From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0E500C433ED for ; Tue, 18 May 2021 14:13:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E63726117A for ; Tue, 18 May 2021 14:13:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349847AbhEROOX (ORCPT ); Tue, 18 May 2021 10:14:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349872AbhEROOQ (ORCPT ); Tue, 18 May 2021 10:14:16 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 960A3C06175F; Tue, 18 May 2021 07:12:58 -0700 (PDT) Received: from localhost (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: bbrezillon) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id 58D541F42A10; Tue, 18 May 2021 15:12:56 +0100 (BST) Date: Tue, 18 May 2021 16:12:52 +0200 From: Boris Brezillon To: Cc: Mark Brown , Miquel Raynal , Vignesh Raghavendra , , Alexandre Torgue , , , , , Subject: Re: [PATCH v4 1/3] spi: spi-mem: add automatic poll status functions Message-ID: <20210518161252.3e4f2999@collabora.com> In-Reply-To: <20210518134332.17826-2-patrice.chotard@foss.st.com> References: <20210518134332.17826-1-patrice.chotard@foss.st.com> <20210518134332.17826-2-patrice.chotard@foss.st.com> Organization: Collabora X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 May 2021 15:43:30 +0200 wrote: > From: Patrice Chotard > > With STM32 QSPI, it is possible to poll the status register of the device. > This could be done to offload the CPU during an operation (erase or > program a SPI NAND for example). > > spi_mem_poll_status API has been added to handle this feature. > This new function take care of the offload/non-offload cases. > > For the non-offload case, use read_poll_timeout() to poll the status in > order to release CPU during this phase. > For example, previously, when erasing large area, in non-offload case, > CPU load can reach ~50%, now it decrease to ~35%. > > Signed-off-by: Patrice Chotard > Signed-off-by: Christophe Kerello > --- > Changes in v4: > - Remove init_completion() from spi_mem_probe() added in v2. > - Add missing static for spi_mem_read_status(). > - Check if operation in spi_mem_poll_status() is a READ. > > Changes in v3: > - Add spi_mem_read_status() which allows to read 8 or 16 bits status. > - Add initial_delay_us and polling_delay_us parameters to spi_mem_poll_status() > and also to poll_status() callback. > - Move spi_mem_supports_op() in SW-based polling case. > - Add delay before invoking read_poll_timeout(). > - Remove the reinit/wait_for_completion() added in v2. > > Changes in v2: > - Indicates the spi_mem_poll_status() timeout unit > - Use 2-byte wide status register > - Add spi_mem_supports_op() call in spi_mem_poll_status() > - Add completion management in spi_mem_poll_status() > - Add offload/non-offload case management in spi_mem_poll_status() > - Optimize the non-offload case by using read_poll_timeout() > > drivers/spi/spi-mem.c | 85 +++++++++++++++++++++++++++++++++++++ > include/linux/spi/spi-mem.h | 14 ++++++ > 2 files changed, 99 insertions(+) > > diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c > index 1513553e4080..97c7a83686c7 100644 > --- a/drivers/spi/spi-mem.c > +++ b/drivers/spi/spi-mem.c > @@ -6,6 +6,7 @@ > * Author: Boris Brezillon > */ > #include > +#include > #include > #include > #include > @@ -743,6 +744,90 @@ static inline struct spi_mem_driver *to_spi_mem_drv(struct device_driver *drv) > return container_of(drv, struct spi_mem_driver, spidrv.driver); > } > > +static int spi_mem_read_status(struct spi_mem *mem, > + const struct spi_mem_op *op, > + u16 *status) > +{ > + const u8 *bytes = (u8 *)op->data.buf.in; > + int ret; > + > + ret = spi_mem_exec_op(mem, op); > + if (ret) > + return ret; > + > + if (op->data.nbytes > 1) > + *status = ((u16)bytes[0] << 8) | bytes[1]; > + else > + *status = bytes[0]; > + > + return 0; > +} > + > +/** > + * spi_mem_poll_status() - Poll memory device status > + * @mem: SPI memory device > + * @op: the memory operation to execute > + * @mask: status bitmask to ckeck > + * @match: (status & mask) expected value > + * @initial_delay_us: delay in us before starting to poll > + * @polling_delay_us: time to sleep between reads in us > + * @timeout_ms: timeout in milliseconds > + * > + * This function send a polling status request to the controller driver " This function polls a status register and returns when (status & mask) == match or when the timeout has expired. " > + * > + * Return: 0 in case of success, -ETIMEDOUT in case of error, > + * -EOPNOTSUPP if not supported. > + */ > +int spi_mem_poll_status(struct spi_mem *mem, > + const struct spi_mem_op *op, > + u16 mask, u16 match, > + unsigned long initial_delay_us, > + unsigned long polling_delay_us, > + u16 timeout_ms) > +{ > + struct spi_controller *ctlr = mem->spi->controller; > + int ret = -EOPNOTSUPP; > + int read_status_ret; > + u16 status; > + > + if (op->data.nbytes < 1 || op->data.nbytes > 2 || > + op->data.dir != SPI_MEM_DATA_IN) > + return (-EINVAL); s/return (-EINVAL);/return -EINVAL;/ [...] > /** > @@ -369,6 +376,13 @@ devm_spi_mem_dirmap_create(struct device *dev, struct spi_mem *mem, > void devm_spi_mem_dirmap_destroy(struct device *dev, > struct spi_mem_dirmap_desc *desc); > > +int spi_mem_poll_status(struct spi_mem *mem, > + const struct spi_mem_op *op, > + u16 mask, u16 match, > + unsigned long initial_delay_us, > + unsigned long polling_delay_us, > + u16 timeout); s/timeout/timeout_ms/. With those minor things fixed Reviewed-by: Boris Brezillon > + > int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv, > struct module *owner); >