diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index 61278a2..7f9c306 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -58,4 +58,9 @@ 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 bf1f8a9..bc1960e 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 0000000..d1eaafd --- /dev/null +++ b/drivers/mtd/devices/mtdram.c @@ -0,0 +1,122 @@ +/* + * Author: Sebastian Block + * Copyright (c) 2014 + * + * Some parts are based on mtdram.c found in Linux kernel + * by Alexander Larsson + * and Joern Engel . + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +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");