From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: [PATCH v2 05/10] spi: Make support for regular transfers optional when ->mem_ops != NULL Date: Wed, 11 Apr 2018 00:44:34 +0200 Message-ID: <20180410224439.9260-6-boris.brezillon@bootlin.com> References: <20180410224439.9260-1-boris.brezillon@bootlin.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Yogesh Gaur , Vignesh R , Kamal Dasu , Maxime Chevallier , Peter Pan , Frieder Schrempf , =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Sourav Poddar To: David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , linux-mtd@lists.infradead.org, Miquel Raynal , Mark Brown , linux-spi@vger.kernel.org Return-path: In-Reply-To: <20180410224439.9260-1-boris.brezillon@bootlin.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+gldm-linux-mtd-36=gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org Some SPI/QuadSPI controllers only expose a high-level SPI memory interface, thus preventing any regular SPI transfers from being done. In that case, SPI controller drivers can leave all ->transfer_xxx() hooks empty and only implement the spi_mem_ops interface. Adjust the core to allow such situations: - extend spi_controller_check_ops() to accept situations where all ->transfer_xxx() pointers are NULL only if ->mem_ops != NULL - make sure we do not initialize the SPI message queue if ctlr->transfer_one and ctlr->transfer_one_message are missing - return -ENOTSUPP if someone tries to do a regular SPI transfer on a controller that does not support it Signed-off-by: Boris Brezillon --- drivers/spi/spi.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index d7e046128b3f..4961a5e91941 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -2069,12 +2070,19 @@ static int of_spi_register_master(struct spi_controller *ctlr) static int spi_controller_check_ops(struct spi_controller *ctlr) { /* - * The controller must at least implement one of the ->transfer() - * hooks. + * The controller may implement only the high-level SPI-memory like + * operations if it does not support regular SPI transfers, and this is + * valid use case. + * If ->mem_ops is NULL, we request that at least one of the + * ->transfer_xxx() method be implemented. */ - if (!ctlr->transfer && !ctlr->transfer_one && - !ctlr->transfer_one_message) + if (ctlr->mem_ops) { + if (!ctlr->mem_ops->exec_op) + return -EINVAL; + } else if (!ctlr->transfer && !ctlr->transfer_one && + !ctlr->transfer_one_message) { return -EINVAL; + } return 0; } @@ -2185,10 +2193,14 @@ int spi_register_controller(struct spi_controller *ctlr) spi_controller_is_slave(ctlr) ? "slave" : "master", dev_name(&ctlr->dev)); - /* If we're using a queued driver, start the queue */ - if (ctlr->transfer) + /* + * If we're using a queued driver, start the queue. Note that we don't + * need the queueing logic if the driver is only supporting high-level + * memory operations. + */ + if (ctlr->transfer) { dev_info(dev, "controller is unqueued, this is deprecated\n"); - else { + } else if (ctlr->transfer_one || ctlr->transfer_one_message) { status = spi_controller_initialize_queue(ctlr); if (status) { device_del(&ctlr->dev); @@ -2918,6 +2930,13 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; + /* + * Some controllers do not support doing regular SPI transfers. Return + * ENOTSUPP when this is the case. + */ + if (!ctlr->transfer) + return -ENOTSUPP; + message->spi = spi; SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async); -- 2.14.1 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.bootlin.com ([62.4.15.54]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1f620j-0006H9-MO for linux-mtd@lists.infradead.org; Tue, 10 Apr 2018 22:45:12 +0000 From: Boris Brezillon To: David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , linux-mtd@lists.infradead.org, Miquel Raynal , Mark Brown , linux-spi@vger.kernel.org Cc: Peter Pan , Frieder Schrempf , Vignesh R , Yogesh Gaur , =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= , Kamal Dasu , Sourav Poddar , Maxime Chevallier Subject: [PATCH v2 05/10] spi: Make support for regular transfers optional when ->mem_ops != NULL Date: Wed, 11 Apr 2018 00:44:34 +0200 Message-Id: <20180410224439.9260-6-boris.brezillon@bootlin.com> In-Reply-To: <20180410224439.9260-1-boris.brezillon@bootlin.com> References: <20180410224439.9260-1-boris.brezillon@bootlin.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Some SPI/QuadSPI controllers only expose a high-level SPI memory interface, thus preventing any regular SPI transfers from being done. In that case, SPI controller drivers can leave all ->transfer_xxx() hooks empty and only implement the spi_mem_ops interface. Adjust the core to allow such situations: - extend spi_controller_check_ops() to accept situations where all ->transfer_xxx() pointers are NULL only if ->mem_ops != NULL - make sure we do not initialize the SPI message queue if ctlr->transfer_one and ctlr->transfer_one_message are missing - return -ENOTSUPP if someone tries to do a regular SPI transfer on a controller that does not support it Signed-off-by: Boris Brezillon --- drivers/spi/spi.c | 33 ++++++++++++++++++++++++++------- 1 file changed, 26 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index d7e046128b3f..4961a5e91941 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include #include @@ -2069,12 +2070,19 @@ static int of_spi_register_master(struct spi_controller *ctlr) static int spi_controller_check_ops(struct spi_controller *ctlr) { /* - * The controller must at least implement one of the ->transfer() - * hooks. + * The controller may implement only the high-level SPI-memory like + * operations if it does not support regular SPI transfers, and this is + * valid use case. + * If ->mem_ops is NULL, we request that at least one of the + * ->transfer_xxx() method be implemented. */ - if (!ctlr->transfer && !ctlr->transfer_one && - !ctlr->transfer_one_message) + if (ctlr->mem_ops) { + if (!ctlr->mem_ops->exec_op) + return -EINVAL; + } else if (!ctlr->transfer && !ctlr->transfer_one && + !ctlr->transfer_one_message) { return -EINVAL; + } return 0; } @@ -2185,10 +2193,14 @@ int spi_register_controller(struct spi_controller *ctlr) spi_controller_is_slave(ctlr) ? "slave" : "master", dev_name(&ctlr->dev)); - /* If we're using a queued driver, start the queue */ - if (ctlr->transfer) + /* + * If we're using a queued driver, start the queue. Note that we don't + * need the queueing logic if the driver is only supporting high-level + * memory operations. + */ + if (ctlr->transfer) { dev_info(dev, "controller is unqueued, this is deprecated\n"); - else { + } else if (ctlr->transfer_one || ctlr->transfer_one_message) { status = spi_controller_initialize_queue(ctlr); if (status) { device_del(&ctlr->dev); @@ -2918,6 +2930,13 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; + /* + * Some controllers do not support doing regular SPI transfers. Return + * ENOTSUPP when this is the case. + */ + if (!ctlr->transfer) + return -ENOTSUPP; + message->spi = spi; SPI_STATISTICS_INCREMENT_FIELD(&ctlr->statistics, spi_async); -- 2.14.1