[18/18,RFC] spi: rspi: Add DT support to DMA setup

Commit Message

Geert Uytterhoeven June 2, 2014, 1:38 p.m. UTC

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Cc: [e-mail]
---
The format of the DMA specifiers depends on the DT bindings for SHDMA,
which are still under development.
---
 Documentation/devicetree/bindings/spi/spi-rspi.txt |  6 ++++
 drivers/spi/spi-rspi.c                             | 37 ++++++++++++++--------
 2 files changed, 29 insertions(+), 14 deletions(-)

Comments

Mark Brown June 2, 2014, 2:54 p.m. UTC | #1

On Mon, Jun 02, 2014 at 03:38:20PM +0200, Geert Uytterhoeven wrote:
> Signed-off-by: Geert Uytterhoeven <[e-mail]>
> Cc: [e-mail]
> ---
> The format of the DMA specifiers depends on the DT bindings for SHDMA,
> which are still under development.

This looks fine to me, can you resend when the DMA specifiers for the
controller are resolved?  I've applied everything up to here, it all
looks good especially the performance improvement.

Geert Uytterhoeven June 2, 2014, 2:57 p.m. UTC | #2

Hi Mark,

On Mon, Jun 2, 2014 at 4:54 PM, Mark Brown <[e-mail]> wrote:
> On Mon, Jun 02, 2014 at 03:38:20PM +0200, Geert Uytterhoeven wrote:
>> Signed-off-by: Geert Uytterhoeven <[e-mail]>
>> Cc: [e-mail]
>> ---
>> The format of the DMA specifiers depends on the DT bindings for SHDMA,
>> which are still under development.
>
> This looks fine to me, can you resend when the DMA specifiers for the
> controller are resolved?  I've applied everything up to here, it all

Sure.

> looks good especially the performance improvement.

That was quick, thanks a lot!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [e-mail]

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when I'm talking to journalists I just say "programmer" or something like that.
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Patch

diff --git a/Documentation/devicetree/bindings/spi/spi-rspi.txt b/Documentation/devicetree/bindings/spi/spi-rspi.txt
index d57d82a74054..a274073bd41d 100644
--- a/Documentation/devicetree/bindings/spi/spi-rspi.txt
+++ b/Documentation/devicetree/bindings/spi/spi-rspi.txt
@@ -30,6 +30,9 @@  Required properties:
 
 Optional properties:
 - clocks           : Must contain a reference to the functional clock.
+- dmas             : Must contain a list of two references to DMA specifiers,
+		     one for transmission, and one for reception.
+- dma-names        : Must contain a list of two DMA names, "tx" and "rx".
 
 Pinctrl properties might be needed, too.  See
 Documentation/devicetree/bindings/pinctrl/renesas,*.
@@ -58,4 +61,7 @@  Examples:
 		num-cs = <1>;
 		#address-cells = <1>;
 		#size-cells = <0>;
+		dmas = <&dma0 R8A7791_DMA_QSPI_TX CHCR_TX_8BIT>,
+		       <&dma0 R8A7791_DMA_QSPI_RX CHCR_RX_8BIT>;
+		dma-names = "tx", "rx";
 	};
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 10112745bb17..16de9ad60d74 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -874,10 +874,11 @@  static struct dma_chan *rspi_request_dma_chan(struct device *dev,
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	chan = dma_request_channel(mask, shdma_chan_filter,
-				   (void *)(unsigned long)id);
+	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
+				(void *)(unsigned long)id, dev,
+				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
 	if (!chan) {
-		dev_warn(dev, "dma_request_channel failed\n");
+		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
 		return NULL;
 	}
 
@@ -903,22 +904,30 @@  static int rspi_request_dma(struct device *dev, struct spi_master *master,
 			    const struct resource *res)
 {
 	const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
+	unsigned int dma_tx_id, dma_rx_id;
+
+	if (dev->of_node) {
+		/* In the OF case we will get the slave IDs from the DT */
+		dma_tx_id = 0;
+		dma_rx_id = 0;
+	} else if (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
+		dma_tx_id = rspi_pd->dma_tx_id;
+		dma_rx_id = rspi_pd->dma_rx_id;
+	} else {
+		/* The driver assumes no error. */
+		return 0;
+	}
 
-	if (!rspi_pd || !rspi_pd->dma_rx_id || !rspi_pd->dma_tx_id)
-		return 0;	/* The driver assumes no error. */
-
-	master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM,
-					       rspi_pd->dma_rx_id,
+	master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
 					       res->start + RSPI_SPDR);
-	if (!master->dma_rx)
+	if (!master->dma_tx)
 		return -ENODEV;
 
-	master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV,
-					       rspi_pd->dma_tx_id,
+	master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
 					       res->start + RSPI_SPDR);
-	if (!master->dma_tx) {
-		dma_release_channel(master->dma_rx);
-		master->dma_rx = NULL;
+	if (!master->dma_rx) {
+		dma_release_channel(master->dma_tx);
+		master->dma_tx = NULL;
 		return -ENODEV;
 	}