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Commit 9479e17c authored by Shawn Guo's avatar Shawn Guo Committed by Vinod Koul
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dma: imx-sdma: move to generic device tree bindings 



Update imx-sdma driver to adopt generic DMA device tree bindings.  It
calls of_dma_controller_register() with imx-sdma specific of_dma_xlate
to get the generic DMA device tree helper support.  The #dma-cells for
imx-sdma must be 3, which includes request ID, peripheral type and
priority.

The existing way of requesting channel, clients directly call
dma_request_channel(), still work there, and will be removed after
all imx-sdma clients get converted to generic DMA device tree helper.

Signed-off-by: default avatarShawn Guo <shawn.guo@linaro.org>
Signed-off-by: default avatarVinod Koul <vinod.koul@intel.com>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
parent add93b57

Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt

+56 −0
Original line number Diff line number Diff line
@@ -4,14 +4,70 @@ Required properties: 
- compatible : Should be "fsl,<chip>-sdma"

- reg : Should contain SDMA registers location and length

- interrupts : Should contain SDMA interrupt

- #dma-cells : Must be <3>.

  The first cell specifies the DMA request/event ID.  See details below

  about the second and third cell.

- fsl,sdma-ram-script-name : Should contain the full path of SDMA RAM

  scripts firmware



The second cell of dma phandle specifies the peripheral type of DMA transfer.

The full ID of peripheral types can be found below.



	ID	transfer type

	---------------------

	0	MCU domain SSI

	1	Shared SSI

	2	MMC

	3	SDHC

	4	MCU domain UART

	5	Shared UART

	6	FIRI

	7	MCU domain CSPI

	8	Shared CSPI

	9	SIM

	10	ATA

	11	CCM

	12	External peripheral

	13	Memory Stick Host Controller

	14	Shared Memory Stick Host Controller

	15	DSP

	16	Memory

	17	FIFO type Memory

	18	SPDIF

	19	IPU Memory

	20	ASRC

	21	ESAI



The third cell specifies the transfer priority as below.



	ID	transfer priority

	-------------------------

	0	High

	1	Medium

	2	Low



Examples:



sdma@83fb0000 {

	compatible = "fsl,imx51-sdma", "fsl,imx35-sdma";

	reg = <0x83fb0000 0x4000>;

	interrupts = <6>;

	#dma-cells = <3>;

	fsl,sdma-ram-script-name = "sdma-imx51.bin";

};



DMA clients connected to the i.MX SDMA controller must use the format

described in the dma.txt file.



Examples:



ssi2: ssi@70014000 {

	compatible = "fsl,imx51-ssi", "fsl,imx21-ssi";

	reg = <0x70014000 0x4000>;

	interrupts = <30>;

	clocks = <&clks 49>;

	dmas = <&sdma 24 1 0>,

	       <&sdma 25 1 0>;

	dma-names = "rx", "tx";

	fsl,fifo-depth = <15>;

};

drivers/dma/imx-sdma.c

+40 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
#include <linux/dmaengine.h>

#include <linux/of.h>

#include <linux/of_device.h>

#include <linux/of_dma.h>



#include <asm/irq.h>

#include <linux/platform_data/dma-imx-sdma.h>
@@ -1296,6 +1297,35 @@ static int __init sdma_init(struct sdma_engine *sdma) 
	return ret;

}



static bool sdma_filter_fn(struct dma_chan *chan, void *fn_param)

{

	struct imx_dma_data *data = fn_param;



	if (!imx_dma_is_general_purpose(chan))

		return false;



	chan->private = data;



	return true;

}



static struct dma_chan *sdma_xlate(struct of_phandle_args *dma_spec,

				   struct of_dma *ofdma)

{

	struct sdma_engine *sdma = ofdma->of_dma_data;

	dma_cap_mask_t mask = sdma->dma_device.cap_mask;

	struct imx_dma_data data;



	if (dma_spec->args_count != 3)

		return NULL;



	data.dma_request = dma_spec->args[0];

	data.peripheral_type = dma_spec->args[1];

	data.priority = dma_spec->args[2];



	return dma_request_channel(mask, sdma_filter_fn, &data);

}



static int __init sdma_probe(struct platform_device *pdev)

{

	const struct of_device_id *of_id =
@@ -1443,10 +1473,20 @@ static int __init sdma_probe(struct platform_device *pdev) 
		goto err_init;

	}



	if (np) {

		ret = of_dma_controller_register(np, sdma_xlate, sdma);

		if (ret) {

			dev_err(&pdev->dev, "failed to register controller\n");

			goto err_register;

		}

	}



	dev_info(sdma->dev, "initialized\n");



	return 0;



err_register:

	dma_async_device_unregister(&sdma->dma_device);

err_init:

	kfree(sdma->script_addrs);

err_alloc: