spi: spi-ep93xx: use the default master transfer queueing mechanism
authorH Hartley Sweeten <hsweeten@visionengravers.com>
Tue, 8 Aug 2017 20:51:31 +0000 (08:51 +1200)
committerMark Brown <broonie@kernel.org>
Wed, 9 Aug 2017 16:53:14 +0000 (17:53 +0100)
Update this driver to the default implementation of transfer_one_message().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Mark Brown <broonie@kernel.org>
drivers/spi/spi-ep93xx.c

index cf7d817..e5cc073 100644 (file)
@@ -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.