Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755071AbaDUVty (ORCPT ); Mon, 21 Apr 2014 17:49:54 -0400 Received: from mail-wi0-f172.google.com ([209.85.212.172]:49238 "EHLO mail-wi0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755032AbaDUVtq (ORCPT ); Mon, 21 Apr 2014 17:49:46 -0400 From: srinivas.kandagatla@linaro.org To: linux-mmc@vger.kernel.org Cc: Russell King , Chris Ball , Ulf Hansson , linux-kernel@vger.kernel.org, agross@quicinc.com, linux-arm-msm@vger.kernel.org, Srinivas Kandagatla Subject: [PATCH RFC 12/12] mmc: mmci: Add Qcom specific pio_read function. Date: Mon, 21 Apr 2014 22:49:38 +0100 Message-Id: <1398116978-31772-1-git-send-email-srinivas.kandagatla@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1398116624-31052-1-git-send-email-srinivas.kandagatla@linaro.org> References: <1398116624-31052-1-git-send-email-srinivas.kandagatla@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. This patch implements qcom_pio_read function so as existing mmci_pio_read is not suitable for Qcom SOCs. Signed-off-by: Srinivas Kandagatla --- drivers/mmc/host/mmci.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c index 8fcd8ef..585888e 100644 --- a/drivers/mmc/host/mmci.c +++ b/drivers/mmc/host/mmci.c @@ -1047,6 +1047,29 @@ 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) +{ + uint32_t *ptr = (uint32_t *) buffer; + int count = 0; + struct variant_data *variant = host->variant; + int fifo_size = variant->fifosize; + + if (remain % 4) + remain = ((remain >> 2) + 1) << 2; + + while (readl(host->base + MMCISTATUS) & MCI_RXDATAAVLBL) { + *ptr = readl(host->base + MMCIFIFO + (count % fifo_size)); + ptr++; + count += sizeof(uint32_t); + + remain -= sizeof(uint32_t); + if (remain == 0) + break; + } + return count; +} + static int mmci_pio_read(struct mmci_host *host, char *buffer, unsigned int remain) { void __iomem *base = host->base; @@ -1168,8 +1191,12 @@ 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 (host->hw_designer == AMBA_VENDOR_QCOM) + 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); -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/