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author | Sebastian Block <basti@linux-source.de> | 2014-09-06 13:21:03 +0200 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2014-09-09 09:52:53 +0200 |
commit | b7014e9819e6f2606e49fdd33fc5472a65fceba5 (patch) | |
tree | 0dbdac1037ec09d8d9450e4622711b77504b18d4 /drivers | |
parent | 5a5ba5ad30f22f0e3a4c0c56d180261136e3dfe4 (diff) | |
download | barebox-b7014e9819e6f2606e49fdd33fc5472a65fceba5.tar.gz barebox-b7014e9819e6f2606e49fdd33fc5472a65fceba5.tar.xz |
mtd: add mtdram device (which build mtd over ram area - useful for FRAM oder MRAM)
Change since v1 (Sascha, thanks for review):
* use xzalloc instead of kzalloc and control check
* correct help and names
* fix coding style issue
* remove verbose and unneeded messages
This adds support for MTD in RAM devices (like FRAM or MRAM).
Signed-off-by: Sebastian Block <basti@linux-source.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/mtd/devices/Kconfig | 5 | ||||
-rw-r--r-- | drivers/mtd/devices/Makefile | 1 | ||||
-rw-r--r-- | drivers/mtd/devices/mtdram.c | 122 |
3 files changed, 128 insertions, 0 deletions
diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index 61278a235d..7f9c306258 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -58,4 +58,9 @@ config MTD_DOCG3 M-Systems and now Sandisk. The support is very experimental, and doesn't give access to any write operations. +config MTD_MTDRAM + tristate "Support for NVRAM devices (FRAM, MRAM, ...)" + help + This enables non volatile RAM to used as MTD devices. + endmenu diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile index bf1f8a9f15..bc1960e1b2 100644 --- a/drivers/mtd/devices/Makefile +++ b/drivers/mtd/devices/Makefile @@ -5,3 +5,4 @@ obj-$(CONFIG_MTD_DATAFLASH) += mtd_dataflash.o obj-$(CONFIG_MTD_DOCG3) += docg3.o obj-$(CONFIG_MTD_M25P80) += m25p80.o +obj-$(CONFIG_MTD_MTDRAM) += mtdram.o diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c new file mode 100644 index 0000000000..d1eaafdab5 --- /dev/null +++ b/drivers/mtd/devices/mtdram.c @@ -0,0 +1,122 @@ +/* + * Author: Sebastian Block <basti@linux-source.de> + * Copyright (c) 2014 + * + * Some parts are based on mtdram.c found in Linux kernel + * by Alexander Larsson <alex@cendio.se> + * and Joern Engel <joern@wh.fh-wedel.de>. + * + * This code 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. + * + */ +#include <common.h> +#include <environment.h> +#include <errno.h> +#include <init.h> +#include <io.h> +#include <linux/mtd/mtd.h> +#include <malloc.h> +#include <of.h> + +struct mtdram_priv_data { + struct mtd_info mtd; + void *base; +}; + +static int ram_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + memset((char *)mtd->priv + instr->addr, 0xff, instr->len); + instr->state = MTD_ERASE_DONE; + mtd_erase_callback(instr); + return 0; +} + +static int ram_write(struct mtd_info *mtd, loff_t to, size_t len, size_t *retlen, const u_char *buf) +{ + memcpy((char*)mtd->priv + to, buf, len); + *retlen = len; + return 0; +} + +static int ram_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + memcpy(buf, mtd->priv + from, len); + *retlen = len; + return 0; +} + +static int mtdram_probe(struct device_d *dev) +{ + void __iomem *base; + int device_id; + struct mtd_info *mtd; + struct resource *res; + loff_t size; + int ret = 0; + + mtd = xzalloc(sizeof(struct mtd_info)); + + device_id = DEVICE_ID_SINGLE; + if (dev->device_node) { + const char *alias = of_alias_get(dev->device_node); + if (alias) + mtd->name = xstrdup(alias); + } + + if (!mtd->name) { + device_id = DEVICE_ID_DYNAMIC; + mtd->name = "mtdram"; + } + + base = dev_request_mem_region(dev, 0); + if (!base) { + ret = -EBUSY; + goto nobase; + } + + res = dev_get_resource(dev, IORESOURCE_MEM, 0); + size = (unsigned long) resource_size(res); + mtd->priv = base; + + mtd->type = MTD_RAM; + mtd->writesize = 1; + mtd->writebufsize = 64; + mtd->flags = MTD_CAP_RAM; + mtd->size = size; + + mtd->read = ram_read; + mtd->write = ram_write; + mtd->erase = ram_erase; + mtd->erasesize = 1; + + mtd->parent = dev; + + ret = add_mtd_device(mtd, mtd->name, device_id); + return ret; + +nobase: + kfree(mtd); + + return ret; +} + +static __maybe_unused struct of_device_id mtdram_dt_ids[] = { + { + .compatible = "mtd-ram", + }, { + /* sentinel */ + } +}; + +static struct driver_d mtdram_driver = { + .name = "mtdram", + .probe = mtdram_probe, + .of_compatible = DRV_OF_COMPAT(mtdram_dt_ids), +}; +device_platform_driver(mtdram_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sebastian Block"); +MODULE_DESCRIPTION("MTD RAM driver for NVRAMs"); |