spi: rspi: Add support for more than one interrupt

Add support for multiple interrupts, based on the SDK reference code.
This is needed for RZ/A1H, which supports 3 interrupts.

When using multiple interrupts, they must be called "rx" (SPRI) and "tx"
(SPTI). The error interrupt (SPEI) is not used, as it matters for slave
mode only.

When using a single interrupt, it may be called "mux". If it cannot be
found, the first interrupt in the device's resources will be used.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 87 insertions, 19 deletions

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 5d39cd3eba62..d2ade5e09f58 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -1,7 +1,7 @@
 /*
  * SH RSPI driver
  *
- * Copyright (C) 2012  Renesas Solutions Corp.
+ * Copyright (C) 2012, 2013  Renesas Solutions Corp.
  *
  * Based on spi-sh.c:
  * Copyright (C) 2011 Renesas Solutions Corp.
@@ -183,12 +183,12 @@ struct rspi_data {
         struct clk *clk;
         u8 spsr;
         u16 spcmd;
+        int rx_irq, tx_irq;
         const struct spi_ops *ops;
 
         /* for dmaengine */
         struct dma_chan *chan_tx;
         struct dma_chan *chan_rx;
-        int irq;
 
         unsigned dma_width_16bit:1;
         unsigned dma_callbacked:1;
@@ -440,7 +440,7 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
         struct scatterlist sg;
         const void *buf = NULL;
         struct dma_async_tx_descriptor *desc;
-        unsigned len;
+        unsigned int len;
         int ret = 0;
 
         if (rspi->dma_width_16bit) {
@@ -478,7 +478,7 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
          * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
          * called. So, this driver disables the IRQ while DMA transfer.
          */
-        disable_irq(rspi->irq);
+        disable_irq(rspi->tx_irq);
 
         rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, RSPI_SPCR);
         rspi_enable_irq(rspi, SPCR_SPTIE);
@@ -497,7 +497,7 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
                 ret = -ETIMEDOUT;
         rspi_disable_irq(rspi, SPCR_SPTIE);
 
-        enable_irq(rspi->irq);
+        enable_irq(rspi->tx_irq);
 
 end:
         rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
@@ -536,7 +536,7 @@ static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
         struct scatterlist sg, sg_dummy;
         void *dummy = NULL, *rx_buf = NULL;
         struct dma_async_tx_descriptor *desc, *desc_dummy;
-        unsigned len;
+        unsigned int len;
         int ret = 0;
 
         if (rspi->dma_width_16bit) {
@@ -594,7 +594,9 @@ static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
          * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
          * called. So, this driver disables the IRQ while DMA transfer.
          */
-        disable_irq(rspi->irq);
+        disable_irq(rspi->tx_irq);
+        if (rspi->rx_irq != rspi->tx_irq)
+                disable_irq(rspi->rx_irq);
 
         rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, RSPI_SPCR);
         rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
@@ -617,7 +619,9 @@ static int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
                 ret = -ETIMEDOUT;
         rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
 
-        enable_irq(rspi->irq);
+        enable_irq(rspi->tx_irq);
+        if (rspi->rx_irq != rspi->tx_irq)
+                enable_irq(rspi->rx_irq);
 
 end:
         rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE);
@@ -775,7 +779,7 @@ static int rspi_unprepare_message(struct spi_master *master,
         return 0;
 }
 
-static irqreturn_t rspi_irq(int irq, void *_sr)
+static irqreturn_t rspi_irq_mux(int irq, void *_sr)
 {
         struct rspi_data *rspi = _sr;
         u8 spsr;
@@ -797,6 +801,36 @@ static irqreturn_t rspi_irq(int irq, void *_sr)
         return ret;
 }
 
+static irqreturn_t rspi_irq_rx(int irq, void *_sr)
+{
+        struct rspi_data *rspi = _sr;
+        u8 spsr;
+
+        rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
+        if (spsr & SPSR_SPRF) {
+                rspi_disable_irq(rspi, SPCR_SPRIE);
+                wake_up(&rspi->wait);
+                return IRQ_HANDLED;
+        }
+
+        return 0;
+}
+
+static irqreturn_t rspi_irq_tx(int irq, void *_sr)
+{
+        struct rspi_data *rspi = _sr;
+        u8 spsr;
+
+        rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
+        if (spsr & SPSR_SPTEF) {
+                rspi_disable_irq(rspi, SPCR_SPTIE);
+                wake_up(&rspi->wait);
+                return IRQ_HANDLED;
+        }
+
+        return 0;
+}
+
 static int rspi_request_dma(struct rspi_data *rspi,
                                       struct platform_device *pdev)
 {
@@ -868,12 +902,25 @@ static int rspi_remove(struct platform_device *pdev)
         return 0;
 }
 
+static int rspi_request_irq(struct device *dev, unsigned int irq,
+                            irq_handler_t handler, const char *suffix,
+                            void *dev_id)
+{
+        const char *base = dev_name(dev);
+        size_t len = strlen(base) + strlen(suffix) + 2;
+        char *name = devm_kzalloc(dev, len, GFP_KERNEL);
+        if (!name)
+                return -ENOMEM;
+        snprintf(name, len, "%s:%s", base, suffix);
+        return devm_request_irq(dev, irq, handler, 0, name, dev_id);
+}
+
 static int rspi_probe(struct platform_device *pdev)
 {
         struct resource *res;
         struct spi_master *master;
         struct rspi_data *rspi;
-        int ret, irq;
+        int ret;
         char clk_name[16];
         const struct rspi_plat_data *rspi_pd = dev_get_platdata(&pdev->dev);
         const struct spi_ops *ops;
@@ -886,12 +933,6 @@ static int rspi_probe(struct platform_device *pdev)
                 return -ENODEV;
         }
 
-        irq = platform_get_irq(pdev, 0);
-        if (irq < 0) {
-                dev_err(&pdev->dev, "platform_get_irq error\n");
-                return -ENODEV;
-        }
-
         master = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
         if (master == NULL) {
                 dev_err(&pdev->dev, "spi_alloc_master error.\n");
@@ -934,14 +975,41 @@ static int rspi_probe(struct platform_device *pdev)
         master->unprepare_message = rspi_unprepare_message;
         master->mode_bits = SPI_CPHA | SPI_CPOL;
 
-        ret = devm_request_irq(&pdev->dev, irq, rspi_irq, 0,
-                               dev_name(&pdev->dev), rspi);
+        ret = platform_get_irq_byname(pdev, "rx");
+        if (ret < 0) {
+                ret = platform_get_irq_byname(pdev, "mux");
+                if (ret < 0)
+                        ret = platform_get_irq(pdev, 0);
+                if (ret >= 0)
+                        rspi->rx_irq = rspi->tx_irq = ret;
+        } else {
+                rspi->rx_irq = ret;
+                ret = platform_get_irq_byname(pdev, "tx");
+                if (ret >= 0)
+                        rspi->tx_irq = ret;
+        }
+        if (ret < 0) {
+                dev_err(&pdev->dev, "platform_get_irq error\n");
+                goto error2;
+        }
+
+        if (rspi->rx_irq == rspi->tx_irq) {
+                /* Single multiplexed interrupt */
+                ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
+                                       "mux", rspi);
+        } else {
+                /* Multi-interrupt mode, only SPRI and SPTI are used */
+                ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
+                                       "rx", rspi);
+                if (!ret)
+                        ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
+                                               rspi_irq_tx, "tx", rspi);
+        }
         if (ret < 0) {
                 dev_err(&pdev->dev, "request_irq error\n");
                 goto error2;
         }
 
-        rspi->irq = irq;
         ret = rspi_request_dma(rspi, pdev);
         if (ret < 0) {
                 dev_err(&pdev->dev, "rspi_request_dma failed.\n");