From patchwork Fri May 23 12:53:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Srinivas Kandagatla X-Patchwork-Id: 4232431 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 63D889F32B for ; Fri, 23 May 2014 12:53:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 90534202C8 for ; Fri, 23 May 2014 12:53:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5DDC20108 for ; Fri, 23 May 2014 12:53:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753194AbaEWMxR (ORCPT ); Fri, 23 May 2014 08:53:17 -0400 Received: from mail-we0-f181.google.com ([74.125.82.181]:49203 "EHLO mail-we0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753190AbaEWMxP (ORCPT ); Fri, 23 May 2014 08:53:15 -0400 Received: by mail-we0-f181.google.com with SMTP id w61so4922041wes.12 for ; Fri, 23 May 2014 05:53:13 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=GOI1y8kO3FwF8ecWrnO4GQ1OFHuHzayRy5+7w9vxqiY=; b=BFz/om+uDdRo29T45t1qzNpBIFsXYxZC46vjNZ6a3Ye8r/xYOUOxW1bzHStGEVp1qW 1eLLXuayRlYeiP8R4xi68yWiSlu4zNtqtIOvSRtSbl3iumJ7mHyBxxm+48Dc5TU9Xdii HIWKWGyGmHNnj2iEb7zU1hrCTrSFAI78BXKE+WpOp1JZx+s8xNncsDvCTfotLGrJhwjv AiWxkBPIA2BfR6+GkMvciYE533Ep6tND7MVwW98O78XeIsNMT321F8EU1nCf2KZteSCk +8IYYoODn6RtFx1Oxacsz67X/SzxDsWBznqQfSDnjxkusX0erNHCUzD/An04n33f2XLD i0GQ== X-Gm-Message-State: ALoCoQk809Y57Z8cW8hPEnFK4B7Im5buk5EevQZedjwD9aSEdAXAbgAnp0dtPr8xXGCKMsVkgBa4 X-Received: by 10.194.184.179 with SMTP id ev19mr1758829wjc.85.1400849593755; Fri, 23 May 2014 05:53:13 -0700 (PDT) Received: from srini-ThinkPad-X1-Carbon-2nd.dlink.com (host-78-149-4-211.as13285.net. [78.149.4.211]) by mx.google.com with ESMTPSA id vp5sm3804037wjc.31.2014.05.23.05.53.11 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 23 May 2014 05:53:12 -0700 (PDT) From: srinivas.kandagatla@linaro.org To: Russell King , Ulf Hansson , linux-mmc@vger.kernel.org Cc: Chris Ball , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linus.walleij@linaro.org, Srinivas Kandagatla Subject: [PATCH v3 13/13] mmc: mmci: Add Qcom specific pio_read function. Date: Fri, 23 May 2014 13:53:09 +0100 Message-Id: <1400849589-7626-1-git-send-email-srinivas.kandagatla@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1400849362-7007-1-git-send-email-srinivas.kandagatla@linaro.org> References: <1400849362-7007-1-git-send-email-srinivas.kandagatla@linaro.org> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Srinivas Kandagatla MCIFIFOCNT register behaviour on Qcom chips is very different than the other pl180 integrations. MCIFIFOCNT register contains the number of words that are still waiting to be transferred through the FIFO. It keeps decrementing once the host CPU reads the MCIFIFO. With the existing logic and the MCIFIFOCNT behaviour, mmci_pio_read will loop forever, as the FIFOCNT register will always return transfer size before reading the FIFO. Also the data sheet states that "This register is only useful for debug purposes and should not be used for normal operation since it does not reflect data which may or may not be in the pipeline". This patch implements qcom_pio_read function so as existing mmci_pio_read is not suitable for Qcom SOCs. qcom_pio_read function is only selected based on qcom_fifo flag in variant data structure. Signed-off-by: Srinivas Kandagatla --- drivers/mmc/host/mmci.c | 46 ++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index f6dfd24..51ce493 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -75,6 +75,7 @@ static unsigned int fmax = 515633; * are not ignored. * @explicit_mclk_control: enable explicit mclk control in driver. * @cclk_is_mclk: enable iff card clock is multimedia card adapter clock. + * @qcom_fifo: enables qcom specific fifo pio read function. */ struct variant_data { unsigned int clkreg; @@ -98,6 +99,7 @@ struct variant_data { bool mclk_delayed_writes; bool explicit_mclk_control; bool cclk_is_mclk; + bool qcom_fifo; }; static struct variant_data variant_arm = { @@ -208,6 +210,7 @@ static struct variant_data variant_qcom = { .mclk_delayed_writes = true, .explicit_mclk_control = true, .cclk_is_mclk = true, + .qcom_fifo = true, }; static inline u32 mmci_readl(struct mmci_host *host, u32 off) @@ -1022,6 +1025,40 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd, } } +static int mmci_qcom_pio_read(struct mmci_host *host, char *buffer, + unsigned int remain) +{ + u32 *ptr = (u32 *) buffer; + unsigned int count = 0; + unsigned int words, bytes; + unsigned int fsize = host->variant->fifosize; + + words = remain >> 2; + bytes = remain % 4; + /* read full words followed by leftover bytes */ + if (words) { + while (readl(host->base + MMCISTATUS) & MCI_RXDATAAVLBL) { + *ptr = readl(host->base + MMCIFIFO + (count % fsize)); + ptr++; + count += 4; + words--; + if (!words) + break; + } + } + + if (unlikely(bytes)) { + unsigned char buf[4]; + if (readl(host->base + MMCISTATUS) & MCI_RXDATAAVLBL) { + *buf = readl(host->base + MMCIFIFO + (count % fsize)); + memcpy(ptr, buf, bytes); + count += bytes; + } + } + + return count; +} + static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain) { void __iomem *base = host->base; @@ -1143,8 +1180,13 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id) remain = sg_miter->length; len = 0; - if (status & MCI_RXACTIVE) - len = mmci_pio_read(host, buffer, remain); + if (status & MCI_RXACTIVE) { + if (variant->qcom_fifo) + len = mmci_qcom_pio_read(host, buffer, remain); + else + len = mmci_pio_read(host, buffer, remain); + } + if (status & MCI_TXACTIVE) len = mmci_pio_write(host, buffer, remain, status);