spi: mxs-spi: 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.

Since mxs is a DT only platform now, along with the changes, the non-DT
case handling in probe function also gets removed.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 18 insertions, 58 deletions

diff --git a/Documentation/devicetree/bindings/spi/mxs-spi.txt b/Documentation/devicetree/bindings/spi/mxs-spi.txt
index e2e13957c2a4..3499b73293c2 100644
--- a/Documentation/devicetree/bindings/spi/mxs-spi.txt
+++ b/Documentation/devicetree/bindings/spi/mxs-spi.txt
@@ -3,8 +3,11 @@
 Required properties:
 - compatible: Should be "fsl,<soc>-spi", where soc is "imx23" or "imx28"
 - reg: Offset and length of the register set for the device
-- interrupts: Should contain SSP interrupts (error irq first, dma irq second)
-- fsl,ssp-dma-channel: APBX DMA channel for the SSP
+- interrupts: Should contain SSP ERROR interrupt
+- dmas: DMA specifier, consisting of a phandle to DMA controller node
+  and SSP DMA channel ID.
+  Refer to dma.txt and fsl-mxs-dma.txt for details.
+- dma-names: Must be "rx-tx".
 
 Optional properties:
 - clock-frequency : Input clock frequency to the SPI block in Hz.
@@ -17,6 +20,7 @@ ssp0: ssp@80010000 {
         #size-cells = <0>;
         compatible = "fsl,imx28-spi";
         reg = <0x80010000 0x2000>;
-        interrupts = <96 82>;
-        fsl,ssp-dma-channel = <0>;
+        interrupts = <96>;
+        dmas = <&dma_apbh 0>;
+        dma-names = "rx-tx";
 };
diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c
index 22a0af0147fb..7b1c014b0740 100644
--- a/drivers/spi/spi-mxs.c
+++ b/drivers/spi/spi-mxs.c
@@ -490,21 +490,6 @@ static int mxs_spi_transfer_one(struct spi_master *master,
         return status;
 }
 
-static bool mxs_ssp_dma_filter(struct dma_chan *chan, void *param)
-{
-        struct mxs_ssp *ssp = param;
-
-        if (!mxs_dma_is_apbh(chan))
-                return false;
-
-        if (chan->chan_id != ssp->dma_channel)
-                return false;
-
-        chan->private = &ssp->dma_data;
-
-        return true;
-}
-
 static const struct of_device_id mxs_spi_dt_ids[] = {
         { .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, },
         { .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, },
@@ -520,13 +505,12 @@ static int mxs_spi_probe(struct platform_device *pdev)
         struct spi_master *master;
         struct mxs_spi *spi;
         struct mxs_ssp *ssp;
-        struct resource *iores, *dmares;
+        struct resource *iores;
         struct pinctrl *pinctrl;
         struct clk *clk;
         void __iomem *base;
-        int devid, dma_channel, clk_freq;
-        int ret = 0, irq_err, irq_dma;
-        dma_cap_mask_t mask;
+        int devid, clk_freq;
+        int ret = 0, irq_err;
 
         /*
          * Default clock speed for the SPI core. 160MHz seems to
@@ -537,8 +521,7 @@ static int mxs_spi_probe(struct platform_device *pdev)
 
         iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
         irq_err = platform_get_irq(pdev, 0);
-        irq_dma = platform_get_irq(pdev, 1);
-        if (!iores || irq_err < 0 || irq_dma < 0)
+        if (!iores || irq_err < 0)
                 return -EINVAL;
 
         base = devm_ioremap_resource(&pdev->dev, iores);
@@ -553,32 +536,11 @@ static int mxs_spi_probe(struct platform_device *pdev)
         if (IS_ERR(clk))
                 return PTR_ERR(clk);
 
-        if (np) {
-                devid = (enum mxs_ssp_id) of_id->data;
-                /*
-                 * 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(np, "fsl,ssp-dma-channel",
-                                           &dma_channel);
-                if (ret) {
-                        dev_err(&pdev->dev,
-                                "Failed to get DMA channel\n");
-                        return -EINVAL;
-                }
-
-                ret = of_property_read_u32(np, "clock-frequency",
-                                           &clk_freq);
-                if (ret)
-                        clk_freq = clk_freq_default;
-        } else {
-                dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0);
-                if (!dmares)
-                        return -EINVAL;
-                devid = pdev->id_entry->driver_data;
-                dma_channel = dmares->start;
+        devid = (enum mxs_ssp_id) of_id->data;
+        ret = of_property_read_u32(np, "clock-frequency",
+                                   &clk_freq);
+        if (ret)
                 clk_freq = clk_freq_default;
-        }
 
         master = spi_alloc_master(&pdev->dev, sizeof(*spi));
         if (!master)
@@ -597,7 +559,6 @@ static int mxs_spi_probe(struct platform_device *pdev)
         ssp->clk = clk;
         ssp->base = base;
         ssp->devid = devid;
-        ssp->dma_channel = dma_channel;
 
         init_completion(&spi->c);
 
@@ -606,10 +567,7 @@ static int mxs_spi_probe(struct platform_device *pdev)
         if (ret)
                 goto out_master_free;
 
-        dma_cap_zero(mask);
-        dma_cap_set(DMA_SLAVE, mask);
-        ssp->dma_data.chan_irq = irq_dma;
-        ssp->dmach = dma_request_channel(mask, mxs_ssp_dma_filter, ssp);
+        ssp->dmach = dma_request_slave_channel(&pdev->dev, "rx-tx");
         if (!ssp->dmach) {
                 dev_err(ssp->dev, "Failed to request DMA\n");
                 goto out_master_free;
diff --git a/include/linux/spi/mxs-spi.h b/include/linux/spi/mxs-spi.h
index 61ae1306db23..4835486f58e5 100644
--- a/include/linux/spi/mxs-spi.h
+++ b/include/linux/spi/mxs-spi.h
@@ -24,7 +24,7 @@
 #ifndef __LINUX_SPI_MXS_SPI_H__
 #define __LINUX_SPI_MXS_SPI_H__
 
-#include <linux/fsl/mxs-dma.h>
+#include <linux/dmaengine.h>
 
 #define ssp_is_old(host)        ((host)->devid == IMX23_SSP)
 
@@ -137,9 +137,7 @@ struct mxs_ssp {
         unsigned int                    clk_rate;
         enum mxs_ssp_id                 devid;
 
-        int                             dma_channel;
         struct dma_chan                 *dmach;
-        struct mxs_dma_data             dma_data;
         unsigned int                    dma_dir;
         enum dma_transfer_direction     slave_dirn;
         u32                             ssp_pio_words[SSP_PIO_NUM];