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>
(cherry picked from commit 9372220678cd4c62992f7637b2ee36b47fa58d37)
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 5d39cd3..d2ade5e 100644 (file)
--- 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");