From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753848Ab2IUMGu (ORCPT ); Fri, 21 Sep 2012 08:06:50 -0400 Received: from mga01.intel.com ([192.55.52.88]:55548 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752469Ab2IUMF5 (ORCPT ); Fri, 21 Sep 2012 08:05:57 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,462,1344236400"; d="scan'208";a="224857183" From: Andy Shevchenko To: Viresh Kumar , Vinod Koul , spear-devel@list.st.com, linux-kernel@vger.kernel.org, Hein Tibosch Cc: Andy Shevchenko Subject: [PATCHv2 3/6] dw_dmac: get number of channels from hardware if possible Date: Fri, 21 Sep 2012 15:05:46 +0300 Message-Id: <1348229149-29040-4-git-send-email-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1348229149-29040-1-git-send-email-andriy.shevchenko@linux.intel.com> References: <1347867577-13170-1-git-send-email-andriy.shevchenko@linux.intel.com> <1348229149-29040-1-git-send-email-andriy.shevchenko@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case the controller has the encoded parameters feature enabled the driver will use it to get the number of channels. In the future it will be used for the other important parameters as well. Signed-off-by: Andy Shevchenko --- drivers/dma/dw_dmac.c | 33 +++++++++++++++++++++++---------- 1 file changed, 23 insertions(+), 10 deletions(-) diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c index 2272f79..c964f6e 100644 --- a/drivers/dma/dw_dmac.c +++ b/drivers/dma/dw_dmac.c @@ -1381,6 +1381,10 @@ static int __devinit dw_probe(struct platform_device *pdev) struct resource *io; struct dw_dma *dw; size_t size; + void __iomem *regs; + bool autocfg; + unsigned int dw_params; + unsigned int nr_channels; int irq; int err; int i; @@ -1397,23 +1401,32 @@ static int __devinit dw_probe(struct platform_device *pdev) if (irq < 0) return irq; - size = sizeof(struct dw_dma); - size += pdata->nr_channels * sizeof(struct dw_dma_chan); + regs = devm_request_and_ioremap(&pdev->dev, io); + if (!regs) + return -EBUSY; + + dw_params = dma_read_byaddr(regs, DW_PARAMS); + autocfg = dw_params >> DW_PARAMS_EN & 0x1; + + if (autocfg) + nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 0x7) + 1; + else + nr_channels = pdata->nr_channels; + + size = sizeof(struct dw_dma) + nr_channels * sizeof(struct dw_dma_chan); dw = devm_kzalloc(&pdev->dev, size, GFP_KERNEL); if (!dw) return -ENOMEM; - dw->regs = devm_request_and_ioremap(&pdev->dev, io); - if (!dw->regs) - return -EBUSY; - dw->clk = devm_clk_get(&pdev->dev, "hclk"); if (IS_ERR(dw->clk)) return PTR_ERR(dw->clk); clk_prepare_enable(dw->clk); + dw->regs = regs; + /* Calculate all channel mask before DMA setup */ - dw->all_chan_mask = (1 << pdata->nr_channels) - 1; + dw->all_chan_mask = (1 << nr_channels) - 1; /* force dma off, just in case */ dw_dma_off(dw); @@ -1431,7 +1444,7 @@ static int __devinit dw_probe(struct platform_device *pdev) tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw); INIT_LIST_HEAD(&dw->dma.channels); - for (i = 0; i < pdata->nr_channels; i++) { + for (i = 0; i < nr_channels; i++) { struct dw_dma_chan *dwc = &dw->chan[i]; dwc->chan.device = &dw->dma; @@ -1444,7 +1457,7 @@ static int __devinit dw_probe(struct platform_device *pdev) /* 7 is highest priority & 0 is lowest. */ if (pdata->chan_priority == CHAN_PRIORITY_ASCENDING) - dwc->priority = pdata->nr_channels - i - 1; + dwc->priority = nr_channels - i - 1; else dwc->priority = i; @@ -1485,7 +1498,7 @@ static int __devinit dw_probe(struct platform_device *pdev) dma_writel(dw, CFG, DW_CFG_DMA_EN); printk(KERN_INFO "%s: DesignWare DMA Controller, %d channels\n", - dev_name(&pdev->dev), pdata->nr_channels); + dev_name(&pdev->dev), nr_channels); dma_async_device_register(&dw->dma); -- 1.7.10.4