Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752576AbdHQMIR (ORCPT ); Thu, 17 Aug 2017 08:08:17 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:34642 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751149AbdHQMIM (ORCPT ); Thu, 17 Aug 2017 08:08:12 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 30E4460415 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=absahu@codeaurora.org From: Abhishek Sahu To: Boris Brezillon Cc: David Woodhouse , Brian Norris , Marek Vasut , Richard Weinberger , Cyrille Pitchen , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org, Andy Gross , Archit Taneja , Sricharan R , Abhishek Sahu Subject: [PATCH v5 01/16] mtd: nand: qcom: DMA mapping support for register read buffer Date: Thu, 17 Aug 2017 17:37:39 +0530 Message-Id: <1502971674-13810-2-git-send-email-absahu@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1502971674-13810-1-git-send-email-absahu@codeaurora.org> References: <1502971674-13810-1-git-send-email-absahu@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5002 Lines: 140 The EBI2 NAND controller directly remaps register read buffer with dma_map_sg and DMA address of this buffer will be passed to DMA API’s. While, on QPIC NAND controller, which uses BAM DMA, we read the controller registers by preparing a BAM command descriptor. This command descriptor requires the - controller register address - the DMA address in which we want to store the value read back from the controller register. This command descriptor will be remapped with dma_map_sg and its DMA address will be passed to DMA API’s. Therefore, it's required that we also map our register read buffer for DMA (using dma_map_single). We use the returned DMA address for preparing entries in our command descriptor. This patch adds the DMA mapping support for register read buffer. This buffer will be DMA mapped during allocation time. Before starting of any operation, this buffer will be synced for device operation and after operation completion, it will be synced again for CPU. Reviewed-by: Archit Taneja Signed-off-by: Abhishek Sahu --- * Changes from v4: None drivers/mtd/nand/qcom_nandc.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c index 59b764a..590fc1d 100644 --- a/drivers/mtd/nand/qcom_nandc.c +++ b/drivers/mtd/nand/qcom_nandc.c @@ -234,6 +234,7 @@ struct nandc_regs { * by upper layers directly * @buf_size/count/start: markers for chip->read_buf/write_buf functions * @reg_read_buf: local buffer for reading back registers via DMA + * @reg_read_dma: contains dma address for register read buffer * @reg_read_pos: marker for data read in reg_read_buf * * @regs: a contiguous chunk of memory for DMA register @@ -279,6 +280,7 @@ struct qcom_nand_controller { int buf_start; __le32 *reg_read_buf; + dma_addr_t reg_read_dma; int reg_read_pos; struct nandc_regs *regs; @@ -371,6 +373,24 @@ static inline void nandc_write(struct qcom_nand_controller *nandc, int offset, iowrite32(val, nandc->base + offset); } +static inline void nandc_read_buffer_sync(struct qcom_nand_controller *nandc, + bool is_cpu) +{ + if (!nandc->props->is_bam) + return; + + if (is_cpu) + dma_sync_single_for_cpu(nandc->dev, nandc->reg_read_dma, + MAX_REG_RD * + sizeof(*nandc->reg_read_buf), + DMA_FROM_DEVICE); + else + dma_sync_single_for_device(nandc->dev, nandc->reg_read_dma, + MAX_REG_RD * + sizeof(*nandc->reg_read_buf), + DMA_FROM_DEVICE); +} + static __le32 *offset_to_nandc_reg(struct nandc_regs *regs, int offset) { switch (offset) { @@ -854,6 +874,7 @@ static void free_descs(struct qcom_nand_controller *nandc) static void clear_read_regs(struct qcom_nand_controller *nandc) { nandc->reg_read_pos = 0; + nandc_read_buffer_sync(nandc, false); } static void pre_command(struct qcom_nand_host *host, int command) @@ -883,6 +904,7 @@ static void parse_erase_write_errors(struct qcom_nand_host *host, int command) int i; num_cw = command == NAND_CMD_PAGEPROG ? ecc->steps : 1; + nandc_read_buffer_sync(nandc, true); for (i = 0; i < num_cw; i++) { u32 flash_status = le32_to_cpu(nandc->reg_read_buf[i]); @@ -904,6 +926,7 @@ static void post_command(struct qcom_nand_host *host, int command) switch (command) { case NAND_CMD_READID: + nandc_read_buffer_sync(nandc, true); memcpy(nandc->data_buffer, nandc->reg_read_buf, nandc->buf_count); break; @@ -1067,6 +1090,7 @@ static int parse_read_errors(struct qcom_nand_host *host, u8 *data_buf, int i; buf = (struct read_stats *)nandc->reg_read_buf; + nandc_read_buffer_sync(nandc, true); for (i = 0; i < ecc->steps; i++, buf++) { u32 flash, buffer, erased_cw; @@ -2003,6 +2027,16 @@ static int qcom_nandc_alloc(struct qcom_nand_controller *nandc) return -ENOMEM; if (nandc->props->is_bam) { + nandc->reg_read_dma = + dma_map_single(nandc->dev, nandc->reg_read_buf, + MAX_REG_RD * + sizeof(*nandc->reg_read_buf), + DMA_FROM_DEVICE); + if (dma_mapping_error(nandc->dev, nandc->reg_read_dma)) { + dev_err(nandc->dev, "failed to DMA MAP reg buffer\n"); + return -EIO; + } + nandc->tx_chan = dma_request_slave_channel(nandc->dev, "tx"); if (!nandc->tx_chan) { dev_err(nandc->dev, "failed to request tx channel\n"); @@ -2040,6 +2074,12 @@ static int qcom_nandc_alloc(struct qcom_nand_controller *nandc) static void qcom_nandc_unalloc(struct qcom_nand_controller *nandc) { if (nandc->props->is_bam) { + if (!dma_mapping_error(nandc->dev, nandc->reg_read_dma)) + dma_unmap_single(nandc->dev, nandc->reg_read_dma, + MAX_REG_RD * + sizeof(*nandc->reg_read_buf), + DMA_FROM_DEVICE); + if (nandc->tx_chan) dma_release_channel(nandc->tx_chan); -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation