From patchwork Wed May 28 13:48:06 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Srinivas Kandagatla X-Patchwork-Id: 4255351 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6BA70BF90B for ; Wed, 28 May 2014 13:48:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 70CA120138 for ; Wed, 28 May 2014 13:48:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55FBB20131 for ; Wed, 28 May 2014 13:48:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754467AbaE1NsQ (ORCPT ); Wed, 28 May 2014 09:48:16 -0400 Received: from mail-we0-f170.google.com ([74.125.82.170]:43104 "EHLO mail-we0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754448AbaE1NsO (ORCPT ); Wed, 28 May 2014 09:48:14 -0400 Received: by mail-we0-f170.google.com with SMTP id u57so11485720wes.29 for ; Wed, 28 May 2014 06:48:12 -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=83h5TRJ0e5JUfBTGZj7SvMSAFwzYW61iUy8XOGHtGr0=; b=bwZQ1oIyCycEf/dxMzCxiZlTlzA7krsACfDBAjs+3abFyUNR3tvCYnbl3eMnI5ICmz f+xC2yanuN6ASG7H8g2uM+ag9tqz3rd5/oBSavcQQw7xT7Gh7bbFmp9JfNBJl2f30BpR Lk33IGtkHtHJ2pHpbBR0b72jy+euuxp11Ew8G8d6ZjsmtGvW5csbaBrpKfjfYRT+vBhV AhJu7et/Zu3kJUUrYNEe4c0w7W71BVH4vzf+z7GlCyfQFXFYI48yhl/2i3mQ0BwZZmJr GFo/iVAjKo5rH1Px/aUjWXN4YyMneRhZZWn/A9IiccSnxns/57Vqv/Zud+ciDGwwIh/x dXfQ== X-Gm-Message-State: ALoCoQkoQrMVcJ0rYsE17idLh34ymTS5/cs9BqP6APw9qJ4kQaKmVmCXVAD7tLk7+kBMTiVhk0jc X-Received: by 10.180.149.240 with SMTP id ud16mr1015901wib.3.1401284892629; Wed, 28 May 2014 06:48:12 -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 b16sm43404610wjx.45.2014.05.28.06.48.08 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 28 May 2014 06:48:09 -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 v4 13/13] mmc: mmci: Add Qcom specific pio_read function. Date: Wed, 28 May 2014 14:48:06 +0100 Message-Id: <1401284886-16978-1-git-send-email-srinivas.kandagatla@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1401284608-16428-1-git-send-email-srinivas.kandagatla@linaro.org> References: <1401284608-16428-1-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 | 45 ++++++++++++++++++++++++++++++++++++++++++++- drivers/mmc/host/mmci.h | 1 + 2 files changed, 45 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 6eb0a29..b68223a 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -73,6 +73,7 @@ static unsigned int fmax = 515633; * @busy_detect: true if busy detection on dat0 is supported * @pwrreg_nopower: bits in MMCIPOWER don't controls ext. power supply * @explicit_mclk_control: enable explicit mclk control in driver. + * @qcom_fifo: enables qcom specific fifo pio read function. */ struct variant_data { unsigned int clkreg; @@ -95,6 +96,7 @@ struct variant_data { bool busy_detect; bool pwrreg_nopower; bool explicit_mclk_control; + bool qcom_fifo; }; static struct variant_data variant_arm = { @@ -202,6 +204,7 @@ static struct variant_data variant_qcom = { .pwrreg_powerup = MCI_PWR_UP, .f_max = 208000000, .explicit_mclk_control = true, + .qcom_fifo = true, }; static int mmci_card_busy(struct mmc_host *mmc) @@ -1006,6 +1009,40 @@ 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 (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; @@ -1129,7 +1166,8 @@ static irqreturn_t mmci_pio_irq(int irq, void *dev_id) len = 0; if (status & MCI_RXACTIVE) - len = mmci_pio_read(host, buffer, remain); + len = host->pio_read(host, buffer, remain); + if (status & MCI_TXACTIVE) len = mmci_pio_write(host, buffer, remain, status); @@ -1504,6 +1542,11 @@ static int mmci_probe(struct amba_device *dev, if (ret) goto host_free; + if (variant->qcom_fifo) + host->pio_read = mmci_qcom_pio_read; + else + host->pio_read = mmci_pio_read; + host->plat = plat; host->variant = variant; host->mclk = clk_get_rate(host->clk); diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h index 1882e20..dc9fe0a 100644 --- a/drivers/mmc/host/mmci.h +++ b/drivers/mmc/host/mmci.h @@ -229,6 +229,7 @@ struct mmci_host { /* pio stuff */ struct sg_mapping_iter sg_miter; unsigned int size; + int (*pio_read)(struct mmci_host *h, char *buf, unsigned int remain); #ifdef CONFIG_DMA_ENGINE /* DMA stuff */