From e5aba13da0cc598a5573ea059717949fbd7536ad Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Tue, 26 Feb 2013 11:20:22 +0800 Subject: [PATCH] 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 Reviewed-by: Arnd Bergmann Acked-by: Wolfram Sang --- .../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 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,-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 #include #include -#include #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; -- 2.30.2