spi-topcliff-pch: Fix issue for transmitting over 4KByte

Currently, when spi-topcliff-pch receives transmit request over 4KByte,
this driver can't process correctly. This driver needs to divide the data
into 4Kbyte unit.
This patch fixes the issue.

Signed-off-by: Tomoya MORINAGA <tomoya.rohm@gmail.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 55 insertions, 11 deletions

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 4b32fd7d0570..4fdb83a765d8 100644
--- a/drivers/spi/spi-topcliff-pch.c
+++ b/drivers/spi/spi-topcliff-pch.c
@@ -196,6 +196,7 @@ struct pch_spi_data {
         struct pch_spi_dma_ctrl dma;
         int use_dma;
         u8 irq_reg_sts;
+        int save_total_len;
 };
 
 /**
@@ -823,11 +824,13 @@ static void pch_spi_copy_rx_data_for_dma(struct pch_spi_data *data, int bpw)
                 rx_dma_buf = data->dma.rx_buf_virt;
                 for (j = 0; j < data->bpw_len; j++)
                         *rx_buf++ = *rx_dma_buf++ & 0xFF;
+                data->cur_trans->rx_buf = rx_buf;
         } else {
                 rx_sbuf = data->cur_trans->rx_buf;
                 rx_dma_sbuf = data->dma.rx_buf_virt;
                 for (j = 0; j < data->bpw_len; j++)
                         *rx_sbuf++ = *rx_dma_sbuf++;
+                data->cur_trans->rx_buf = rx_sbuf;
         }
 }
 
@@ -853,6 +856,9 @@ static int pch_spi_start_transfer(struct pch_spi_data *data)
         rtn = wait_event_interruptible_timeout(data->wait,
                                                data->transfer_complete,
                                                msecs_to_jiffies(2 * HZ));
+        if (!rtn)
+                dev_err(&data->master->dev,
+                        "%s wait-event timeout\n", __func__);
 
         dma_sync_sg_for_cpu(&data->master->dev, dma->sg_rx_p, dma->nent,
                             DMA_FROM_DEVICE);
@@ -989,6 +995,7 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
         int i;
         int size;
         int rem;
+        int head;
         unsigned long flags;
         struct pch_spi_dma_ctrl *dma;
 
@@ -1017,6 +1024,11 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
         }
         data->bpw_len = data->cur_trans->len / (*bpw / 8);
 
+        if (data->bpw_len > PCH_BUF_SIZE) {
+                data->bpw_len = PCH_BUF_SIZE;
+                data->cur_trans->len -= PCH_BUF_SIZE;
+        }
+
         /* copy Tx Data */
         if (data->cur_trans->tx_buf != NULL) {
                 if (*bpw == 8) {
@@ -1031,10 +1043,17 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
                                 *tx_dma_sbuf++ = *tx_sbuf++;
                 }
         }
+
+        /* Calculate Rx parameter for DMA transmitting */
         if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
-                num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
+                if (data->bpw_len % PCH_DMA_TRANS_SIZE) {
+                        num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
+                        rem = data->bpw_len % PCH_DMA_TRANS_SIZE;
+                } else {
+                        num = data->bpw_len / PCH_DMA_TRANS_SIZE;
+                        rem = PCH_DMA_TRANS_SIZE;
+                }
                 size = PCH_DMA_TRANS_SIZE;
-                rem = data->bpw_len % PCH_DMA_TRANS_SIZE;
         } else {
                 num = 1;
                 size = data->bpw_len;
@@ -1094,15 +1113,23 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
         dma->nent = num;
         dma->desc_rx = desc_rx;
 
-        /* TX */
-        if (data->bpw_len > PCH_DMA_TRANS_SIZE) {
-                num = data->bpw_len / PCH_DMA_TRANS_SIZE;
+        /* Calculate Tx parameter for DMA transmitting */
+        if (data->bpw_len > PCH_MAX_FIFO_DEPTH) {
+                head = PCH_MAX_FIFO_DEPTH - PCH_DMA_TRANS_SIZE;
+                if (data->bpw_len % PCH_DMA_TRANS_SIZE > 4) {
+                        num = data->bpw_len / PCH_DMA_TRANS_SIZE + 1;
+                        rem = data->bpw_len % PCH_DMA_TRANS_SIZE - head;
+                } else {
+                        num = data->bpw_len / PCH_DMA_TRANS_SIZE;
+                        rem = data->bpw_len % PCH_DMA_TRANS_SIZE +
+                              PCH_DMA_TRANS_SIZE - head;
+                }
                 size = PCH_DMA_TRANS_SIZE;
-                rem = 16;
         } else {
                 num = 1;
                 size = data->bpw_len;
                 rem = data->bpw_len;
+                head = 0;
         }
 
         dma->sg_tx_p = kzalloc(sizeof(struct scatterlist)*num, GFP_ATOMIC);
@@ -1112,11 +1139,17 @@ static void pch_spi_handle_dma(struct pch_spi_data *data, int *bpw)
         for (i = 0; i < num; i++, sg++) {
                 if (i == 0) {
                         sg->offset = 0;
+                        sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size + head,
+                                    sg->offset);
+                        sg_dma_len(sg) = size + head;
+                } else if (i == (num - 1)) {
+                        sg->offset = head + size * i;
+                        sg->offset = sg->offset * (*bpw / 8);
                         sg_set_page(sg, virt_to_page(dma->tx_buf_virt), rem,
                                     sg->offset);
                         sg_dma_len(sg) = rem;
                 } else {
-                        sg->offset = rem + size * (i - 1);
+                        sg->offset = head + size * i;
                         sg->offset = sg->offset * (*bpw / 8);
                         sg_set_page(sg, virt_to_page(dma->tx_buf_virt), size,
                                     sg->offset);
@@ -1204,6 +1237,7 @@ static void pch_spi_process_messages(struct work_struct *pwork)
                                     data->current_msg->spi->bits_per_word);
         pch_spi_writereg(data->master, PCH_SSNXCR, SSN_NO_CONTROL);
         do {
+                int cnt;
                 /* If we are already processing a message get the next
                 transfer structure from the message otherwise retrieve
                 the 1st transfer request from the message. */
@@ -1223,11 +1257,20 @@ static void pch_spi_process_messages(struct work_struct *pwork)
                 }
                 spin_unlock(&data->lock);
 
+                if (!data->cur_trans->len)
+                        goto out;
+                cnt = (data->cur_trans->len - 1) / PCH_BUF_SIZE + 1;
+                data->save_total_len = data->cur_trans->len;
                 if (data->use_dma) {
-                        pch_spi_handle_dma(data, &bpw);
-                        if (!pch_spi_start_transfer(data))
-                                goto out;
-                        pch_spi_copy_rx_data_for_dma(data, bpw);
+                        int i;
+                        char *save_rx_buf = data->cur_trans->rx_buf;
+                        for (i = 0; i < cnt; i ++) {
+                                pch_spi_handle_dma(data, &bpw);
+                                if (!pch_spi_start_transfer(data))
+                                        goto out;
+                                pch_spi_copy_rx_data_for_dma(data, bpw);
+                        }
+                        data->cur_trans->rx_buf = save_rx_buf;
                 } else {
                         pch_spi_set_tx(data, &bpw);
                         pch_spi_set_ir(data);
@@ -1238,6 +1281,7 @@ static void pch_spi_process_messages(struct work_struct *pwork)
                         data->pkt_tx_buff = NULL;
                 }
                 /* increment message count */
+                data->cur_trans->len = data->save_total_len;
                 data->current_msg->actual_length += data->cur_trans->len;
 
                 dev_dbg(&data->master->dev,