Kay, On Montag, 3. November 2008, Kay Sievers wrote: > On Mon, Nov 3, 2008 at 14:18, Kay Sievers <kay.sievers@xxxxxxxx> wrote: > > On Mon, Nov 3, 2008 at 12:12, Juergen Beisert <jbe@xxxxxxxxxxxxxx> wrote: > >> On Montag, 3. November 2008, Kay Sievers wrote: > >>> On Mon, Nov 3, 2008 at 11:12, Juergen Beisert <jbe@xxxxxxxxxxxxxx> wrote: > >>> > has anybody an idea how to write some rules to match devices from the > >>> > mtd framework? > > > > ... > > > >>> Seems, there is not much you can do with the current information it > >>> exposes. What is the hardware behind these mtd devices? Are these > >>> devices show up somewhere in /sys/devices/, maybe as platform devices? > >>> Then we could try to make the kernel use these as parents for the > >>> block devices, so the block devices would not be "virtual". > >> > >> MTDs are simple memory devices. Flash (NOR or NAND type) and SRAM for > >> example. They are connected through a simple address/data bus, some also > >> via SPI interface. About each of these devices the kernel knows at least > >> the manufacturer and the device name (for flash memory this info can be > >> autodetected). For the other types mostly a platform structure provides > >> this information. On my ARM (i.MX27 CPU) tree types of memory is > >> available: > >> > >> SRAM: > >> /sys/bus/platform/devices/mtd-ram.0 > >> > >> NAND-flash: > >> /sys/bus/platform/devices/mxc_nand.0 > >> > >> NOR-flash: > >> /sys/bus/platform/devices/physmap-flash.0 > >> > >> Currently the NOR flash is using three partitions so I get: > >> > >> $ ls -l /dev/mtd* > >> crw-rw---- 1 root root 90, 0 Jan 1 00:00 /dev/mtd0 > >> crw-rw---- 1 root root 90, 1 Jan 1 00:00 /dev/mtd0ro > >> crw-rw---- 1 root root 90, 2 Jan 1 00:00 /dev/mtd1 > >> crw-rw---- 1 root root 90, 3 Jan 1 00:00 /dev/mtd1ro > >> crw-rw---- 1 root root 90, 4 Jan 1 00:00 /dev/mtd2 > >> crw-rw---- 1 root root 90, 5 Jan 1 00:00 /dev/mtd2ro > >> crw-rw---- 1 root root 90, 6 Jan 1 00:00 /dev/mtd3 > >> crw-rw---- 1 root root 90, 7 Jan 1 00:00 /dev/mtd3ro > >> crw-rw---- 1 root root 90, 8 Jan 1 00:00 /dev/mtd4 > >> crw-rw---- 1 root root 90, 9 Jan 1 00:00 /dev/mtd4ro > >> crw-rw---- 1 root root 90, 10 Jan 1 00:00 /dev/mtd5 > >> crw-rw---- 1 root root 90, 11 Jan 1 00:00 /dev/mtd5ro > >> brw-rw---- 1 root root 31, 0 Jan 1 00:00 /dev/mtdblock0 > >> brw-rw---- 1 root root 31, 1 Jan 1 00:00 /dev/mtdblock1 > >> brw-rw---- 1 root root 31, 2 Jan 1 00:00 /dev/mtdblock2 > >> brw-rw---- 1 root root 31, 3 Jan 1 00:00 /dev/mtdblock3 > >> brw-rw---- 1 root root 31, 4 Jan 1 00:00 /dev/mtdblock4 > >> brw-rw---- 1 root root 31, 5 Jan 1 00:00 /dev/mtdblock5 > >> > >> mtd*0 ... mtd*3 are the three partitions on the NOR flash (its also the > >> memory to boot from), mtd*4 is the NAND memory, mtd*5 is the SRAM. All I > >> want is to detect the NAND and the SRAM to create special links or node > >> names for these devices to be independent from the partition count of > >> the NOR memory and the changing device node numbers when this count > >> changes. > > > > It is something that should be changed in mtd. NAND for example > > registers the device in drivers/mtd/nand/mxc_nand.c. Before that, it > > has handled the platform device *pdev. What does it mean? Should we forward this to the mdt mail list? Regards Juergen -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
