diff options
Diffstat (limited to 'drivers/spi/spi-fsl-dspi.c')
-rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 306 |
1 files changed, 302 insertions, 4 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index a67b0ff..14c8e7c 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -15,6 +15,8 @@ #include <linux/clk.h> #include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/interrupt.h> @@ -40,6 +42,7 @@ #define TRAN_STATE_WORD_ODD_NUM 0x04 #define DSPI_FIFO_SIZE 4 +#define DSPI_DMA_BUFSIZE (DSPI_FIFO_SIZE * 1024) #define SPI_MCR 0x00 #define SPI_MCR_MASTER (1 << 31) @@ -72,6 +75,11 @@ #define SPI_SR_TCFQF 0x80000000 #define SPI_SR_CLEAR 0xdaad0000 +#define SPI_RSER_TFFFE BIT(25) +#define SPI_RSER_TFFFD BIT(24) +#define SPI_RSER_RFDFE BIT(17) +#define SPI_RSER_RFDFD BIT(16) + #define SPI_RSER 0x30 #define SPI_RSER_EOQFE 0x10000000 #define SPI_RSER_TCFQE 0x80000000 @@ -109,6 +117,8 @@ #define SPI_TCR_TCNT_MAX 0x10000 +#define DMA_COMPLETION_TIMEOUT msecs_to_jiffies(3000) + struct chip_data { u32 mcr_val; u32 ctar_val; @@ -118,6 +128,7 @@ struct chip_data { enum dspi_trans_mode { DSPI_EOQ_MODE = 0, DSPI_TCFQ_MODE, + DSPI_DMA_MODE, }; struct fsl_dspi_devtype_data { @@ -126,7 +137,7 @@ struct fsl_dspi_devtype_data { }; static const struct fsl_dspi_devtype_data vf610_data = { - .trans_mode = DSPI_EOQ_MODE, + .trans_mode = DSPI_DMA_MODE, .max_clock_factor = 2, }; @@ -140,6 +151,23 @@ static const struct fsl_dspi_devtype_data ls2085a_data = { .max_clock_factor = 8, }; +struct fsl_dspi_dma { + /* Length of transfer in words of DSPI_FIFO_SIZE */ + u32 curr_xfer_len; + + u32 *tx_dma_buf; + struct dma_chan *chan_tx; + dma_addr_t tx_dma_phys; + struct completion cmd_tx_complete; + struct dma_async_tx_descriptor *tx_desc; + + u32 *rx_dma_buf; + struct dma_chan *chan_rx; + dma_addr_t rx_dma_phys; + struct completion cmd_rx_complete; + struct dma_async_tx_descriptor *rx_desc; +}; + struct fsl_dspi { struct spi_master *master; struct platform_device *pdev; @@ -166,8 +194,11 @@ struct fsl_dspi { u32 waitflags; u32 spi_tcnt; + struct fsl_dspi_dma *dma; }; +static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word); + static inline int is_double_byte_mode(struct fsl_dspi *dspi) { unsigned int val; @@ -177,6 +208,255 @@ static inline int is_double_byte_mode(struct fsl_dspi *dspi) return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1; } +static void dspi_tx_dma_callback(void *arg) +{ + struct fsl_dspi *dspi = arg; + struct fsl_dspi_dma *dma = dspi->dma; + + complete(&dma->cmd_tx_complete); +} + +static void dspi_rx_dma_callback(void *arg) +{ + struct fsl_dspi *dspi = arg; + struct fsl_dspi_dma *dma = dspi->dma; + int rx_word; + int i; + u16 d; + + rx_word = is_double_byte_mode(dspi); + + if (!(dspi->dataflags & TRAN_STATE_RX_VOID)) { + for (i = 0; i < dma->curr_xfer_len; i++) { + d = dspi->dma->rx_dma_buf[i]; + rx_word ? (*(u16 *)dspi->rx = d) : + (*(u8 *)dspi->rx = d); + dspi->rx += rx_word + 1; + } + } + + complete(&dma->cmd_rx_complete); +} + +static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) +{ + struct fsl_dspi_dma *dma = dspi->dma; + struct device *dev = &dspi->pdev->dev; + int time_left; + int tx_word; + int i; + + tx_word = is_double_byte_mode(dspi); + + for (i = 0; i < dma->curr_xfer_len; i++) { + dspi->dma->tx_dma_buf[i] = dspi_data_to_pushr(dspi, tx_word); + if ((dspi->cs_change) && (!dspi->len)) + dspi->dma->tx_dma_buf[i] &= ~SPI_PUSHR_CONT; + } + + dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx, + dma->tx_dma_phys, + dma->curr_xfer_len * + DMA_SLAVE_BUSWIDTH_4_BYTES, + 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; + } + + dma->tx_desc->callback = dspi_tx_dma_callback; + dma->tx_desc->callback_param = dspi; + if (dma_submit_error(dmaengine_submit(dma->tx_desc))) { + dev_err(dev, "DMA submit failed\n"); + return -EINVAL; + } + + dma->rx_desc = dmaengine_prep_slave_single(dma->chan_rx, + dma->rx_dma_phys, + dma->curr_xfer_len * + DMA_SLAVE_BUSWIDTH_4_BYTES, + 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; + } + + dma->rx_desc->callback = dspi_rx_dma_callback; + dma->rx_desc->callback_param = dspi; + if (dma_submit_error(dmaengine_submit(dma->rx_desc))) { + dev_err(dev, "DMA submit failed\n"); + return -EINVAL; + } + + reinit_completion(&dspi->dma->cmd_rx_complete); + reinit_completion(&dspi->dma->cmd_tx_complete); + + dma_async_issue_pending(dma->chan_rx); + dma_async_issue_pending(dma->chan_tx); + + time_left = wait_for_completion_timeout(&dspi->dma->cmd_tx_complete, + DMA_COMPLETION_TIMEOUT); + if (time_left == 0) { + dev_err(dev, "DMA tx timeout\n"); + dmaengine_terminate_all(dma->chan_tx); + dmaengine_terminate_all(dma->chan_rx); + return -ETIMEDOUT; + } + + time_left = wait_for_completion_timeout(&dspi->dma->cmd_rx_complete, + DMA_COMPLETION_TIMEOUT); + if (time_left == 0) { + dev_err(dev, "DMA rx timeout\n"); + dmaengine_terminate_all(dma->chan_tx); + dmaengine_terminate_all(dma->chan_rx); + return -ETIMEDOUT; + } + + return 0; +} + +static int dspi_dma_xfer(struct fsl_dspi *dspi) +{ + struct fsl_dspi_dma *dma = dspi->dma; + struct device *dev = &dspi->pdev->dev; + int curr_remaining_bytes; + int bytes_per_buffer; + int word = 1; + int ret = 0; + + if (is_double_byte_mode(dspi)) + word = 2; + curr_remaining_bytes = dspi->len; + bytes_per_buffer = DSPI_DMA_BUFSIZE / DSPI_FIFO_SIZE; + while (curr_remaining_bytes) { + /* Check if current transfer fits the DMA buffer */ + dma->curr_xfer_len = curr_remaining_bytes / word; + if (dma->curr_xfer_len > bytes_per_buffer) + dma->curr_xfer_len = bytes_per_buffer; + + ret = dspi_next_xfer_dma_submit(dspi); + if (ret) { + dev_err(dev, "DMA transfer failed\n"); + goto exit; + + } else { + curr_remaining_bytes -= dma->curr_xfer_len * word; + if (curr_remaining_bytes < 0) + curr_remaining_bytes = 0; + } + } + +exit: + return ret; +} + +static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) +{ + struct fsl_dspi_dma *dma; + struct dma_slave_config cfg; + struct device *dev = &dspi->pdev->dev; + int ret; + + dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL); + if (!dma) + return -ENOMEM; + + dma->chan_rx = dma_request_slave_channel(dev, "rx"); + if (!dma->chan_rx) { + dev_err(dev, "rx dma channel not available\n"); + ret = -ENODEV; + return ret; + } + + dma->chan_tx = dma_request_slave_channel(dev, "tx"); + if (!dma->chan_tx) { + dev_err(dev, "tx dma channel not available\n"); + ret = -ENODEV; + goto err_tx_channel; + } + + dma->tx_dma_buf = dma_alloc_coherent(dev, DSPI_DMA_BUFSIZE, + &dma->tx_dma_phys, GFP_KERNEL); + if (!dma->tx_dma_buf) { + ret = -ENOMEM; + goto err_tx_dma_buf; + } + + dma->rx_dma_buf = dma_alloc_coherent(dev, DSPI_DMA_BUFSIZE, + &dma->rx_dma_phys, GFP_KERNEL); + if (!dma->rx_dma_buf) { + ret = -ENOMEM; + goto err_rx_dma_buf; + } + + cfg.src_addr = phy_addr + SPI_POPR; + cfg.dst_addr = phy_addr + SPI_PUSHR; + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + cfg.src_maxburst = 1; + cfg.dst_maxburst = 1; + + cfg.direction = DMA_DEV_TO_MEM; + ret = dmaengine_slave_config(dma->chan_rx, &cfg); + if (ret) { + dev_err(dev, "can't configure rx dma channel\n"); + ret = -EINVAL; + goto err_slave_config; + } + + cfg.direction = DMA_MEM_TO_DEV; + ret = dmaengine_slave_config(dma->chan_tx, &cfg); + if (ret) { + dev_err(dev, "can't configure tx dma channel\n"); + ret = -EINVAL; + goto err_slave_config; + } + + dspi->dma = dma; + init_completion(&dma->cmd_tx_complete); + init_completion(&dma->cmd_rx_complete); + + return 0; + +err_slave_config: + dma_free_coherent(dev, DSPI_DMA_BUFSIZE, + dma->rx_dma_buf, dma->rx_dma_phys); +err_rx_dma_buf: + dma_free_coherent(dev, DSPI_DMA_BUFSIZE, + dma->tx_dma_buf, dma->tx_dma_phys); +err_tx_dma_buf: + dma_release_channel(dma->chan_tx); +err_tx_channel: + dma_release_channel(dma->chan_rx); + + devm_kfree(dev, dma); + dspi->dma = NULL; + + return ret; +} + +static void dspi_release_dma(struct fsl_dspi *dspi) +{ + struct fsl_dspi_dma *dma = dspi->dma; + struct device *dev = &dspi->pdev->dev; + + if (dma) { + if (dma->chan_tx) { + dma_unmap_single(dev, dma->tx_dma_phys, + DSPI_DMA_BUFSIZE, DMA_TO_DEVICE); + dma_release_channel(dma->chan_tx); + } + + if (dma->chan_rx) { + dma_unmap_single(dev, dma->rx_dma_phys, + DSPI_DMA_BUFSIZE, DMA_FROM_DEVICE); + dma_release_channel(dma->chan_rx); + } + } +} + static void hz_to_spi_baud(char *pbr, char *br, int speed_hz, unsigned long clkrate) { @@ -425,6 +705,12 @@ static int dspi_transfer_one_message(struct spi_master *master, regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE); dspi_tcfq_write(dspi); break; + case DSPI_DMA_MODE: + regmap_write(dspi->regmap, SPI_RSER, + SPI_RSER_TFFFE | SPI_RSER_TFFFD | + SPI_RSER_RFDFE | SPI_RSER_RFDFD); + status = dspi_dma_xfer(dspi); + break; default: dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n", trans_mode); @@ -432,9 +718,13 @@ static int dspi_transfer_one_message(struct spi_master *master, goto out; } - if (wait_event_interruptible(dspi->waitq, dspi->waitflags)) - dev_err(&dspi->pdev->dev, "wait transfer complete fail!\n"); - dspi->waitflags = 0; + if (trans_mode != DSPI_DMA_MODE) { + if (wait_event_interruptible(dspi->waitq, + dspi->waitflags)) + dev_err(&dspi->pdev->dev, + "wait transfer complete fail!\n"); + dspi->waitflags = 0; + } if (transfer->delay_usecs) udelay(transfer->delay_usecs); @@ -740,6 +1030,13 @@ static int dspi_probe(struct platform_device *pdev) if (ret) goto out_master_put; + if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) { + if (dspi_request_dma(dspi, res->start)) { + dev_err(&pdev->dev, "can't get dma channels\n"); + goto out_clk_put; + } + } + master->max_speed_hz = clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor; @@ -768,6 +1065,7 @@ static int dspi_remove(struct platform_device *pdev) struct fsl_dspi *dspi = spi_master_get_devdata(master); /* Disconnect from the SPI framework */ + dspi_release_dma(dspi); clk_disable_unprepare(dspi->clk); spi_unregister_master(dspi->master); |