From nobody Wed Jul 1 14:37:25 2026 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 BD8E7C4332F for ; Mon, 20 Dec 2021 19:09:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240730AbhLTTJB (ORCPT ); Mon, 20 Dec 2021 14:09:01 -0500 Received: from aposti.net ([89.234.176.197]:34358 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240701AbhLTTI7 (ORCPT ); Mon, 20 Dec 2021 14:08:59 -0500 From: Paul Cercueil To: Ulf Hansson , Rob Herring Cc: list@opendingux.net, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, Paul Cercueil Subject: [PATCH 1/2] dt-bindings: mmc: ingenic: Support using bi-directional DMA channel Date: Mon, 20 Dec 2021 19:08:39 +0000 Message-Id: <20211220190840.108061-2-paul@crapouillou.net> In-Reply-To: <20211220190840.108061-1-paul@crapouillou.net> References: <20211220190840.108061-1-paul@crapouillou.net> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Update the binding documentation and the examples to support bi-directional DMA channels. Signed-off-by: Paul Cercueil --- .../devicetree/bindings/mmc/ingenic,mmc.yaml | 37 ++++++++++++++++--- 1 file changed, 31 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml b/Docum= entation/devicetree/bindings/mmc/ingenic,mmc.yaml index 01d5c6da0eeb..2d10aedf2e00 100644 --- a/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml +++ b/Documentation/devicetree/bindings/mmc/ingenic,mmc.yaml @@ -39,14 +39,15 @@ properties: const: mmc =20 dmas: - items: - - description: DMA controller phandle and request line for RX - - description: DMA controller phandle and request line for TX + minItems: 1 + maxItems: 2 =20 dma-names: - items: - - const: rx - - const: tx + oneOf: + - items: + - const: rx + - const: tx + - const: tx-rx =20 required: - compatible @@ -80,3 +81,27 @@ examples: <&dma JZ4780_DMA_MSC0_TX 0xffffffff>; dma-names =3D "rx", "tx"; }; + - | + #include + #include + /* + * Alternative version of the example above, + * but using one single DMA channel for both + * TX and RX. + */ + mmc1: mmc@13460000 { + compatible =3D "ingenic,jz4780-mmc"; + reg =3D <0x13460000 0x1000>; + + interrupt-parent =3D <&intc>; + interrupts =3D <36>; + + clocks =3D <&cgu JZ4780_CLK_MSC1>; + clock-names =3D "mmc"; + + cap-sd-highspeed; + cap-mmc-highspeed; + cap-sdio-irq; + dmas =3D <&dma JZ4780_DMA_MSC1_TX JZ4780_DMA_MSC1_RX 0xffffffff>; + dma-names =3D "tx-rx"; + }; --=20 2.34.1 From nobody Wed Jul 1 14:37:25 2026 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 DEF02C433EF for ; Mon, 20 Dec 2021 19:09:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240560AbhLTTJL (ORCPT ); Mon, 20 Dec 2021 14:09:11 -0500 Received: from aposti.net ([89.234.176.197]:34378 "EHLO aposti.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240733AbhLTTJH (ORCPT ); Mon, 20 Dec 2021 14:09:07 -0500 From: Paul Cercueil To: Ulf Hansson , Rob Herring Cc: list@opendingux.net, linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, Paul Cercueil Subject: [PATCH 2/2] mmc: jz4740: Support using a bi-directional DMA channel Date: Mon, 20 Dec 2021 19:08:40 +0000 Message-Id: <20211220190840.108061-3-paul@crapouillou.net> In-Reply-To: <20211220190840.108061-1-paul@crapouillou.net> References: <20211220190840.108061-1-paul@crapouillou.net> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Since the MMC/SD controller in Ingenic SoCs work in half-duplex, it is possible to use one single DMA channel for both TX and RX operations, instead of using separate channels. As some older Ingenic SoCs offer only a handful of DMA channels, supporting bi-directional channels allow more hardware to use the channels that would otherwise be used for the MMC/SD operation. Signed-off-by: Paul Cercueil --- drivers/mmc/host/jz4740_mmc.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/jz4740_mmc.c b/drivers/mmc/host/jz4740_mmc.c index 80a2c270d502..a0b94f61ddcf 100644 --- a/drivers/mmc/host/jz4740_mmc.c +++ b/drivers/mmc/host/jz4740_mmc.c @@ -217,11 +217,23 @@ static void jz4740_mmc_release_dma_channels(struct jz= 4740_mmc_host *host) return; =20 dma_release_channel(host->dma_tx); - dma_release_channel(host->dma_rx); + if (host->dma_rx) + dma_release_channel(host->dma_rx); } =20 static int jz4740_mmc_acquire_dma_channels(struct jz4740_mmc_host *host) { + struct device *dev =3D mmc_dev(host->mmc); + + host->dma_tx =3D dma_request_chan(dev, "tx-rx"); + if (!IS_ERR(host->dma_tx)) + return 0; + + if (PTR_ERR(host->dma_tx) !=3D -ENODEV) { + dev_err(dev, "Failed to get dma tx-rx channel\n"); + return PTR_ERR(host->dma_tx); + } + host->dma_tx =3D dma_request_chan(mmc_dev(host->mmc), "tx"); if (IS_ERR(host->dma_tx)) { dev_err(mmc_dev(host->mmc), "Failed to get dma_tx channel\n"); @@ -241,7 +253,10 @@ static int jz4740_mmc_acquire_dma_channels(struct jz47= 40_mmc_host *host) static inline struct dma_chan *jz4740_mmc_get_dma_chan(struct jz4740_mmc_h= ost *host, struct mmc_data *data) { - return (data->flags & MMC_DATA_READ) ? host->dma_rx : host->dma_tx; + if ((data->flags & MMC_DATA_READ) && host->dma_rx) + return host->dma_rx; + else + return host->dma_tx; } =20 static void jz4740_mmc_dma_unmap(struct jz4740_mmc_host *host, --=20 2.34.1