From patchwork Thu Jan 10 16:31:37 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: [1/2,v3] mtd/uclinux: support ROM and allow passing the base address Date: Thu, 10 Jan 2013 06:31:37 -0000 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 211081 Message-Id: <1357835498-23904-1-git-send-email-u.kleine-koenig@pengutronix.de> To: linux-mtd@lists.infradead.org Cc: Artem Bityutskiy , Mike Frysinger , kernel@pengutronix.de, Greg Ungerer This allows to put the filesystem at a defined address in ROM allowing to save more precious RAM. I think it's safe to default to ROM because the intention of using the uclinux map is to use a romfs and so mtd-ram doesn't give you anything that mtd-rom doesn't. Just in case I missed something a warning is added if the driver has to fall back to the RAM mapping. Signed-off-by: Uwe Kleine-König --- Changes since v2, id:1350027693-19528-1-git-send-email-u.kleine-koenig@pengutronix.de: - drop a few "ram"s from printks instead of making them "ram/rom" - fix a typo in the commit log and add rational for the introduced warning. Who is responsible for taking (or not) these two patches? David? Artem? Best regards Uwe --- drivers/mtd/maps/Kconfig | 2 +- drivers/mtd/maps/uclinux.c | 26 +++++++++++++++++++++----- 2 files changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig index 2e47c2e..0dc86fc 100644 --- a/drivers/mtd/maps/Kconfig +++ b/drivers/mtd/maps/Kconfig @@ -443,7 +443,7 @@ config MTD_GPIO_ADDR config MTD_UCLINUX bool "Generic uClinux RAM/ROM filesystem support" - depends on MTD_RAM=y && (!MMU || COLDFIRE) + depends on (MTD_RAM=y || MTD_ROM=y) && (!MMU || COLDFIRE) help Map driver to support image based filesystems for uClinux. diff --git a/drivers/mtd/maps/uclinux.c b/drivers/mtd/maps/uclinux.c index 299bf88..b3a9c54 100644 --- a/drivers/mtd/maps/uclinux.c +++ b/drivers/mtd/maps/uclinux.c @@ -24,11 +24,12 @@ /****************************************************************************/ struct map_info uclinux_ram_map = { - .name = "RAM", - .phys = (unsigned long)__bss_stop, .size = 0, }; +static unsigned long physaddr = -1; +module_param(physaddr, ulong, S_IRUGO); + static struct mtd_info *uclinux_ram_mtdinfo; /****************************************************************************/ @@ -60,11 +61,17 @@ static int __init uclinux_mtd_init(void) struct map_info *mapp; mapp = &uclinux_ram_map; + + if (physaddr == -1) + mapp->phys = (resource_size_t)__bss_stop; + else + mapp->phys = physaddr; + if (!mapp->size) mapp->size = PAGE_ALIGN(ntohl(*((unsigned long *)(mapp->phys + 8)))); mapp->bankwidth = 4; - printk("uclinux[mtd]: RAM probe address=0x%x size=0x%x\n", + printk("uclinux[mtd]: probe address=0x%x size=0x%x\n", (int) mapp->phys, (int) mapp->size); /* @@ -82,7 +89,16 @@ static int __init uclinux_mtd_init(void) simple_map_init(mapp); - mtd = do_map_probe("map_ram", mapp); + mapp->name = "ROM"; + mtd = do_map_probe("map_rom", mapp); + if (!mtd) { + /* fall back to ram probing for compatibility reasons */ + mapp->name = "RAM"; + mtd = do_map_probe("map_ram", mapp); + if (mtd && IS_ENABLED(CONFIG_MTD_ROM)) + pr_err("Failed to map rom, but ram succeeded. Please report this issue!\n"); + } + if (!mtd) { printk("uclinux[mtd]: failed to find a mapping?\n"); return(-ENXIO); @@ -118,6 +134,6 @@ module_exit(uclinux_mtd_cleanup); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Greg Ungerer "); -MODULE_DESCRIPTION("Generic RAM based MTD for uClinux"); +MODULE_DESCRIPTION("Generic MTD for uClinux"); /****************************************************************************/