From nobody Tue Dec 23 14:30:02 2025 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 02CF4268C40 for ; Wed, 9 Apr 2025 14:43:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744209810; cv=none; b=hMHLrvhjmXw/WOv7xCOXAg7sXk6owDGPBpm/DlFCEV7yAHx0lb04Pb9fTfKb1vn4Gj0i9YvMeCkcFi8oLFsgkl75Lpx1mYholsyhqQmMh+xIWji3wTjj33gP/nvejTV6FmF0YutCY5s8Wbj63yA9D5RTTzX9doNjAJq4Kvhwcf0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744209810; c=relaxed/simple; bh=kQ9GHfesH0VP3UbX5nxEs6wOWpoqClYTSG7LdtlBlS8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VI1jtvPyGfJaLIho8ZQCCZ4LXsh5q9kjvG3arCrqv71skK5F4sBawSHNgXIP7IXr6giJhO3d+Sz750iWQ0Vd2X02VZRhinJcijdzgaZDuWJ/zq2lWpMpzmBpcqVLUXbKHElDjleljMOyFkBiGimEotDWcWgRqsJeh8Itp0GsIdY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=LKiJS8zn; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="LKiJS8zn" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1744209808; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wcivbUEWC4kBHEWoC8mH97RWcHUUu64DZ8iwYH5064E=; b=LKiJS8zn9FgsjKMqfYQbDBVyWvGtXRqVMjVjdeNC8WfiO2FZ5KSiKImFzN/tW1ZgCrjU1I jqZAC6W2KhyWDlUVGklTWlJN4dKl9xgcSRdFmMRVaZqz0ELyTFRuNVKv2BL4R0XDutpETy DsvzcpI04JfBTXuyIJkvXVGeIxUgArM= Received: from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-695-B_um9ZZTMveArSVeNO6W7A-1; Wed, 09 Apr 2025 10:43:23 -0400 X-MC-Unique: B_um9ZZTMveArSVeNO6W7A-1 X-Mimecast-MFC-AGG-ID: B_um9ZZTMveArSVeNO6W7A_1744209801 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8CDBA18007E1; Wed, 9 Apr 2025 14:43:21 +0000 (UTC) Received: from p16v.luc.cera.cz (unknown [10.44.32.72]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id F3BFD18009BC; Wed, 9 Apr 2025 14:43:16 +0000 (UTC) From: Ivan Vecera To: netdev@vger.kernel.org Cc: Vadim Fedorenko , Arkadiusz Kubalewski , Jiri Pirko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Prathosh Satish , Lee Jones , Kees Cook , Andy Shevchenko , Andrew Morton , Michal Schmidt , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v2 05/14] mfd: zl3073x: Add register access helpers Date: Wed, 9 Apr 2025 16:42:41 +0200 Message-ID: <20250409144250.206590-6-ivecera@redhat.com> In-Reply-To: <20250409144250.206590-1-ivecera@redhat.com> References: <20250409144250.206590-1-ivecera@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Content-Type: text/plain; charset="utf-8" Add helpers zl3073x_{read,write}_reg() to access device registers. These functions have to be called with device lock that can be taken by zl3073x_{lock,unlock}() or a caller can use defined guard. Locking mechanism of regmap is not sufficient because sometimes is necessary to perform several register operations at once. This is especially a case of register mailboxes (more details in patch 7 & 8). Disable regmap locking mechanism and use this device lock instead. Signed-off-by: Ivan Vecera --- v1->v2: * disabled regmap locking --- drivers/mfd/zl3073x-core.c | 90 +++++++++++++++++++++++++++++++++++++ include/linux/mfd/zl3073x.h | 33 ++++++++++++++ 2 files changed, 123 insertions(+) diff --git a/drivers/mfd/zl3073x-core.c b/drivers/mfd/zl3073x-core.c index 116c6dd9eebc7..f0d85f77a7a76 100644 --- a/drivers/mfd/zl3073x-core.c +++ b/drivers/mfd/zl3073x-core.c @@ -5,9 +5,11 @@ #include #include #include +#include #include #include #include +#include #include #include "zl3073x.h" =20 @@ -46,6 +48,7 @@ const struct regmap_config zl3073x_regmap_config =3D { .max_register =3D ZL3073x_NUM_PAGES * ZL3073x_PAGE_SIZE, .ranges =3D zl3073x_regmap_ranges, .num_ranges =3D ARRAY_SIZE(zl3073x_regmap_ranges), + .disable_locking =3D true, }; =20 /** @@ -59,6 +62,93 @@ const struct regmap_config *zl3073x_get_regmap_config(vo= id) } EXPORT_SYMBOL_NS_GPL(zl3073x_get_regmap_config, "ZL3073X"); =20 +/** + * zl3073x_read_reg - Read value from device register + * @zldev: pointer to zl3073x device + * @reg: register to be read + * @len: number of bytes to read + * @value: pointer to place to store value read from the register + * + * Caller has to hold the device lock that can be obtained + * by zl3073x_lock(). + * + * Return: 0 on success or <0 on error + */ +int zl3073x_read_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, void *value) +{ + u8 buf[6]; + int rc; + + lockdep_assert_held(&zldev->lock); + + rc =3D regmap_bulk_read(zldev->regmap, reg, buf, len); + if (rc) + return rc; + + switch (len) { + case 1: + *(u8 *)value =3D buf[0]; + break; + case 2: + *(u16 *)value =3D get_unaligned_be16(buf); + break; + case 4: + *(u32 *)value =3D get_unaligned_be32(buf); + break; + case 6: + *(u64 *)value =3D get_unaligned_be48(buf); + break; + default: + WARN(true, "Unsupported register size: %u\n", len); + break; + } + + return rc; +} +EXPORT_SYMBOL_GPL(zl3073x_read_reg); + +/** + * zl3073x_write_reg - Write value to device register + * @zldev: pointer to zl3073x device + * @reg: register to be written + * @len: number of bytes to write + * @value: pointer to value to write to the register + * + * Caller has to hold the device lock that can be obtained + * by zl3073x_lock(). + * + * Return: 0 on success, <0 on error + */ +int zl3073x_write_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, const void *value) +{ + u8 buf[6]; + + lockdep_assert_held(&zldev->lock); + + switch (len) { + case 1: + buf[0] =3D *(u8 *)value; + break; + case 2: + put_unaligned_be16(*(u16 *)value, buf); + break; + case 4: + put_unaligned_be32(*(u32 *)value, buf); + break; + case 6: + put_unaligned_be48(*(u64 *)value, buf); + break; + default: + WARN(true, "Unsupported register size: %u\n", len); + break; + } + + return regmap_bulk_write(zldev->regmap, reg, buf, len); +} +EXPORT_SYMBOL_GPL(zl3073x_write_reg); + static const struct devlink_ops zl3073x_devlink_ops =3D { }; =20 diff --git a/include/linux/mfd/zl3073x.h b/include/linux/mfd/zl3073x.h index f3f33ef8bfa18..00dcc73aeeb34 100644 --- a/include/linux/mfd/zl3073x.h +++ b/include/linux/mfd/zl3073x.h @@ -3,6 +3,7 @@ #ifndef __LINUX_MFD_ZL3073X_H #define __LINUX_MFD_ZL3073X_H =20 +#include #include =20 struct device; @@ -20,4 +21,36 @@ struct zl3073x_dev { struct mutex lock; }; =20 +/** + * zl3073x_lock - Lock the device + * @zldev: device structure pointer + * + * Caller has to take this lock when it needs to access device registers. + */ +static inline void zl3073x_lock(struct zl3073x_dev *zldev) +{ + mutex_lock(&zldev->lock); +} + +/** + * zl3073x_unlock - Unlock the device + * @zldev: device structure pointer + * + * Caller unlocks the device when it does not need to access device + * registers anymore. + */ +static inline void zl3073x_unlock(struct zl3073x_dev *zldev) +{ + mutex_unlock(&zldev->lock); +} + +DEFINE_GUARD(zl3073x, struct zl3073x_dev *, zl3073x_lock(_T), + zl3073x_unlock(_T)); + +int zl3073x_read_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, void *value); + +int zl3073x_write_reg(struct zl3073x_dev *zldev, unsigned int reg, + unsigned int len, const void *value); + #endif /* __LINUX_MFD_ZL3073X_H */ --=20 2.48.1