682696605c
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 <ulf.hansson@linaro.org> Tested-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org>
44 lines
1.2 KiB
C
44 lines
1.2 KiB
C
/*
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* linux/drivers/mmc/sdio_ops.c
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*
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* Copyright 2006-2007 Pierre Ossman
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or (at
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* your option) any later version.
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*/
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#ifndef _MMC_SDIO_OPS_H
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#define _MMC_SDIO_OPS_H
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#include <linux/types.h>
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#include <linux/mmc/sdio.h>
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struct mmc_host;
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struct mmc_card;
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struct work_struct;
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int mmc_send_io_op_cond(struct mmc_host *host, u32 ocr, u32 *rocr);
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int mmc_io_rw_direct(struct mmc_card *card, int write, unsigned fn,
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unsigned addr, u8 in, u8* out);
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int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
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unsigned addr, int incr_addr, u8 *buf, unsigned blocks, unsigned blksz);
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int sdio_reset(struct mmc_host *host);
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unsigned int mmc_align_data_size(struct mmc_card *card, unsigned int sz);
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void sdio_irq_work(struct work_struct *work);
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static inline bool sdio_is_io_busy(u32 opcode, u32 arg)
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{
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u32 addr;
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addr = (arg >> 9) & 0x1FFFF;
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return (opcode == SD_IO_RW_EXTENDED ||
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(opcode == SD_IO_RW_DIRECT &&
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!(addr == SDIO_CCCR_ABORT || addr == SDIO_CCCR_SUSPEND)));
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}
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#endif
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