Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760047AbcKDH6I (ORCPT ); Fri, 4 Nov 2016 03:58:08 -0400 Received: from bear.ext.ti.com ([198.47.19.11]:58582 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757258AbcKDH6G (ORCPT ); Fri, 4 Nov 2016 03:58:06 -0400 From: Peter Ujfalusi To: , CC: , Subject: [PATCH v2] media: omap3isp: Use dma_request_chan_by_mask() to request the DMA channel Date: Fri, 4 Nov 2016 09:58:02 +0200 Message-ID: <20161104075802.19063-1-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.10.2 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2593 Lines: 83 When requesting the DMA channel it was mandatory that we do not have DMA resource nor valid DMA channel via DT. In this case the dma_request_slave_channel_compat() would fall back and request any channel with SW trigger. The same can be achieved with the dma_request_chan_by_mask() without the misleading use of the DMAengine API - implying that the omap3isp does need to have DMA resource or valid dma binding in DT. Signed-off-by: Peter Ujfalusi CC: Laurent Pinchart CC: Mauro Carvalho Chehab --- Hi, Changes sicne v1: - use dma_request_chan_by_mask() to request the channel as for the histogram data reading we do not have hw syncronisation. Add comment about this also to clarify the reason. Regards, Peter drivers/media/platform/omap3isp/isphist.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/drivers/media/platform/omap3isp/isphist.c b/drivers/media/platform/omap3isp/isphist.c index 7138b043a4aa..a4ed5d140d48 100644 --- a/drivers/media/platform/omap3isp/isphist.c +++ b/drivers/media/platform/omap3isp/isphist.c @@ -18,7 +18,6 @@ #include #include #include -#include #include #include @@ -486,27 +485,30 @@ int omap3isp_hist_init(struct isp_device *isp) hist->isp = isp; if (HIST_CONFIG_DMA) { - struct platform_device *pdev = to_platform_device(isp->dev); - struct resource *res; - unsigned int sig = 0; dma_cap_mask_t mask; + /* + * We need slave capable channel without DMA request line for + * reading out the data. + * For this we can use dma_request_chan_by_mask() as we are + * happy with any channel as long as it is capable of slave + * configuration. + */ dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); + hist->dma_ch = dma_request_chan_by_mask(&mask); + if (IS_ERR(hist->dma_ch)) { + ret = PTR_ERR(hist->dma_ch); + if (ret == -EPROBE_DEFER) + return ret; - res = platform_get_resource_byname(pdev, IORESOURCE_DMA, - "hist"); - if (res) - sig = res->start; - - hist->dma_ch = dma_request_slave_channel_compat(mask, - omap_dma_filter_fn, &sig, isp->dev, "hist"); - if (!hist->dma_ch) + hist->dma_ch = NULL; dev_warn(isp->dev, "hist: DMA channel request failed, using PIO\n"); - else + } else { dev_dbg(isp->dev, "hist: using DMA channel %s\n", dma_chan_name(hist->dma_ch)); + } } hist->ops = &hist_ops; -- 2.10.2