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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>
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2 changed files with 11 additions and 41 deletions
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@ -3,10 +3,13 @@
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Required properties:
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- compatible: Should be "fsl,<chip>-i2c"
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- reg: Should contain registers location and length
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- interrupts: Should contain ERROR and DMA interrupts
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- interrupts: Should contain ERROR interrupt number
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- clock-frequency: Desired I2C bus clock frequency in Hz.
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Only 100000Hz and 400000Hz modes are supported.
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- fsl,i2c-dma-channel: APBX DMA channel for the I2C
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- dmas: DMA specifier, consisting of a phandle to DMA controller node
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and I2C DMA channel ID.
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Refer to dma.txt and fsl-mxs-dma.txt for details.
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- dma-names: Must be "rx-tx".
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Examples:
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@ -15,7 +18,8 @@ i2c0: i2c@80058000 {
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#size-cells = <0>;
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compatible = "fsl,imx28-i2c";
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reg = <0x80058000 2000>;
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interrupts = <111 68>;
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interrupts = <111>;
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clock-frequency = <100000>;
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fsl,i2c-dma-channel = <6>;
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dmas = <&dma_apbx 6>;
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dma-names = "rx-tx";
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};
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@ -31,7 +31,6 @@
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#include <linux/of_i2c.h>
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#include <linux/dma-mapping.h>
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#include <linux/dmaengine.h>
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#include <linux/fsl/mxs-dma.h>
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#define DRIVER_NAME "mxs-i2c"
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@ -113,9 +112,7 @@ struct mxs_i2c_dev {
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uint32_t timing1;
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/* DMA support components */
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int dma_channel;
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struct dma_chan *dmach;
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struct mxs_dma_data dma_data;
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uint32_t pio_data[2];
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uint32_t addr_data;
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struct scatterlist sg_io[2];
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@ -518,21 +515,6 @@ static const struct i2c_algorithm mxs_i2c_algo = {
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.functionality = mxs_i2c_func,
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};
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static bool mxs_i2c_dma_filter(struct dma_chan *chan, void *param)
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{
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struct mxs_i2c_dev *i2c = param;
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if (!mxs_dma_is_apbx(chan))
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return false;
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if (chan->chan_id != i2c->dma_channel)
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return false;
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chan->private = &i2c->dma_data;
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return true;
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}
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static void mxs_i2c_derive_timing(struct mxs_i2c_dev *i2c, int speed)
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{
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/* The I2C block clock run at 24MHz */
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@ -577,17 +559,6 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c)
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struct device_node *node = dev->of_node;
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int ret;
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/*
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* TODO: This is a temporary solution and should be changed
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* to use generic DMA binding later when the helpers get in.
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*/
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ret = of_property_read_u32(node, "fsl,i2c-dma-channel",
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&i2c->dma_channel);
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if (ret) {
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dev_err(dev, "Failed to get DMA channel!\n");
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return -ENODEV;
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}
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ret = of_property_read_u32(node, "clock-frequency", &speed);
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if (ret) {
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dev_warn(dev, "No I2C speed selected, using 100kHz\n");
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@ -607,8 +578,7 @@ static int mxs_i2c_probe(struct platform_device *pdev)
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struct pinctrl *pinctrl;
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struct resource *res;
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resource_size_t res_size;
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int err, irq, dmairq;
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dma_cap_mask_t mask;
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int err, irq;
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pinctrl = devm_pinctrl_get_select_default(dev);
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if (IS_ERR(pinctrl))
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@ -620,9 +590,8 @@ static int mxs_i2c_probe(struct platform_device *pdev)
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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irq = platform_get_irq(pdev, 0);
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dmairq = platform_get_irq(pdev, 1);
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if (!res || irq < 0 || dmairq < 0)
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if (!res || irq < 0)
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return -ENOENT;
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res_size = resource_size(res);
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@ -648,10 +617,7 @@ static int mxs_i2c_probe(struct platform_device *pdev)
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}
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/* Setup the DMA */
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dma_cap_zero(mask);
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dma_cap_set(DMA_SLAVE, mask);
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i2c->dma_data.chan_irq = dmairq;
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i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c);
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i2c->dmach = dma_request_slave_channel(dev, "rx-tx");
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if (!i2c->dmach) {
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dev_err(dev, "Failed to request dma\n");
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return -ENODEV;
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