Commit e0ddaab7 authored by Sascha Hauer's avatar Sascha Hauer Committed by Miquel Raynal
Browse files

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: default avatarSascha Hauer <s.hauer@pengutronix.de>
Acked-by: default avatarVinod Koul <vkoul@kernel.org>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
parent 475345e8

drivers/dma/mxs-dma.c

+1 −0
Original line number Diff line number Diff line
@@ -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>

drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c

+14 −22
Original line number Diff line number Diff line
@@ -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;

include/linux/dma/mxs-dma.h

0 → 100644
+21 −0
Original line number Diff line number Diff line 
/* 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_ */

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