cregit-Linux how code gets into the kernel

Release 4.7 drivers/mtd/maps/lantiq-flash.c

Directory: drivers/mtd/maps
/*
 *  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; }

Contributors

PersonTokensPropCommitsCommitProp
john crispinjohn crispin73100.00%1100.00%
Total73100.00%1100.00%


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); }

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PersonTokensPropCommitsCommitProp
john crispinjohn crispin70100.00%1100.00%
Total70100.00%1100.00%

/* * 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); }

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PersonTokensPropCommitsCommitProp
john crispinjohn crispin83100.00%1100.00%
Total83100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
john crispinjohn crispin84100.00%1100.00%
Total84100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
john crispinjohn crispin34283.01%333.33%
jingoo hanjingoo han389.22%111.11%
brian norrisbrian norris153.64%222.22%
thierry redingthierry reding92.18%111.11%
frans klaverfrans klaver71.70%111.11%
dmitry eremin-baryshkovdmitry eremin-baryshkov10.24%111.11%
Total412100.00%9100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
john crispinjohn crispin4797.92%266.67%
jingoo hanjingoo han12.08%133.33%
Total48100.00%3100.00%

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");

Overall Contributors

PersonTokensPropCommitsCommitProp
john crispinjohn crispin85392.02%440.00%
jingoo hanjingoo han394.21%110.00%
brian norrisbrian norris151.62%220.00%
thierry redingthierry reding121.29%110.00%
frans klaverfrans klaver70.76%110.00%
dmitry eremin-baryshkovdmitry eremin-baryshkov10.11%110.00%
Total927100.00%10100.00%
Directory: drivers/mtd/maps
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