From patchwork Fri Mar 14 11:36:01 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleksij Rempel X-Patchwork-Id: 873724 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 630841FE455 for ; Fri, 14 Mar 2025 11:36:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741952187; cv=none; b=D6fPF5lwNm0vNj3HDuNphVnrPYdxTMeg6+KXxRE7Zss166D2lmetocI1baNv77aEB7ClpBYZQcYyqdt8rbpeWV5f4Qdb5kAiQXa6m8H1XA6LxNBM/Ymm5h8ENXnZWMBSo/vzYDk2TN9GKnlSYtDSMiRQ1UsjZClIbClvSyGGAXs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741952187; c=relaxed/simple; bh=uUmYJxs95mrM4B2aqNw/3s0vKcVGkdJCqAA4sx9f114=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cAbJtbfLu8hPHBls8j/s+QsK3B+JR4Ore3X8GLOYI9K0CGqRNCxDGCj4hw0eJ8ujI/jPITykop2ArvhsmRMvvotWphZTFccdnxL+gzpRf+Fc0MJDa8dtxPhx3mcqZlK5ZCDqc78x6GxZUcLEekL85iMjPaoQwl8Orr0QoZxtvuY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tt3Kg-0007Nc-QD; Fri, 14 Mar 2025 12:36:06 +0100 Received: from dude04.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::ac]) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tt3Kf-005h5t-25; Fri, 14 Mar 2025 12:36:05 +0100 Received: from ore by dude04.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1tt3Kf-007S6Y-1o; Fri, 14 Mar 2025 12:36:05 +0100 From: Oleksij Rempel To: Sebastian Reichel , Srinivas Kandagatla , Benson Leung , Tzung-Bi Shih , Daniel Lezcano Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, Liam Girdwood , Mark Brown , "Rafael J. Wysocki" , Zhang Rui , Lukasz Luba , linux-pm@vger.kernel.org, =?utf-8?q?S=C3=B8ren_Andersen?= , Guenter Roeck , Matti Vaittinen , Ahmad Fatoum , Andrew Morton , chrome-platform@lists.linux.dev Subject: [PATCH v6 4/7] nvmem: provide consumer access to cell size metrics Date: Fri, 14 Mar 2025 12:36:01 +0100 Message-Id: <20250314113604.1776201-5-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250314113604.1776201-1-o.rempel@pengutronix.de> References: <20250314113604.1776201-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-pm@vger.kernel.org Add nvmem_cell_get_size() function to provide access to cell size metrics. In some cases we may get cell size less as consumer would expect it. So, nvmem_cell_write() would fail with incorrect buffer size. Signed-off-by: Oleksij Rempel --- changes v6: - update function comment for nvmem_cell_get_size() --- drivers/nvmem/core.c | 29 +++++++++++++++++++++++++++++ include/linux/nvmem-consumer.h | 7 +++++++ 2 files changed, 36 insertions(+) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index fff85bbf0ecd..754a9448c39d 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -1828,6 +1828,35 @@ int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len) EXPORT_SYMBOL_GPL(nvmem_cell_write); +/** + * nvmem_cell_get_size() - Retrieve the storage size of an NVMEM cell. + * @cell: Pointer to the NVMEM cell structure. + * @bytes: Optional pointer to store the cell size in bytes (can be NULL). + * @bits: Optional pointer to store the cell size in bits (can be NULL). + * + * This function allows consumers to retrieve the size of a specific NVMEM + * cell before performing read/write operations. It is useful for validating + * buffer sizes to prevent mismatched writes. + * + * Return: 0 on success or negative on failure. + */ +int nvmem_cell_get_size(struct nvmem_cell *cell, size_t *bytes, size_t *bits) +{ + struct nvmem_cell_entry *entry = cell->entry; + + if (!entry->nvmem) + return -EINVAL; + + if (bytes) + *bytes = entry->bytes; + + if (bits) + *bits = entry->nbits; + + return 0; +} +EXPORT_SYMBOL_GPL(nvmem_cell_get_size); + static int nvmem_cell_read_common(struct device *dev, const char *cell_id, void *val, size_t count) { diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h index 34c0e58dfa26..bcb0e17e415d 100644 --- a/include/linux/nvmem-consumer.h +++ b/include/linux/nvmem-consumer.h @@ -56,6 +56,7 @@ void nvmem_cell_put(struct nvmem_cell *cell); void devm_nvmem_cell_put(struct device *dev, struct nvmem_cell *cell); void *nvmem_cell_read(struct nvmem_cell *cell, size_t *len); int nvmem_cell_write(struct nvmem_cell *cell, void *buf, size_t len); +int nvmem_cell_get_size(struct nvmem_cell *cell, size_t *bytes, size_t *bits); int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val); int nvmem_cell_read_u16(struct device *dev, const char *cell_id, u16 *val); int nvmem_cell_read_u32(struct device *dev, const char *cell_id, u32 *val); @@ -128,6 +129,12 @@ static inline int nvmem_cell_write(struct nvmem_cell *cell, return -EOPNOTSUPP; } +static inline int nvmem_cell_get_size(struct nvmem_cell *cell, size_t *bytes, + size_t *bits) +{ + return -EOPNOTSUPP; +} + static inline int nvmem_cell_read_u8(struct device *dev, const char *cell_id, u8 *val) {