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path: root/drivers/spi
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Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi_imx.c223
1 files changed, 114 insertions, 109 deletions
diff --git a/drivers/spi/spi_imx.c b/drivers/spi/spi_imx.c
index d4ba640366b6..c730d05bfeb6 100644
--- a/drivers/spi/spi_imx.c
+++ b/drivers/spi/spi_imx.c
@@ -270,19 +270,26 @@ struct chip_data {
static void pump_messages(struct work_struct *work);
-static int flush(struct driver_data *drv_data)
+static void flush(struct driver_data *drv_data)
{
- unsigned long limit = loops_per_jiffy << 1;
void __iomem *regs = drv_data->regs;
- volatile u32 d;
+ u32 control;
dev_dbg(&drv_data->pdev->dev, "flush\n");
+
+ /* Wait for end of transaction */
do {
- while (readl(regs + SPI_INT_STATUS) & SPI_STATUS_RR)
- d = readl(regs + SPI_RXDATA);
- } while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) && limit--);
+ control = readl(regs + SPI_CONTROL);
+ } while (control & SPI_CONTROL_XCH);
+
+ /* Release chip select if requested, transfer delays are
+ handled in pump_transfers */
+ if (drv_data->cs_change)
+ drv_data->cs_control(SPI_CS_DEASSERT);
- return limit;
+ /* Disable SPI to flush FIFOs */
+ writel(control & ~SPI_CONTROL_SPIEN, regs + SPI_CONTROL);
+ writel(control, regs + SPI_CONTROL);
}
static void restore_state(struct driver_data *drv_data)
@@ -570,6 +577,7 @@ static void giveback(struct spi_message *message, struct driver_data *drv_data)
writel(0, regs + SPI_INT_STATUS);
writel(0, regs + SPI_DMA);
+ /* Unconditioned deselct */
drv_data->cs_control(SPI_CS_DEASSERT);
message->state = NULL;
@@ -592,13 +600,10 @@ static void dma_err_handler(int channel, void *data, int errcode)
/* Disable both rx and tx dma channels */
imx_dma_disable(drv_data->rx_channel);
imx_dma_disable(drv_data->tx_channel);
-
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "dma_err_handler - flush failed\n");
-
unmap_dma_buffers(drv_data);
+ flush(drv_data);
+
msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
}
@@ -612,8 +617,7 @@ static void dma_tx_handler(int channel, void *data)
imx_dma_disable(channel);
/* Now waits for TX FIFO empty */
- writel(readl(drv_data->regs + SPI_INT_STATUS) | SPI_INTEN_TE,
- drv_data->regs + SPI_INT_STATUS);
+ writel(SPI_INTEN_TE, drv_data->regs + SPI_INT_STATUS);
}
static irqreturn_t dma_transfer(struct driver_data *drv_data)
@@ -621,19 +625,18 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data)
u32 status;
struct spi_message *msg = drv_data->cur_msg;
void __iomem *regs = drv_data->regs;
- unsigned long limit;
status = readl(regs + SPI_INT_STATUS);
- if ((status & SPI_INTEN_RO) && (status & SPI_STATUS_RO)) {
+ if ((status & (SPI_INTEN_RO | SPI_STATUS_RO))
+ == (SPI_INTEN_RO | SPI_STATUS_RO)) {
writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
+ imx_dma_disable(drv_data->tx_channel);
imx_dma_disable(drv_data->rx_channel);
unmap_dma_buffers(drv_data);
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "dma_transfer - flush failed\n");
+ flush(drv_data);
dev_warn(&drv_data->pdev->dev,
"dma_transfer - fifo overun\n");
@@ -649,20 +652,17 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data)
if (drv_data->rx) {
/* Wait end of transfer before read trailing data */
- limit = loops_per_jiffy << 1;
- while ((readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH) &&
- limit--);
-
- if (limit == 0)
- dev_err(&drv_data->pdev->dev,
- "dma_transfer - end of tx failed\n");
- else
- dev_dbg(&drv_data->pdev->dev,
- "dma_transfer - end of tx\n");
+ while (readl(regs + SPI_CONTROL) & SPI_CONTROL_XCH)
+ cpu_relax();
imx_dma_disable(drv_data->rx_channel);
unmap_dma_buffers(drv_data);
+ /* Release chip select if requested, transfer delays are
+ handled in pump_transfers() */
+ if (drv_data->cs_change)
+ drv_data->cs_control(SPI_CS_DEASSERT);
+
/* Calculate number of trailing data and read them */
dev_dbg(&drv_data->pdev->dev,
"dma_transfer - test = 0x%08X\n",
@@ -676,19 +676,12 @@ static irqreturn_t dma_transfer(struct driver_data *drv_data)
/* Write only transfer */
unmap_dma_buffers(drv_data);
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "dma_transfer - flush failed\n");
+ flush(drv_data);
}
/* End of transfer, update total byte transfered */
msg->actual_length += drv_data->len;
- /* Release chip select if requested, transfer delays are
- handled in pump_transfers() */
- if (drv_data->cs_change)
- drv_data->cs_control(SPI_CS_DEASSERT);
-
/* Move to next transfer */
msg->state = next_transfer(drv_data);
@@ -711,44 +704,43 @@ static irqreturn_t interrupt_wronly_transfer(struct driver_data *drv_data)
status = readl(regs + SPI_INT_STATUS);
- while (status & SPI_STATUS_TH) {
+ if (status & SPI_INTEN_TE) {
+ /* TXFIFO Empty Interrupt on the last transfered word */
+ writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
dev_dbg(&drv_data->pdev->dev,
- "interrupt_wronly_transfer - status = 0x%08X\n", status);
+ "interrupt_wronly_transfer - end of tx\n");
- /* Pump data */
- if (write(drv_data)) {
- writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
- regs + SPI_INT_STATUS);
+ flush(drv_data);
- dev_dbg(&drv_data->pdev->dev,
- "interrupt_wronly_transfer - end of tx\n");
+ /* Update total byte transfered */
+ msg->actual_length += drv_data->len;
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "interrupt_wronly_transfer - "
- "flush failed\n");
+ /* Move to next transfer */
+ msg->state = next_transfer(drv_data);
- /* End of transfer, update total byte transfered */
- msg->actual_length += drv_data->len;
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
- /* Release chip select if requested, transfer delays are
- handled in pump_transfers */
- if (drv_data->cs_change)
- drv_data->cs_control(SPI_CS_DEASSERT);
+ return IRQ_HANDLED;
+ } else {
+ while (status & SPI_STATUS_TH) {
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_wronly_transfer - status = 0x%08X\n",
+ status);
- /* Move to next transfer */
- msg->state = next_transfer(drv_data);
+ /* Pump data */
+ if (write(drv_data)) {
+ /* End of TXFIFO writes,
+ now wait until TXFIFO is empty */
+ writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
+ return IRQ_HANDLED;
+ }
- /* Schedule transfer tasklet */
- tasklet_schedule(&drv_data->pump_transfers);
+ status = readl(regs + SPI_INT_STATUS);
- return IRQ_HANDLED;
+ /* We did something */
+ handled = IRQ_HANDLED;
}
-
- status = readl(regs + SPI_INT_STATUS);
-
- /* We did something */
- handled = IRQ_HANDLED;
}
return handled;
@@ -758,45 +750,31 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
void __iomem *regs = drv_data->regs;
- u32 status;
+ u32 status, control;
irqreturn_t handled = IRQ_NONE;
unsigned long limit;
status = readl(regs + SPI_INT_STATUS);
- while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
+ if (status & SPI_INTEN_TE) {
+ /* TXFIFO Empty Interrupt on the last transfered word */
+ writel(status & ~SPI_INTEN, regs + SPI_INT_STATUS);
dev_dbg(&drv_data->pdev->dev,
- "interrupt_transfer - status = 0x%08X\n", status);
-
- if (status & SPI_STATUS_RO) {
- writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
- regs + SPI_INT_STATUS);
-
- dev_warn(&drv_data->pdev->dev,
- "interrupt_transfer - fifo overun\n"
- " data not yet written = %d\n"
- " data not yet read = %d\n",
- data_to_write(drv_data),
- data_to_read(drv_data));
-
- if (flush(drv_data) == 0)
- dev_err(&drv_data->pdev->dev,
- "interrupt_transfer - flush failed\n");
-
- msg->state = ERROR_STATE;
- tasklet_schedule(&drv_data->pump_transfers);
+ "interrupt_transfer - end of tx\n");
- return IRQ_HANDLED;
- }
-
- /* Pump data */
- read(drv_data);
- if (write(drv_data)) {
- writel(readl(regs + SPI_INT_STATUS) & ~SPI_INTEN,
- regs + SPI_INT_STATUS);
+ if (msg->state == ERROR_STATE) {
+ /* RXFIFO overrun was detected and message aborted */
+ flush(drv_data);
+ } else {
+ /* Wait for end of transaction */
+ do {
+ control = readl(regs + SPI_CONTROL);
+ } while (control & SPI_CONTROL_XCH);
- dev_dbg(&drv_data->pdev->dev,
- "interrupt_transfer - end of tx\n");
+ /* Release chip select if requested, transfer delays are
+ handled in pump_transfers */
+ if (drv_data->cs_change)
+ drv_data->cs_control(SPI_CS_DEASSERT);
/* Read trailing bytes */
limit = loops_per_jiffy << 1;
@@ -810,27 +788,54 @@ static irqreturn_t interrupt_transfer(struct driver_data *drv_data)
dev_dbg(&drv_data->pdev->dev,
"interrupt_transfer - end of rx\n");
- /* End of transfer, update total byte transfered */
+ /* Update total byte transfered */
msg->actual_length += drv_data->len;
- /* Release chip select if requested, transfer delays are
- handled in pump_transfers */
- if (drv_data->cs_change)
- drv_data->cs_control(SPI_CS_DEASSERT);
-
/* Move to next transfer */
msg->state = next_transfer(drv_data);
+ }
- /* Schedule transfer tasklet */
- tasklet_schedule(&drv_data->pump_transfers);
+ /* Schedule transfer tasklet */
+ tasklet_schedule(&drv_data->pump_transfers);
- return IRQ_HANDLED;
- }
+ return IRQ_HANDLED;
+ } else {
+ while (status & (SPI_STATUS_TH | SPI_STATUS_RO)) {
+ dev_dbg(&drv_data->pdev->dev,
+ "interrupt_transfer - status = 0x%08X\n",
+ status);
+
+ if (status & SPI_STATUS_RO) {
+ /* RXFIFO overrun, abort message end wait
+ until TXFIFO is empty */
+ writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
+
+ dev_warn(&drv_data->pdev->dev,
+ "interrupt_transfer - fifo overun\n"
+ " data not yet written = %d\n"
+ " data not yet read = %d\n",
+ data_to_write(drv_data),
+ data_to_read(drv_data));
+
+ msg->state = ERROR_STATE;
+
+ return IRQ_HANDLED;
+ }
- status = readl(regs + SPI_INT_STATUS);
+ /* Pump data */
+ read(drv_data);
+ if (write(drv_data)) {
+ /* End of TXFIFO writes,
+ now wait until TXFIFO is empty */
+ writel(SPI_INTEN_TE, regs + SPI_INT_STATUS);
+ return IRQ_HANDLED;
+ }
- /* We did something */
- handled = IRQ_HANDLED;
+ status = readl(regs + SPI_INT_STATUS);
+
+ /* We did something */
+ handled = IRQ_HANDLED;
+ }
}
return handled;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-19 09:44:55 +0000