From patchwork Mon Mar 27 14:03:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cristian Marussi X-Patchwork-Id: 13189417 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D3F64C76195 for ; Mon, 27 Mar 2023 14:05:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=ndYnNmD6SeLi+YnKcjIWX47r+jp5UMhbiEXuCSBOvNg=; b=AwI3jRqKAUDRGS L3hCgpjk205TdVrFUP4DJsaPJwgWohYD5tyBeMSEs2KQmrKULN6hd4Mim9Jfrx1NMntHNZJiHNdTi onAJuTOIONBw+UIq5Tl2A3OumgvmleBDBkxfNIHJygNqNz8Y4r59pbRt2azXppXHpbnZZsbX3SbAK 6Oq4GiUK0ONkKuU4BVn0/08FJhHz7RzJrc+KN5uvp/ZJjjiFbHLawVwRWWPti74x8dXfO67R9//My zh2QDY+AghVixZ9JDBBzMnhJOiA80pTHZhreORazfEhHpFvH/frqAYwDcl9D/0F2Z9+lxgdCCDZN3 o+885rUIPZvgeB6AYm2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pgnSl-00BCo1-1X; Mon, 27 Mar 2023 14:04:43 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pgnSW-00BCl5-1P for linux-arm-kernel@lists.infradead.org; Mon, 27 Mar 2023 14:04:34 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 9A62E1042; Mon, 27 Mar 2023 07:05:08 -0700 (PDT) Received: from e120937-lin.. (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 087A93F6C4; Mon, 27 Mar 2023 07:04:22 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org Cc: sudeep.holla@arm.com, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, nicola.mazzucato@arm.com, cristian.marussi@arm.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org Subject: [PATCH 1/2] dt-bindings: firmware: arm,scmi: Support mailboxes unidirectional channels Date: Mon, 27 Mar 2023 15:03:41 +0100 Message-Id: <20230327140342.222168-2-cristian.marussi@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230327140342.222168-1-cristian.marussi@arm.com> References: <20230327140342.222168-1-cristian.marussi@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230327_070428_578040_F16B5E36 X-CRM114-Status: GOOD ( 16.09 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org SCMI defines two kinds of communication channels between the agent and the platform: one bidirectional 'a2p' channel used by the agent to send SCMI commands and synchronously receive the related replies, and an optional 'p2a' unidirectional channel used to asynchronously receive delayed responses and notifications emitted from the platform. When configuring an SCMI transport based on mailboxes, the current binding supports only mailboxes providing bidirectional channels: in such a case one mailbox channel can be easily assigned to each SCMI channel as above described. In case, instead, to have to deal with mailboxes providing only distinct unidirectional channels, it becomes necessary to extend the binding in order to be able to bind 2 distinct unidirectional mailbox channels to the same SCMI 'a2p' channel. Bidirectional and unidirectional channels support for the SCMI mailbox transport can coexist by carefully considering the effective combination of defined 'mboxes' and 'shmem' descriptors. Cc: Rob Herring Cc: Krzysztof Kozlowski Cc: devicetree@vger.kernel.org Signed-off-by: Cristian Marussi --- .../bindings/firmware/arm,scmi.yaml | 42 +++++++++++++++++-- 1 file changed, 38 insertions(+), 4 deletions(-) diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml index 2f7c51c75e85..9a7dc30e386f 100644 --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml @@ -63,10 +63,24 @@ properties: mboxes: description: List of phandle and mailbox channel specifiers. It should contain - exactly one or two mailboxes, one for transmitting messages("tx") - and another optional for receiving the notifications("rx") if supported. + exactly one, two or three mailboxes; the first one or two for transmitting + messages ("tx") and another optional ("rx") for receiving notifications + and delayed responses, if supported by the platform. + The number of mailboxes needed for transmitting messages depends on the + type of channels exposed by the specific underlying mailbox controller; + one single channel descriptor is enough if such channel is bidirectional, + while two channel descriptors are needed to represent the SCMI ("tx") + channel if the underlying mailbox channels are of unidirectional type. + The effective combination in numbers of mboxes and shmem descriptors let + the SCMI subsystem determine unambiguosly which type of SCMI channels are + made available by the underlying mailbox controller and how to use them. + 1 mbox / 1 shmem => SCMI TX over 1 mailbox bidirectional channel + 2 mbox / 2 shmem => SCMI TX and RX over 2 mailbox bidirectional channels + 2 mbox / 1 shmem => SCMI TX over 2 mailbox unidirectional channels + 3 mbox / 2 shmem => SCMI TX and RX over 3 mailbox unidirectional channels + Any other combination of mboxes and shmem is invalid. minItems: 1 - maxItems: 2 + maxItems: 3 shmem: description: @@ -234,7 +248,7 @@ $defs: mboxes: minItems: 1 - maxItems: 2 + maxItems: 3 shmem: minItems: 1 @@ -393,6 +407,26 @@ examples: }; }; + - | + firmware { + scmi { + compatible = "arm,scmi"; + mboxes = <&mhu_U_tx 0 0>, <&mhu_U_rx 0 0>; + shmem = <&cpu_scp_lpri0>; + + #address-cells = <1>; + #size-cells = <0>; + + scmi_dvfs_2: protocol@13 { + reg = <0x13>; + #clock-cells = <1>; + + mboxes = <&mhu_U_tx 1 0>, <&mhu_U_rx 1 0>, <&mhu_U_rx 1 1>; + shmem = <&cpu_scp_hpri0>, <&cpu_scp_hpri1>; + }; + }; + }; + - | firmware { scmi { From patchwork Mon Mar 27 14:03:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cristian Marussi X-Patchwork-Id: 13189418 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0EA5FC76195 for ; Mon, 27 Mar 2023 14:05:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=AkFHxmv9a0tSkQFwBXHkB/eYbTwNRdM8J9pco1RdXKA=; b=QGuh0SRjT1Ql3R Bn6UBGs//4JDEHBF9sNHhEANHr6hOxrVv28YYZNCBT1siKM5upmzlb+tgwEoDp2GMRbK+LLgz6wYf wu0cPCouUukew5nkAeGeGtvygk0sRXunxul3DIl1+lkRn8i3uJMxJhJ1UCiPjvn+GGtgoqk4fPW3/ uTwBFLG487vUwDuRJIu1WapP7d0JBZdtoD325WqUIilqhro0DI8h9rt4n/t9iJscmjtpSVgwY8AZ9 +PQMfxRxRNJcKSTeKNhdOGCIccFuP/RWf8PrUlYl+iKgNb2pHE3kC8pWpQttM4BstGzEvQONcKqQC 9lLTuPjzMGZZd8vqamzA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pgnSm-00BCoS-1k; Mon, 27 Mar 2023 14:04:44 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pgnSW-00BCkx-1Q for linux-arm-kernel@lists.infradead.org; Mon, 27 Mar 2023 14:04:37 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 44996143D; Mon, 27 Mar 2023 07:05:10 -0700 (PDT) Received: from e120937-lin.. (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A60FF3F6C4; Mon, 27 Mar 2023 07:04:24 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org Cc: sudeep.holla@arm.com, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, nicola.mazzucato@arm.com, cristian.marussi@arm.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org Subject: [PATCH 2/2] firmware: arm_scmi: Add support for unidirectional mailbox channels Date: Mon, 27 Mar 2023 15:03:42 +0100 Message-Id: <20230327140342.222168-3-cristian.marussi@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230327140342.222168-1-cristian.marussi@arm.com> References: <20230327140342.222168-1-cristian.marussi@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230327_070428_577675_6647788C X-CRM114-Status: GOOD ( 21.60 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Extend the SCMI transport layer to support mailbox controllers that expose communication channels that are unidirectional by nature. Signed-off-by: Cristian Marussi --- drivers/firmware/arm_scmi/mailbox.c | 95 +++++++++++++++++++++++++---- 1 file changed, 84 insertions(+), 11 deletions(-) diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c index 112c285deb97..1efa5e9392c4 100644 --- a/drivers/firmware/arm_scmi/mailbox.c +++ b/drivers/firmware/arm_scmi/mailbox.c @@ -19,13 +19,15 @@ * struct scmi_mailbox - Structure representing a SCMI mailbox transport * * @cl: Mailbox Client - * @chan: Transmit/Receive mailbox channel + * @chan: Transmit/Receive mailbox uni/bi-directional channel + * @chan_receiver: Optional Receiver mailbox unidirectional channel * @cinfo: SCMI channel info * @shmem: Transmit/Receive shared memory area */ struct scmi_mailbox { struct mbox_client cl; struct mbox_chan *chan; + struct mbox_chan *chan_receiver; struct scmi_chan_info *cinfo; struct scmi_shared_mem __iomem *shmem; }; @@ -48,30 +50,62 @@ static void rx_callback(struct mbox_client *cl, void *m) static bool mailbox_chan_available(struct device_node *of_node, int idx) { + int num_mb; + + /* + * Just check if bidirrectional channels are involved, and check the + * index accordingly; proper full validation will be made later + * in mailbox_chan_setup(). + */ + num_mb = of_count_phandle_with_args(of_node, "mboxes", "#mbox-cells"); + if (num_mb == 3 && idx == 1) + idx = 2; + return !of_parse_phandle_with_args(of_node, "mboxes", "#mbox-cells", idx, NULL); } -static int mailbox_chan_validate(struct device *cdev) +/** + * mailbox_chan_validate - Validate transport configuration and map channels + * + * @cdev: Reference to the underlying transport device carrying the + * of_node descriptor to analyze. + * @a2p_rx_chan: A reference to an optional unidirectional channel to use + * for replies on the a2p channel. Set as zero if not present. + * @p2a_chan: A reference to the optional p2a channel. + * Set as zero if not present. + * + * At first, validate the transport configuration as described in terms of + * 'mboxes' and 'shmem', then determin which mailbox channel indexes are + * appropriate to be use in the current configuration. + * + * Return: 0 on Success or error + */ +static int mailbox_chan_validate(struct device *cdev, + int *a2p_rx_chan, int *p2a_chan) { int num_mb, num_sh, ret = 0; struct device_node *np = cdev->of_node; num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells"); num_sh = of_count_phandle_with_args(np, "shmem", NULL); + dev_dbg(cdev, "Found %d mboxes and %d shmems !\n", num_mb, num_sh); + /* Bail out if mboxes and shmem descriptors are inconsistent */ - if (num_mb <= 0 || num_sh > 2 || num_mb != num_sh) { - dev_warn(cdev, "Invalid channel descriptor for '%s'\n", - of_node_full_name(np)); + if (num_mb <= 0 || num_sh <= 0 || num_sh > 2 || num_mb > 3 || + (num_mb == 1 && num_sh != 1) || (num_mb == 3 && num_sh != 2)) { + dev_warn(cdev, + "Invalid channel descriptor for '%s' - mbs:%d shm:%d\n", + of_node_full_name(np), num_mb, num_sh); return -EINVAL; } + /* Bail out if provided shmem descriptors do not refer distinct areas */ if (num_sh > 1) { struct device_node *np_tx, *np_rx; np_tx = of_parse_phandle(np, "shmem", 0); np_rx = of_parse_phandle(np, "shmem", 1); - /* SCMI Tx and Rx shared mem areas have to be distinct */ if (!np_tx || !np_rx || np_tx == np_rx) { dev_warn(cdev, "Invalid shmem descriptor for '%s'\n", of_node_full_name(np)); @@ -82,6 +116,29 @@ static int mailbox_chan_validate(struct device *cdev) of_node_put(np_rx); } + /* Calculate channels IDs to use depending on mboxes/shmem layout */ + if (!ret) { + switch (num_mb) { + case 1: + *a2p_rx_chan = 0; + *p2a_chan = 0; + break; + case 2: + if (num_sh == 2) { + *a2p_rx_chan = 0; + *p2a_chan = 1; + } else { + *a2p_rx_chan = 1; + *p2a_chan = 0; + } + break; + case 3: + *a2p_rx_chan = 1; + *p2a_chan = 2; + break; + } + } + return ret; } @@ -92,15 +149,18 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, struct device *cdev = cinfo->dev; struct scmi_mailbox *smbox; struct device_node *shmem; - int ret, idx = tx ? 0 : 1; + int ret, a2p_rx_chan, p2a_chan, idx = tx ? 0 : 1; struct mbox_client *cl; resource_size_t size; struct resource res; - ret = mailbox_chan_validate(cdev); + ret = mailbox_chan_validate(cdev, &a2p_rx_chan, &p2a_chan); if (ret) return ret; + if (!tx && !p2a_chan) + return -ENODEV; + smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL); if (!smbox) return -ENOMEM; @@ -130,15 +190,26 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, cl->tx_block = false; cl->knows_txdone = tx; - smbox->chan = mbox_request_channel(cl, tx ? 0 : 1); + smbox->chan = mbox_request_channel(cl, tx ? 0 : p2a_chan); if (IS_ERR(smbox->chan)) { ret = PTR_ERR(smbox->chan); if (ret != -EPROBE_DEFER) - dev_err(cdev, "failed to request SCMI %s mailbox\n", - tx ? "Tx" : "Rx"); + dev_err(cdev, + "failed to request SCMI %s mailbox\n", desc); return ret; } + /* Additional unidirectional channel for TX if needed */ + if (tx && a2p_rx_chan) { + smbox->chan_receiver = mbox_request_channel(cl, a2p_rx_chan); + if (IS_ERR(smbox->chan_receiver)) { + ret = PTR_ERR(smbox->chan_receiver); + if (ret != -EPROBE_DEFER) + dev_err(cdev, "failed to request SCMI Tx Receiver mailbox\n"); + return ret; + } + } + cinfo->transport_info = smbox; smbox->cinfo = cinfo; @@ -152,8 +223,10 @@ static int mailbox_chan_free(int id, void *p, void *data) if (smbox && !IS_ERR(smbox->chan)) { mbox_free_channel(smbox->chan); + mbox_free_channel(smbox->chan_receiver); cinfo->transport_info = NULL; smbox->chan = NULL; + smbox->chan_receiver = NULL; smbox->cinfo = NULL; }