilst probing the chip.
	33	* Once probing is complete we stop swapping the addresses but swizzle the
	34	* unlock addresses to ensure that access to the NOR device works correctly.
	35	*/
	36
	37	enum {
	38	LTQ_NOR_PROBING,
	39	LTQ_NOR_NORMAL
	40	};
	41
	42	struct ltq_mtd {
	43	struct resource *res;
	44	struct mtd_info *mtd;
	45	struct map_info *map;
	46	};
	47
02fa961f	48	static const char ltq_map_name[] = "ltq_nor";
5e75e86e	49	static const char *ltq_probe_types[] = {
02fa961f	50	"cmdlinepart", "ofpart", NULL };
3c544739 JC	51
	52	static map_word
	53	ltq_read16(struct map_info *map, unsigned long adr)
	54	{
	55	unsigned long flags;
	56	map_word temp;
	57
	58	if (map->map_priv_1 == LTQ_NOR_PROBING)
	59	adr ^= 2;
	60	spin_lock_irqsave(&ebu_lock, flags);
	61	temp.x[0] = (u16 )(map->virt + adr);
	62	spin_unlock_irqrestore(&ebu_lock, flags);
	63	return temp;
	64	}
	65
	66	static void
	67	ltq_write16(struct map_info *map, map_word d, unsigned long adr)
	68	{
	69	unsigned long flags;
	70
	71	if (map->map_priv_1 == LTQ_NOR_PROBING)
	72	adr ^= 2;
	73	spin_lock_irqsave(&ebu_lock, flags);
	74	(u16 )(map->virt + adr) = d.x[0];
	75	spin_unlock_irqrestore(&ebu_lock, flags);
	76	}
	77
	78	/*
	79	* The following 2 functions copy data between iomem and a cached memory
	80	* section. As memcpy() makes use of pre-fetching we cannot use it here.
	81	* The normal alternative of using memcpy_{to,from}io also makes use of
	82	* memcpy() on MIPS so it is not applicable either. We are therefore stuck
	83	* with having to use our own loop.
	84	*/
	85	static void
	86	ltq_copy_from(struct map_info map, void to,
	87	unsigned long from, ssize_t len)
	88	{
	89	unsigned char f = (unsigned char )map->virt + from;
	90	unsigned char t = (unsigned char )to;
	91	unsigned long flags;
	92
	93	spin_lock_irqsave(&ebu_lock, flags);
	94	while (len--)
	95	t++ = f++;
	96	spin_unlock_irqrestore(&ebu_lock, flags);
	97	}
	98
	99	static void
	100	ltq_copy_to(struct map_info *map, unsigned long to,
	101	const void *from, ssize_t len)
	102	{
	103	unsigned char f = (unsigned char )from;
	104	unsigned char t = (unsigned char )map->virt + to;
	105	unsigned long flags;
	106
	107	spin_lock_irqsave(&ebu_lock, flags);
	108	while (len--)
	109	t++ = f++;
	110	spin_unlock_irqrestore(&ebu_lock, flags);
	111	}
	112
06f25510	113	static int
3c544739 JC	114	ltq_mtd_probe(struct platform_device *pdev)
3c544739 JC	115	{
02fa961f	116	struct mtd_part_parser_data ppdata;
3c544739	117	struct ltq_mtd *ltq_mtd;
3c544739 JC	118	struct cfi_private *cfi;
	119	int err;
	120
fa09eded JC	121	if (of_machine_is_compatible("lantiq,falcon") &&
	122	(ltq_boot_select() != BS_FLASH)) {
	123	dev_err(&pdev->dev, "invalid bootstrap options\n");
	124	return -ENODEV;
	125	}
	126
3c544739 JC	127	ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
	128	platform_set_drvdata(pdev, ltq_mtd);
	129
	130	ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	131	if (!ltq_mtd->res) {
02fa961f	132	dev_err(&pdev->dev, "failed to get memory resource\n");
3c544739 JC	133	err = -ENOENT;
	134	goto err_out;
	135	}
	136
3c544739	137	ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
02fa961f JC	138	ltq_mtd->map->phys = ltq_mtd->res->start;
02fa961f JC	139	ltq_mtd->map->size = resource_size(ltq_mtd->res);
b0de774c TR	140	ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
	141	if (IS_ERR(ltq_mtd->map->virt)) {
	142	err = PTR_ERR(ltq_mtd->map->virt);
02fa961f	143	goto err_out;
3c544739 JC	144	}
	145
	146	ltq_mtd->map->name = ltq_map_name;
	147	ltq_mtd->map->bankwidth = 2;
	148	ltq_mtd->map->read = ltq_read16;
	149	ltq_mtd->map->write = ltq_write16;
	150	ltq_mtd->map->copy_from = ltq_copy_from;
	151	ltq_mtd->map->copy_to = ltq_copy_to;
	152
	153	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
	154	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
	155	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
	156
	157	if (!ltq_mtd->mtd) {
	158	dev_err(&pdev->dev, "probing failed\n");
	159	err = -ENXIO;
af32b360	160	goto err_free;
3c544739 JC	161	}
	162
	163	ltq_mtd->mtd->owner = THIS_MODULE;
	164
	165	cfi = ltq_mtd->map->fldrv_priv;
	166	cfi->addr_unlock1 ^= 1;
	167	cfi->addr_unlock2 ^= 1;
	168
02fa961f JC	169	ppdata.of_node = pdev->dev.of_node;
	170	err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types,
	171	&ppdata, NULL, 0);
3c544739 JC	172	if (err) {
	173	dev_err(&pdev->dev, "failed to add partitions\n");
	174	goto err_destroy;
	175	}
	176
	177	return 0;
	178
	179	err_destroy:
	180	map_destroy(ltq_mtd->mtd);
3c544739 JC	181	err_free:
	182	kfree(ltq_mtd->map);
	183	err_out:
	184	kfree(ltq_mtd);
	185	return err;
	186	}
	187
810b7e06	188	static int
3c544739 JC	189	ltq_mtd_remove(struct platform_device *pdev)
	190	{
	191	struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
	192
	193	if (ltq_mtd) {
	194	if (ltq_mtd->mtd) {
2e5db86d	195	mtd_device_unregister(ltq_mtd->mtd);
3c544739 JC	196	map_destroy(ltq_mtd->mtd);
3c544739 JC	197	}
3c544739 JC	198	kfree(ltq_mtd->map);
	199	kfree(ltq_mtd);
	200	}
	201	return 0;
	202	}
	203
02fa961f JC	204	static const struct of_device_id ltq_mtd_match[] = {
	205	{ .compatible = "lantiq,nor" },
	206	{},
	207	};
	208	MODULE_DEVICE_TABLE(of, ltq_mtd_match);
	209
3c544739	210	static struct platform_driver ltq_mtd_driver = {
02fa961f	211	.probe = ltq_mtd_probe,
5153b88c	212	.remove = ltq_mtd_remove,
3c544739	213	.driver = {
02fa961f	214	.name = "ltq-nor",
3c544739	215	.owner = THIS_MODULE,
02fa961f	216	.of_match_table = ltq_mtd_match,
3c544739 JC	217	},
	218	};
	219
02fa961f	220	module_platform_driver(ltq_mtd_driver);
3c544739 JC	221
	222	MODULE_LICENSE("GPL");
	223	MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
	224	MODULE_DESCRIPTION("Lantiq SoC NOR");