From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guodong Xu Subject: [PATCH v2 2/4] k3dma: add support to reserved minimum channels Date: Fri, 6 Jul 2018 11:55:19 +0800 Message-ID: <20180706035521.13736-3-guodong.xu@linaro.org> References: <20180706035521.13736-1-guodong.xu@linaro.org> Return-path: In-Reply-To: <20180706035521.13736-1-guodong.xu@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: vkoul@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, dan.j.williams@intel.com, xuwei5@hisilicon.com, catalin.marinas@arm.com, will.deacon@arm.com Cc: liyu65@hisilicon.com, suzhuangluan@hisilicon.com, xuhongtao8@hisilicon.com, zhongkaihua@huawei.com, xuezhiliang@hisilicon.com, xupeng7@huawei.com, sunliang10@huawei.com, fengbaopeng@hisilicon.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Guodong Xu List-Id: devicetree@vger.kernel.org From: Li Yu On k3 series of SoC, DMA controller reserves some channels for other on-chip coprocessors. By reading property "hisilicon,dma-min-chan" from dts node, kernel will not use these reserved channels. As an example, on Hi3660, channel 0 is reserved for lpm3. Refer to Documentation/devicetree/bindings/dma/k3dma.txt for more information. Signed-off-by: Li Yu Signed-off-by: Guodong Xu --- drivers/dma/k3dma.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/dma/k3dma.c b/drivers/dma/k3dma.c index fa31cccbe04f..33efb541acb2 100644 --- a/drivers/dma/k3dma.c +++ b/drivers/dma/k3dma.c @@ -113,6 +113,7 @@ struct k3_dma_dev { struct dma_pool *pool; u32 dma_channels; u32 dma_requests; + u32 dma_min_chan; unsigned int irq; }; @@ -309,7 +310,7 @@ static void k3_dma_tasklet(unsigned long arg) /* check new channel request in d->chan_pending */ spin_lock_irq(&d->lock); - for (pch = 0; pch < d->dma_channels; pch++) { + for (pch = d->dma_min_chan; pch < d->dma_channels; pch++) { p = &d->phy[pch]; if (p->vchan == NULL && !list_empty(&d->chan_pending)) { @@ -326,7 +327,7 @@ static void k3_dma_tasklet(unsigned long arg) } spin_unlock_irq(&d->lock); - for (pch = 0; pch < d->dma_channels; pch++) { + for (pch = d->dma_min_chan; pch < d->dma_channels; pch++) { if (pch_alloc & (1 << pch)) { p = &d->phy[pch]; c = p->vchan; @@ -825,6 +826,8 @@ static int k3_dma_probe(struct platform_device *op) "dma-channels", &d->dma_channels); of_property_read_u32((&op->dev)->of_node, "dma-requests", &d->dma_requests); + of_property_read_u32((&op->dev)->of_node, + "hisilicon,dma-min-chan", &d->dma_min_chan); } d->clk = devm_clk_get(&op->dev, NULL); @@ -848,12 +851,12 @@ static int k3_dma_probe(struct platform_device *op) return -ENOMEM; /* init phy channel */ - d->phy = devm_kcalloc(&op->dev, - d->dma_channels, sizeof(struct k3_dma_phy), GFP_KERNEL); + d->phy = devm_kcalloc(&op->dev, (d->dma_channels - d->dma_min_chan), + sizeof(struct k3_dma_phy), GFP_KERNEL); if (d->phy == NULL) return -ENOMEM; - for (i = 0; i < d->dma_channels; i++) { + for (i = d->dma_min_chan; i < d->dma_channels; i++) { struct k3_dma_phy *p = &d->phy[i]; p->idx = i; -- 2.17.1