The patch titled spi: handle TX-only/RX-only has been added to the -mm tree. Its filename is spi-handle-tx-only-rx-only.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: spi: handle TX-only/RX-only From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx> Support two new half-duplex SPI implementation restrictions, for links that talk to TX-only or RX-only devices. (Existing half-duplex flavors support both transfer directions, just not at the same time.) Move spi_async() into the spi.c core, and stop inlining it. Then make that function perform error checks and reject messages that demand more than the underlying controller can support. Based on a patch from Marek Szyprowski which did this only for the bitbanged GPIO driver. Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/spi/spi.c | 59 ++++++++++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 39 +------------------------ 2 files changed, 62 insertions(+), 36 deletions(-) diff -puN drivers/spi/spi.c~spi-handle-tx-only-rx-only drivers/spi/spi.c --- a/drivers/spi/spi.c~spi-handle-tx-only-rx-only +++ a/drivers/spi/spi.c @@ -663,6 +663,65 @@ int spi_setup(struct spi_device *spi) } EXPORT_SYMBOL_GPL(spi_setup); +/** + * spi_async - asynchronous SPI transfer + * @spi: device with which data will be exchanged + * @message: describes the data transfers, including completion callback + * Context: any (irqs may be blocked, etc) + * + * This call may be used in_irq and other contexts which can't sleep, + * as well as from task contexts which can sleep. + * + * The completion callback is invoked in a context which can't sleep. + * Before that invocation, the value of message->status is undefined. + * When the callback is issued, message->status holds either zero (to + * indicate complete success) or a negative error code. After that + * callback returns, the driver which issued the transfer request may + * deallocate the associated memory; it's no longer in use by any SPI + * core or controller driver code. + * + * Note that although all messages to a spi_device are handled in + * FIFO order, messages may go to different devices in other orders. + * Some device might be higher priority, or have various "hard" access + * time requirements, for example. + * + * On detection of any fault during the transfer, processing of + * the entire message is aborted, and the device is deselected. + * Until returning from the associated message completion callback, + * no other spi_message queued to that device will be processed. + * (This rule applies equally to all the synchronous transfer calls, + * which are wrappers around this core asynchronous primitive.) + */ +int spi_async(struct spi_device *spi, struct spi_message *message) +{ + struct spi_master *master = spi->master; + + /* Half-duplex links include original MicroWire, and ones with + * only one data pin like SPI_3WIRE (switches direction) or where + * either MOSI or MISO is missing. They can also be caused by + * software limitations. + */ + if ((master->flags & SPI_MASTER_HALF_DUPLEX) + || (spi->mode & SPI_3WIRE)) { + struct spi_transfer *xfer; + unsigned flags = master->flags; + + list_for_each_entry(xfer, &message->transfers, transfer_list) { + if (xfer->rx_buf && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_MASTER_NO_TX) && xfer->tx_buf) + return -EINVAL; + if ((flags & SPI_MASTER_NO_RX) && xfer->rx_buf) + return -EINVAL; + } + } + + message->spi = spi; + message->status = -EINPROGRESS; + return master->transfer(spi, message); +} +EXPORT_SYMBOL_GPL(spi_async); + /*-------------------------------------------------------------------------*/ diff -puN include/linux/spi/spi.h~spi-handle-tx-only-rx-only include/linux/spi/spi.h --- a/include/linux/spi/spi.h~spi-handle-tx-only-rx-only +++ a/include/linux/spi/spi.h @@ -258,6 +258,8 @@ struct spi_master { /* other constraints relevant to this driver */ u16 flags; #define SPI_MASTER_HALF_DUPLEX BIT(0) /* can't do full duplex */ +#define SPI_MASTER_NO_RX BIT(1) /* can't do buffer read */ +#define SPI_MASTER_NO_TX BIT(2) /* can't do buffer write */ /* Setup mode and clock, etc (spi driver may call many times). * @@ -538,42 +540,7 @@ static inline void spi_message_free(stru } extern int spi_setup(struct spi_device *spi); - -/** - * spi_async - asynchronous SPI transfer - * @spi: device with which data will be exchanged - * @message: describes the data transfers, including completion callback - * Context: any (irqs may be blocked, etc) - * - * This call may be used in_irq and other contexts which can't sleep, - * as well as from task contexts which can sleep. - * - * The completion callback is invoked in a context which can't sleep. - * Before that invocation, the value of message->status is undefined. - * When the callback is issued, message->status holds either zero (to - * indicate complete success) or a negative error code. After that - * callback returns, the driver which issued the transfer request may - * deallocate the associated memory; it's no longer in use by any SPI - * core or controller driver code. - * - * Note that although all messages to a spi_device are handled in - * FIFO order, messages may go to different devices in other orders. - * Some device might be higher priority, or have various "hard" access - * time requirements, for example. - * - * On detection of any fault during the transfer, processing of - * the entire message is aborted, and the device is deselected. - * Until returning from the associated message completion callback, - * no other spi_message queued to that device will be processed. - * (This rule applies equally to all the synchronous transfer calls, - * which are wrappers around this core asynchronous primitive.) - */ -static inline int -spi_async(struct spi_device *spi, struct spi_message *message) -{ - message->spi = spi; - return spi->master->transfer(spi, message); -} +extern int spi_async(struct spi_device *spi, struct spi_message *message); /*---------------------------------------------------------------------------*/ _ Patches currently in -mm which might be from dbrownell@xxxxxxxxxxxxxxxxxxxxx are linux-next.patch mtd-nand-add-page-parameter-to-all-read_page-read_page_raw-apis.patch mtd-nand-add-new-ecc-mode-ecc_hw_oob_first.patch mtd-nand-davinci-add-4-bit-ecc-support-for-large-page-nand-chips.patch mtd-nand-davinci-add-4-bit-ecc-support-for-large-page-nand-chips-update.patch mmc-register-mmci-omap-hs-using-platform_driver_probe.patch spi-omap2_mcspi-use-bitn.patch spi-add-spi_ppc4xx-driver.patch spih-add-missing-kernel-doc-for-struct-spi_master.patch spi-add-default-selection-of-pl022-for-arm-reference-platforms.patch spi-add-support-for-device-table-matching.patch mtd-m25p80-convert-to-device-table-matching.patch of-remove-stmm25p40-alias.patch hwmon-adxx-convert-to-device-table-matching.patch hwmon-lm70-convert-to-device-table-matching.patch spi-prefix-modalias-with-spi.patch pxa2xx_spi-register-earlier.patch spi-freescale-stmp-driver.patch spi-mcspi-off-mode-support.patch spi-mcspi-saves-chconfx-too.patch spi-mcspi-support-for-omap4.patch spi-handle-tx-only-rx-only.patch rtc-at91rm9200-fixes.patch rtc-set-wakeup-capability-for-i2c-and-spi-rtc-drivers.patch gpiolib-add-names-file-in-gpio-chip-sysfs.patch gpiolib-add-names-file-in-gpio-chip-sysfs-checkpatch-fixes.patch gpiolib-add-names-file-in-gpio-chip-sysfs-checkpatch-fixes-fix.patch gpiolib-allow-poll-on-value.patch omapfb-add-support-for-the-2430sdp-lcd.patch omapfb-add-support-for-the-omap2evm-lcd.patch omapfb-add-support-for-the-omap3-evm-lcd.patch omapfb-add-support-for-the-omap3-beagle-dvi-output.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html