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authorSascha Hauer <s.hauer@pengutronix.de>2019-05-21 10:06:41 +0300
committerMiquel Raynal <miquel.raynal@bootlin.com>2019-06-27 21:05:29 +0300
commite0ddaab76802d3179013f4864535043e2aea6c69 (patch)
tree992fba574f07acb858f55e728b3f566f8bde2ab1
parent475345e89ced298afbeefed6c86122bb8415593d (diff)
downloadlinux-e0ddaab76802d3179013f4864535043e2aea6c69.tar.xz
dmaengine: mxs: Add header file to be shared with gpmi nand driver
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> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
-rw-r--r--drivers/dma/mxs-dma.c1
-rw-r--r--drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c36
-rw-r--r--include/linux/dma/mxs-dma.h21
3 files changed, 36 insertions, 22 deletions
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 74c4de0b1a3d..45c7b91aae23 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_ */