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: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
index 273a8d5..2c00ec6 100644
--- a/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
+++ b/Documentation/devicetree/bindings/tty/serial/fsl-mxs-auart.txt
@@ -5,20 +5,18 @@
imx23 and imx28.
- reg : Address and length of the register set for the device
- interrupts : Should contain the auart interrupt numbers
-
-Optional properties:
-- fsl,auart-dma-channel : The DMA channels, the first is for RX, the other
- is for TX. If you add this property, it also means that you
- 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.
+- dmas: DMA specifier, consisting of a phandle to DMA controller node
+ and AUART DMA channel ID.
+ Refer to dma.txt and fsl-mxs-dma.txt for details.
+- dma-names: "rx" for RX channel, "tx" for TX channel.
Example:
auart0: serial@8006a000 {
compatible = "fsl,imx28-auart", "fsl,imx23-auart";
reg = <0x8006a000 0x2000>;
- interrupts = <112 70 71>;
- fsl,auart-dma-channel = <8 9>;
+ interrupts = <112>;
+ dmas = <&dma_apbx 8>, <&dma_apbx 9>;
+ dma-names = "rx", "tx";
};
Note: Each auart port should have an alias correctly numbered in "aliases"
diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index d549fe1..269a27ca 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -35,7 +35,7 @@
#include <linux/pinctrl/consumer.h>
#include <linux/of_device.h>
#include <linux/dma-mapping.h>
-#include <linux/fsl/mxs-dma.h>
+#include <linux/dmaengine.h>
#include <asm/cacheflush.h>
@@ -148,11 +148,6 @@
struct device *dev;
/* 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 dma_chan *tx_dma_chan;
void *tx_dma_buf;
@@ -440,20 +435,6 @@
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 void dma_rx_callback(void *arg)
{
@@ -545,21 +526,11 @@
static int mxs_auart_dma_init(struct mxs_auart_port *s)
{
- dma_cap_mask_t mask;
-
if (auart_dma_enabled(s))
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 */
- dma_cap_zero(mask);
- 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);
+ s->rx_dma_chan = dma_request_slave_channel(s->dev, "rx");
if (!s->rx_dma_chan)
goto err_out;
s->rx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
@@ -567,9 +538,7 @@
goto err_out;
/* init for TX */
- s->dma_channel = s->dma_channel_tx;
- s->dma_data.chan_irq = s->dma_irq_tx;
- s->tx_dma_chan = dma_request_channel(mask, mxs_auart_dma_filter, s);
+ s->tx_dma_chan = dma_request_slave_channel(s->dev, "tx");
if (!s->tx_dma_chan)
goto err_out;
s->tx_dma_buf = kzalloc(UART_XMIT_SIZE, GFP_KERNEL | GFP_DMA);
@@ -1020,7 +989,6 @@
struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
- u32 dma_channel[2];
int ret;
if (!np)
@@ -1034,20 +1002,8 @@
}
s->port.line = ret;
- s->dma_irq_rx = platform_get_irq(pdev, 1);
- s->dma_irq_tx = platform_get_irq(pdev, 2);
+ s->flags |= MXS_AUART_DMA_CONFIG;
- 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;
- } else {
- s->dma_channel_rx = -1;
- s->dma_channel_tx = -1;
- }
return 0;
}