[PATCH v4 0/2] patch set about the MXS-DMA

[PATCH v4 0/2] patch set about the MXS-DMA

[Huang Shijie]

patch 1: move the mxs dma header to a more common place.
	Beside the mx23/mx28, the apbh-dma is also used by MX50 and MX6Q.
	So move the mxs dma header file to a more common place, and rename
	it to mxs-dma.h

patch 2: rewrite the last parameter of mxs_dma_prep_slave_sg().
	In the new GPMI version, some hardware behavior changes.
	The WAIT4END bit should be set in the middle one of the ECC READ page DMA chain.
	The DMA chain should be set like this:

          +-----+               +-----+                      +-----+
          | cmd | ------------> | cmd | ------------------>  | cmd |
          +-----+               +-----+                      +-----+
                                   ^                            ^
                                   |                            |
                                   |                            |
                              set WAIT4END here too        set WAIT4END here

        So rewrite the last parameter of mxs_dma_prep_slave_sg(), use the
	dma_ctrl_flags to set the proper DMA bit for DMA Command Structure.
	And change the relative drivers with the dma_ctrl_flags.

TEST:
	Tested the mxs-mmc driver and gpmi-nand drive with the two patches
	in MX28 board.

v3 --> v4:
	[1] create a new folder include/linux/fsl/ for store the Freescale's
	    header files.
	[2] add more CCs.

v2 --> v3:
	[1] remove field gpmi_version, use GPMI_IS_MX6Q() instead.

v1 --> v2:
	[1] squash the trial patches into single patch.
	[2] use the dma_ctrl_flags.

Huang Shijie (2):
  mxs-dma : move the mxs dma.h to a more common place
  mxs-dma : rewrite the last parameter of mxs_dma_prep_slave_sg()

 drivers/dma/mxs-dma.c                              |   34 +++++++++++++++++---
 drivers/mmc/host/mxs-mmc.c                         |   12 +++---
 drivers/mtd/nand/gpmi-nand/gpmi-lib.c              |   24 ++++++++++---
 drivers/mtd/nand/gpmi-nand/gpmi-nand.h             |    2 +-
 .../mach/dma.h => include/linux/fsl/mxs-dma.h      |    0
 sound/soc/mxs/mxs-pcm.c                            |    2 +-
 sound/soc/mxs/mxs-pcm.h                            |    2 +-
 sound/soc/mxs/mxs-saif.c                           |    2 +-
 8 files changed, 57 insertions(+), 21 deletions(-)
 rename arch/arm/mach-mxs/include/mach/dma.h => include/linux/fsl/mxs-dma.h (100%)

[PATCH v4 1/2] mxs-dma : move the mxs dma.h to a more common place

[Huang Shijie]

Move the header to a more common place.
The mxs dma engine is not only used in mx23/mx28, but also used
in mx50/mx6q.  It will also be used in the future chips.

Rename it to mxs-dma.h, and create a new folder include/linux/fsl/ to
store the Freescale's header files.

change mxs-dma driver, mxs-mmc driver, gpmi-nand driver, mxs-saif driver
to the new header file.

Signed-off-by: Huang Shijie <b32955@freescale.com>
---
 drivers/dma/mxs-dma.c                              |    2 +-
 drivers/mmc/host/mxs-mmc.c                         |    2 +-
 drivers/mtd/nand/gpmi-nand/gpmi-nand.h             |    2 +-
 .../mach/dma.h => include/linux/fsl/mxs-dma.h      |    0
 sound/soc/mxs/mxs-pcm.c                            |    2 +-
 sound/soc/mxs/mxs-pcm.h                            |    2 +-
 sound/soc/mxs/mxs-saif.c                           |    2 +-
 7 files changed, 6 insertions(+), 6 deletions(-)
 rename arch/arm/mach-mxs/include/mach/dma.h => include/linux/fsl/mxs-dma.h (100%)

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index b06cd4c..0afcedb 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -22,10 +22,10 @@
 #include <linux/platform_device.h>
 #include <linux/dmaengine.h>
 #include <linux/delay.h>
+#include <linux/fsl/mxs-dma.h>
 
 #include <asm/irq.h>
 #include <mach/mxs.h>
-#include <mach/dma.h>
 #include <mach/common.h>
 
 /*
diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index 382c835..e5ea2b1 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -38,10 +38,10 @@
 #include <linux/gpio.h>
 #include <linux/regulator/consumer.h>
 #include <linux/module.h>
+#include <linux/fsl/mxs-dma.h>
 
 #include <mach/mxs.h>
 #include <mach/common.h>
-#include <mach/dma.h>
 #include <mach/mmc.h>
 
 #define DRIVER_NAME	"mxs-mmc"
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
index c93b0ae..b9002c8 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.h
@@ -20,7 +20,7 @@
 #include <linux/mtd/nand.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
-#include <mach/dma.h>
+#include <linux/fsl/mxs-dma.h>
 
 struct resources {
 	void          *gpmi_regs;
diff --git a/arch/arm/mach-mxs/include/mach/dma.h b/include/linux/fsl/mxs-dma.h
similarity index 100%
rename from arch/arm/mach-mxs/include/mach/dma.h
rename to include/linux/fsl/mxs-dma.h
diff --git a/sound/soc/mxs/mxs-pcm.c b/sound/soc/mxs/mxs-pcm.c
index 105f42a..420715e 100644
--- a/sound/soc/mxs/mxs-pcm.c
+++ b/sound/soc/mxs/mxs-pcm.c
@@ -28,6 +28,7 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/dmaengine.h>
+#include <linux/fsl/mxs-dma.h>
 
 #include <sound/core.h>
 #include <sound/initval.h>
@@ -35,7 +36,6 @@
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 
-#include <mach/dma.h>
 #include "mxs-pcm.h"
 
 static struct snd_pcm_hardware snd_mxs_hardware = {
diff --git a/sound/soc/mxs/mxs-pcm.h b/sound/soc/mxs/mxs-pcm.h
index f55ac4f..d2c8b12 100644
--- a/sound/soc/mxs/mxs-pcm.h
+++ b/sound/soc/mxs/mxs-pcm.h
@@ -19,7 +19,7 @@
 #ifndef _MXS_PCM_H
 #define _MXS_PCM_H
 
-#include <mach/dma.h>
+#include <linux/fsl/mxs-dma.h>
 
 struct mxs_pcm_dma_params {
 	int chan_irq;
diff --git a/sound/soc/mxs/mxs-saif.c b/sound/soc/mxs/mxs-saif.c
index f204dba..ce59112 100644
--- a/sound/soc/mxs/mxs-saif.c
+++ b/sound/soc/mxs/mxs-saif.c
@@ -24,12 +24,12 @@
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/time.h>
+#include <linux/fsl/mxs-dma.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/saif.h>
-#include <mach/dma.h>
 #include <asm/mach-types.h>
 #include <mach/hardware.h>
 #include <mach/mxs.h>
-- 
1.7.0.4

[PATCH v4 2/2] mxs-dma : rewrite the last parameter of mxs_dma_prep_slave_sg()

[Huang Shijie]

[1] Background :
    The GPMI does ECC read page operation with a DMA chain consist of three DMA
    Command Structures. The middle one of the chain is used to enable the BCH,
    and read out the NAND page.

    The WAIT4END(wait for command end) is a comunication signal between
    the GPMI and MXS-DMA.

[2] The current DMA code sets the WAIT4END bit at the last one, such as:

    +-----+               +-----+                      +-----+
    | cmd | ------------> | cmd | ------------------>  | cmd |
    +-----+               +-----+                      +-----+
                                                          ^
                                                          |
                                                          |
                                                     set WAIT4END here

    This chain works fine in the mx23/mx28.

[3] But in the new GPMI version (used in MX50/MX60), the WAIT4END bit should
    be set not only at the last DMA Command Structure,
    but also at the middle one, such as:

    +-----+               +-----+                      +-----+
    | cmd | ------------> | cmd | ------------------>  | cmd |
    +-----+               +-----+                      +-----+
                             ^                            ^
                             |                            |
                             |                            |
                        set WAIT4END here too        set WAIT4END here

    If we do not set WAIT4END, the BCH maybe stalls in "ECC reading page" state.
    In the next ECC write page operation, a DMA-timeout occurs.
    This has been catched in the MX6Q board.

[4] In order to fix the bug, rewrite the last parameter of mxs_dma_prep_slave_sg(),
    and use the dma_ctrl_flags:
    ---------------------------------------------------------
      DMA_PREP_INTERRUPT : append a new DMA Command Structrue.
      DMA_CTRL_ACK       : set the WAIT4END bit for this DMA Command Structure.
    ---------------------------------------------------------

[5] changes to the relative drivers:
    <1> For mxs-mmc driver, just use the new flags, do not change any logic.
    <2> For gpmi-nand driver, add new field `gpmi_version` to distinguish
        different gpmi versions, and use the new flags.

Signed-off-by: Huang Shijie <b32955@freescale.com>
---
 drivers/dma/mxs-dma.c                 |   32 ++++++++++++++++++++++++++++----
 drivers/mmc/host/mxs-mmc.c            |   10 +++++-----
 drivers/mtd/nand/gpmi-nand/gpmi-lib.c |   24 ++++++++++++++++++------
 3 files changed, 51 insertions(+), 15 deletions(-)

diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
index 0afcedb..0ddfd30 100644
--- a/drivers/dma/mxs-dma.c
+++ b/drivers/dma/mxs-dma.c
@@ -349,10 +349,32 @@ static void mxs_dma_free_chan_resources(struct dma_chan *chan)
 	clk_disable_unprepare(mxs_dma->clk);
 }
 
+/*
+ * How to use the flags for ->device_prep_slave_sg() :
+ *    [1] If there is only one DMA command in the DMA chain, the code should be:
+ *            ......
+ *            ->device_prep_slave_sg(DMA_CTRL_ACK);
+ *            ......
+ *    [2] If there are two DMA commands in the DMA chain, the code should be
+ *            ......
+ *            ->device_prep_slave_sg(0);
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ *            ......
+ *    [3] If there are more than two DMA commands in the DMA chain, the code
+ *        should be:
+ *            ......
+ *            ->device_prep_slave_sg(0);                                // First
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT [| DMA_CTRL_ACK]);
+ *            ......
+ *            ->device_prep_slave_sg(DMA_PREP_INTERRUPT | DMA_CTRL_ACK); // Last
+ *            ......
+ */
 static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 		struct dma_chan *chan, struct scatterlist *sgl,
 		unsigned int sg_len, enum dma_transfer_direction direction,
-		unsigned long append)
+		unsigned long flags)
 {
 	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
 	struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma;
@@ -360,6 +382,7 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 	struct scatterlist *sg;
 	int i, j;
 	u32 *pio;
+	bool append = flags & DMA_PREP_INTERRUPT;
 	int idx = append ? mxs_chan->desc_count : 0;
 
 	if (mxs_chan->status == DMA_IN_PROGRESS && !append)
@@ -386,7 +409,6 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 		ccw->bits |= CCW_CHAIN;
 		ccw->bits &= ~CCW_IRQ;
 		ccw->bits &= ~CCW_DEC_SEM;
-		ccw->bits &= ~CCW_WAIT4END;
 	} else {
 		idx = 0;
 	}
@@ -401,7 +423,8 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 		ccw->bits = 0;
 		ccw->bits |= CCW_IRQ;
 		ccw->bits |= CCW_DEC_SEM;
-		ccw->bits |= CCW_WAIT4END;
+		if (flags & DMA_CTRL_ACK)
+			ccw->bits |= CCW_WAIT4END;
 		ccw->bits |= CCW_HALT_ON_TERM;
 		ccw->bits |= CCW_TERM_FLUSH;
 		ccw->bits |= BF_CCW(sg_len, PIO_NUM);
@@ -432,7 +455,8 @@ static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg(
 				ccw->bits &= ~CCW_CHAIN;
 				ccw->bits |= CCW_IRQ;
 				ccw->bits |= CCW_DEC_SEM;
-				ccw->bits |= CCW_WAIT4END;
+				if (flags & DMA_CTRL_ACK)
+					ccw->bits |= CCW_WAIT4END;
 			}
 		}
 	}
diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
index e5ea2b1..4062812 100644
--- a/drivers/mmc/host/mxs-mmc.c
+++ b/drivers/mmc/host/mxs-mmc.c
@@ -305,7 +305,7 @@ static irqreturn_t mxs_mmc_irq_handler(int irq, void *dev_id)
 }
 
 static struct dma_async_tx_descriptor *mxs_mmc_prep_dma(
-	struct mxs_mmc_host *host, unsigned int append)
+	struct mxs_mmc_host *host, unsigned long flags)
 {
 	struct dma_async_tx_descriptor *desc;
 	struct mmc_data *data = host->data;
@@ -325,7 +325,7 @@ static struct dma_async_tx_descriptor *mxs_mmc_prep_dma(
 	}
 
 	desc = host->dmach->device->device_prep_slave_sg(host->dmach,
-				sgl, sg_len, host->slave_dirn, append);
+				sgl, sg_len, host->slave_dirn, flags);
 	if (desc) {
 		desc->callback = mxs_mmc_dma_irq_callback;
 		desc->callback_param = host;
@@ -358,7 +358,7 @@ static void mxs_mmc_bc(struct mxs_mmc_host *host)
 	host->ssp_pio_words[2] = cmd1;
 	host->dma_dir = DMA_NONE;
 	host->slave_dirn = DMA_TRANS_NONE;
-	desc = mxs_mmc_prep_dma(host, 0);
+	desc = mxs_mmc_prep_dma(host, DMA_CTRL_ACK);
 	if (!desc)
 		goto out;
 
@@ -398,7 +398,7 @@ static void mxs_mmc_ac(struct mxs_mmc_host *host)
 	host->ssp_pio_words[2] = cmd1;
 	host->dma_dir = DMA_NONE;
 	host->slave_dirn = DMA_TRANS_NONE;
-	desc = mxs_mmc_prep_dma(host, 0);
+	desc = mxs_mmc_prep_dma(host, DMA_CTRL_ACK);
 	if (!desc)
 		goto out;
 
@@ -526,7 +526,7 @@ static void mxs_mmc_adtc(struct mxs_mmc_host *host)
 	host->data = data;
 	host->dma_dir = dma_data_dir;
 	host->slave_dirn = slave_dirn;
-	desc = mxs_mmc_prep_dma(host, 1);
+	desc = mxs_mmc_prep_dma(host, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc)
 		goto out;
 
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
index cbcf022..81ddf59 100644
--- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
+++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c
@@ -850,7 +850,9 @@ int gpmi_send_command(struct gpmi_nand_data *this)
 	sg_init_one(sgl, this->cmd_buffer, this->command_length);
 	dma_map_sg(this->dev, sgl, 1, DMA_TO_DEVICE);
 	desc = channel->device->device_prep_slave_sg(channel,
-					sgl, 1, DMA_MEM_TO_DEV, 1);
+				sgl, 1, DMA_MEM_TO_DEV,
+				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+
 	if (!desc) {
 		pr_err("step 2 error\n");
 		return -1;
@@ -892,7 +894,8 @@ int gpmi_send_data(struct gpmi_nand_data *this)
 	/* [2] send DMA request */
 	prepare_data_dma(this, DMA_TO_DEVICE);
 	desc = channel->device->device_prep_slave_sg(channel, &this->data_sgl,
-						1, DMA_MEM_TO_DEV, 1);
+					1, DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		pr_err("step 2 error\n");
 		return -1;
@@ -928,7 +931,8 @@ int gpmi_read_data(struct gpmi_nand_data *this)
 	/* [2] : send DMA request */
 	prepare_data_dma(this, DMA_FROM_DEVICE);
 	desc = channel->device->device_prep_slave_sg(channel, &this->data_sgl,
-						1, DMA_DEV_TO_MEM, 1);
+					1, DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		pr_err("step 2 error\n");
 		return -1;
@@ -975,7 +979,8 @@ int gpmi_send_page(struct gpmi_nand_data *this,
 
 	desc = channel->device->device_prep_slave_sg(channel,
 					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 0);
+					ARRAY_SIZE(pio), DMA_TRANS_NONE,
+					DMA_CTRL_ACK);
 	if (!desc) {
 		pr_err("step 2 error\n");
 		return -1;
@@ -995,6 +1000,7 @@ int gpmi_read_page(struct gpmi_nand_data *this,
 	struct dma_async_tx_descriptor *desc;
 	struct dma_chan *channel = get_dma_chan(this);
 	int chip = this->current_chip;
+	unsigned long flags;
 	u32 pio[6];
 
 	/* [1] Wait for the chip to report ready. */
@@ -1037,9 +1043,14 @@ int gpmi_read_page(struct gpmi_nand_data *this,
 	pio[3] = geo->page_size;
 	pio[4] = payload;
 	pio[5] = auxiliary;
+
+	/* Set DMA_CTRL_ACK for mx6q which uses the new GPMI version. */
+	flags = DMA_PREP_INTERRUPT;
+	if (GPMI_IS_MX6Q(this))
+		flags |= DMA_CTRL_ACK;
 	desc = channel->device->device_prep_slave_sg(channel,
 					(struct scatterlist *)pio,
-					ARRAY_SIZE(pio), DMA_TRANS_NONE, 1);
+					ARRAY_SIZE(pio), DMA_TRANS_NONE, flags);
 	if (!desc) {
 		pr_err("step 2 error\n");
 		return -1;
@@ -1059,7 +1070,8 @@ int gpmi_read_page(struct gpmi_nand_data *this,
 	pio[2] = 0; /* Set GPMI_HW_GPMI_ECCCTRL, disable the BCH. */
 	desc = channel->device->device_prep_slave_sg(channel,
 				(struct scatterlist *)pio, 3,
-				DMA_TRANS_NONE, 1);
+				DMA_TRANS_NONE,
+				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
 		pr_err("step 3 error\n");
 		return -1;
-- 
1.7.0.4