kernel/linux.git/drivers/mmc/core/sdio_ops.h, branch linux-4.16.y

mmc: sdio: Add API to manage SDIO IRQs from a workqueue

2017-06-20T08:30:11+00:00

For hosts not supporting MMC_CAP2_SDIO_IRQ_NOTHREAD but MMC_CAP_SDIO_IRQ, the SDIO IRQs are processed from a dedicated kernel thread. For these cases, the host calls mmc_signal_sdio_irq() from its ISR to signal a new SDIO IRQ. Signaling an SDIO IRQ makes the host's ->enable_sdio_irq() callback to be invoked to temporary disable the IRQs, before the kernel thread is woken up to process it. When processing of the IRQs are completed, they are re-enabled by the kernel thread, again via invoking the host's ->enable_sdio_irq(). The observation from this, is that the execution path is being unnecessary complex, as the host driver already knows that it needs to temporary disable the IRQs before signaling a new one. Moreover, replacing the kernel thread with a work/workqueue would not only greatly simplify the code, but also make it more robust. To address the above problems, let's continue to build upon the support for MMC_CAP2_SDIO_IRQ_NOTHREAD, as it already implements SDIO IRQs to be processed without using the clumsy kernel thread and without the ping-pong calls of the host's ->enable_sdio_irq() callback for each processed IRQ. Therefore, let's add new API sdio_signal_irq(), which enables hosts to signal/process SDIO IRQs by using a work/workqueue, rather than using the kernel thread. Add also a new host callback ->ack_sdio_irq(), which the work invokes when the SDIO IRQs have been processed. This informs the host about when it shall re-enable the SDIO IRQs. Potentially, we could re-use the existing ->enable_sdio_irq() callback instead of adding a new one, however it has turned out that it's more convenient for hosts to get this information via a separate callback. Hosts that wants to use this new method to signal/process SDIO IRQs, must enable MMC_CAP2_SDIO_IRQ_NOTHREAD and implement the ->ack_sdio_irq() callback. Signed-off-by: Ulf Hansson Tested-by: Douglas Anderson Reviewed-by: Douglas Anderson

mmc: sdio: Fix sdio wait busy implement limitation

2017-04-24T19:45:09+00:00

The host may issue an I/O abort by writing to the CCCR at any time during I/O read operation via CMD52. And host may need suspend transcation during write busy stage in SDIO suspend/resume scenario. >From other side, a card may accept CMD52 during data transfer phase. Previous implement would block issuing above command in busy stage. It cause function driver can't implement as proper way and has no opportunity to do some coverage in error case via I/O abort etc. We need bypass some necessary operation during busy check stage. Signed-off-by: Jiajie Hao Signed-off-by: Ulf Hansson

mmc: core: Move public functions from core.h to private headers

2017-02-13T12:20:21+00:00

A significant amount of functions are available through the public mmc core.h header file. Let's slim down this public mmc interface, as to prevent users from abusing it, by moving some of the functions to private mmc header files. This change concentrates on moving the functions into private mmc headers, following changes may continue with additional clean-ups, as an example some functions can be turned into static. Signed-off-by: Ulf Hansson Reviewed-by: Linus Walleij Reviewed-by: Shawn Lin

mmc: core: First step in cleaning up private mmc header files

2017-02-13T12:20:20+00:00

This is the first step in cleaning up the private mmc header files. In this change we makes sure each header file builds standalone, as that helps to resolve dependencies. While changing this, it also seems reasonable to stop including other headers from inside a header itself which it don't depend upon. Additionally, in some cases such dependencies are better resolved by forward declaring the needed struct. Signed-off-by: Ulf Hansson Reviewed-by: Shawn Lin

mmc: Add mmc_is_io_op helper function

2015-10-26T15:00:01+00:00

Add a helper function to check if an opcode is a sd-io-rw-* opcode. Signed-off-by: Hans de Goede Signed-off-by: Ulf Hansson

sdio: recognize io card without powercycle

2010-03-12T23:52:28+00:00

SDIO Simplified Specification V2.00 states that it is strongly recommended that the host executes either a power reset or issues a CMD52 (I/O Reset) to re-initialize an I/O only card or the I/O portion of a combo card. Additionally, the CMD52 must be issued first because it cannot be issued after a CMD0. With this patch the Nintendo Wii SDIO-based WLAN card is detected after a system reset, without requiring a complete system powercycle. Signed-off-by: Albert Herranz Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sdio: extend sdio_readsb() and friends to handle any length of buffer

2007-09-23T19:21:32+00:00

Extend sdio_readsb(), sdio_writesb(), sdio_memcpy_fromio(), and sdio_memcpy_toio() to handle any length of buffer by splitting the transfer into several IO_RW_EXTENDED commands. Typically, a transfer would be split into a single block mode transfer followed by a byte mode transfer for the remainder but we also handle lack of block mode support and the block size being greater than 512 (the maximum byte mode transfer size). host->max_seg_size <= host->max_req_size so there's no need to check both when determining the maximum data size for a single command. Signed-off-by: David Vrabel Signed-off-by: Pierre Ossman

sdio: support IO_RW_EXTENDED

2007-09-23T19:09:34+00:00

Support the multi-byte transfer operation, including handlers for common operations like writel()/readl(). Signed-off-by: Pierre Ossman

mmc: implement SDIO IO_RW_DIRECT operation

2007-09-23T17:42:37+00:00

Signed-off-by: Pierre Ossman

mmc: detect SDIO cards

2007-09-23T17:40:07+00:00

Really basic init sequence for SDIO cards. Signed-off-by: Pierre Ossman