i2c: i2c-mxs: move to use generic DMA helper

With the generic DMA device tree helper supported by mxs-dma driver,
client devices only need to call dma_request_slave_channel() for
requesting a DMA channel from dmaengine.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Wolfram Sang <wsa@the-dreams.de>

2 files changed, 11 insertions, 41 deletions

diff --git a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt
index 7a3fe9e5f4cb..4e1c8ac01eba 100644
--- a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt
+++ b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt
@@ -3,10 +3,13 @@
 Required properties:
 - compatible: Should be "fsl,<chip>-i2c"
 - reg: Should contain registers location and length
-- interrupts: Should contain ERROR and DMA interrupts
+- interrupts: Should contain ERROR interrupt number
 - clock-frequency: Desired I2C bus clock frequency in Hz.
                    Only 100000Hz and 400000Hz modes are supported.
-- fsl,i2c-dma-channel: APBX DMA channel for the I2C
+- dmas: DMA specifier, consisting of a phandle to DMA controller node
+  and I2C DMA channel ID.
+  Refer to dma.txt and fsl-mxs-dma.txt for details.
+- dma-names: Must be "rx-tx".
 
 Examples:
 
@@ -15,7 +18,8 @@ i2c0: i2c@80058000 {
         #size-cells = <0>;
         compatible = "fsl,imx28-i2c";
         reg = <0x80058000 2000>;
-        interrupts = <111 68>;
+        interrupts = <111>;
         clock-frequency = <100000>;
-        fsl,i2c-dma-channel = <6>;
+        dmas = <&dma_apbx 6>;
+        dma-names = "rx-tx";
 };
diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c
index 120f24646696..d1ba6b403b84 100644
--- a/drivers/i2c/busses/i2c-mxs.c
+++ b/drivers/i2c/busses/i2c-mxs.c
@@ -31,7 +31,6 @@
 #include <linux/of_i2c.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
-#include <linux/fsl/mxs-dma.h>
 
 #define DRIVER_NAME "mxs-i2c"
 
@@ -113,9 +112,7 @@ struct mxs_i2c_dev {
         uint32_t timing1;
 
         /* DMA support components */
-        int                             dma_channel;
         struct dma_chan                 *dmach;
-        struct mxs_dma_data             dma_data;
         uint32_t                        pio_data[2];
         uint32_t                        addr_data;
         struct scatterlist              sg_io[2];
@@ -518,21 +515,6 @@ static const struct i2c_algorithm mxs_i2c_algo = {
         .functionality = mxs_i2c_func,
 };
 
-static bool mxs_i2c_dma_filter(struct dma_chan *chan, void *param)
-{
-        struct mxs_i2c_dev *i2c = param;
-
-        if (!mxs_dma_is_apbx(chan))
-                return false;
-
-        if (chan->chan_id != i2c->dma_channel)
-                return false;
-
-        chan->private = &i2c->dma_data;
-
-        return true;
-}
-
 static void mxs_i2c_derive_timing(struct mxs_i2c_dev *i2c, int speed)
 {
         /* The I2C block clock run at 24MHz */
@@ -577,17 +559,6 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c)
         struct device_node *node = dev->of_node;
         int ret;
 
-        /*
-         * TODO: This is a temporary solution and should be changed
-         * to use generic DMA binding later when the helpers get in.
-         */
-        ret = of_property_read_u32(node, "fsl,i2c-dma-channel",
-                                   &i2c->dma_channel);
-        if (ret) {
-                dev_err(dev, "Failed to get DMA channel!\n");
-                return -ENODEV;
-        }
-
         ret = of_property_read_u32(node, "clock-frequency", &speed);
         if (ret) {
                 dev_warn(dev, "No I2C speed selected, using 100kHz\n");
@@ -607,8 +578,7 @@ static int mxs_i2c_probe(struct platform_device *pdev)
         struct pinctrl *pinctrl;
         struct resource *res;
         resource_size_t res_size;
-        int err, irq, dmairq;
-        dma_cap_mask_t mask;
+        int err, irq;
 
         pinctrl = devm_pinctrl_get_select_default(dev);
         if (IS_ERR(pinctrl))
@@ -620,9 +590,8 @@ static int mxs_i2c_probe(struct platform_device *pdev)
 
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         irq = platform_get_irq(pdev, 0);
-        dmairq = platform_get_irq(pdev, 1);
 
-        if (!res || irq < 0 || dmairq < 0)
+        if (!res || irq < 0)
                 return -ENOENT;
 
         res_size = resource_size(res);
@@ -648,10 +617,7 @@ static int mxs_i2c_probe(struct platform_device *pdev)
         }
 
         /* Setup the DMA */
-        dma_cap_zero(mask);
-        dma_cap_set(DMA_SLAVE, mask);
-        i2c->dma_data.chan_irq = dmairq;
-        i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c);
+        i2c->dmach = dma_request_slave_channel(dev, "rx-tx");
         if (!i2c->dmach) {
                 dev_err(dev, "Failed to request dma\n");
                 return -ENODEV;