diff options
Diffstat (limited to 'drivers/spi/spi-fsl-dspi.c')
| -rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 232 |
1 files changed, 162 insertions, 70 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 4bd4377551b5..83ea296597e9 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -331,6 +331,8 @@ struct fsl_dspi_dma { dma_addr_t rx_dma_phys; struct completion cmd_rx_complete; struct dma_async_tx_descriptor *rx_desc; + + size_t bufsize; }; struct fsl_dspi { @@ -373,6 +375,8 @@ struct fsl_dspi { void (*dev_to_host)(struct fsl_dspi *dspi, u32 rxdata); }; +static void dspi_setup_accel(struct fsl_dspi *dspi); + static bool is_s32g_dspi(struct fsl_dspi *data) { return data->devtype_data == &devtype_data[S32G] || @@ -468,6 +472,27 @@ static u32 dspi_pop_tx(struct fsl_dspi *dspi) return txdata; } +/* Push one word to the RX buffer from the POPR register (RX FIFO) */ +static void dspi_push_rx(struct fsl_dspi *dspi, u32 rxdata) +{ + if (!dspi->rx) + return; + dspi->dev_to_host(dspi, rxdata); +} + +static int dspi_fifo_error(struct fsl_dspi *dspi, u32 spi_sr) +{ + if (spi_sr & (SPI_SR_TFUF | SPI_SR_RFOF)) { + dev_err_ratelimited(&dspi->pdev->dev, "FIFO errors:%s%s\n", + spi_sr & SPI_SR_TFUF ? " TX underflow," : "", + spi_sr & SPI_SR_RFOF ? " RX overflow," : ""); + return -EIO; + } + return 0; +} + +#if IS_ENABLED(CONFIG_DMA_ENGINE) + /* Prepare one TX FIFO entry (txdata plus cmd) */ static u32 dspi_pop_tx_pushr(struct fsl_dspi *dspi) { @@ -481,19 +506,37 @@ static u32 dspi_pop_tx_pushr(struct fsl_dspi *dspi) return cmd << 16 | data; } -/* Push one word to the RX buffer from the POPR register (RX FIFO) */ -static void dspi_push_rx(struct fsl_dspi *dspi, u32 rxdata) +static size_t dspi_dma_max_datawords(struct fsl_dspi *dspi) { - if (!dspi->rx) - return; - dspi->dev_to_host(dspi, rxdata); + /* + * Transfers look like one of these, so we always use a full DMA word + * regardless of SPI word size: + * + * 31 16 15 0 + * ----------------------------------------- + * | CONTROL WORD | 16-bit DATA | + * ----------------------------------------- + * or + * ----------------------------------------- + * | CONTROL WORD | UNUSED | 8-bit DATA | + * ----------------------------------------- + */ + return dspi->dma->bufsize / DMA_SLAVE_BUSWIDTH_4_BYTES; +} + +static size_t dspi_dma_transfer_size(struct fsl_dspi *dspi) +{ + return dspi->words_in_flight * DMA_SLAVE_BUSWIDTH_4_BYTES; } static void dspi_tx_dma_callback(void *arg) { struct fsl_dspi *dspi = arg; struct fsl_dspi_dma *dma = dspi->dma; + struct device *dev = &dspi->pdev->dev; + dma_sync_single_for_cpu(dev, dma->tx_dma_phys, + dspi_dma_transfer_size(dspi), DMA_TO_DEVICE); complete(&dma->cmd_tx_complete); } @@ -501,9 +544,13 @@ static void dspi_rx_dma_callback(void *arg) { struct fsl_dspi *dspi = arg; struct fsl_dspi_dma *dma = dspi->dma; + struct device *dev = &dspi->pdev->dev; int i; if (dspi->rx) { + dma_sync_single_for_cpu(dev, dma->rx_dma_phys, + dspi_dma_transfer_size(dspi), + DMA_FROM_DEVICE); for (i = 0; i < dspi->words_in_flight; i++) dspi_push_rx(dspi, dspi->dma->rx_dma_buf[i]); } @@ -513,20 +560,22 @@ static void dspi_rx_dma_callback(void *arg) static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) { + size_t size = dspi_dma_transfer_size(dspi); struct device *dev = &dspi->pdev->dev; struct fsl_dspi_dma *dma = dspi->dma; int time_left; + u32 spi_sr; int i; for (i = 0; i < dspi->words_in_flight; i++) dspi->dma->tx_dma_buf[i] = dspi_pop_tx_pushr(dspi); + dma_sync_single_for_device(dev, dma->tx_dma_phys, size, DMA_TO_DEVICE); dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx, - dma->tx_dma_phys, - dspi->words_in_flight * - DMA_SLAVE_BUSWIDTH_4_BYTES, - DMA_MEM_TO_DEV, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + dma->tx_dma_phys, size, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); if (!dma->tx_desc) { dev_err(dev, "Not able to get desc for DMA xfer\n"); return -EIO; @@ -539,12 +588,13 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) return -EINVAL; } + dma_sync_single_for_device(dev, dma->rx_dma_phys, size, + DMA_FROM_DEVICE); dma->rx_desc = dmaengine_prep_slave_single(dma->chan_rx, - dma->rx_dma_phys, - dspi->words_in_flight * - DMA_SLAVE_BUSWIDTH_4_BYTES, - DMA_DEV_TO_MEM, - DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + dma->rx_dma_phys, size, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | + DMA_CTRL_ACK); if (!dma->rx_desc) { dev_err(dev, "Not able to get desc for DMA xfer\n"); return -EIO; @@ -565,7 +615,8 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) if (spi_controller_is_target(dspi->ctlr)) { wait_for_completion_interruptible(&dspi->dma->cmd_rx_complete); - return 0; + regmap_read(dspi->regmap, SPI_SR, &spi_sr); + return dspi_fifo_error(dspi, spi_sr); } time_left = wait_for_completion_timeout(&dspi->dma->cmd_tx_complete, @@ -589,13 +640,10 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) return 0; } -static void dspi_setup_accel(struct fsl_dspi *dspi); - -static int dspi_dma_xfer(struct fsl_dspi *dspi) +static void dspi_dma_xfer(struct fsl_dspi *dspi) { struct spi_message *message = dspi->cur_msg; struct device *dev = &dspi->pdev->dev; - int ret = 0; /* * dspi->len gets decremented by dspi_pop_tx_pushr in @@ -605,26 +653,22 @@ static int dspi_dma_xfer(struct fsl_dspi *dspi) /* Figure out operational bits-per-word for this chunk */ dspi_setup_accel(dspi); - dspi->words_in_flight = dspi->len / dspi->oper_word_size; - if (dspi->words_in_flight > dspi->devtype_data->fifo_size) - dspi->words_in_flight = dspi->devtype_data->fifo_size; + dspi->words_in_flight = min(dspi->len / dspi->oper_word_size, + dspi_dma_max_datawords(dspi)); message->actual_length += dspi->words_in_flight * dspi->oper_word_size; - ret = dspi_next_xfer_dma_submit(dspi); - if (ret) { + message->status = dspi_next_xfer_dma_submit(dspi); + if (message->status) { dev_err(dev, "DMA transfer failed\n"); break; } } - - return ret; } static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) { - int dma_bufsize = dspi->devtype_data->fifo_size * 2; struct device *dev = &dspi->pdev->dev; struct dma_slave_config cfg; struct fsl_dspi_dma *dma; @@ -644,17 +688,30 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) goto err_tx_channel; } - dma->tx_dma_buf = dma_alloc_coherent(dma->chan_tx->device->dev, - dma_bufsize, &dma->tx_dma_phys, - GFP_KERNEL); + if (spi_controller_is_target(dspi->ctlr)) { + /* + * In target mode we have to be ready to receive the maximum + * that can possibly be transferred at once by EDMA without any + * FIFO underflows. + */ + dma->bufsize = min(dma_get_max_seg_size(dma->chan_rx->device->dev), + dma_get_max_seg_size(dma->chan_tx->device->dev)) * + DMA_SLAVE_BUSWIDTH_4_BYTES; + } else { + dma->bufsize = PAGE_SIZE; + } + + dma->tx_dma_buf = dma_alloc_noncoherent(dma->chan_tx->device->dev, + dma->bufsize, &dma->tx_dma_phys, + DMA_TO_DEVICE, GFP_KERNEL); if (!dma->tx_dma_buf) { ret = -ENOMEM; goto err_tx_dma_buf; } - dma->rx_dma_buf = dma_alloc_coherent(dma->chan_rx->device->dev, - dma_bufsize, &dma->rx_dma_phys, - GFP_KERNEL); + dma->rx_dma_buf = dma_alloc_noncoherent(dma->chan_rx->device->dev, + dma->bufsize, &dma->rx_dma_phys, + DMA_FROM_DEVICE, GFP_KERNEL); if (!dma->rx_dma_buf) { ret = -ENOMEM; goto err_rx_dma_buf; @@ -689,11 +746,12 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) return 0; err_slave_config: - dma_free_coherent(dma->chan_rx->device->dev, - dma_bufsize, dma->rx_dma_buf, dma->rx_dma_phys); + dma_free_noncoherent(dma->chan_rx->device->dev, dma->bufsize, + dma->rx_dma_buf, dma->rx_dma_phys, + DMA_FROM_DEVICE); err_rx_dma_buf: - dma_free_coherent(dma->chan_tx->device->dev, - dma_bufsize, dma->tx_dma_buf, dma->tx_dma_phys); + dma_free_noncoherent(dma->chan_tx->device->dev, dma->bufsize, + dma->tx_dma_buf, dma->tx_dma_phys, DMA_TO_DEVICE); err_tx_dma_buf: dma_release_channel(dma->chan_tx); err_tx_channel: @@ -707,24 +765,37 @@ err_tx_channel: static void dspi_release_dma(struct fsl_dspi *dspi) { - int dma_bufsize = dspi->devtype_data->fifo_size * 2; struct fsl_dspi_dma *dma = dspi->dma; if (!dma) return; if (dma->chan_tx) { - dma_free_coherent(dma->chan_tx->device->dev, dma_bufsize, - dma->tx_dma_buf, dma->tx_dma_phys); + dma_free_noncoherent(dma->chan_tx->device->dev, dma->bufsize, + dma->tx_dma_buf, dma->tx_dma_phys, + DMA_TO_DEVICE); dma_release_channel(dma->chan_tx); } if (dma->chan_rx) { - dma_free_coherent(dma->chan_rx->device->dev, dma_bufsize, - dma->rx_dma_buf, dma->rx_dma_phys); + dma_free_noncoherent(dma->chan_rx->device->dev, dma->bufsize, + dma->rx_dma_buf, dma->rx_dma_phys, + DMA_FROM_DEVICE); dma_release_channel(dma->chan_rx); } } +#else +static void dspi_dma_xfer(struct fsl_dspi *dspi) +{ + dspi->cur_msg->status = -EINVAL; +} +static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) +{ + dev_err(&dspi->pdev->dev, "DMA support not enabled in kernel\n"); + return -EINVAL; +} +static void dspi_release_dma(struct fsl_dspi *dspi) {} +#endif static void hz_to_spi_baud(char *pbr, char *br, int speed_hz, unsigned long clkrate, bool mtf_enabled) @@ -986,41 +1057,55 @@ static void dspi_fifo_write(struct fsl_dspi *dspi) dspi->progress, !dspi->irq); } -static int dspi_rxtx(struct fsl_dspi *dspi) +/* + * Read the previous transfer from the FIFO and transmit the next one. + * + * Returns false if the buffer to be transmitted is empty, and true if there is + * still data to transmit. + */ +static bool dspi_rxtx(struct fsl_dspi *dspi) { dspi_fifo_read(dspi); if (!dspi->len) /* Success! */ - return 0; + return false; dspi_fifo_write(dspi); - return -EINPROGRESS; + return true; } -static int dspi_poll(struct fsl_dspi *dspi) +static void dspi_poll(struct fsl_dspi *dspi) { - int tries = 1000; + int tries; + int err = 0; u32 spi_sr; do { - regmap_read(dspi->regmap, SPI_SR, &spi_sr); - regmap_write(dspi->regmap, SPI_SR, spi_sr); - - if (spi_sr & SPI_SR_CMDTCF) + for (tries = 1000; tries > 0; --tries) { + regmap_read(dspi->regmap, SPI_SR, &spi_sr); + regmap_write(dspi->regmap, SPI_SR, spi_sr); + + dspi->cur_msg->status = dspi_fifo_error(dspi, spi_sr); + if (dspi->cur_msg->status) + return; + if (spi_sr & SPI_SR_CMDTCF) + break; + } + if (!tries) { + err = -ETIMEDOUT; break; - } while (--tries); - - if (!tries) - return -ETIMEDOUT; + } + } while (dspi_rxtx(dspi)); - return dspi_rxtx(dspi); + dspi->cur_msg->status = err; } static irqreturn_t dspi_interrupt(int irq, void *dev_id) { struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id; + int status; u32 spi_sr; regmap_read(dspi->regmap, SPI_SR, &spi_sr); @@ -1029,8 +1114,19 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id) if (!(spi_sr & SPI_SR_CMDTCF)) return IRQ_NONE; - if (dspi_rxtx(dspi) == 0) + status = dspi_fifo_error(dspi, spi_sr); + if (status) { + if (dspi->cur_msg) + WRITE_ONCE(dspi->cur_msg->status, status); + complete(&dspi->xfer_done); + return IRQ_HANDLED; + } + + if (dspi_rxtx(dspi) == false) { + if (dspi->cur_msg) + WRITE_ONCE(dspi->cur_msg->status, 0); complete(&dspi->xfer_done); + } return IRQ_HANDLED; } @@ -1060,7 +1156,6 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, struct spi_device *spi = message->spi; struct spi_transfer *transfer; bool cs = false; - int status = 0; u32 val = 0; bool cs_change = false; @@ -1120,7 +1215,7 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, dspi->progress, !dspi->irq); if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) { - status = dspi_dma_xfer(dspi); + dspi_dma_xfer(dspi); } else { /* * Reinitialize the completion before transferring data @@ -1134,15 +1229,12 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, dspi_fifo_write(dspi); - if (dspi->irq) { + if (dspi->irq) wait_for_completion(&dspi->xfer_done); - } else { - do { - status = dspi_poll(dspi); - } while (status == -EINPROGRESS); - } + else + dspi_poll(dspi); } - if (status) + if (READ_ONCE(message->status)) break; spi_transfer_delay_exec(transfer); @@ -1151,7 +1243,8 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, dspi_deassert_cs(spi, &cs); } - if (status || !cs_change) { + dspi->cur_msg = NULL; + if (message->status || !cs_change) { /* Put DSPI in stop mode */ regmap_update_bits(dspi->regmap, SPI_MCR, SPI_MCR_HALT, SPI_MCR_HALT); @@ -1160,10 +1253,9 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, ; } - message->status = status; spi_finalize_current_message(ctlr); - return status; + return message->status; } static int dspi_set_mtf(struct fsl_dspi *dspi) |