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spi: rspi: Add support for more than one interrupt
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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>
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Geert Uytterhoeven authored and Mark Brown committed Jan 27, 2014
1 parent 340a15e commit 9372220
Showing 1 changed file with 87 additions and 19 deletions.
106 changes: 87 additions & 19 deletions drivers/spi/spi-rspi.c
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Original file line number Diff line number Diff line change
@@ -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.
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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;
Expand All @@ -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)
{
Expand Down Expand Up @@ -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;
Expand All @@ -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");
Expand Down Expand Up @@ -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");
Expand Down

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