diff mbox series

[12/14] dmaengine: mxs: Add header file to be shared with gpmi nand driver

Message ID 20190521070643.6244-13-s.hauer@pengutronix.de
State Accepted
Delegated to: Miquel Raynal
Headers show
Series Implement exec_op for GPMI nand driver | expand

Commit Message

Sascha Hauer May 21, 2019, 7:06 a.m. UTC 
The mxs dma driver can do PIO transfers. A pointer to the PIO words
to transfer is passed in the struct scatterlist * argument of
dmaengine_prep_slave_sg(). It's quite ugly and non obvious to cast
u32 * to struct scatterlist * each time when calling
dmaengine_prep_slave_sg(), so add a static inline wrapper function
to be called by the user along with a description what is going on.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/dma/mxs-dma.c                      |  1 +
 drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c | 36 +++++++++-------------
 include/linux/dma/mxs-dma.h                | 21 +++++++++++++
 3 files changed, 36 insertions(+), 22 deletions(-)
 create mode 100644 include/linux/dma/mxs-dma.h

Comments

Miquel Raynal June 3, 2019, 8:03 a.m. UTC | #1 
On Tue, 2019-05-21 at 07:06:41 UTC, Sascha Hauer wrote:
> The mxs dma driver can do PIO transfers. A pointer to the PIO words
> to transfer is passed in the struct scatterlist * argument of
> dmaengine_prep_slave_sg(). It's quite ugly and non obvious to cast
> u32 * to struct scatterlist * each time when calling
> dmaengine_prep_slave_sg(), so add a static inline wrapper function
> to be called by the user along with a description what is going on.
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> Acked-by: Vinod Koul <vkoul@kernel.org>

Applied to https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git nand/next, thanks.

Miquel
diff mbox series

Patch

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index ce92a3626ea4..62ee9328aea1 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -24,6 +24,7 @@ 
 #include <linux/of_device.h>
 #include <linux/of_dma.h>
 #include <linux/list.h>
+#include <linux/dma/mxs-dma.h>
 
 #include <asm/irq.h>
 
diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index 87af02f34dc0..9c44d6d21d04 100644
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -15,6 +15,7 @@ 
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/dma/mxs-dma.h>
 #include "gpmi-nand.h"
 #include "gpmi-regs.h"
 #include "bch-regs.h"
@@ -914,9 +915,8 @@  static int gpmi_send_command(struct gpmi_nand_data *this)
 		| BM_GPMI_CTRL0_ADDRESS_INCREMENT
 		| BF_GPMI_CTRL0_XFER_COUNT(this->command_length);
 	pio[1] = pio[2] = 0;
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, 0);
 	if (!desc)
 		return -EINVAL;
 
@@ -988,8 +988,8 @@  static int gpmi_send_data(struct gpmi_nand_data *this, const void *buf, int len)
 		| BF_GPMI_CTRL0_ADDRESS(address)
 		| BF_GPMI_CTRL0_XFER_COUNT(len);
 	pio[1] = 0;
-	desc = dmaengine_prep_slave_sg(channel, (struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, 0);
 	if (!desc)
 		return -EINVAL;
 
@@ -1025,9 +1025,8 @@  static int gpmi_read_data(struct gpmi_nand_data *this, void *buf, int len)
 		| BF_GPMI_CTRL0_ADDRESS(BV_GPMI_CTRL0_ADDRESS__NAND_DATA)
 		| BF_GPMI_CTRL0_XFER_COUNT(len);
 	pio[1] = 0;
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, 0);
 	if (!desc)
 		return -EINVAL;
 
@@ -1083,10 +1082,8 @@  static int gpmi_send_page(struct gpmi_nand_data *this, dma_addr_t payload,
 	pio[4] = payload;
 	pio[5] = auxiliary;
 
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE,
-					DMA_CTRL_ACK);
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, DMA_CTRL_ACK);
 	if (!desc)
 		return -EINVAL;
 
@@ -1117,9 +1114,7 @@  static int gpmi_read_page(struct gpmi_nand_data *this, dma_addr_t payload,
 		| BF_GPMI_CTRL0_ADDRESS(address)
 		| BF_GPMI_CTRL0_XFER_COUNT(0);
 	pio[1] = 0;
-	desc = dmaengine_prep_slave_sg(channel,
-				(struct scatterlist *)pio, 2,
-				DMA_TRANS_NONE, 0);
+	desc = mxs_dmaengine_prep_pio(channel, pio, 2, DMA_TRANS_NONE, 0);
 	if (!desc)
 		return -EINVAL;
 
@@ -1144,10 +1139,8 @@  static int gpmi_read_page(struct gpmi_nand_data *this, dma_addr_t payload,
 	pio[3] = geo->page_size;
 	pio[4] = payload;
 	pio[5] = auxiliary;
-	desc = dmaengine_prep_slave_sg(channel,
-					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE,
-					DMA_CTRL_ACK);
+	desc = mxs_dmaengine_prep_pio(channel, pio, ARRAY_SIZE(pio),
+				      DMA_TRANS_NONE, DMA_CTRL_ACK);
 	if (!desc)
 		return -EINVAL;
 
@@ -1163,9 +1156,8 @@  static int gpmi_read_page(struct gpmi_nand_data *this, dma_addr_t payload,
 		| BF_GPMI_CTRL0_XFER_COUNT(geo->page_size);
 	pio[1] = 0;
 	pio[2] = 0; /* clear GPMI_HW_GPMI_ECCCTRL, disable the BCH. */
-	desc = dmaengine_prep_slave_sg(channel,
-				(struct scatterlist *)pio, 3,
-				DMA_TRANS_NONE, DMA_CTRL_ACK);
+	desc = mxs_dmaengine_prep_pio(channel, pio, 3, DMA_TRANS_NONE,
+				      DMA_CTRL_ACK);
 	if (!desc)
 		return -EINVAL;
 
diff --git a/include/linux/dma/mxs-dma.h b/include/linux/dma/mxs-dma.h
new file mode 100644
index 000000000000..092b2a7b92ac
--- /dev/null
+++ b/include/linux/dma/mxs-dma.h
@@ -0,0 +1,21 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _MXS_DMA_H_
+#define _MXS_DMA_H_
+
+#include <linux/dmaengine.h>
+
+/*
+ * The mxs dmaengine can do PIO transfers. We pass a pointer to the PIO words
+ * in the second argument to dmaengine_prep_slave_sg when the direction is
+ * set to DMA_TRANS_NONE. To make this clear and to prevent users from doing
+ * the error prone casting we have this wrapper function
+ */
+static inline struct dma_async_tx_descriptor *mxs_dmaengine_prep_pio(
+        struct dma_chan *chan, u32 *pio, unsigned int npio,
+        enum dma_transfer_direction dir, unsigned long flags)
+{
+	return dmaengine_prep_slave_sg(chan, (struct scatterlist *)pio, npio,
+				       dir, flags);
+}
+
+#endif /* _MXS_DMA_H_ */