From patchwork Mon Jun 26 03:10:06 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeffy Chen X-Patchwork-Id: 9808605 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 54E4E60209 for ; Mon, 26 Jun 2017 03:15:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5800C28111 for ; Mon, 26 Jun 2017 03:15:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4CD892818A; Mon, 26 Jun 2017 03:15:40 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,URIBL_BLACK autolearn=no version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 035B528111 for ; Mon, 26 Jun 2017 03:15:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=n0ATuUcyUWYpRbeE11GScaIR/cr8qgsnKIXJf50ely4=; b=f/R etcPoGfbdDIRCftTol0j+4judlRRC6KtliJyum1quzJYceH+RIBcr1ZyanmjwQrM6uKbcaVQ1DIWI KtCEmFsVO3EAWvO+l0j2AaN7Sy5hr/I+Mq/aObL6nnBEar6Hm6QFJyD3T7VsRBuzH5tqBYTBd4s+u cMa97Tbb5CkVLeml8vplW+ZoT1T1758SA2MgyVbMXsPvo/YDIB8G02/J6WUBbJk+RQh0VtdULjfC7 dWfI2sUqQPlZDi2dty2vUO/PAVDE6EPtPpmTgwRvMlkMsE4cmdYkJK4qtzxFP5CPpHLTzYwqzNENF DaAubYqGLEFdbEg7cYL+U2bWVL5g4Zg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dPKV0-00038u-Jo; Mon, 26 Jun 2017 03:15:38 +0000 Received: from regular1.263xmail.com ([211.150.99.141]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dPKUn-0001hM-G7; Mon, 26 Jun 2017 03:15:27 +0000 Received: from jeffy.chen?rock-chips.com (unknown [192.168.167.76]) by regular1.263xmail.com (Postfix) with ESMTP id 8E83E80; Mon, 26 Jun 2017 11:14:54 +0800 (CST) X-263anti-spam: X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-ABS-CHECKED: 4 Received: from localhost (localhost [127.0.0.1]) by smtp.263.net (Postfix) with ESMTPA id C00543CB; Mon, 26 Jun 2017 11:14:50 +0800 (CST) X-RL-SENDER: jeffy.chen@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: jeffy.chen@rock-chips.com X-UNIQUE-TAG: <2289c68ef3d088c8e3fc9f799d78832f> X-ATTACHMENT-NUM: 0 X-SENDER: cjf@rock-chips.com X-DNS-TYPE: 0 Received: from localhost (unknown [103.29.142.67]) by smtp.263.net (Postfix) whith ESMTP id 22838GXIBO4; Mon, 26 Jun 2017 11:14:53 +0800 (CST) From: Jeffy Chen To: linux-kernel@vger.kernel.org, broonie@kernel.org Subject: [PATCH] spi: rockchip: Keep master alive when CS asserted Date: Mon, 26 Jun 2017 11:10:06 +0800 Message-Id: <1498446606-5529-1-git-send-email-jeffy.chen@rock-chips.com> X-Mailer: git-send-email 2.1.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170625_201525_978113_6D91F863 X-CRM114-Status: UNSURE ( 6.87 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: briannorris@chromium.org, heiko@sntech.de, Jeffy Chen , dianders@chromium.org, linux-spi@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+patchwork-linux-rockchip=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The cros_ec requires CS line to be active after last message. But the CS would be toggled when powering off/on rockchip spi, which breaks ec xfer. Keep spi alive after CS asserted to prevent that. Suggested-by: Doug Anderson Signed-off-by: Jeffy Chen --- drivers/spi/spi-rockchip.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index acf31f3..df016a1 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -264,7 +264,7 @@ static inline u32 rx_max(struct rockchip_spi *rs) static void rockchip_spi_set_cs(struct spi_device *spi, bool enable) { - u32 ser; + u32 ser, new_ser; struct spi_master *master = spi->master; struct rockchip_spi *rs = spi_master_get_devdata(master); @@ -288,13 +288,25 @@ static void rockchip_spi_set_cs(struct spi_device *spi, bool enable) * Note: enable(rockchip_spi_set_cs) = !enable(spi_set_cs) */ if (!enable) - ser |= 1 << spi->chip_select; + new_ser = ser | BIT(spi->chip_select); else - ser &= ~(1 << spi->chip_select); + new_ser = ser & ~BIT(spi->chip_select); - writel_relaxed(ser, rs->regs + ROCKCHIP_SPI_SER); + if (new_ser == ser) + goto out; - pm_runtime_put_sync(rs->dev); + writel_relaxed(new_ser, rs->regs + ROCKCHIP_SPI_SER); + + /* + * The rockchip spi would stop driving CS when power down. + * So we need to keep it alive after CS asserted + */ + if (!enable) + return; + pm_runtime_put(rs->dev); + +out: + pm_runtime_put(rs->dev); } static int rockchip_spi_prepare_message(struct spi_master *master,