new file mode 100644
@@ -0,0 +1,48 @@
+* Freescale Direct Memory Access (DMA) Controller for i.MX
+
+This document will only describe differences to the generic DMA Controller and
+DMA request bindings as described in dma/dma.txt .
+
+* DMA controller
+
+Required properties:
+- compatible : Should be "fsl,<chip>-dma". chip can be imx1, imx21 or imx27
+- reg : Should contain DMA registers location and length
+- interrupts : First item should be DMA interrupt, second one is optional and
+ should contain DMA Error interrupt
+- #dma-cells : Has to be 1. imx-dma does not support anything else.
+
+Optional properties:
+- #dma-channels : Number of DMA channels supported. Should be 16.
+- #dma-requests : Number of DMA requests supported.
+
+Example:
+
+ dma: dma@10001000 {
+ compatible = "fsl,imx27-dma";
+ reg = <0x10001000 0x1000>;
+ interrupts = <32 33>;
+ #dma-cells = <1>;
+ #dma-channels = <16>;
+ };
+
+
+* DMA client
+
+Clients have to specify the DMA requests with phandles in a list.
+
+Required properties:
+- dmas: List of one or more DMA request specifiers. One DMA request specifier
+ consists of a phandle to the DMA controller followed by the integer
+ specifiying the request line.
+- dma-names: List of string identifiers for the DMA requests. For the correct
+ names, have a look at the specific client driver.
+
+Example:
+
+ sdhci1: sdhci@10013000 {
+ ...
+ dmas = <&dma 7>;
+ dma-names = "rx-tx";
+ ...
+ };
@@ -27,6 +27,8 @@
#include <linux/clk.h>
#include <linux/dmaengine.h>
#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of_dma.h>
#include <asm/irq.h>
#include <linux/platform_data/dma-imx.h>
@@ -186,6 +188,11 @@ struct imxdma_engine {
enum imx_dma_type devtype;
};
+struct imxdma_filter_data {
+ struct imxdma_engine *imxdma;
+ int request;
+};
+
static struct platform_device_id imx_dma_devtype[] = {
{
.name = "imx1-dma",
@@ -202,6 +209,22 @@ static struct platform_device_id imx_dma_devtype[] = {
};
MODULE_DEVICE_TABLE(platform, imx_dma_devtype);
+static const struct of_device_id imx_dma_of_dev_id[] = {
+ {
+ .compatible = "fsl,imx1-dma",
+ .data = &imx_dma_devtype[IMX1_DMA],
+ }, {
+ .compatible = "fsl,imx21-dma",
+ .data = &imx_dma_devtype[IMX21_DMA],
+ }, {
+ .compatible = "fsl,imx27-dma",
+ .data = &imx_dma_devtype[IMX27_DMA],
+ }, {
+ /* sentinel */
+ }
+};
+MODULE_DEVICE_TABLE(of, imx_dma_of_dev_id);
+
static inline int is_imx1_dma(struct imxdma_engine *imxdma)
{
return imxdma->devtype == IMX1_DMA;
@@ -996,13 +1019,50 @@ static void imxdma_issue_pending(struct dma_chan *chan)
spin_unlock_irqrestore(&imxdma->lock, flags);
}
+static bool imxdma_filter_fn(struct dma_chan *chan, void *param)
+{
+ struct imxdma_filter_data *fdata = param;
+ struct imxdma_channel *imxdma_chan = to_imxdma_chan(chan);
+
+ if (chan->device->dev != fdata->imxdma->dev)
+ return false;
+
+ imxdma_chan->dma_request = fdata->request;
+ chan->private = NULL;
+
+ return true;
+}
+
+static struct dma_chan *imxdma_xlate(struct of_phandle_args *dma_spec,
+ struct of_dma *ofdma)
+{
+ int count = dma_spec->args_count;
+ struct imxdma_engine *imxdma = ofdma->of_dma_data;
+ struct imxdma_filter_data fdata = {
+ .imxdma = imxdma,
+ };
+
+ if (count != 1)
+ return NULL;
+
+ fdata.request = dma_spec->args[0];
+
+ return dma_request_channel(imxdma->dma_device.cap_mask,
+ imxdma_filter_fn, &fdata);
+}
+
static int __init imxdma_probe(struct platform_device *pdev)
{
struct imxdma_engine *imxdma;
struct resource *res;
+ const struct of_device_id *of_id;
int ret, i;
int irq, irq_err;
+ of_id = of_match_device(imx_dma_of_dev_id, &pdev->dev);
+ if (of_id)
+ pdev->id_entry = of_id->data;
+
imxdma = devm_kzalloc(&pdev->dev, sizeof(*imxdma), GFP_KERNEL);
if (!imxdma)
return -ENOMEM;
@@ -1136,8 +1196,19 @@ static int __init imxdma_probe(struct platform_device *pdev)
goto err;
}
+ if (pdev->dev.of_node) {
+ ret = of_dma_controller_register(pdev->dev.of_node,
+ imxdma_xlate, imxdma);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to register of_dma_controller\n");
+ goto err_of_dma_controller;
+ }
+ }
+
return 0;
+err_of_dma_controller:
+ dma_async_device_unregister(&imxdma->dma_device);
err:
clk_disable_unprepare(imxdma->dma_ipg);
clk_disable_unprepare(imxdma->dma_ahb);
@@ -1150,6 +1221,9 @@ static int imxdma_remove(struct platform_device *pdev)
dma_async_device_unregister(&imxdma->dma_device);
+ if (pdev->dev.of_node)
+ of_dma_controller_free(pdev->dev.of_node);
+
clk_disable_unprepare(imxdma->dma_ipg);
clk_disable_unprepare(imxdma->dma_ahb);
@@ -1159,6 +1233,7 @@ static int imxdma_remove(struct platform_device *pdev)
static struct platform_driver imxdma_driver = {
.driver = {
.name = "imx-dma",
+ .of_match_table = imx_dma_of_dev_id,
},
.id_table = imx_dma_devtype,
.remove = imxdma_remove,
@@ -60,10 +60,8 @@ static inline int imx_dma_is_ipu(struct dma_chan *chan)
static inline int imx_dma_is_general_purpose(struct dma_chan *chan)
{
- return strstr(dev_name(chan->device->dev), "sdma") ||
- !strcmp(dev_name(chan->device->dev), "imx1-dma") ||
- !strcmp(dev_name(chan->device->dev), "imx21-dma") ||
- !strcmp(dev_name(chan->device->dev), "imx27-dma");
+ return !strcmp(chan->device->dev->driver->name, "imx-sdma") ||
+ !strcmp(chan->device->dev->driver->name, "imx-dma");
}
#endif