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@xxxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: linux-i2c@xxxxxxxxxxxxxxx
---
Documentation/devicetree/bindings/i2c/i2c-mxs.txt | 12 ++++---
drivers/i2c/busses/i2c-mxs.c | 40 ++-------------------
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 7a3fe9e..4e1c8ac 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 120f246..d1ba6b4 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;
--
1.7.9.5
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