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>

diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c
index 7a98caa3aed2b5b3d9b6e39833ed6c73b572ddeb..c36d516570666c7a6767b89c80d4a5f2e574928d 100644 (file)
--- 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);
 }