irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data)
{
u32 irq_status;
irq_status = pxa2xx_spi_read(drv_data, SSSR) & drv_data->mask_sr;
if (irq_status & SSSR_ROR) {
pxa2xx_spi_dma_error_stop(drv_data,
"dma_transfer: fifo overrun");
return IRQ_HANDLED;
}
/* Check for false positive timeout */
if ((irq_status & SSSR_TINT)
&& (DCSR(drv_data->tx_channel) & DCSR_RUN)) {
pxa2xx_spi_write(drv_data, SSSR, SSSR_TINT);
return IRQ_HANDLED;
}
if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) {
/* Clear and disable timeout interrupt, do the rest in
* dma_transfer_complete */
if (!pxa25x_ssp_comp(drv_data))
pxa2xx_spi_write(drv_data, SSTO, 0);
/* finish this transfer, start the next */
pxa2xx_spi_dma_transfer_complete(drv_data);
return IRQ_HANDLED;
}
/* Opps problem detected */
return IRQ_NONE;
}
static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data,
bool error)
{
struct spi_message *msg = drv_data->master->cur_msg;
/*
* It is possible that one CPU is handling ROR interrupt and other
* just gets DMA completion. Calling pump_transfers() twice for the
* same transfer leads to problems thus we prevent concurrent calls
* by using ->dma_running.
*/
if (atomic_dec_and_test(&drv_data->dma_running)) {
/*
* If the other CPU is still handling the ROR interrupt we
* might not know about the error yet. So we re-check the
* ROR bit here before we clear the status register.
*/
if (!error) {
u32 status = pxa2xx_spi_read(drv_data, SSSR)
& drv_data->mask_sr;
error = status & SSSR_ROR;
}
/* Clear status & disable interrupts */
pxa2xx_spi_write(drv_data, SSCR1,
pxa2xx_spi_read(drv_data, SSCR1)
& ~drv_data->dma_cr1);
write_SSSR_CS(drv_data, drv_data->clear_sr);
if (!pxa25x_ssp_comp(drv_data))
pxa2xx_spi_write(drv_data, SSTO, 0);
if (!error) {
msg->actual_length += drv_data->len;
msg->state = pxa2xx_spi_next_transfer(drv_data);
} else {
/* In case we got an error we disable the SSP now */
pxa2xx_spi_write(drv_data, SSCR0,
pxa2xx_spi_read(drv_data, SSCR0)
& ~SSCR0_SSE);
msg->state = ERROR_STATE;
}
tasklet_schedule(&drv_data->pump_transfers);
}
}
static int u32_writer(struct driver_data *drv_data)
{
if (pxa2xx_spi_txfifo_full(drv_data)
|| (drv_data->tx == drv_data->tx_end))
return 0;
pxa2xx_spi_write(drv_data, SSDR, *(u32 *)(drv_data->tx));
drv_data->tx += 4;
return 1;
}
static int null_writer(struct driver_data *drv_data)
{
u8 n_bytes = drv_data->n_bytes;
if (pxa2xx_spi_txfifo_full(drv_data)
|| (drv_data->tx == drv_data->tx_end))
return 0;
pxa2xx_spi_write(drv_data, SSDR, 0);
drv_data->tx += n_bytes;
return 1;
}
static void pxa2xx_spi_dma_error_stop(struct driver_data *drv_data,
const char *msg)
{
/* Stop and reset */
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
write_SSSR_CS(drv_data, drv_data->clear_sr);
pxa2xx_spi_write(drv_data, SSCR1,
pxa2xx_spi_read(drv_data, SSCR1)
& ~drv_data->dma_cr1);
if (!pxa25x_ssp_comp(drv_data))
pxa2xx_spi_write(drv_data, SSTO, 0);
pxa2xx_spi_flush(drv_data);
pxa2xx_spi_write(drv_data, SSCR0,
pxa2xx_spi_read(drv_data, SSCR0) & ~SSCR0_SSE);
pxa2xx_spi_unmap_dma_buffers(drv_data);
dev_err(&drv_data->pdev->dev, "%s\n", msg);
drv_data->cur_msg->state = ERROR_STATE;
tasklet_schedule(&drv_data->pump_transfers);
}
static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data)
{
struct spi_message *msg = drv_data->cur_msg;
/* Clear and disable interrupts on SSP and DMA channels*/
pxa2xx_spi_write(drv_data, SSCR1,
pxa2xx_spi_read(drv_data, SSCR1)
& ~drv_data->dma_cr1);
write_SSSR_CS(drv_data, drv_data->clear_sr);
DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL;
DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL;
if (wait_dma_channel_stop(drv_data->rx_channel) == 0)
dev_err(&drv_data->pdev->dev,
"dma_handler: dma rx channel stop failed\n");
if (wait_ssp_rx_stall(drv_data->ioaddr) == 0)
dev_err(&drv_data->pdev->dev,
"dma_transfer: ssp rx stall failed\n");
pxa2xx_spi_unmap_dma_buffers(drv_data);
/* update the buffer pointer for the amount completed in dma */
drv_data->rx += drv_data->len -
(DCMD(drv_data->rx_channel) & DCMD_LENGTH);
/* read trailing data from fifo, it does not matter how many
* bytes are in the fifo just read until buffer is full
* or fifo is empty, which ever occurs first */
drv_data->read(drv_data);
/* return count of what was actually read */
msg->actual_length += drv_data->len -
(drv_data->rx_end - drv_data->rx);
/* Transfer delays and chip select release are
* handled in pump_transfers or giveback
*/
/* Move to next transfer */
msg->state = pxa2xx_spi_next_transfer(drv_data);
/* Schedule transfer tasklet */
tasklet_schedule(&drv_data->pump_transfers);
}
static void cs_assert(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
if (drv_data->ssp_type == CE4100_SSP) {
pxa2xx_spi_write(drv_data, SSSR, drv_data->cur_chip->frm);
return;
}
if (chip->cs_control) {
chip->cs_control(PXA2XX_CS_ASSERT);
return;
}
if (gpio_is_valid(chip->gpio_cs)) {
gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted);
return;
}
if (is_lpss_ssp(drv_data))
lpss_ssp_cs_control(drv_data, true);
}