From mboxrd@z Thu Jan 1 00:00:00 1970 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 7D56CC433FE for ; Tue, 15 Feb 2022 12:06:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234984AbiBOMGn (ORCPT ); Tue, 15 Feb 2022 07:06:43 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:46418 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237465AbiBOMGm (ORCPT ); Tue, 15 Feb 2022 07:06:42 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09E624BFD8; Tue, 15 Feb 2022 04:06:31 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 26B1CB81865; Tue, 15 Feb 2022 12:06:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1AB2C340ED; Tue, 15 Feb 2022 12:06:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1644926788; bh=Sv9IrvT5EE6VlBqnofRFBXi83PWWmXl7XCHCvVMjTJ0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TC0Q5IOz+/cfPgB6GZyxOj2vONGKWZOSW/Ih1uRBCYZR1Qmj609401JmPDeVKJZJ3 tUJ68Ul/5/LUNCQjg/FHvkmz1iyzTxYBvADGDT8JnTPNvxkhMnzDuLyBQngMdIKq8q mDkmuHzn7rbo+0J65Jg4/Dxx6b9jos6tA481AdD3ayv2ZtrFvoNVg5yIBBpj2tyTux NcTv+R2NBbZ+ZFzKMLd5xkWgPYDzi0dLU03inPV00eC7jyO+G1xVofCFGfU8gVF/dD aYUugWTkbiPCi06+F1joVdES+3TFhBaR264LZSVO9guNuti4oNhuKlTrIO7kllJIK8 nArzNJO2zQbEg== Date: Tue, 15 Feb 2022 17:36:24 +0530 From: Vinod Koul To: Zong Li Cc: robh+dt@kernel.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, krzysztof.kozlowski@canonical.com, conor.dooley@microchip.com, geert@linux-m68k.org, bin.meng@windriver.com, green.wan@sifive.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org Subject: Re: [PATCH v5 3/3] dmaengine: sf-pdma: Get number of channel by device tree Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 07-02-22, 14:30, Zong Li wrote: > It currently assumes that there are always four channels, it would > cause the error if there is actually less than four channels. Change > that by getting number of channel from device tree. > > For backwards-compatibility, it uses the default value (i.e. 4) when > there is no 'dma-channels' information in dts. > > Signed-off-by: Zong Li > --- > drivers/dma/sf-pdma/sf-pdma.c | 21 ++++++++++++++------- > drivers/dma/sf-pdma/sf-pdma.h | 8 ++------ > 2 files changed, 16 insertions(+), 13 deletions(-) > > diff --git a/drivers/dma/sf-pdma/sf-pdma.c b/drivers/dma/sf-pdma/sf-pdma.c > index f12606aeff87..2ae10b61dfa1 100644 > --- a/drivers/dma/sf-pdma/sf-pdma.c > +++ b/drivers/dma/sf-pdma/sf-pdma.c > @@ -482,9 +482,7 @@ static void sf_pdma_setup_chans(struct sf_pdma *pdma) > static int sf_pdma_probe(struct platform_device *pdev) > { > struct sf_pdma *pdma; > - struct sf_pdma_chan *chan; > struct resource *res; > - int len, chans; > int ret; > const enum dma_slave_buswidth widths = > DMA_SLAVE_BUSWIDTH_1_BYTE | DMA_SLAVE_BUSWIDTH_2_BYTES | > @@ -492,13 +490,21 @@ static int sf_pdma_probe(struct platform_device *pdev) > DMA_SLAVE_BUSWIDTH_16_BYTES | DMA_SLAVE_BUSWIDTH_32_BYTES | > DMA_SLAVE_BUSWIDTH_64_BYTES; > > - chans = PDMA_NR_CH; > - len = sizeof(*pdma) + sizeof(*chan) * chans; > - pdma = devm_kzalloc(&pdev->dev, len, GFP_KERNEL); > + pdma = devm_kzalloc(&pdev->dev, sizeof(*pdma), GFP_KERNEL); > if (!pdma) > return -ENOMEM; > > - pdma->n_chans = chans; > + ret = of_property_read_u32(pdev->dev.of_node, "dma-channels", > + &pdma->n_chans); > + if (ret) { > + dev_notice(&pdev->dev, "set number of channels to default value: 4\n"); This is useful for only debug i think, so dev_dbg perhaps > + pdma->n_chans = PDMA_MAX_NR_CH; > + } > + > + if (pdma->n_chans > PDMA_MAX_NR_CH) { > + dev_err(&pdev->dev, "the number of channels exceeds the maximum\n"); > + return -EINVAL; > + } > > res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > pdma->membase = devm_ioremap_resource(&pdev->dev, res); > @@ -556,7 +562,7 @@ static int sf_pdma_remove(struct platform_device *pdev) > struct sf_pdma_chan *ch; > int i; > > - for (i = 0; i < PDMA_NR_CH; i++) { > + for (i = 0; i < pdma->n_chans; i++) { > ch = &pdma->chans[i]; > > devm_free_irq(&pdev->dev, ch->txirq, ch); > @@ -574,6 +580,7 @@ static int sf_pdma_remove(struct platform_device *pdev) > > static const struct of_device_id sf_pdma_dt_ids[] = { > { .compatible = "sifive,fu540-c000-pdma" }, > + { .compatible = "sifive,pdma0" }, > {}, > }; > MODULE_DEVICE_TABLE(of, sf_pdma_dt_ids); > diff --git a/drivers/dma/sf-pdma/sf-pdma.h b/drivers/dma/sf-pdma/sf-pdma.h > index 0c20167b097d..8127d792f639 100644 > --- a/drivers/dma/sf-pdma/sf-pdma.h > +++ b/drivers/dma/sf-pdma/sf-pdma.h > @@ -22,11 +22,7 @@ > #include "../dmaengine.h" > #include "../virt-dma.h" > > -#define PDMA_NR_CH 4 > - > -#if (PDMA_NR_CH != 4) > -#error "Please define PDMA_NR_CH to 4" > -#endif > +#define PDMA_MAX_NR_CH 4 > > #define PDMA_BASE_ADDR 0x3000000 > #define PDMA_CHAN_OFFSET 0x1000 > @@ -118,7 +114,7 @@ struct sf_pdma { > void __iomem *membase; > void __iomem *mappedbase; > u32 n_chans; > - struct sf_pdma_chan chans[PDMA_NR_CH]; > + struct sf_pdma_chan chans[PDMA_MAX_NR_CH]; why waste memory allocating max, we know number of channels in probe, why not allocate runtime? -- ~Vinod