From 27504be5c10bdc61761ec0126b3645428598ad91 Mon Sep 17 00:00:00 2001
From: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Date: Tue, 6 Sep 2011 17:16:34 +0900
Subject: [PATCH 1/5] spi-topcliff-pch: add tx-memory clear after complete
 transmitting

Currently, in case of reading date from SPI flash,
command is sent twice.
The cause is that tx-memory clear processing is missing .
This patch adds the tx-momory clear processing.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/spi/spi-topcliff-pch.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 1d23f3831866..7a98caa3aed2 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -837,6 +837,11 @@ static void pch_spi_start_transfer(struct pch_spi_data *data)
 
 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
 			    DMA_FROM_DEVICE);
+
+	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_tx_p, dma->nent,
+			    DMA_FROM_DEVICE);
+	memset(data->dma.tx_buf_virt, 0, PAGE_SIZE);
+
 	async_tx_ack(dma->desc_rx);
 	async_tx_ack(dma->desc_tx);
 	kfree(dma->sg_tx_p);

From 8b7aa961a815dad389525dcd1c36a44c249b1760 Mon Sep 17 00:00:00 2001
From: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Date: Tue, 6 Sep 2011 17:16:35 +0900
Subject: [PATCH 2/5] spi-topcliff-pch: Fix SSN Control issue

During processing 1 command/data series,
SSN should keep LOW.
However, currently, SSN becomes HIGH.
This patch fixes the issue.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/spi/spi-topcliff-pch.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 7a98caa3aed2..c36d51657066 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -58,6 +58,7 @@
 #define PCH_SLEEP_TIME		10
 
 #define SSN_LOW			0x02U
+#define SSN_HIGH		0x03U
 #define SSN_NO_CONTROL		0x00U
 #define PCH_MAX_CS		0xFF
 #define PCI_DEVICE_ID_GE_SPI	0x8816
@@ -756,10 +757,6 @@ static void pch_spi_set_ir(struct pch_spi_data *data)
 
 	wait_event_interruptible(data->wait, data->transfer_complete);
 
-	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
-	dev_dbg(&data->master->dev,
-		"%s:no more control over SSN-writing 0 to SSNXCR.", __func__);
-
 	/* clear all interrupts */
 	pch_spi_writereg(data->master, PCH_SPSR,
 			 pch_spi_readreg(data->master, PCH_SPSR));
@@ -848,9 +845,6 @@ static void pch_spi_start_transfer(struct pch_spi_data *data)
 	kfree(dma->sg_rx_p);
 
 	spin_lock_irqsave(&data->lock, flags);
-	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
-	dev_dbg(&data->master->dev,
-		"%s:no more control over SSN-writing 0 to SSNXCR.", __func__);
 
 	/* clear fifo threshold, disable interrupts, disable SPI transfer */
 	pch_spi_setclr_reg(data->master, PCH_SPCR, 0,
@@ -1167,6 +1161,7 @@ static void pch_spi_process_messages(struct work_struct *pwork)
 	if (data->use_dma)
 		pch_spi_request_dma(data,
 				    data->current_msg->spi->bits_per_word);
+	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
 	do {
 		/* If we are already processing a message get the next
 		transfer structure from the message otherwise retrieve
@@ -1227,6 +1222,7 @@ static void pch_spi_process_messages(struct work_struct *pwork)
 
 	} while (data->cur_trans != NULL);
 
+	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_HIGH);
 	if (data->use_dma)
 		pch_spi_release_dma(data);
 }

From 373b0eb64b9c97a14720896dcfdebfa3268b1991 Mon Sep 17 00:00:00 2001
From: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Date: Tue, 6 Sep 2011 17:16:36 +0900
Subject: [PATCH 3/5] spi-topcliff-pch: Fix CPU read complete condition issue

We found Rx data sometimes drops.(with non-DMA transfer mode)
The cause is read complete condition is not true.

This patch fixes the issue.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/spi/spi-topcliff-pch.c | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index c36d51657066..6cb2fdbe5dba 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -317,16 +317,19 @@ static void pch_spi_handler_sub(struct pch_spi_data *data, u32 reg_spsr_val,
 
 	/* if transfer complete interrupt */
 	if (reg_spsr_val & SPSR_FI_BIT) {
-		if (tx_index < bpw_len)
+		if ((tx_index == bpw_len) && (rx_index == tx_index)) {
+			/* disable interrupts */
+			pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
+
+			/* transfer is completed;
+			   inform pch_spi_process_messages */
+			data->transfer_complete = true;
+			data->transfer_active = false;
+			wake_up(&data->wait);
+		} else {
 			dev_err(&data->master->dev,
 				"%s : Transfer is not completed", __func__);
-		/* disable interrupts */
-		pch_spi_setclr_reg(data->master, PCH_SPCR, 0, PCH_ALL);
-
-		/* transfer is completed;inform pch_spi_process_messages */
-		data->transfer_complete = true;
-		data->transfer_active = false;
-		wake_up(&data->wait);
+		}
 	}
 }
 

From 25e803f9c339a070cd7361e853aebde11b1f9217 Mon Sep 17 00:00:00 2001
From: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Date: Tue, 6 Sep 2011 17:16:37 +0900
Subject: [PATCH 4/5] spi-topcliff-pch: Add recovery processing in case FIFO
 overrun error occurs

Add recovery processing in case FIFO overrun error occurs with DMA transfer mode.

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/spi/spi-topcliff-pch.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 6cb2fdbe5dba..c8efa757fdaa 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -352,16 +352,26 @@ static irqreturn_t pch_spi_handler(int irq, void *dev_id)
 			"%s returning due to suspend\n", __func__);
 		return IRQ_NONE;
 	}
-	if (data->use_dma)
-		return IRQ_NONE;
 
 	io_remap_addr = data->io_remap_addr;
 	spsr = io_remap_addr + PCH_SPSR;
 
 	reg_spsr_val = ioread32(spsr);
 
-	if (reg_spsr_val & SPSR_ORF_BIT)
-		dev_err(&board_dat->pdev->dev, "%s Over run error", __func__);
+	if (reg_spsr_val & SPSR_ORF_BIT) {
+		dev_err(&board_dat->pdev->dev, "%s Over run error\n", __func__);
+		if (data->current_msg->complete != 0) {
+			data->transfer_complete = true;
+			data->current_msg->status = -EIO;
+			data->current_msg->complete(data->current_msg->context);
+			data->bcurrent_msg_processing = false;
+			data->current_msg = NULL;
+			data->cur_trans = NULL;
+		}
+	}
+
+	if (data->use_dma)
+		return IRQ_NONE;
 
 	/* Check if the interrupt is for SPI device */
 	if (reg_spsr_val & (SPSR_FI_BIT | SPSR_RFI_BIT)) {
@@ -815,10 +825,11 @@ static void pch_spi_copy_rx_data_for_dma(struct pch_spi_data *data, int bpw)
 	}
 }
 
-static void pch_spi_start_transfer(struct pch_spi_data *data)
+static int pch_spi_start_transfer(struct pch_spi_data *data)
 {
 	struct pch_spi_dma_ctrl *dma;
 	unsigned long flags;
+	int rtn;
 
 	dma = &data->dma;
 
@@ -833,7 +844,9 @@ static void pch_spi_start_transfer(struct pch_spi_data *data)
 				 initiating the transfer. */
 	dev_dbg(&data->master->dev,
 		"%s:waiting for transfer to get over\n", __func__);
-	wait_event_interruptible(data->wait, data->transfer_complete);
+	rtn = wait_event_interruptible_timeout(data->wait,
+					       data->transfer_complete,
+					       msecs_to_jiffies(2 * HZ));
 
 	dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
 			    DMA_FROM_DEVICE);
@@ -860,6 +873,8 @@ static void pch_spi_start_transfer(struct pch_spi_data *data)
 	pch_spi_clear_fifo(data->master);
 
 	spin_unlock_irqrestore(&data->lock, flags);
+
+	return rtn;
 }
 
 static void pch_dma_rx_complete(void *arg)
@@ -1187,7 +1202,8 @@ static void pch_spi_process_messages(struct work_struct *pwork)
 
 		if (data->use_dma) {
 			pch_spi_handle_dma(data, &bpw);
-			pch_spi_start_transfer(data);
+			if (!pch_spi_start_transfer(data))
+				goto out;
 			pch_spi_copy_rx_data_for_dma(data, bpw);
 		} else {
 			pch_spi_set_tx(data, &bpw);
@@ -1225,6 +1241,7 @@ static void pch_spi_process_messages(struct work_struct *pwork)
 
 	} while (data->cur_trans != NULL);
 
+out:
 	pch_spi_writereg(data->master, PCH_SSNXCR, SSN_HIGH);
 	if (data->use_dma)
 		pch_spi_release_dma(data);

From f3e03e2eb0bcd9266720695b82a523e6bc526ff7 Mon Sep 17 00:00:00 2001
From: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Date: Tue, 6 Sep 2011 17:16:38 +0900
Subject: [PATCH 5/5] spi-topcliff-pch: Fix overrun issue

We found that adding load, Rx data sometimes drops.(with DMA transfer mode)
The cause is that before starting Rx-DMA processing, Tx-DMA processing starts.
This causes FIFO overrun occurs.

This patch fixes the issue by modifying FIFO tx-threshold and DMA descriptor
size like below.

                      Current                   this patch
Rx-descriptor   4Byte+12Byte*341    -->    12Byte*340-4Byte-12Byte
Rx-threshold                   (Not modified)
Tx-descriptor   4Byte+12Byte*341    -->    16Byte-12Byte*340
Rx-threshold    12Byte              -->    2Byte

Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---
 drivers/spi/spi-topcliff-pch.c | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index c8efa757fdaa..6a80749391db 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -50,6 +50,8 @@
 #define PCH_RX_THOLD		7
 #define PCH_RX_THOLD_MAX	15
 
+#define PCH_TX_THOLD		2
+
 #define PCH_MAX_BAUDRATE	5000000
 #define PCH_MAX_FIFO_DEPTH	16
 
@@ -1040,8 +1042,7 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
 	/* set receive fifo threshold and transmit fifo threshold */
 	pch_spi_setclr_reg(data->master, PCH_SPCR,
 			   ((size - 1) << SPCR_RFIC_FIELD) |
-			   ((PCH_MAX_FIFO_DEPTH - PCH_DMA_TRANS_SIZE) <<
-			    SPCR_TFIC_FIELD),
+			   (PCH_TX_THOLD << SPCR_TFIC_FIELD),
 			   MASK_RFIC_SPCR_BITS | MASK_TFIC_SPCR_BITS);
 
 	spin_unlock_irqrestore(&data->lock, flags);
@@ -1052,13 +1053,20 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
 	/* offset, length setting */
 	sg = dma->sg_rx_p;
 	for (i = 0; i < num; i++, sg++) {
-		if (i == 0) {
-			sg->offset = 0;
+		if (i == (num - 2)) {
+			sg->offset = size * i;
+			sg->offset = sg->offset * (*bpw / 8);
 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), rem,
 				    sg->offset);
 			sg_dma_len(sg) = rem;
+		} else if (i == (num - 1)) {
+			sg->offset = size * (i - 1) + rem;
+			sg->offset = sg->offset * (*bpw / 8);
+			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
+				    sg->offset);
+			sg_dma_len(sg) = size;
 		} else {
-			sg->offset = rem + size * (i - 1);
+			sg->offset = size * i;
 			sg->offset = sg->offset * (*bpw / 8);
 			sg_set_page(sg, virt_to_page(dma->rx_buf_virt), size,
 				    sg->offset);
@@ -1082,6 +1090,16 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
 	dma->desc_rx = desc_rx;
 
 	/* TX */
+	if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
+		num = data->bpw_len / PCH_DMA_TRANS_SIZE;
+		size = PCH_DMA_TRANS_SIZE;
+		rem = 16;
+	} else {
+		num = 1;
+		size = data->bpw_len;
+		rem = data->bpw_len;
+	}
+
 	dma->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
 	sg_init_table(dma->sg_tx_p, num); /* Initialize SG table */
 	/* offset, length setting */