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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80575C433F5 for ; Mon, 2 May 2022 09:03:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1384061AbiEBJGh (ORCPT ); Mon, 2 May 2022 05:06:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37422 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1384058AbiEBJGg (ORCPT ); Mon, 2 May 2022 05:06:36 -0400 Received: from mail.marcansoft.com (marcansoft.com [IPv6:2a01:298:fe:f::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 839CA58E70; Mon, 2 May 2022 02:03:06 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: hector@marcansoft.com) by mail.marcansoft.com (Postfix) with ESMTPSA id CEA984246A; Mon, 2 May 2022 09:02:56 +0000 (UTC) From: Hector Martin Cc: Hector Martin , Anup Patel , Vinod Koul , Sven Peter , Alyssa Rosenzweig , Mun Yew Tham , Chen-Yu Tsai , Jernej Skrabec , Samuel Holland , Michal Simek , Arnd Bergmann , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@lists.linux.dev Subject: [PATCH 6/7] mailbox: apple: Implement flush() operation Date: Mon, 2 May 2022 18:02:24 +0900 Message-Id: <20220502090225.26478-7-marcan@marcan.st> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220502090225.26478-1-marcan@marcan.st> References: <20220502090225.26478-1-marcan@marcan.st> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org This allows clients to use the atomic-safe mailbox API style. Signed-off-by: Hector Martin --- drivers/mailbox/apple-mailbox.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/mailbox/apple-mailbox.c b/drivers/mailbox/apple-mailbox.c index 496c4951ccb1..33e7acf71e3e 100644 --- a/drivers/mailbox/apple-mailbox.c +++ b/drivers/mailbox/apple-mailbox.c @@ -17,6 +17,7 @@ */ #include +#include #include #include #include @@ -112,6 +113,14 @@ static bool apple_mbox_hw_can_send(struct apple_mbox *apple_mbox) return !(mbox_ctrl & apple_mbox->hw->control_full); } +static bool apple_mbox_hw_send_empty(struct apple_mbox *apple_mbox) +{ + u32 mbox_ctrl = + readl_relaxed(apple_mbox->regs + apple_mbox->hw->a2i_control); + + return mbox_ctrl & apple_mbox->hw->control_empty; +} + static int apple_mbox_hw_send(struct apple_mbox *apple_mbox, struct apple_mbox_msg *msg) { @@ -219,6 +228,23 @@ static irqreturn_t apple_mbox_recv_irq(int irq, void *data) return IRQ_HANDLED; } +static int apple_mbox_chan_flush(struct mbox_chan *chan, unsigned long timeout) +{ + struct apple_mbox *apple_mbox = chan->con_priv; + unsigned long deadline = jiffies + msecs_to_jiffies(timeout); + + while (time_before(jiffies, deadline)) { + if (apple_mbox_hw_send_empty(apple_mbox)) { + mbox_chan_txdone(&apple_mbox->chan, 0); + return 0; + } + + udelay(1); + } + + return -ETIME; +} + static int apple_mbox_chan_startup(struct mbox_chan *chan) { struct apple_mbox *apple_mbox = chan->con_priv; @@ -250,6 +276,7 @@ static void apple_mbox_chan_shutdown(struct mbox_chan *chan) static const struct mbox_chan_ops apple_mbox_ops = { .send_data = apple_mbox_chan_send_data, + .flush = apple_mbox_chan_flush, .startup = apple_mbox_chan_startup, .shutdown = apple_mbox_chan_shutdown, }; -- 2.35.1