Read-only support.
This patch adds a new callback for the drivers to facilitate reading the SD card read-only switch. If the callback is not provided then a warning will be printed and it will default to write-enable.
The read-only switch is a host enforced read-only so the MMC block layer has been changed to not allow rw mounts of ro cards. It also prints a '(ro)' for read-only cards.
Index: linux-sd/include/linux/mmc/card.h =================================================================== --- linux-sd/include/linux/mmc/card.h (revision 137) +++ linux-sd/include/linux/mmc/card.h (working copy) @@ -48,6 +48,7 @@ #define MMC_STATE_DEAD (1<<1) /* device no longer in stack */ #define MMC_STATE_BAD (1<<2) /* unrecognised device */ #define MMC_STATE_SDCARD (1<<3) /* is an SD card */ +#define MMC_STATE_READONLY (1<<4) /* card is read-only */ u32 raw_cid[4]; /* raw card CID */ u32 raw_csd[4]; /* raw card CSD */ struct mmc_cid cid; /* card identification */ @@ -58,11 +59,13 @@ #define mmc_card_dead(c) ((c)->state & MMC_STATE_DEAD) #define mmc_card_bad(c) ((c)->state & MMC_STATE_BAD) #define mmc_card_sd(c) ((c)->state & MMC_STATE_SDCARD) +#define mmc_card_readonly(c) ((c)->state & MMC_STATE_READONLY) #define mmc_card_set_present(c) ((c)->state |= MMC_STATE_PRESENT) #define mmc_card_set_dead(c) ((c)->state |= MMC_STATE_DEAD) #define mmc_card_set_bad(c) ((c)->state |= MMC_STATE_BAD) #define mmc_card_set_sd(c) ((c)->state |= MMC_STATE_SDCARD) +#define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY) #define mmc_card_name(c) ((c)->cid.prod_name) #define mmc_card_id(c) ((c)->dev.bus_id) Index: linux-sd/include/linux/mmc/host.h =================================================================== --- linux-sd/include/linux/mmc/host.h (revision 137) +++ linux-sd/include/linux/mmc/host.h (working copy) @@ -56,6 +56,7 @@ struct mmc_host_ops { void (*request)(struct mmc_host *host, struct mmc_request *req); void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios); + int (*get_ro)(struct mmc_host *host); }; struct mmc_card; Index: linux-sd/drivers/mmc/mmc_block.c =================================================================== --- linux-sd/drivers/mmc/mmc_block.c (revision 135) +++ linux-sd/drivers/mmc/mmc_block.c (working copy) @@ -95,6 +95,10 @@ if (md->usage == 2) check_disk_change(inode->i_bdev); ret = 0; + + if ((filp->f_mode & FMODE_WRITE) && + mmc_card_readonly(md->queue.card)) + ret = -EROFS; } return ret; @@ -400,9 +404,10 @@ if (err) goto out; - printk(KERN_INFO "%s: %s %s %dKiB\n", + printk(KERN_INFO "%s: %s %s %dKiB %s\n", md->disk->disk_name, mmc_card_id(card), mmc_card_name(card), - (card->csd.capacity << card->csd.read_blkbits) / 1024); + (card->csd.capacity << card->csd.read_blkbits) / 1024, + mmc_card_readonly(card)?"(ro)":""); mmc_set_drvdata(card, md); add_disk(md->disk); Index: linux-sd/drivers/mmc/mmc.c =================================================================== --- linux-sd/drivers/mmc/mmc.c (revision 137) +++ linux-sd/drivers/mmc/mmc.c (working copy) @@ -726,8 +726,20 @@ err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES); if (err != MMC_ERR_NONE) mmc_card_set_dead(card); - else + else { card->rca = cmd.resp[0] >> 16; + + if (!host->ops->get_ro) { + printk(KERN_WARNING "%s: host does not " + "support reading read-only " + "switch. assuming write-enable.\n", + host->host_name); + } + else { + if (host->ops->get_ro(host)) + mmc_card_set_readonly(card); + } + } } else { cmd.opcode = MMC_SET_RELATIVE_ADDR;