From d9a017713d909697f528a3f6569d5deb7477cea1 Mon Sep 17 00:00:00 2001 From: H Hartley Sweeten Date: Wed, 9 Aug 2017 08:51:31 +1200 Subject: [PATCH] spi: spi-ep93xx: use the default master transfer queueing mechanism Update this driver to the default implementation of transfer_one_message(). Signed-off-by: H Hartley Sweeten Reviewed-by: Andy Shevchenko Signed-off-by: Chris Packham Signed-off-by: Mark Brown --- drivers/spi/spi-ep93xx.c | 322 +++++++++++++-------------------------- 1 file changed, 108 insertions(+), 214 deletions(-) diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c index cf7d8175bf79..e5cc07357746 100644 --- a/drivers/spi/spi-ep93xx.c +++ b/drivers/spi/spi-ep93xx.c @@ -73,7 +73,6 @@ * @clk: clock for the controller * @mmio: pointer to ioremap()'d registers * @sspdr_phys: physical address of the SSPDR register - * @wait: wait here until given transfer is completed * @tx: current byte in transfer to transmit * @rx: current byte in transfer to receive * @fifo_level: how full is FIFO (%0..%SPI_FIFO_SIZE - %1). Receiving one @@ -91,7 +90,6 @@ struct ep93xx_spi { struct clk *clk; void __iomem *mmio; unsigned long sspdr_phys; - struct completion wait; size_t tx; size_t rx; size_t fifo_level; @@ -123,8 +121,7 @@ static int ep93xx_spi_calc_divisors(struct spi_master *master, /* * Make sure that max value is between values supported by the - * controller. Note that minimum value is already checked in - * ep93xx_spi_transfer_one_message(). + * controller. */ rate = clamp(rate, master->min_speed_hz, master->max_speed_hz); @@ -149,15 +146,6 @@ static int ep93xx_spi_calc_divisors(struct spi_master *master, return -EINVAL; } -static void ep93xx_spi_cs_control(struct spi_device *spi, bool enable) -{ - if (spi->mode & SPI_CS_HIGH) - enable = !enable; - - if (gpio_is_valid(spi->cs_gpio)) - gpio_set_value(spi->cs_gpio, !enable); -} - static int ep93xx_spi_chip_setup(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) @@ -188,34 +176,38 @@ static int ep93xx_spi_chip_setup(struct spi_master *master, return 0; } -static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t) +static void ep93xx_do_write(struct spi_master *master) { + struct ep93xx_spi *espi = spi_master_get_devdata(master); + struct spi_transfer *xfer = master->cur_msg->state; u32 val = 0; - if (t->bits_per_word > 8) { - if (t->tx_buf) - val = ((u16 *)t->tx_buf)[espi->tx]; + if (xfer->bits_per_word > 8) { + if (xfer->tx_buf) + val = ((u16 *)xfer->tx_buf)[espi->tx]; espi->tx += 2; } else { - if (t->tx_buf) - val = ((u8 *)t->tx_buf)[espi->tx]; + if (xfer->tx_buf) + val = ((u8 *)xfer->tx_buf)[espi->tx]; espi->tx += 1; } writel(val, espi->mmio + SSPDR); } -static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t) +static void ep93xx_do_read(struct spi_master *master) { + struct ep93xx_spi *espi = spi_master_get_devdata(master); + struct spi_transfer *xfer = master->cur_msg->state; u32 val; val = readl(espi->mmio + SSPDR); - if (t->bits_per_word > 8) { - if (t->rx_buf) - ((u16 *)t->rx_buf)[espi->rx] = val; + if (xfer->bits_per_word > 8) { + if (xfer->rx_buf) + ((u16 *)xfer->rx_buf)[espi->rx] = val; espi->rx += 2; } else { - if (t->rx_buf) - ((u8 *)t->rx_buf)[espi->rx] = val; + if (xfer->rx_buf) + ((u8 *)xfer->rx_buf)[espi->rx] = val; espi->rx += 1; } } @@ -234,45 +226,26 @@ static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t) static int ep93xx_spi_read_write(struct spi_master *master) { struct ep93xx_spi *espi = spi_master_get_devdata(master); - struct spi_transfer *t = master->cur_msg->state; + struct spi_transfer *xfer = master->cur_msg->state; /* read as long as RX FIFO has frames in it */ while ((readl(espi->mmio + SSPSR) & SSPSR_RNE)) { - ep93xx_do_read(espi, t); + ep93xx_do_read(master); espi->fifo_level--; } /* write as long as TX FIFO has room */ - while (espi->fifo_level < SPI_FIFO_SIZE && espi->tx < t->len) { - ep93xx_do_write(espi, t); + while (espi->fifo_level < SPI_FIFO_SIZE && espi->tx < xfer->len) { + ep93xx_do_write(master); espi->fifo_level++; } - if (espi->rx == t->len) + if (espi->rx == xfer->len) return 0; return -EINPROGRESS; } -static void ep93xx_spi_pio_transfer(struct spi_master *master) -{ - struct ep93xx_spi *espi = spi_master_get_devdata(master); - - /* - * Now everything is set up for the current transfer. We prime the TX - * FIFO, enable interrupts, and wait for the transfer to complete. - */ - if (ep93xx_spi_read_write(master)) { - u32 val; - - val = readl(espi->mmio + SSPCR1); - val |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE); - writel(val, espi->mmio + SSPCR1); - - wait_for_completion(&espi->wait); - } -} - /** * ep93xx_spi_dma_prepare() - prepares a DMA transfer * @master: SPI master @@ -287,7 +260,7 @@ ep93xx_spi_dma_prepare(struct spi_master *master, enum dma_transfer_direction dir) { struct ep93xx_spi *espi = spi_master_get_devdata(master); - struct spi_transfer *t = master->cur_msg->state; + struct spi_transfer *xfer = master->cur_msg->state; struct dma_async_tx_descriptor *txd; enum dma_slave_buswidth buswidth; struct dma_slave_config conf; @@ -295,10 +268,10 @@ ep93xx_spi_dma_prepare(struct spi_master *master, struct sg_table *sgt; struct dma_chan *chan; const void *buf, *pbuf; - size_t len = t->len; + size_t len = xfer->len; int i, ret, nents; - if (t->bits_per_word > 8) + if (xfer->bits_per_word > 8) buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; else buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; @@ -308,14 +281,14 @@ ep93xx_spi_dma_prepare(struct spi_master *master, if (dir == DMA_DEV_TO_MEM) { chan = espi->dma_rx; - buf = t->rx_buf; + buf = xfer->rx_buf; sgt = &espi->rx_sgt; conf.src_addr = espi->sspdr_phys; conf.src_addr_width = buswidth; } else { chan = espi->dma_tx; - buf = t->tx_buf; + buf = xfer->tx_buf; sgt = &espi->tx_sgt; conf.dst_addr = espi->sspdr_phys; @@ -406,10 +379,15 @@ static void ep93xx_spi_dma_finish(struct spi_master *master, static void ep93xx_spi_dma_callback(void *callback_param) { - complete(callback_param); + struct spi_master *master = callback_param; + + ep93xx_spi_dma_finish(master, DMA_MEM_TO_DEV); + ep93xx_spi_dma_finish(master, DMA_DEV_TO_MEM); + + spi_finalize_current_transfer(master); } -static void ep93xx_spi_dma_transfer(struct spi_master *master) +static int ep93xx_spi_dma_transfer(struct spi_master *master) { struct ep93xx_spi *espi = spi_master_get_devdata(master); struct dma_async_tx_descriptor *rxd, *txd; @@ -417,177 +395,29 @@ static void ep93xx_spi_dma_transfer(struct spi_master *master) rxd = ep93xx_spi_dma_prepare(master, DMA_DEV_TO_MEM); if (IS_ERR(rxd)) { dev_err(&master->dev, "DMA RX failed: %ld\n", PTR_ERR(rxd)); - master->cur_msg->status = PTR_ERR(rxd); - return; + return PTR_ERR(rxd); } txd = ep93xx_spi_dma_prepare(master, DMA_MEM_TO_DEV); if (IS_ERR(txd)) { ep93xx_spi_dma_finish(master, DMA_DEV_TO_MEM); dev_err(&master->dev, "DMA TX failed: %ld\n", PTR_ERR(txd)); - master->cur_msg->status = PTR_ERR(txd); - return; + return PTR_ERR(txd); } /* We are ready when RX is done */ rxd->callback = ep93xx_spi_dma_callback; - rxd->callback_param = &espi->wait; + rxd->callback_param = master; - /* Now submit both descriptors and wait while they finish */ + /* Now submit both descriptors and start DMA */ dmaengine_submit(rxd); dmaengine_submit(txd); dma_async_issue_pending(espi->dma_rx); dma_async_issue_pending(espi->dma_tx); - wait_for_completion(&espi->wait); - - ep93xx_spi_dma_finish(master, DMA_MEM_TO_DEV); - ep93xx_spi_dma_finish(master, DMA_DEV_TO_MEM); -} - -/** - * ep93xx_spi_process_transfer() - processes one SPI transfer - * @master: SPI master - * @msg: current message - * @t: transfer to process - * - * This function processes one SPI transfer given in @t. Function waits until - * transfer is complete (may sleep) and updates @msg->status based on whether - * transfer was successfully processed or not. - */ -static void ep93xx_spi_process_transfer(struct spi_master *master, - struct spi_message *msg, - struct spi_transfer *t) -{ - struct ep93xx_spi *espi = spi_master_get_devdata(master); - int err; - - msg->state = t; - - err = ep93xx_spi_chip_setup(master, msg->spi, t); - if (err) { - dev_err(&master->dev, - "failed to setup chip for transfer\n"); - msg->status = err; - return; - } - - espi->rx = 0; - espi->tx = 0; - - /* - * There is no point of setting up DMA for the transfers which will - * fit into the FIFO and can be transferred with a single interrupt. - * So in these cases we will be using PIO and don't bother for DMA. - */ - if (espi->dma_rx && t->len > SPI_FIFO_SIZE) - ep93xx_spi_dma_transfer(master); - else - ep93xx_spi_pio_transfer(master); - - /* - * In case of error during transmit, we bail out from processing - * the message. - */ - if (msg->status) - return; - - msg->actual_length += t->len; - - /* - * After this transfer is finished, perform any possible - * post-transfer actions requested by the protocol driver. - */ - if (t->delay_usecs) { - set_current_state(TASK_UNINTERRUPTIBLE); - schedule_timeout(usecs_to_jiffies(t->delay_usecs)); - } - if (t->cs_change) { - if (!list_is_last(&t->transfer_list, &msg->transfers)) { - /* - * In case protocol driver is asking us to drop the - * chipselect briefly, we let the scheduler to handle - * any "delay" here. - */ - ep93xx_spi_cs_control(msg->spi, false); - cond_resched(); - ep93xx_spi_cs_control(msg->spi, true); - } - } -} - -/* - * ep93xx_spi_process_message() - process one SPI message - * @master: SPI master - * @msg: message to process - * - * This function processes a single SPI message. We go through all transfers in - * the message and pass them to ep93xx_spi_process_transfer(). Chipselect is - * asserted during the whole message (unless per transfer cs_change is set). - * - * @msg->status contains %0 in case of success or negative error code in case of - * failure. - */ -static void ep93xx_spi_process_message(struct spi_master *master, - struct spi_message *msg) -{ - struct ep93xx_spi *espi = spi_master_get_devdata(master); - unsigned long timeout; - struct spi_transfer *t; - - /* - * Just to be sure: flush any data from RX FIFO. - */ - timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT); - while (readl(espi->mmio + SSPSR) & SSPSR_RNE) { - if (time_after(jiffies, timeout)) { - dev_warn(&master->dev, - "timeout while flushing RX FIFO\n"); - msg->status = -ETIMEDOUT; - return; - } - readl(espi->mmio + SSPDR); - } - - /* - * We explicitly handle FIFO level. This way we don't have to check TX - * FIFO status using %SSPSR_TNF bit which may cause RX FIFO overruns. - */ - espi->fifo_level = 0; - - /* - * Assert the chipselect. - */ - ep93xx_spi_cs_control(msg->spi, true); - - list_for_each_entry(t, &msg->transfers, transfer_list) { - ep93xx_spi_process_transfer(master, msg, t); - if (msg->status) - break; - } - - /* - * Now the whole message is transferred (or failed for some reason). We - * deselect the device and disable the SPI controller. - */ - ep93xx_spi_cs_control(msg->spi, false); -} - -static int ep93xx_spi_transfer_one_message(struct spi_master *master, - struct spi_message *msg) -{ - struct ep93xx_spi *espi = spi_master_get_devdata(master); - - msg->state = NULL; - msg->status = 0; - msg->actual_length = 0; - - ep93xx_spi_process_message(master, msg); - - spi_finalize_current_message(master); - - return 0; + /* signal that we need to wait for completion */ + return 1; } static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id) @@ -630,11 +460,76 @@ static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id) val &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE); writel(val, espi->mmio + SSPCR1); - complete(&espi->wait); + spi_finalize_current_transfer(master); return IRQ_HANDLED; } +static int ep93xx_spi_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct ep93xx_spi *espi = spi_master_get_devdata(master); + u32 val; + int ret; + + ret = ep93xx_spi_chip_setup(master, spi, xfer); + if (ret) { + dev_err(&master->dev, "failed to setup chip for transfer\n"); + return ret; + } + + master->cur_msg->state = xfer; + espi->rx = 0; + espi->tx = 0; + + /* + * There is no point of setting up DMA for the transfers which will + * fit into the FIFO and can be transferred with a single interrupt. + * So in these cases we will be using PIO and don't bother for DMA. + */ + if (espi->dma_rx && xfer->len > SPI_FIFO_SIZE) + return ep93xx_spi_dma_transfer(master); + + /* Using PIO so prime the TX FIFO and enable interrupts */ + ep93xx_spi_read_write(master); + + val = readl(espi->mmio + SSPCR1); + val |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE); + writel(val, espi->mmio + SSPCR1); + + /* signal that we need to wait for completion */ + return 1; +} + +static int ep93xx_spi_prepare_message(struct spi_master *master, + struct spi_message *msg) +{ + struct ep93xx_spi *espi = spi_master_get_devdata(master); + unsigned long timeout; + + /* + * Just to be sure: flush any data from RX FIFO. + */ + timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT); + while (readl(espi->mmio + SSPSR) & SSPSR_RNE) { + if (time_after(jiffies, timeout)) { + dev_warn(&master->dev, + "timeout while flushing RX FIFO\n"); + return -ETIMEDOUT; + } + readl(espi->mmio + SSPDR); + } + + /* + * We explicitly handle FIFO level. This way we don't have to check TX + * FIFO status using %SSPSR_TNF bit which may cause RX FIFO overruns. + */ + espi->fifo_level = 0; + + return 0; +} + static int ep93xx_spi_prepare_hardware(struct spi_master *master) { struct ep93xx_spi *espi = spi_master_get_devdata(master); @@ -769,7 +664,8 @@ static int ep93xx_spi_probe(struct platform_device *pdev) master->prepare_transfer_hardware = ep93xx_spi_prepare_hardware; master->unprepare_transfer_hardware = ep93xx_spi_unprepare_hardware; - master->transfer_one_message = ep93xx_spi_transfer_one_message; + master->prepare_message = ep93xx_spi_prepare_message; + master->transfer_one = ep93xx_spi_transfer_one; master->bus_num = pdev->id; master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16); @@ -810,8 +706,6 @@ static int ep93xx_spi_probe(struct platform_device *pdev) goto fail_release_master; } - init_completion(&espi->wait); - /* * Calculate maximum and minimum supported clock rates * for the controller.