From 28f52482b41edc88cdf575aa6ed414c6e116ce10 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 17 Jun 2008 18:17:15 +0400 Subject: mmc: add support for card-detection polling Some hosts (and boards that use mmc_spi) do not use interrupts on the CD line, so they can't trigger mmc_detect_change. We want to poll the card and see if there was a change. 1 second poll interval seems resonable. This patch also implements .get_cd() host operation, that could be used by the hosts that are able to report card-detect status without need to talk MMC. Signed-off-by: Anton Vorontsov Signed-off-by: Pierre Ossman --- include/linux/mmc/host.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'include/linux/mmc/host.h') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 7ab962fa1d73..6188e19d2331 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -51,8 +51,18 @@ struct mmc_ios { struct mmc_host_ops { void (*request)(struct mmc_host *host, struct mmc_request *req); + /* + * Avoid calling these three functions too often or in a "fast path", + * since underlaying controller might implement them in an expensive + * and/or slow way. + * + * Also note that these functions might sleep, so don't call them + * in the atomic contexts! + */ void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios); int (*get_ro)(struct mmc_host *host); + int (*get_cd)(struct mmc_host *host); + void (*enable_sdio_irq)(struct mmc_host *host, int enable); }; @@ -94,6 +104,7 @@ struct mmc_host { #define MMC_CAP_SD_HIGHSPEED (1 << 3) /* Can do SD high-speed timing */ #define MMC_CAP_SDIO_IRQ (1 << 4) /* Can signal pending SDIO IRQs */ #define MMC_CAP_SPI (1 << 5) /* Talks only SPI protocols */ +#define MMC_CAP_NEEDS_POLL (1 << 6) /* Needs polling for card-detection */ /* host specific block data */ unsigned int max_seg_size; /* see blk_queue_max_segment_size */ -- cgit v1.2.3 From 08f80bb5196517a0dfe50dc7c10f234c0ff2f0e8 Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Tue, 17 Jun 2008 18:17:39 +0400 Subject: mmc: change .get_ro() callback semantics Now get_ro() callback must return 0/1 values for its logical states, and negative errno values in case of error. If particular host instance doesn't support RO/WP switch, it should return -ENOSYS. This patch changes some hosts in two ways: 1. Now functions should be smart to not return negative values in "RO asserted" case (particularly gpio_ calls could return negative values for the outermost GPIOs). Also, board code usually passes get_ro() callbacks that directly return gpioreg & bit result, so at91_mci, imxmmc, pxamci and mmc_spi's get_ro() handlers need take special care when returning platform's values to the mmc core. 2. In case of host instance didn't implement get_ro() callback, it should really return -ENOSYS and let the mmc core decide what to do about it (mmc core thinks the same way as the hosts, so it isn't functional change). Signed-off-by: Anton Vorontsov Signed-off-by: Pierre Ossman --- include/linux/mmc/host.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/linux/mmc/host.h') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 6188e19d2331..753b7231b887 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -58,6 +58,18 @@ struct mmc_host_ops { * * Also note that these functions might sleep, so don't call them * in the atomic contexts! + * + * Return values for the get_ro callback should be: + * 0 for a read/write card + * 1 for a read-only card + * -ENOSYS when not supported (equal to NULL callback) + * or a negative errno value when something bad happened + * + * Return values for the get_ro callback should be: + * 0 for a absent card + * 1 for a present card + * -ENOSYS when not supported (equal to NULL callback) + * or a negative errno value when something bad happened */ void (*set_ios)(struct mmc_host *host, struct mmc_ios *ios); int (*get_ro)(struct mmc_host *host); -- cgit v1.2.3 From 23af60398af2f5033e2f53665538a09f498dbc03 Mon Sep 17 00:00:00 2001 From: Pierre Ossman Date: Sun, 6 Jul 2008 01:10:27 +0200 Subject: mmc: remove multiwrite capability Relax requirements on host controllers and only require that they do not report a transfer count than is larger than the actual one (i.e. a lower value is okay). This is how many other parts of the kernel behaves so upper layers should already be prepared to handle that scenario. This gives us a performance boost on MMC cards. Signed-off-by: Pierre Ossman --- include/linux/mmc/host.h | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) (limited to 'include/linux/mmc/host.h') diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 753b7231b887..10a2080086ca 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -111,12 +111,11 @@ struct mmc_host { unsigned long caps; /* Host capabilities */ #define MMC_CAP_4_BIT_DATA (1 << 0) /* Can the host do 4 bit transfers */ -#define MMC_CAP_MULTIWRITE (1 << 1) /* Can accurately report bytes sent to card on error */ -#define MMC_CAP_MMC_HIGHSPEED (1 << 2) /* Can do MMC high-speed timing */ -#define MMC_CAP_SD_HIGHSPEED (1 << 3) /* Can do SD high-speed timing */ -#define MMC_CAP_SDIO_IRQ (1 << 4) /* Can signal pending SDIO IRQs */ -#define MMC_CAP_SPI (1 << 5) /* Talks only SPI protocols */ -#define MMC_CAP_NEEDS_POLL (1 << 6) /* Needs polling for card-detection */ +#define MMC_CAP_MMC_HIGHSPEED (1 << 1) /* Can do MMC high-speed timing */ +#define MMC_CAP_SD_HIGHSPEED (1 << 2) /* Can do SD high-speed timing */ +#define MMC_CAP_SDIO_IRQ (1 << 3) /* Can signal pending SDIO IRQs */ +#define MMC_CAP_SPI (1 << 4) /* Talks only SPI protocols */ +#define MMC_CAP_NEEDS_POLL (1 << 5) /* Needs polling for card-detection */ /* host specific block data */ unsigned int max_seg_size; /* see blk_queue_max_segment_size */ -- cgit v1.2.3