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Commit bcc20f9e authored by Shawn Guo's avatar Shawn Guo
Browse files

serial: mxs-auart: 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: default avatarShawn Guo <shawn.guo@linaro.org>
Acked-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 5fac0e18

Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt

+7 −9
Original line number Original line Diff line number Diff line
@@ -5,20 +5,18 @@ Required properties: 
  imx23 and imx28.

  imx23 and imx28.

- reg : Address and length of the register set for the device

- reg : Address and length of the register set for the device

- interrupts : Should contain the auart interrupt numbers

- interrupts : Should contain the auart interrupt numbers



- dmas: DMA specifier, consisting of a phandle to DMA controller node

Optional properties:

  and AUART DMA channel ID.

- fsl,auart-dma-channel : The DMA channels, the first is for RX, the other

  Refer to dma.txt and fsl-mxs-dma.txt for details.

		is for TX. If you add this property, it also means that you

- dma-names: "rx" for RX channel, "tx" for TX channel.

		will enable the DMA support for the auart.

		Note: due to the hardware bug in imx23(see errata : 2836),

		only the imx28 can enable the DMA support for the auart.





Example:

Example:

auart0: serial@8006a000 {

auart0: serial@8006a000 {

	compatible = "fsl,imx28-auart", "fsl,imx23-auart";

	compatible = "fsl,imx28-auart", "fsl,imx23-auart";

	reg = <0x8006a000 0x2000>;

	reg = <0x8006a000 0x2000>;

	interrupts = <112 70 71>;

	interrupts = <112>;

	fsl,auart-dma-channel = <8 9>;

	dmas = <&dma_apbx 8>, <&dma_apbx 9>;

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

};

};





Note: Each auart port should have an alias correctly numbered in "aliases"

Note: Each auart port should have an alias correctly numbered in "aliases"

drivers/tty/serial/mxs-auart.c

+4 −48
Original line number Original line Diff line number Diff line
@@ -35,7 +35,7 @@ 
#include <linux/pinctrl/consumer.h>

#include <linux/pinctrl/consumer.h>

#include <linux/of_device.h>

#include <linux/of_device.h>

#include <linux/dma-mapping.h>

#include <linux/dma-mapping.h>

#include <linux/fsl/mxs-dma.h>

#include <linux/dmaengine.h>





#include <asm/cacheflush.h>

#include <asm/cacheflush.h>
@@ -148,11 +148,6 @@ struct mxs_auart_port { 
	struct device *dev;

	struct device *dev;





	/* for DMA */

	/* for DMA */

	struct mxs_dma_data dma_data;

	int dma_channel_rx, dma_channel_tx;

	int dma_irq_rx, dma_irq_tx;

	int dma_channel;



	struct scatterlist tx_sgl;

	struct scatterlist tx_sgl;

	struct dma_chan	*tx_dma_chan;

	struct dma_chan	*tx_dma_chan;

	void *tx_dma_buf;

	void *tx_dma_buf;
@@ -440,20 +435,6 @@ static u32 mxs_auart_get_mctrl(struct uart_port *u) 
	return mctrl;

	return mctrl;

}

}





static bool mxs_auart_dma_filter(struct dma_chan *chan, void *param)

{

	struct mxs_auart_port *s = param;



	if (!mxs_dma_is_apbx(chan))

		return false;



	if (s->dma_channel == chan->chan_id) {

		chan->private = &s->dma_data;

		return true;

	}

	return false;

}



static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);

static int mxs_auart_dma_prep_rx(struct mxs_auart_port *s);

static void dma_rx_callback(void *arg)

static void dma_rx_callback(void *arg)

{

{
@@ -545,21 +526,11 @@ static void mxs_auart_dma_exit(struct mxs_auart_port *s) 




static int mxs_auart_dma_init(struct mxs_auart_port *s)

static int mxs_auart_dma_init(struct mxs_auart_port *s)

{

{

	dma_cap_mask_t mask;



	if (auart_dma_enabled(s))

	if (auart_dma_enabled(s))

		return 0;

		return 0;





	/* We do not get the right DMA channels. */

	if (s->dma_channel_rx == -1 || s->dma_channel_tx == -1)

		return -EINVAL;



	/* init for RX */

	/* init for RX */

	dma_cap_zero(mask);

	s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx");

	dma_cap_set(DMA_SLAVE, mask);

	s->dma_channel = s->dma_channel_rx;

	s->dma_data.chan_irq = s->dma_irq_rx;

	s->rx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s);

	if (!s->rx_dma_chan)

	if (!s->rx_dma_chan)

		goto err_out;

		goto err_out;

	s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);

	s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
@@ -567,9 +538,7 @@ static int mxs_auart_dma_init(struct mxs_auart_port *s) 
		goto err_out;

		goto err_out;





	/* init for TX */

	/* init for TX */

	s->dma_channel = s->dma_channel_tx;

	s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx");

	s->dma_data.chan_irq = s->dma_irq_tx;

	s->tx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s);

	if (!s->tx_dma_chan)

	if (!s->tx_dma_chan)

		goto err_out;

		goto err_out;

	s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);

	s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
@@ -1020,7 +989,6 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, 
		struct platform_device *pdev)

		struct platform_device *pdev)

{

{

	struct device_node *np = pdev->dev.of_node;

	struct device_node *np = pdev->dev.of_node;

	u32 dma_channel[2];

	int ret;

	int ret;





	if (!np)

	if (!np)
@@ -1034,20 +1002,8 @@ static int serial_mxs_probe_dt(struct mxs_auart_port *s, 
	}

	}

	s->port.line = ret;

	s->port.line = ret;





	s->dma_irq_rx = platform_get_irq(pdev, 1);

	s->dma_irq_tx = platform_get_irq(pdev, 2);



	ret = of_property_read_u32_array(np, "fsl,auart-dma-channel",

					dma_channel, 2);

	if (ret == 0) {

		s->dma_channel_rx = dma_channel[0];

		s->dma_channel_tx = dma_channel[1];



	s->flags |= MXS_AUART_DMA_CONFIG;

	s->flags |= MXS_AUART_DMA_CONFIG;

	} else {



		s->dma_channel_rx = -1;

		s->dma_channel_tx = -1;

	}

	return 0;

	return 0;

}

}