From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757979Ab0CPUnX (ORCPT ); Tue, 16 Mar 2010 16:43:23 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:36947 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752915Ab0CPUnW (ORCPT ); Tue, 16 Mar 2010 16:43:22 -0400 From: Kevin Hilman To: linux-mtd@lists.infradead.org Cc: Sudhakar Rajashekhara , David Brownell , David Woodhouse , Andrew Morton , Bernd Schmidt , David Howells , David Brownell , Nicolas Pitre , Kevin Hilman , linux-kernel@vger.kernel.org Subject: [PATCH 1/2] mtdpart: memory accessor interface for MTD layer Date: Tue, 16 Mar 2010 13:41:19 -0700 Message-Id: <1268772081-6534-1-git-send-email-khilman@deeprootsystems.com> X-Mailer: git-send-email 1.7.0.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sudhakar Rajashekhara This patch implements memory accessor interface in the MTD layer which enables the kernel to access flash data. This patch adds two new members to the mtd_partition structure, a function handler which will be called during setup of the partition and an argument to be passed to this setup function. Example: +static struct mtd_partition spi_flash_partitions[] = { + [0] = { + .name = "U-Boot", + .offset = 0, + .size = SZ_256K, + .mask_flags = MTD_WRITEABLE, + }, + [1] = { + .name = "U-Boot Environment", + .offset = MTDPART_OFS_NXTBLK, + .size = SZ_64K, + .mask_flags = MTD_WRITEABLE, + }, + [2] = { + .name = "Linux", + .offset = MTDPART_OFS_NXTBLK, + .size = SZ_7M, + .mask_flags = 0, + }, + [3] = { + .name = "MAC Address", + .offset = MTDPART_OFS_NXTBLK, + .size = SZ_64K, + .mask_flags = 0, + .setup = davinci_get_mac_addr, + .context = (void *)0, + }, +}; The davinci_get_mac_addr function reads the MAC address from offset ZERO of last MTD partition. Signed-off-by: Sudhakar Rajashekhara Acked-by: Kevin Hilman Cc: David Brownell Cc: David Woodhouse Signed-off-by: Andrew Morton --- I thought this had made it to -mm, but was dropped waiting for subsystem maintainer to pick it up. Here it is againg for 2.6.35. drivers/mtd/mtdpart.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/partitions.h | 3 +++ 2 files changed, 43 insertions(+), 0 deletions(-) diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c index b8043a9..9f4d5f8 100644 --- a/drivers/mtd/mtdpart.c +++ b/drivers/mtd/mtdpart.c @@ -26,6 +26,7 @@ static LIST_HEAD(mtd_partitions); struct mtd_part { struct mtd_info mtd; struct mtd_info *master; + struct memory_accessor macc; uint64_t offset; struct list_head list; }; @@ -327,6 +328,39 @@ int del_mtd_partitions(struct mtd_info *master) } EXPORT_SYMBOL(del_mtd_partitions); +/* + * This lets other kernel code access the flash data. For example, it + * might hold a board's Ethernet address, or board-specific calibration + * data generated on the manufacturing floor. + */ +static ssize_t mtd_macc_read(struct memory_accessor *macc, char *buf, + off_t offset, size_t count) +{ + struct mtd_part *part = container_of(macc, struct mtd_part, macc); + ssize_t ret = -EIO; + size_t retlen; + + if (part_read((struct mtd_info *)part, offset, count, + &retlen, buf) == 0) + ret = retlen; + + return ret; +} + +static ssize_t mtd_macc_write(struct memory_accessor *macc, const char *buf, + off_t offset, size_t count) +{ + struct mtd_part *part = container_of(macc, struct mtd_part, macc); + ssize_t ret = -EIO; + size_t retlen; + + if (part_write((struct mtd_info *)part, offset, count, + &retlen, buf) == 0) + ret = retlen; + + return ret; +} + static struct mtd_part *add_one_partition(struct mtd_info *master, const struct mtd_partition *part, int partno, uint64_t cur_offset) @@ -364,6 +398,9 @@ static struct mtd_part *add_one_partition(struct mtd_info *master, slave->mtd.read = part_read; slave->mtd.write = part_write; + slave->macc.read = mtd_macc_read; + slave->macc.write = mtd_macc_write; + if (master->panic_write) slave->mtd.panic_write = part_panic_write; @@ -428,6 +465,9 @@ static struct mtd_part *add_one_partition(struct mtd_info *master, printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset, (unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name); + if (part->setup) + part->setup(&slave->macc, (void *)part->context); + /* let's do some sanity checks */ if (slave->offset >= master->size) { /* let's register it anyway to preserve ordering */ diff --git a/include/linux/mtd/partitions.h b/include/linux/mtd/partitions.h index 274b619..39782a6 100644 --- a/include/linux/mtd/partitions.h +++ b/include/linux/mtd/partitions.h @@ -10,6 +10,7 @@ #define MTD_PARTITIONS_H #include +#include /* @@ -40,6 +41,8 @@ struct mtd_partition { uint64_t offset; /* offset within the master MTD space */ uint32_t mask_flags; /* master MTD flags to mask out for this partition */ struct nand_ecclayout *ecclayout; /* out of band layout for this partition (NAND only)*/ + void (*setup)(struct memory_accessor *, void *context); + void *context; }; #define MTDPART_OFS_NXTBLK (-2) -- 1.7.0.2