From 13d515c796adc49a49b0cd2212ccd7f43a37fc5a Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Mon, 15 Oct 2018 12:08:27 +0530 Subject: spi: omap2-mcspi: Switch to readl_poll_timeout() Use standard readl_poll_timeout() macro for polling on status bits. Signed-off-by: Vignesh R Signed-off-by: Mark Brown --- drivers/spi/spi-omap2-mcspi.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) (limited to 'drivers/spi/spi-omap2-mcspi.c') diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 508c61c669e7..985f00d8a964 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -353,19 +354,9 @@ disable_fifo: static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit) { - unsigned long timeout; - - timeout = jiffies + msecs_to_jiffies(1000); - while (!(readl_relaxed(reg) & bit)) { - if (time_after(jiffies, timeout)) { - if (!(readl_relaxed(reg) & bit)) - return -ETIMEDOUT; - else - return 0; - } - cpu_relax(); - } - return 0; + u32 val; + + return readl_poll_timeout(reg, val, val & bit, 1, MSEC_PER_SEC); } static void omap2_mcspi_rx_callback(void *data) -- cgit v1.2.3 From b682cffa3ac6d9d9e16e9b413c45caee3b391fab Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Mon, 15 Oct 2018 12:08:28 +0530 Subject: spi: omap2-mcspi: Set FIFO DMA trigger level to word length McSPI has 32 byte FIFO in Transmit-Receive mode. Current code tries to configuration FIFO watermark level for DMA trigger to be GCD of transfer length and max FIFO size which would mean trigger level may be set to 32 for transmit-receive mode if length is aligned. This does not work in case of SPI slave mode where FIFO always needs to have data ready whenever master starts the clock. With DMA trigger size of 32 there will be a small window during slave TX where DMA is still putting data into FIFO but master would have started clock for next byte, resulting in shifting out of stale data. Similarly, on Slave RX side there may be RX FIFO overflow Fix this by setting FIFO watermark for DMA trigger to word length. This means DMA is triggered as soon as FIFO has space for word length bytes and DMA would make sure FIFO is almost always full therefore improving FIFO occupancy in both master and slave mode. Signed-off-by: Vignesh R Signed-off-by: Mark Brown --- drivers/spi/spi-omap2-mcspi.c | 26 +++++++------------------- 1 file changed, 7 insertions(+), 19 deletions(-) (limited to 'drivers/spi/spi-omap2-mcspi.c') diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 985f00d8a964..88469bb22235 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -300,7 +300,7 @@ static void omap2_mcspi_set_fifo(const struct spi_device *spi, struct omap2_mcspi_cs *cs = spi->controller_state; struct omap2_mcspi *mcspi; unsigned int wcnt; - int max_fifo_depth, fifo_depth, bytes_per_word; + int max_fifo_depth, bytes_per_word; u32 chconf, xferlevel; mcspi = spi_master_get_devdata(master); @@ -316,10 +316,6 @@ static void omap2_mcspi_set_fifo(const struct spi_device *spi, else max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH; - fifo_depth = gcd(t->len, max_fifo_depth); - if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0) - goto disable_fifo; - wcnt = t->len / bytes_per_word; if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT) goto disable_fifo; @@ -327,16 +323,17 @@ static void omap2_mcspi_set_fifo(const struct spi_device *spi, xferlevel = wcnt << 16; if (t->rx_buf != NULL) { chconf |= OMAP2_MCSPI_CHCONF_FFER; - xferlevel |= (fifo_depth - 1) << 8; + xferlevel |= (bytes_per_word - 1) << 8; } + if (t->tx_buf != NULL) { chconf |= OMAP2_MCSPI_CHCONF_FFET; - xferlevel |= fifo_depth - 1; + xferlevel |= bytes_per_word - 1; } mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel); mcspi_write_chconf0(spi, chconf); - mcspi->fifo_depth = fifo_depth; + mcspi->fifo_depth = max_fifo_depth; return; } @@ -576,7 +573,6 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) struct dma_slave_config cfg; enum dma_slave_buswidth width; unsigned es; - u32 burst; void __iomem *chstat_reg; void __iomem *irqstat_reg; int wait_res; @@ -596,22 +592,14 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) } count = xfer->len; - burst = 1; - - if (mcspi->fifo_depth > 0) { - if (count > mcspi->fifo_depth) - burst = mcspi->fifo_depth / es; - else - burst = count / es; - } memset(&cfg, 0, sizeof(cfg)); cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0; cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0; cfg.src_addr_width = width; cfg.dst_addr_width = width; - cfg.src_maxburst = burst; - cfg.dst_maxburst = burst; + cfg.src_maxburst = es; + cfg.dst_maxburst = es; rx = xfer->rx_buf; tx = xfer->tx_buf; -- cgit v1.2.3 From 89e8b9cb846515e4435eb42df7009b824cf3405a Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Mon, 15 Oct 2018 12:08:29 +0530 Subject: spi: omap2-mcspi: Add slave mode support Add support to use McSPI controller as SPI slave. In slave mode, DMA TX completion does not mean entire data has been shifted out as data might still be stuck in FIFO waiting for master to clock the bus. Therefore, add an IRQ handler for slave mode to know when entire data in FIFO has been shifted out. Signed-off-by: Vignesh R Signed-off-by: Mark Brown --- drivers/spi/spi-omap2-mcspi.c | 138 +++++++++++++++++++++++++++++++++++++----- 1 file changed, 122 insertions(+), 16 deletions(-) (limited to 'drivers/spi/spi-omap2-mcspi.c') diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 88469bb22235..f024c3fc3679 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -127,6 +127,7 @@ struct omap2_mcspi_regs { }; struct omap2_mcspi { + struct completion txdone; struct spi_master *master; /* Virtual base address of the controller */ void __iomem *base; @@ -136,6 +137,7 @@ struct omap2_mcspi { struct device *dev; struct omap2_mcspi_regs ctx; int fifo_depth; + bool slave_aborted; unsigned int pin_dir:1; }; @@ -275,19 +277,23 @@ static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) } } -static void omap2_mcspi_set_master_mode(struct spi_master *master) +static void omap2_mcspi_set_mode(struct spi_master *master) { struct omap2_mcspi *mcspi = spi_master_get_devdata(master); struct omap2_mcspi_regs *ctx = &mcspi->ctx; u32 l; /* - * Setup when switching from (reset default) slave mode - * to single-channel master mode + * Choose master or slave mode */ l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL); - l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS); - l |= OMAP2_MCSPI_MODULCTRL_SINGLE; + l &= ~(OMAP2_MCSPI_MODULCTRL_STEST); + if (spi_controller_is_slave(master)) { + l |= (OMAP2_MCSPI_MODULCTRL_MS); + } else { + l &= ~(OMAP2_MCSPI_MODULCTRL_MS); + l |= OMAP2_MCSPI_MODULCTRL_SINGLE; + } mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l); ctx->modulctrl = l; @@ -356,6 +362,20 @@ static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit) return readl_poll_timeout(reg, val, val & bit, 1, MSEC_PER_SEC); } +static int mcspi_wait_for_completion(struct omap2_mcspi *mcspi, + struct completion *x) +{ + if (spi_controller_is_slave(mcspi->master)) { + if (wait_for_completion_interruptible(x) || + mcspi->slave_aborted) + return -EINTR; + } else { + wait_for_completion(x); + } + + return 0; +} + static void omap2_mcspi_rx_callback(void *data) { struct spi_device *spi = data; @@ -505,7 +525,12 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer, dma_async_issue_pending(mcspi_dma->dma_rx); omap2_mcspi_set_dma_req(spi, 1, 1); - wait_for_completion(&mcspi_dma->dma_rx_completion); + ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion); + if (ret || mcspi->slave_aborted) { + dmaengine_terminate_sync(mcspi_dma->dma_rx); + omap2_mcspi_set_dma_req(spi, 1, 0); + return 0; + } for (x = 0; x < nb_sizes; x++) kfree(sg_out[x]); @@ -604,14 +629,37 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer) rx = xfer->rx_buf; tx = xfer->tx_buf; - if (tx != NULL) + mcspi->slave_aborted = false; + reinit_completion(&mcspi_dma->dma_tx_completion); + reinit_completion(&mcspi_dma->dma_rx_completion); + reinit_completion(&mcspi->txdone); + if (tx) { + /* Enable EOW IRQ to know end of tx in slave mode */ + if (spi_controller_is_slave(spi->master)) + mcspi_write_reg(spi->master, + OMAP2_MCSPI_IRQENABLE, + OMAP2_MCSPI_IRQSTATUS_EOW); omap2_mcspi_tx_dma(spi, xfer, cfg); + } if (rx != NULL) count = omap2_mcspi_rx_dma(spi, xfer, cfg, es); if (tx != NULL) { - wait_for_completion(&mcspi_dma->dma_tx_completion); + int ret; + + ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion); + if (ret || mcspi->slave_aborted) { + dmaengine_terminate_sync(mcspi_dma->dma_tx); + omap2_mcspi_set_dma_req(spi, 0, 0); + return 0; + } + + if (spi_controller_is_slave(mcspi->master)) { + ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone); + if (ret || mcspi->slave_aborted) + return 0; + } if (mcspi->fifo_depth > 0) { irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS; @@ -1068,6 +1116,36 @@ static void omap2_mcspi_cleanup(struct spi_device *spi) gpio_free(spi->cs_gpio); } +static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data) +{ + struct omap2_mcspi *mcspi = data; + u32 irqstat; + + irqstat = mcspi_read_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS); + if (!irqstat) + return IRQ_NONE; + + /* Disable IRQ and wakeup slave xfer task */ + mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0); + if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW) + complete(&mcspi->txdone); + + return IRQ_HANDLED; +} + +static int omap2_mcspi_slave_abort(struct spi_master *master) +{ + struct omap2_mcspi *mcspi = spi_master_get_devdata(master); + struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels; + + mcspi->slave_aborted = true; + complete(&mcspi_dma->dma_rx_completion); + complete(&mcspi_dma->dma_tx_completion); + complete(&mcspi->txdone); + + return 0; +} + static int omap2_mcspi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *t) @@ -1234,10 +1312,20 @@ static bool omap2_mcspi_can_dma(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) { + struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); + struct omap2_mcspi_dma *mcspi_dma = + &mcspi->dma_channels[spi->chip_select]; + + if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) + return false; + + if (spi_controller_is_slave(master)) + return true; + return (xfer->len >= DMA_MIN_BYTES); } -static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi) +static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi) { struct spi_master *master = mcspi->master; struct omap2_mcspi_regs *ctx = &mcspi->ctx; @@ -1254,7 +1342,7 @@ static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi) OMAP2_MCSPI_WAKEUPENABLE_WKEN); ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN; - omap2_mcspi_set_master_mode(master); + omap2_mcspi_set_mode(master); pm_runtime_mark_last_busy(mcspi->dev); pm_runtime_put_autosuspend(mcspi->dev); return 0; @@ -1329,11 +1417,12 @@ static int omap2_mcspi_probe(struct platform_device *pdev) struct device_node *node = pdev->dev.of_node; const struct of_device_id *match; - master = spi_alloc_master(&pdev->dev, sizeof *mcspi); - if (master == NULL) { - dev_dbg(&pdev->dev, "master allocation failed\n"); + if (of_property_read_bool(node, "spi-slave")) + master = spi_alloc_slave(&pdev->dev, sizeof(*mcspi)); + else + master = spi_alloc_master(&pdev->dev, sizeof(*mcspi)); + if (!master) return -ENOMEM; - } /* the spi->mode bits understood by this driver: */ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; @@ -1345,6 +1434,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev) master->transfer_one = omap2_mcspi_transfer_one; master->set_cs = omap2_mcspi_set_cs; master->cleanup = omap2_mcspi_cleanup; + master->slave_abort = omap2_mcspi_slave_abort; master->dev.of_node = node; master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ; master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15; @@ -1396,15 +1486,31 @@ static int omap2_mcspi_probe(struct platform_device *pdev) sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i); } + status = platform_get_irq(pdev, 0); + if (status == -EPROBE_DEFER) + goto free_master; + if (status < 0) { + dev_err(&pdev->dev, "no irq resource found\n"); + goto free_master; + } + init_completion(&mcspi->txdone); + status = devm_request_irq(&pdev->dev, status, + omap2_mcspi_irq_handler, 0, pdev->name, + mcspi); + if (status) { + dev_err(&pdev->dev, "Cannot request IRQ"); + goto free_master; + } + pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT); pm_runtime_enable(&pdev->dev); - status = omap2_mcspi_master_setup(mcspi); + status = omap2_mcspi_controller_setup(mcspi); if (status < 0) goto disable_pm; - status = devm_spi_register_master(&pdev->dev, master); + status = devm_spi_register_controller(&pdev->dev, master); if (status < 0) goto disable_pm; -- cgit v1.2.3