[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/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 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 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 = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL);
	if (!ltq_mtd)
		return -ENOMEM;

	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");
		return -ENOENT;
	}

	ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info),
				    GFP_KERNEL);
	if (!ltq_mtd->map)
		return -ENOMEM;

	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))
		return PTR_ERR(ltq_mtd->map->virt);

	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");
		return -ENXIO;
	}

	ltq_mtd->mtd->dev.parent = &pdev->dev;
	mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);

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

	err = mtd_device_register(ltq_mtd->mtd, 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);
	return err;
}

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

	if (ltq_mtd && ltq_mtd->mtd) {
		mtd_device_unregister(ltq_mtd->mtd);
		map_destroy(ltq_mtd->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",
		.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>
3c544739 JC	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>
fa09eded	22	#include <linux/of.h>
3c544739 JC	23
3c544739 JC	24	#include <lantiq_soc.h>
3c544739 JC	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
02fa961f	47	static const char ltq_map_name[] = "ltq_nor";
3c544739 JC	48
	49	static map_word
	50	ltq_read16(struct map_info *map, unsigned long adr)
	51	{
	52	unsigned long flags;
	53	map_word temp;
	54
	55	if (map->map_priv_1 == LTQ_NOR_PROBING)
	56	adr ^= 2;
	57	spin_lock_irqsave(&ebu_lock, flags);
	58	temp.x[0] = (u16 )(map->virt + adr);
	59	spin_unlock_irqrestore(&ebu_lock, flags);
	60	return temp;
	61	}
	62
	63	static void
	64	ltq_write16(struct map_info *map, map_word d, unsigned long adr)
	65	{
	66	unsigned long flags;
	67
	68	if (map->map_priv_1 == LTQ_NOR_PROBING)
	69	adr ^= 2;
	70	spin_lock_irqsave(&ebu_lock, flags);
	71	(u16 )(map->virt + adr) = d.x[0];
	72	spin_unlock_irqrestore(&ebu_lock, flags);
	73	}
	74
	75	/*
	76	* The following 2 functions copy data between iomem and a cached memory
	77	* section. As memcpy() makes use of pre-fetching we cannot use it here.
	78	* The normal alternative of using memcpy_{to,from}io also makes use of
	79	* memcpy() on MIPS so it is not applicable either. We are therefore stuck
	80	* with having to use our own loop.
	81	*/
	82	static void
	83	ltq_copy_from(struct map_info map, void to,
	84	unsigned long from, ssize_t len)
	85	{
	86	unsigned char f = (unsigned char )map->virt + from;
	87	unsigned char t = (unsigned char )to;
	88	unsigned long flags;
	89
	90	spin_lock_irqsave(&ebu_lock, flags);
	91	while (len--)
	92	t++ = f++;
	93	spin_unlock_irqrestore(&ebu_lock, flags);
	94	}
	95
	96	static void
	97	ltq_copy_to(struct map_info *map, unsigned long to,
	98	const void *from, ssize_t len)
	99	{
	100	unsigned char f = (unsigned char )from;
	101	unsigned char t = (unsigned char )map->virt + to;
	102	unsigned long flags;
	103
	104	spin_lock_irqsave(&ebu_lock, flags);
	105	while (len--)
	106	t++ = f++;
	107	spin_unlock_irqrestore(&ebu_lock, flags);
	108	}
	109
06f25510	110	static int
3c544739 JC	111	ltq_mtd_probe(struct platform_device *pdev)
3c544739 JC	112	{
3c544739	113	struct ltq_mtd *ltq_mtd;
3c544739 JC	114	struct cfi_private *cfi;
	115	int err;
	116
fa09eded JC	117	if (of_machine_is_compatible("lantiq,falcon") &&
	118	(ltq_boot_select() != BS_FLASH)) {
	119	dev_err(&pdev->dev, "invalid bootstrap options\n");
	120	return -ENODEV;
	121	}
	122
436bf63b JH	123	ltq_mtd = devm_kzalloc(&pdev->dev, sizeof(struct ltq_mtd), GFP_KERNEL);
	124	if (!ltq_mtd)
	125	return -ENOMEM;
	126
3c544739 JC	127	platform_set_drvdata(pdev, ltq_mtd);
	128
	129	ltq_mtd->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	130	if (!ltq_mtd->res) {
02fa961f	131	dev_err(&pdev->dev, "failed to get memory resource\n");
436bf63b	132	return -ENOENT;
3c544739 JC	133	}
3c544739 JC	134
436bf63b JH	135	ltq_mtd->map = devm_kzalloc(&pdev->dev, sizeof(struct map_info),
	136	GFP_KERNEL);
	137	if (!ltq_mtd->map)
	138	return -ENOMEM;
	139
02fa961f JC	140	ltq_mtd->map->phys = ltq_mtd->res->start;
02fa961f JC	141	ltq_mtd->map->size = resource_size(ltq_mtd->res);
b0de774c	142	ltq_mtd->map->virt = devm_ioremap_resource(&pdev->dev, ltq_mtd->res);
436bf63b JH	143	if (IS_ERR(ltq_mtd->map->virt))
436bf63b JH	144	return PTR_ERR(ltq_mtd->map->virt);
3c544739 JC	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");
436bf63b	159	return -ENXIO;
3c544739 JC	160	}
3c544739 JC	161
c54c2fb7	162	ltq_mtd->mtd->dev.parent = &pdev->dev;
004b5e60	163	mtd_set_of_node(ltq_mtd->mtd, pdev->dev.of_node);
3c544739 JC	164
	165	cfi = ltq_mtd->map->fldrv_priv;
	166	cfi->addr_unlock1 ^= 1;
	167	cfi->addr_unlock2 ^= 1;
	168
004b5e60	169	err = mtd_device_register(ltq_mtd->mtd, NULL, 0);
3c544739 JC	170	if (err) {
	171	dev_err(&pdev->dev, "failed to add partitions\n");
	172	goto err_destroy;
	173	}
	174
	175	return 0;
	176
	177	err_destroy:
	178	map_destroy(ltq_mtd->mtd);
3c544739 JC	179	return err;
	180	}
	181
810b7e06	182	static int
3c544739 JC	183	ltq_mtd_remove(struct platform_device *pdev)
	184	{
	185	struct ltq_mtd *ltq_mtd = platform_get_drvdata(pdev);
	186
436bf63b JH	187	if (ltq_mtd && ltq_mtd->mtd) {
	188	mtd_device_unregister(ltq_mtd->mtd);
	189	map_destroy(ltq_mtd->mtd);
3c544739 JC	190	}
	191	return 0;
	192	}
	193
02fa961f JC	194	static const struct of_device_id ltq_mtd_match[] = {
	195	{ .compatible = "lantiq,nor" },
	196	{},
	197	};
	198	MODULE_DEVICE_TABLE(of, ltq_mtd_match);
	199
3c544739	200	static struct platform_driver ltq_mtd_driver = {
02fa961f	201	.probe = ltq_mtd_probe,
5153b88c	202	.remove = ltq_mtd_remove,
3c544739	203	.driver = {
02fa961f	204	.name = "ltq-nor",
02fa961f	205	.of_match_table = ltq_mtd_match,
3c544739 JC	206	},
	207	};
	208
02fa961f	209	module_platform_driver(ltq_mtd_driver);
3c544739 JC	210
	211	MODULE_LICENSE("GPL");
	212	MODULE_AUTHOR("John Crispin <blogic@openwrt.org>");
	213	MODULE_DESCRIPTION("Lantiq SoC NOR");