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spi: spi-ep93xx: use 32-bit read/write for all registers
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All the EP93xx SSP registers are 32-bit. Since most of the upper bits
are unused, this driver tries to be tricky and uses 8 or 16-bit I/O to
access the registers. This really just adds a bit of confusion.

Simplify the I/O by using 32-bit read/write's for all of the registers.

Signed-off-by: H Hartley Sweeten <[email protected]>
[chris: use u32 instead of unsigned int]
Signed-off-by: Chris Packham <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
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@bigguiness @broonie
bigguiness authored and broonie committed Aug 9, 2017
1 parent 1232978 commit 8447e47
Showing 1 changed file with 38 additions and 45 deletions.
83 changes: 38 additions & 45 deletions drivers/spi/spi-ep93xx.c
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Original file line number Diff line number Diff line change
Expand Up @@ -113,47 +113,47 @@ struct ep93xx_spi {

static int ep93xx_spi_enable(const struct ep93xx_spi *espi)
{
u8 regval;
u32 val;
int err;

err = clk_enable(espi->clk);
if (err)
return err;

regval = readb(espi->mmio + SSPCR1);
regval |= SSPCR1_SSE;
writeb(regval, espi->mmio + SSPCR1);
val = readl(espi->mmio + SSPCR1);
val |= SSPCR1_SSE;
writel(val, espi->mmio + SSPCR1);

return 0;
}

static void ep93xx_spi_disable(const struct ep93xx_spi *espi)
{
u8 regval;
u32 val;

regval = readb(espi->mmio + SSPCR1);
regval &= ~SSPCR1_SSE;
writeb(regval, espi->mmio + SSPCR1);
val = readl(espi->mmio + SSPCR1);
val &= ~SSPCR1_SSE;
writel(val, espi->mmio + SSPCR1);

clk_disable(espi->clk);
}

static void ep93xx_spi_enable_interrupts(const struct ep93xx_spi *espi)
{
u8 regval;
u32 val;

regval = readb(espi->mmio + SSPCR1);
regval |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
writeb(regval, espi->mmio + SSPCR1);
val = readl(espi->mmio + SSPCR1);
val |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
writel(val, espi->mmio + SSPCR1);
}

static void ep93xx_spi_disable_interrupts(const struct ep93xx_spi *espi)
{
u8 regval;
u32 val;

regval = readb(espi->mmio + SSPCR1);
regval &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
writeb(regval, espi->mmio + SSPCR1);
val = readl(espi->mmio + SSPCR1);
val &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
writel(val, espi->mmio + SSPCR1);
}

/**
Expand Down Expand Up @@ -230,47 +230,41 @@ static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
spi->mode, div_cpsr, div_scr, dss);
dev_dbg(&espi->pdev->dev, "setup: cr0 %#x\n", cr0);

writeb(div_cpsr, espi->mmio + SSPCPSR);
writew(cr0, espi->mmio + SSPCR0);
writel(div_cpsr, espi->mmio + SSPCPSR);
writel(cr0, espi->mmio + SSPCR0);

return 0;
}

static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
{
if (t->bits_per_word > 8) {
u16 tx_val = 0;
u32 val = 0;

if (t->bits_per_word > 8) {
if (t->tx_buf)
tx_val = ((u16 *)t->tx_buf)[espi->tx];
writew(tx_val, espi->mmio + SSPDR);
espi->tx += sizeof(tx_val);
val = ((u16 *)t->tx_buf)[espi->tx];
espi->tx += 2;
} else {
u8 tx_val = 0;

if (t->tx_buf)
tx_val = ((u8 *)t->tx_buf)[espi->tx];
writeb(tx_val, espi->mmio + SSPDR);
espi->tx += sizeof(tx_val);
val = ((u8 *)t->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)
{
if (t->bits_per_word > 8) {
u16 rx_val;
u32 val;

rx_val = readw(espi->mmio + SSPDR);
val = readl(espi->mmio + SSPDR);
if (t->bits_per_word > 8) {
if (t->rx_buf)
((u16 *)t->rx_buf)[espi->rx] = rx_val;
espi->rx += sizeof(rx_val);
((u16 *)t->rx_buf)[espi->rx] = val;
espi->rx += 2;
} else {
u8 rx_val;

rx_val = readb(espi->mmio + SSPDR);
if (t->rx_buf)
((u8 *)t->rx_buf)[espi->rx] = rx_val;
espi->rx += sizeof(rx_val);
((u8 *)t->rx_buf)[espi->rx] = val;
espi->rx += 1;
}
}

Expand All @@ -291,7 +285,7 @@ static int ep93xx_spi_read_write(struct ep93xx_spi *espi)
struct spi_transfer *t = msg->state;

/* read as long as RX FIFO has frames in it */
while ((readb(espi->mmio + SSPSR) & SSPSR_RNE)) {
while ((readl(espi->mmio + SSPSR) & SSPSR_RNE)) {
ep93xx_do_read(espi, t);
espi->fifo_level--;
}
Expand Down Expand Up @@ -593,14 +587,14 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
* Just to be sure: flush any data from RX FIFO.
*/
timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT);
while (readw(espi->mmio + SSPSR) & SSPSR_RNE) {
while (readl(espi->mmio + SSPSR) & SSPSR_RNE) {
if (time_after(jiffies, timeout)) {
dev_warn(&espi->pdev->dev,
"timeout while flushing RX FIFO\n");
msg->status = -ETIMEDOUT;
return;
}
readw(espi->mmio + SSPDR);
readl(espi->mmio + SSPDR);
}

/*
Expand Down Expand Up @@ -649,15 +643,14 @@ static int ep93xx_spi_transfer_one_message(struct spi_master *master,
static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
{
struct ep93xx_spi *espi = dev_id;
u8 irq_status = readb(espi->mmio + SSPIIR);

/*
* If we got ROR (receive overrun) interrupt we know that something is
* wrong. Just abort the message.
*/
if (unlikely(irq_status & SSPIIR_RORIS)) {
if (readl(espi->mmio + SSPIIR) & SSPIIR_RORIS) {
/* clear the overrun interrupt */
writeb(0, espi->mmio + SSPICR);
writel(0, espi->mmio + SSPICR);
dev_warn(&espi->pdev->dev,
"receive overrun, aborting the message\n");
espi->current_msg->status = -EIO;
Expand Down Expand Up @@ -857,7 +850,7 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");

/* make sure that the hardware is disabled */
writeb(0, espi->mmio + SSPCR1);
writel(0, espi->mmio + SSPCR1);

error = devm_spi_register_master(&pdev->dev, master);
if (error) {
Expand Down

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