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dmaengine: mxs: Add header file to be shared with gpmi nand driver

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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>
This commit is contained in:
Sascha Hauer 2019-05-21 09:06:41 +02:00 committed by Miquel Raynal
parent 475345e89c
commit e0ddaab768
3 changed files with 36 additions and 22 deletions
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1
drivers/dma/mxs-dma.c
View File

@ -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>

36
drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
View File

@ -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;

21
include/linux/dma/mxs-dma.h Normal file
View File

@ -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_ */