[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/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 <lantiq_soc.h>
#include <lantiq_platform.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 char ltq_map_name[] = "ltq_nor";
static const char *ltq_probe_types[] __devinitconst = { "cmdlinepart", 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 __init
ltq_mtd_probe(struct platform_device *pdev)
{
	struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
	struct ltq_mtd *ltq_mtd;
	struct resource *res;
	struct cfi_private *cfi;
	int err;

	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");
		err = -ENOENT;
		goto err_out;
	}

	res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
		resource_size(ltq_mtd->res), dev_name(&pdev->dev));
	if (!ltq_mtd->res) {
		dev_err(&pdev->dev, "failed to request mem resource");
		err = -EBUSY;
		goto err_out;
	}

	ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
	ltq_mtd->map->phys = res->start;
	ltq_mtd->map->size = resource_size(res);
	ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
				ltq_mtd->map->phys, ltq_mtd->map->size);
	if (!ltq_mtd->map->virt) {
		dev_err(&pdev->dev, "failed to ioremap!\n");
		err = -ENOMEM;
		goto err_free;
	}

	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;

	err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, NULL,
					ltq_mtd_data->parts,
					ltq_mtd_data->nr_parts);
	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 __devexit
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 struct platform_driver ltq_mtd_driver = {
	.remove = __devexit_p(ltq_mtd_remove),
	.driver = {
		.name = "ltq_nor",
		.owner = THIS_MODULE,
	},
};

static int __init
init_ltq_mtd(void)
{
	int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);

	if (ret)
		pr_err("ltq_nor: error registering platform driver");
	return ret;
}

static void __exit
exit_ltq_mtd(void)
{
	platform_driver_unregister(&ltq_mtd_driver);
}

module_init(init_ltq_mtd);
module_exit(exit_ltq_mtd);

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
	10	#include <linux/module.h>
	11	#include <linux/types.h>
	12	#include <linux/kernel.h>
	13	#include <linux/io.h>
	14	#include <linux/slab.h>
	15	#include <linux/init.h>
	16	#include <linux/mtd/mtd.h>
	17	#include <linux/mtd/map.h>
	18	#include <linux/mtd/partitions.h>
	19	#include <linux/mtd/cfi.h>
	20	#include <linux/platform_device.h>
	21	#include <linux/mtd/physmap.h>
	22
	23	#include <lantiq_soc.h>
	24	#include <lantiq_platform.h>
	25
	26	/*
	27	* The NOR flash is connected to the same external bus unit (EBU) as PCI.
	28	* To make PCI work we need to enable the endianness swapping for the address
	29	* written to the EBU. This endianness swapping works for PCI correctly but
	30	* fails for attached NOR devices. To workaround this we need to use a complex
	31	* map. The workaround involves swapping all addresses whilst probing the chip.
	32	* Once probing is complete we stop swapping the addresses but swizzle the
	33	* unlock addresses to ensure that access to the NOR device works correctly.
	34	*/
	35
	36	enum {
	37	LTQ_NOR_PROBING,
	38	LTQ_NOR_NORMAL
	39	};
	40
	41	struct ltq_mtd {
	42	struct resource *res;
	43	struct mtd_info *mtd;
	44	struct map_info *map;
	45	};
	46
	47	static char ltq_map_name[] = "ltq_nor";
bf011f2e	48	static const char *ltq_probe_types[] __devinitconst = { "cmdlinepart", NULL };
3c544739 JC	49
	50	static map_word
	51	ltq_read16(struct map_info *map, unsigned long adr)
	52	{
	53	unsigned long flags;
	54	map_word temp;
	55
	56	if (map->map_priv_1 == LTQ_NOR_PROBING)
	57	adr ^= 2;
	58	spin_lock_irqsave(&ebu_lock, flags);
	59	temp.x[0] = (u16 )(map->virt + adr);
	60	spin_unlock_irqrestore(&ebu_lock, flags);
	61	return temp;
	62	}
	63
	64	static void
	65	ltq_write16(struct map_info *map, map_word d, unsigned long adr)
	66	{
	67	unsigned long flags;
	68
	69	if (map->map_priv_1 == LTQ_NOR_PROBING)
	70	adr ^= 2;
	71	spin_lock_irqsave(&ebu_lock, flags);
	72	(u16 )(map->virt + adr) = d.x[0];
	73	spin_unlock_irqrestore(&ebu_lock, flags);
	74	}
	75
	76	/*
	77	* The following 2 functions copy data between iomem and a cached memory
	78	* section. As memcpy() makes use of pre-fetching we cannot use it here.
	79	* The normal alternative of using memcpy_{to,from}io also makes use of
	80	* memcpy() on MIPS so it is not applicable either. We are therefore stuck
	81	* with having to use our own loop.
	82	*/
	83	static void
	84	ltq_copy_from(struct map_info map, void to,
	85	unsigned long from, ssize_t len)
	86	{
	87	unsigned char f = (unsigned char )map->virt + from;
	88	unsigned char t = (unsigned char )to;
	89	unsigned long flags;
	90
	91	spin_lock_irqsave(&ebu_lock, flags);
	92	while (len--)
	93	t++ = f++;
	94	spin_unlock_irqrestore(&ebu_lock, flags);
	95	}
	96
	97	static void
	98	ltq_copy_to(struct map_info *map, unsigned long to,
	99	const void *from, ssize_t len)
	100	{
	101	unsigned char f = (unsigned char )from;
	102	unsigned char t = (unsigned char )map->virt + to;
	103	unsigned long flags;
	104
	105	spin_lock_irqsave(&ebu_lock, flags);
	106	while (len--)
	107	t++ = f++;
	108	spin_unlock_irqrestore(&ebu_lock, flags);
	109	}
	110
3c544739 JC	111	static int __init
	112	ltq_mtd_probe(struct platform_device *pdev)
	113	{
	114	struct physmap_flash_data *ltq_mtd_data = dev_get_platdata(&pdev->dev);
	115	struct ltq_mtd *ltq_mtd;
3c544739	116	struct resource *res;
3c544739 JC	117	struct cfi_private *cfi;
	118	int err;
	119
	120	ltq_mtd = kzalloc(sizeof(struct ltq_mtd), GFP_KERNEL);
	121	platform_set_drvdata(pdev, ltq_mtd);
	122
	123	ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	124	if (!ltq_mtd->res) {
	125	dev_err(&pdev->dev, "failed to get memory resource");
	126	err = -ENOENT;
	127	goto err_out;
	128	}
	129
	130	res = devm_request_mem_region(&pdev->dev, ltq_mtd->res->start,
	131	resource_size(ltq_mtd->res), dev_name(&pdev->dev));
	132	if (!ltq_mtd->res) {
	133	dev_err(&pdev->dev, "failed to request mem resource");
	134	err = -EBUSY;
	135	goto err_out;
	136	}
	137
	138	ltq_mtd->map = kzalloc(sizeof(struct map_info), GFP_KERNEL);
	139	ltq_mtd->map->phys = res->start;
	140	ltq_mtd->map->size = resource_size(res);
	141	ltq_mtd->map->virt = devm_ioremap_nocache(&pdev->dev,
	142	ltq_mtd->map->phys, ltq_mtd->map->size);
	143	if (!ltq_mtd->map->virt) {
	144	dev_err(&pdev->dev, "failed to ioremap!\n");
	145	err = -ENOMEM;
	146	goto err_free;
	147	}
	148
	149	ltq_mtd->map->name = ltq_map_name;
	150	ltq_mtd->map->bankwidth = 2;
	151	ltq_mtd->map->read = ltq_read16;
	152	ltq_mtd->map->write = ltq_write16;
	153	ltq_mtd->map->copy_from = ltq_copy_from;
	154	ltq_mtd->map->copy_to = ltq_copy_to;
	155
	156	ltq_mtd->map->map_priv_1 = LTQ_NOR_PROBING;
	157	ltq_mtd->mtd = do_map_probe("cfi_probe", ltq_mtd->map);
	158	ltq_mtd->map->map_priv_1 = LTQ_NOR_NORMAL;
	159
	160	if (!ltq_mtd->mtd) {
	161	dev_err(&pdev->dev, "probing failed\n");
	162	err = -ENXIO;
af32b360	163	goto err_free;
3c544739 JC	164	}
	165
	166	ltq_mtd->mtd->owner = THIS_MODULE;
	167
	168	cfi = ltq_mtd->map->fldrv_priv;
	169	cfi->addr_unlock1 ^= 1;
	170	cfi->addr_unlock2 ^= 1;
	171
42d7fbe2 AB	172	err = mtd_device_parse_register(ltq_mtd->mtd, ltq_probe_types, NULL,
	173	ltq_mtd_data->parts,
	174	ltq_mtd_data->nr_parts);
3c544739 JC	175	if (err) {
	176	dev_err(&pdev->dev, "failed to add partitions\n");
	177	goto err_destroy;
	178	}
	179
	180	return 0;
	181
	182	err_destroy:
	183	map_destroy(ltq_mtd->mtd);
3c544739 JC	184	err_free:
	185	kfree(ltq_mtd->map);
	186	err_out:
	187	kfree(ltq_mtd);
	188	return err;
	189	}
	190
	191	static int __devexit
	192	ltq_mtd_remove(struct platform_device *pdev)
	193	{
	194	struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
	195
	196	if (ltq_mtd) {
	197	if (ltq_mtd->mtd) {
2e5db86d	198	mtd_device_unregister(ltq_mtd->mtd);
3c544739 JC	199	map_destroy(ltq_mtd->mtd);
3c544739 JC	200	}
3c544739 JC	201	kfree(ltq_mtd->map);
	202	kfree(ltq_mtd);
	203	}
	204	return 0;
	205	}
	206
	207	static struct platform_driver ltq_mtd_driver = {
	208	.remove = __devexit_p(ltq_mtd_remove),
	209	.driver = {
	210	.name = "ltq_nor",
	211	.owner = THIS_MODULE,
	212	},
	213	};
	214
	215	static int __init
	216	init_ltq_mtd(void)
	217	{
	218	int ret = platform_driver_probe(&ltq_mtd_driver, ltq_mtd_probe);
	219
	220	if (ret)
	221	pr_err("ltq_nor: error registering platform driver");
	222	return ret;
	223	}
	224
	225	static void __exit
	226	exit_ltq_mtd(void)
	227	{
	228	platform_driver_unregister(&ltq_mtd_driver);
	229	}
	230
	231	module_init(init_ltq_mtd);
	232	module_exit(exit_ltq_mtd);
	233
	234	MODULE_LICENSE("GPL");
	235	MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
	236	MODULE_DESCRIPTION("Lantiq SoC NOR");