From patchwork Mon Apr 24 09:32:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vijaya Krishna Nivarthi X-Patchwork-Id: 676711 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 97CA2C77B7F for ; Mon, 24 Apr 2023 09:33:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231430AbjDXJdC (ORCPT ); Mon, 24 Apr 2023 05:33:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60790 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229625AbjDXJdA (ORCPT ); Mon, 24 Apr 2023 05:33:00 -0400 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AB64A1729; Mon, 24 Apr 2023 02:32:56 -0700 (PDT) Received: from pps.filterd (m0279873.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 33O7t1sZ014778; Mon, 24 Apr 2023 09:32:52 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references; s=qcppdkim1; bh=aVTYFLwanRDSxdt5ACJ6lBq7+3DEk/fUUzejH/aFh9s=; b=LH0O1O38yMi571T3iH3NEFRjmu91shz053jGck9lqmF1mU9X4FAdfw4s6wadMHR1sNF4 +tDLl61sP0uP0dSWtw25hblP6nIgqYz5C6wp8GbncnYVgZUM/1hkBU+HdQg7WQbjh1vr thj/YYm1u0M+Wnf3KPm8dW8nm0Z/Dohj1ISvpdcR+wpcuNEjXOHMhISJ3i89flYqsgGm icoDANBzcAGRurVt72RivMlK1YTQm4EhdHy2gtyZvC6Jta43P7eYXfyWvCxeLMkPqTnf EaVa1/hpvrJoINBRfBs2GiqTVe++y6Cyg7ZVwppkI3ccqWxfzo/38tp9m8YV6cSDIq7l pg== Received: from apblrppmta02.qualcomm.com (blr-bdr-fw-01_GlobalNAT_AllZones-Outside.qualcomm.com [103.229.18.19]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3q48geb0kr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 24 Apr 2023 09:32:52 +0000 Received: from pps.filterd (APBLRPPMTA02.qualcomm.com [127.0.0.1]) by APBLRPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTP id 33O9Wl4g021202; Mon, 24 Apr 2023 09:32:49 GMT Received: from pps.reinject (localhost [127.0.0.1]) by APBLRPPMTA02.qualcomm.com (PPS) with ESMTP id 3q48nkpknf-1; Mon, 24 Apr 2023 09:32:49 +0000 Received: from APBLRPPMTA02.qualcomm.com (APBLRPPMTA02.qualcomm.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 33O9WnHu021229; Mon, 24 Apr 2023 09:32:49 GMT Received: from hu-sgudaval-hyd.qualcomm.com (hu-vnivarth-hyd.qualcomm.com [10.213.111.166]) by APBLRPPMTA02.qualcomm.com (PPS) with ESMTP id 33O9Wm2a021226; Mon, 24 Apr 2023 09:32:49 +0000 Received: by hu-sgudaval-hyd.qualcomm.com (Postfix, from userid 3994820) id 1CD0347CE; Mon, 24 Apr 2023 15:02:48 +0530 (+0530) From: Vijaya Krishna Nivarthi To: agross@kernel.org, andersson@kernel.org, konrad.dybcio@linaro.org, broonie@kernel.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, cros-qcom-dts-watchers@chromium.org, linux-arm-msm@vger.kernel.org, linux-spi@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: quic_msavaliy@quicinc.com, dianders@chromium.org, mka@chromium.org, swboyd@chromium.org, quic_vtanuku@quicinc.com, Vijaya Krishna Nivarthi Subject: [PATCH v5 5/5] spi: spi-qcom-qspi: Add DMA mode support Date: Mon, 24 Apr 2023 15:02:41 +0530 Message-Id: <1682328761-17517-6-git-send-email-quic_vnivarth@quicinc.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1682328761-17517-1-git-send-email-quic_vnivarth@quicinc.com> References: <1682328761-17517-1-git-send-email-quic_vnivarth@quicinc.com> X-QCInternal: smtphost X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: O6LJqXttEjslpKijlt1VCZogF97EhuqK X-Proofpoint-GUID: O6LJqXttEjslpKijlt1VCZogF97EhuqK X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-24_06,2023-04-21_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 lowpriorityscore=0 mlxscore=0 impostorscore=0 phishscore=0 adultscore=0 mlxlogscore=999 clxscore=1015 priorityscore=1501 spamscore=0 malwarescore=0 suspectscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2304240085 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Current driver supports only PIO mode. HW supports DMA, so add DMA mode support to the driver for better performance for larger xfers. Signed-off-by: Vijaya Krishna Nivarthi --- v4 -> v5: - dropped xfer_mode - clear all interrupts in handle_err() - dont log ptr value - dropped some dev_err() - converted some dev_err() to dev_warn_once() - drop few redundant comments - can_dma() disabled if iommus not present in dev_node - other nits v3 -> v4: - corrected tabs spacing - dropped dma data descriptors - dropped INVALID from xfer_mode enum - qspi_buswidth_to_iomode() to return iomode without shifting - dropped non-functional change in qcom_qspi_set_speed() - drop redundant call to wmb() - fallback to pio if dma fails to setup - use dmam_pool_create() the devm version - thus drop dma_pool_destroy() - set dma_alignment field in probe() - other minor changes v2 -> v3: - dropped Reported-by tag v1 -> v2: - modified commit message - addressed kernel test robot error - correct placement of header file includes - added more comments - coding style related changes - renamed variables - used u32/u8 instead of uint32_t/8_t - removed unnecessary casting - retain same MSTR_CONFIG as PIO for DMA - unset fragment bit only for last cmd_desc of last xfer --- drivers/spi/spi-qcom-qspi.c | 218 ++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 212 insertions(+), 6 deletions(-) diff --git a/drivers/spi/spi-qcom-qspi.c b/drivers/spi/spi-qcom-qspi.c index fab1553..a3991e6 100644 --- a/drivers/spi/spi-qcom-qspi.c +++ b/drivers/spi/spi-qcom-qspi.c @@ -2,6 +2,8 @@ // Copyright (c) 2017-2018, The Linux foundation. All rights reserved. #include +#include +#include #include #include #include @@ -62,6 +64,7 @@ #define WR_FIFO_FULL BIT(10) #define WR_FIFO_OVERRUN BIT(11) #define TRANSACTION_DONE BIT(16) +#define DMA_CHAIN_DONE BIT(31) #define QSPI_ERR_IRQS (RESP_FIFO_UNDERRUN | HRESP_FROM_NOC_ERR | \ WR_FIFO_OVERRUN) #define QSPI_ALL_IRQS (QSPI_ERR_IRQS | RESP_FIFO_RDY | \ @@ -108,18 +111,34 @@ #define RD_FIFO_RESET 0x0030 #define RESET_FIFO BIT(0) +#define NEXT_DMA_DESC_ADDR 0x0040 +#define CURRENT_DMA_DESC_ADDR 0x0044 +#define CURRENT_MEM_ADDR 0x0048 + #define CUR_MEM_ADDR 0x0048 #define HW_VERSION 0x004c #define RD_FIFO 0x0050 #define SAMPLING_CLK_CFG 0x0090 #define SAMPLING_CLK_STATUS 0x0094 +#define QSPI_ALIGN_REQ 32 enum qspi_dir { QSPI_READ, QSPI_WRITE, }; +struct qspi_cmd_desc { + u32 data_address; + u32 next_descriptor; + u32 direction:1; + u32 multi_io_mode:3; + u32 reserved1:4; + u32 fragment:1; + u32 reserved2:7; + u32 length:16; +}; + struct qspi_xfer { union { const void *tx_buf; @@ -137,11 +156,23 @@ enum qspi_clocks { QSPI_NUM_CLKS }; +/* + * Number of entries in sgt returned from spi framework that- + * will be supported. Can be modified as required. + * In practice, given max_dma_len is 64KB, the number of + * entries is not expected to exceed 1. + */ +#define QSPI_MAX_SG 5 + struct qcom_qspi { void __iomem *base; struct device *dev; struct clk_bulk_data *clks; struct qspi_xfer xfer; + struct dma_pool *dma_cmd_pool; + dma_addr_t dma_cmd_desc[QSPI_MAX_SG]; + void *virt_cmd_desc[QSPI_MAX_SG]; + unsigned int n_cmd_desc; struct icc_path *icc_path_cpu_to_qspi; unsigned long last_speed; /* Lock to protect data accessed by IRQs */ @@ -153,21 +184,22 @@ static u32 qspi_buswidth_to_iomode(struct qcom_qspi *ctrl, { switch (buswidth) { case 1: - return SDR_1BIT << MULTI_IO_MODE_SHFT; + return SDR_1BIT; case 2: - return SDR_2BIT << MULTI_IO_MODE_SHFT; + return SDR_2BIT; case 4: - return SDR_4BIT << MULTI_IO_MODE_SHFT; + return SDR_4BIT; default: dev_warn_once(ctrl->dev, "Unexpected bus width: %u\n", buswidth); - return SDR_1BIT << MULTI_IO_MODE_SHFT; + return SDR_1BIT; } } static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl) { u32 pio_xfer_cfg; + u32 iomode; const struct qspi_xfer *xfer; xfer = &ctrl->xfer; @@ -179,7 +211,8 @@ static void qcom_qspi_pio_xfer_cfg(struct qcom_qspi *ctrl) else pio_xfer_cfg |= TRANSFER_FRAGMENT; pio_xfer_cfg &= ~MULTI_IO_MODE_MSK; - pio_xfer_cfg |= qspi_buswidth_to_iomode(ctrl, xfer->buswidth); + iomode = qspi_buswidth_to_iomode(ctrl, xfer->buswidth); + pio_xfer_cfg |= iomode << MULTI_IO_MODE_SHFT; writel(pio_xfer_cfg, ctrl->base + PIO_XFER_CFG); } @@ -217,12 +250,22 @@ static void qcom_qspi_pio_xfer(struct qcom_qspi *ctrl) static void qcom_qspi_handle_err(struct spi_master *master, struct spi_message *msg) { + u32 int_status; struct qcom_qspi *ctrl = spi_master_get_devdata(master); unsigned long flags; + int i; spin_lock_irqsave(&ctrl->lock, flags); writel(0, ctrl->base + MSTR_INT_EN); + int_status = readl(ctrl->base + MSTR_INT_STATUS); + writel(int_status, ctrl->base + MSTR_INT_STATUS); ctrl->xfer.rem_bytes = 0; + + /* free cmd descriptors if they are around (DMA mode) */ + for (i = 0; i < ctrl->n_cmd_desc; i++) + dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i], + ctrl->dma_cmd_desc[i]); + ctrl->n_cmd_desc = 0; spin_unlock_irqrestore(&ctrl->lock, flags); } @@ -242,7 +285,7 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz) } /* - * Set BW quota for CPU as driver supports FIFO mode only. + * Set BW quota for CPU. * We don't have explicit peak requirement so keep it equal to avg_bw. */ avg_bw_cpu = Bps_to_icc(speed_hz); @@ -258,6 +301,102 @@ static int qcom_qspi_set_speed(struct qcom_qspi *ctrl, unsigned long speed_hz) return 0; } +static int qcom_qspi_alloc_desc(struct qcom_qspi *ctrl, dma_addr_t dma_ptr, + uint32_t n_bytes) +{ + struct qspi_cmd_desc *virt_cmd_desc, *prev; + dma_addr_t dma_cmd_desc; + + /* allocate for dma cmd descriptor */ + virt_cmd_desc = dma_pool_alloc(ctrl->dma_cmd_pool, GFP_KERNEL | __GFP_ZERO, &dma_cmd_desc); + if (!virt_cmd_desc) + return -ENOMEM; + + ctrl->virt_cmd_desc[ctrl->n_cmd_desc] = virt_cmd_desc; + ctrl->dma_cmd_desc[ctrl->n_cmd_desc] = dma_cmd_desc; + ctrl->n_cmd_desc++; + + /* setup cmd descriptor */ + virt_cmd_desc->data_address = dma_ptr; + virt_cmd_desc->direction = ctrl->xfer.dir; + virt_cmd_desc->multi_io_mode = qspi_buswidth_to_iomode(ctrl, ctrl->xfer.buswidth); + virt_cmd_desc->fragment = !ctrl->xfer.is_last; + virt_cmd_desc->length = n_bytes; + + /* update previous descriptor */ + if (ctrl->n_cmd_desc >= 2) { + prev = (ctrl->virt_cmd_desc)[ctrl->n_cmd_desc - 2]; + prev->next_descriptor = dma_cmd_desc; + prev->fragment = 1; + } + + return 0; +} + +static int qcom_qspi_setup_dma_desc(struct qcom_qspi *ctrl, + struct spi_transfer *xfer) +{ + int ret; + struct sg_table *sgt; + dma_addr_t dma_ptr_sg; + unsigned int dma_len_sg; + int i; + + if (ctrl->n_cmd_desc) { + dev_err(ctrl->dev, "Remnant dma buffers n_cmd_desc-%d\n", ctrl->n_cmd_desc); + return -EIO; + } + + sgt = (ctrl->xfer.dir == QSPI_READ) ? &xfer->rx_sg : &xfer->tx_sg; + if (!sgt->nents || sgt->nents > QSPI_MAX_SG) { + dev_warn_once(ctrl->dev, "Cannot handle %d entries in scatter list\n", sgt->nents); + return -EAGAIN; + } + + for (i = 0; i < sgt->nents; i++) { + dma_ptr_sg = sg_dma_address(sgt->sgl + i); + if (!IS_ALIGNED(dma_ptr_sg, QSPI_ALIGN_REQ)) { + dev_warn_once(ctrl->dev, "dma_address not aligned to %d\n", QSPI_ALIGN_REQ); + return -EAGAIN; + } + } + + for (i = 0; i < sgt->nents; i++) { + dma_ptr_sg = sg_dma_address(sgt->sgl + i); + dma_len_sg = sg_dma_len(sgt->sgl + i); + + ret = qcom_qspi_alloc_desc(ctrl, dma_ptr_sg, dma_len_sg); + if (ret) + goto cleanup; + } + return 0; + +cleanup: + for (i = 0; i < ctrl->n_cmd_desc; i++) + dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i], + ctrl->dma_cmd_desc[i]); + ctrl->n_cmd_desc = 0; + return ret; +} + +static void qcom_qspi_dma_xfer(struct qcom_qspi *ctrl) +{ + /* Setup new interrupts */ + writel(DMA_CHAIN_DONE, ctrl->base + MSTR_INT_EN); + + /* kick off transfer */ + writel((u32)((ctrl->dma_cmd_desc)[0]), ctrl->base + NEXT_DMA_DESC_ADDR); +} + +/* Switch to DMA if transfer length exceeds this */ +#define QSPI_MAX_BYTES_FIFO 64 + +static bool qcom_qspi_can_dma(struct spi_controller *ctlr, + struct spi_device *slv, struct spi_transfer *xfer) +{ + return xfer->len > QSPI_MAX_BYTES_FIFO; +} + static int qcom_qspi_transfer_one(struct spi_master *master, struct spi_device *slv, struct spi_transfer *xfer) @@ -266,6 +405,7 @@ static int qcom_qspi_transfer_one(struct spi_master *master, int ret; unsigned long speed_hz; unsigned long flags; + u32 mstr_cfg; speed_hz = slv->max_speed_hz; if (xfer->speed_hz) @@ -276,6 +416,7 @@ static int qcom_qspi_transfer_one(struct spi_master *master, return ret; spin_lock_irqsave(&ctrl->lock, flags); + mstr_cfg = readl(ctrl->base + MSTR_CONFIG); /* We are half duplex, so either rx or tx will be set */ if (xfer->rx_buf) { @@ -290,10 +431,36 @@ static int qcom_qspi_transfer_one(struct spi_master *master, ctrl->xfer.is_last = list_is_last(&xfer->transfer_list, &master->cur_msg->transfers); ctrl->xfer.rem_bytes = xfer->len; + + if (xfer->rx_sg.nents || xfer->tx_sg.nents) { + /* do DMA transfer */ + if (!(mstr_cfg & DMA_ENABLE)) { + mstr_cfg |= DMA_ENABLE; + writel(mstr_cfg, ctrl->base + MSTR_CONFIG); + } + + ret = qcom_qspi_setup_dma_desc(ctrl, xfer); + if (ret != -EAGAIN) { + if (!ret) + qcom_qspi_dma_xfer(ctrl); + goto exit; + } + dev_warn_once(ctrl->dev, "DMA failure, falling back to PIO"); + ret = 0; /* We'll retry w/ PIO */ + } + + if (mstr_cfg & DMA_ENABLE) { + mstr_cfg &= ~DMA_ENABLE; + writel(mstr_cfg, ctrl->base + MSTR_CONFIG); + } qcom_qspi_pio_xfer(ctrl); +exit: spin_unlock_irqrestore(&ctrl->lock, flags); + if (ret) + return ret; + /* We'll call spi_finalize_current_transfer() when done */ return 1; } @@ -328,6 +495,16 @@ static int qcom_qspi_prepare_message(struct spi_master *master, return 0; } +static int qcom_qspi_alloc_dma(struct qcom_qspi *ctrl) +{ + ctrl->dma_cmd_pool = dmam_pool_create("qspi cmd desc pool", + ctrl->dev, sizeof(struct qspi_cmd_desc), 0, 0); + if (!ctrl->dma_cmd_pool) + return -ENOMEM; + + return 0; +} + static irqreturn_t pio_read(struct qcom_qspi *ctrl) { u32 rd_fifo_status; @@ -426,6 +603,7 @@ static irqreturn_t qcom_qspi_irq(int irq, void *dev_id) int_status = readl(ctrl->base + MSTR_INT_STATUS); writel(int_status, ctrl->base + MSTR_INT_STATUS); + /* PIO mode handling */ if (ctrl->xfer.dir == QSPI_WRITE) { if (int_status & WR_FIFO_EMPTY) ret = pio_write(ctrl); @@ -449,6 +627,22 @@ static irqreturn_t qcom_qspi_irq(int irq, void *dev_id) spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev)); } + /* DMA mode handling */ + if (int_status & DMA_CHAIN_DONE) { + int i; + + writel(0, ctrl->base + MSTR_INT_EN); + ctrl->xfer.rem_bytes = 0; + + for (i = 0; i < ctrl->n_cmd_desc; i++) + dma_pool_free(ctrl->dma_cmd_pool, ctrl->virt_cmd_desc[i], + ctrl->dma_cmd_desc[i]); + ctrl->n_cmd_desc = 0; + + ret = IRQ_HANDLED; + spi_finalize_current_transfer(dev_get_drvdata(ctrl->dev)); + } + spin_unlock(&ctrl->lock); return ret; } @@ -517,7 +711,13 @@ static int qcom_qspi_probe(struct platform_device *pdev) return ret; } + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32)); + if (ret) + return dev_err_probe(dev, ret, "could not set DMA mask\n"); + master->max_speed_hz = 300000000; + master->max_dma_len = 65536; /* as per HPG */ + master->dma_alignment = QSPI_ALIGN_REQ; master->num_chipselect = QSPI_NUM_CS; master->bus_num = -1; master->dev.of_node = pdev->dev.of_node; @@ -528,6 +728,8 @@ static int qcom_qspi_probe(struct platform_device *pdev) master->prepare_message = qcom_qspi_prepare_message; master->transfer_one = qcom_qspi_transfer_one; master->handle_err = qcom_qspi_handle_err; + if (of_property_read_bool(pdev->dev.of_node, "iommus")) + master->can_dma = qcom_qspi_can_dma; master->auto_runtime_pm = true; ret = devm_pm_opp_set_clkname(&pdev->dev, "core"); @@ -540,6 +742,10 @@ static int qcom_qspi_probe(struct platform_device *pdev) return ret; } + ret = qcom_qspi_alloc_dma(ctrl); + if (ret) + return ret; + pm_runtime_use_autosuspend(dev); pm_runtime_set_autosuspend_delay(dev, 250); pm_runtime_enable(dev);