diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi_imx.c | 223 |
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; |
