| Message ID | 1461136800-20334-2-git-send-email-appanad@xilinx.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi, thanks for looking into this. On Wed, Apr 20, 2016 at 12:20 AM, Kedareswara rao Appana <appana.durga.rao@xilinx.com> wrote: > +static int xdma_clk_init(struct xilinx_dma_device *xdev, bool enable) > +{ > + int i = 0, ret; > + > + for (i = 0; i < xdev->numclks; i++) { > + if (enable) { > + ret = clk_prepare_enable(xdev->clks[i]); > + if (ret) { > + dev_err(xdev->dev, > + "failed to enable the axidma clock\n"); > + return ret; What happens to the ones you already turned on, if say the third fails? Cheers, Moritz
Hi Moritz,
Thanks for the review...
> -----Original Message-----
> From: Moritz Fischer [mailto:moritz.fischer@ettus.com]
> Sent: Thursday, April 21, 2016 12:09 AM
> To: Appana Durga Kedareswara Rao <appanad@xilinx.com>
> Cc: Rob Herring <robh+dt@kernel.org>; pawel.moll@arm.com; Mark Rutland
> <mark.rutland@arm.com>; Ian Campbell <ijc+devicetree@hellion.org.uk>;
> Kumar Gala <galak@codeaurora.org>; Michal Simek <michals@xilinx.com>;
> Soren Brinkmann <sorenb@xilinx.com>; Vinod Koul <vinod.koul@intel.com>;
> Dan Williams <dan.j.williams@intel.com>; Appana Durga Kedareswara Rao
> <appanad@xilinx.com>; Laurent Pinchart
> <laurent.pinchart@ideasonboard.com>; Luis de Bethencourt
> <luis@debethencourt.com>; Anirudha Sarangi <anirudh@xilinx.com>; Punnaiah
> Choudary Kalluri <punnaia@xilinx.com>; Devicetree List
> <devicetree@vger.kernel.org>; linux-arm-kernel <linux-arm-
> kernel@lists.infradead.org>; Linux Kernel Mailing List <linux-
> kernel@vger.kernel.org>; dmaengine@vger.kernel.org
> Subject: Re: [PATCH 2/2] dmaengine: vdma: Add clock support
>
> Hi,
>
> thanks for looking into this.
>
> On Wed, Apr 20, 2016 at 12:20 AM, Kedareswara rao Appana
> <appana.durga.rao@xilinx.com> wrote:
>
> > +static int xdma_clk_init(struct xilinx_dma_device *xdev, bool enable)
> > +{
> > + int i = 0, ret;
> > +
> > + for (i = 0; i < xdev->numclks; i++) {
> > + if (enable) {
> > + ret = clk_prepare_enable(xdev->clks[i]);
> > + if (ret) {
> > + dev_err(xdev->dev,
> > + "failed to enable the axidma clock\n");
> > + return ret;
>
> What happens to the ones you already turned on, if say the third fails?
Will fix in the next version of the patch...
Regards,
Kedar.
>
> Cheers,
>
> Moritz
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diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c index 70caea6..d526029 100644 --- a/drivers/dma/xilinx/xilinx_vdma.c +++ b/drivers/dma/xilinx/xilinx_vdma.c @@ -44,6 +44,7 @@ #include <linux/of_platform.h> #include <linux/of_irq.h> #include <linux/slab.h> +#include <linux/clk.h> #include "../dmaengine.h" @@ -352,6 +353,8 @@ struct xilinx_dma_chan { * @flush_on_fsync: Flush on frame sync * @ext_addr: Indicates 64 bit addressing is supported by dma device * @dmatype: DMA ip type + * @clks: pointer to array of clocks + * @numclks: number of clocks available */ struct xilinx_dma_device { void __iomem *regs; @@ -362,6 +365,8 @@ struct xilinx_dma_device { u32 flush_on_fsync; bool ext_addr; enum xdma_ip_type dmatype; + struct clk **clks; + int numclks; }; /* Macros */ @@ -1731,6 +1736,26 @@ int xilinx_vdma_channel_set_config(struct dma_chan *dchan, } EXPORT_SYMBOL(xilinx_vdma_channel_set_config); +static int xdma_clk_init(struct xilinx_dma_device *xdev, bool enable) +{ + int i = 0, ret; + + for (i = 0; i < xdev->numclks; i++) { + if (enable) { + ret = clk_prepare_enable(xdev->clks[i]); + if (ret) { + dev_err(xdev->dev, + "failed to enable the axidma clock\n"); + return ret; + } + } else { + clk_disable_unprepare(xdev->clks[i]); + } + } + + return 0; +} + /* ----------------------------------------------------------------------------- * Probe and remove */ @@ -1919,6 +1944,7 @@ static int xilinx_dma_probe(struct platform_device *pdev) struct resource *io; u32 num_frames, addr_width; int i, err; + const char *str; /* Allocate and initialize the DMA engine structure */ xdev = devm_kzalloc(&pdev->dev, sizeof(*xdev), GFP_KERNEL); @@ -1965,6 +1991,32 @@ static int xilinx_dma_probe(struct platform_device *pdev) /* Set the dma mask bits */ dma_set_mask(xdev->dev, DMA_BIT_MASK(addr_width)); + xdev->numclks = of_property_count_strings(pdev->dev.of_node, + "clock-names"); + if (xdev->numclks > 0) { + xdev->clks = devm_kmalloc_array(&pdev->dev, xdev->numclks, + sizeof(struct clk *), + GFP_KERNEL); + if (!xdev->clks) + return -ENOMEM; + + for (i = 0; i < xdev->numclks; i++) { + of_property_read_string_index(pdev->dev.of_node, + "clock-names", i, &str); + xdev->clks[i] = devm_clk_get(xdev->dev, str); + if (IS_ERR(xdev->clks[i])) { + if (PTR_ERR(xdev->clks[i]) == -ENOENT) + xdev->clks[i] = NULL; + else + return PTR_ERR(xdev->clks[i]); + } + } + + err = xdma_clk_init(xdev, true); + if (err) + return err; + } + /* Initialize the DMA engine */ xdev->common.dev = &pdev->dev; @@ -2025,6 +2077,8 @@ static int xilinx_dma_probe(struct platform_device *pdev) return 0; error: + if (xdev->numclks > 0) + xdma_clk_init(xdev, false); for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++) if (xdev->chan[i]) xilinx_dma_chan_remove(xdev->chan[i]); @@ -2050,6 +2104,8 @@ static int xilinx_dma_remove(struct platform_device *pdev) for (i = 0; i < XILINX_DMA_MAX_CHANS_PER_DEVICE; i++) if (xdev->chan[i]) xilinx_dma_chan_remove(xdev->chan[i]); + if (xdev->numclks > 0) + xdma_clk_init(xdev, false); return 0; }
Added basic clock support. The clocks are requested at probe and released at remove. Signed-off-by: Kedareswara rao Appana <appanad@xilinx.com> --- drivers/dma/xilinx/xilinx_vdma.c | 56 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)