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spi-topcliff-pch: Fix issue for transmitting over 4KByte
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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>
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Tomoya MORINAGA authored and Grant Likely committed Mar 10, 2012
1 parent ee2ece5 commit 7d05b3e
Showing 1 changed file with 55 additions and 11 deletions.
66 changes: 55 additions & 11 deletions drivers/spi/spi-topcliff-pch.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
};

/**
Expand Down Expand Up @@ -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;
}
}

Expand All @@ -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);
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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) {
Expand All @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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. */
Expand All @@ -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);
Expand All @@ -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,
Expand Down

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