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spi: spi-ep93xx: use 32-bit read/write for all registers 

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 <hsweeten@visionengravers.com>
[chris: use u32 instead of unsigned int]
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
H Hartley Sweeten 2017-08-09 08:51:26 +12:00 committed by Mark Brown
parent 1232978a0d
commit 8447e4781f
1 changed files with 38 additions and 45 deletions
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83
drivers/spi/spi-ep93xx.c
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@ -113,47 +113,47 @@ struct ep93xx_spi {
static int ep93xx_spi_enable(const struct ep93xx_spi *espi) static int ep93xx_spi_enable(const struct ep93xx_spi *espi)
{ {
u8 regval; u32 val;
int err; int err;
err = clk_enable(espi->clk); err = clk_enable(espi->clk);
if (err) if (err)
return err; return err;
regval = readb(espi->mmio + SSPCR1); val = readl(espi->mmio + SSPCR1);
regval |= SSPCR1_SSE; val |= SSPCR1_SSE;
writeb(regval, espi->mmio + SSPCR1); writel(val, espi->mmio + SSPCR1);
return 0; return 0;
} }
static void ep93xx_spi_disable(const struct ep93xx_spi *espi) static void ep93xx_spi_disable(const struct ep93xx_spi *espi)
{ {
u8 regval; u32 val;
regval = readb(espi->mmio + SSPCR1); val = readl(espi->mmio + SSPCR1);
regval &= ~SSPCR1_SSE; val &= ~SSPCR1_SSE;
writeb(regval, espi->mmio + SSPCR1); writel(val, espi->mmio + SSPCR1);
clk_disable(espi->clk); clk_disable(espi->clk);
} }
static void ep93xx_spi_enable_interrupts(const struct ep93xx_spi *espi) static void ep93xx_spi_enable_interrupts(const struct ep93xx_spi *espi)
{ {
u8 regval; u32 val;
regval = readb(espi->mmio + SSPCR1); val = readl(espi->mmio + SSPCR1);
regval |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE); val |= (SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
writeb(regval, espi->mmio + SSPCR1); writel(val, espi->mmio + SSPCR1);
} }
static void ep93xx_spi_disable_interrupts(const struct ep93xx_spi *espi) static void ep93xx_spi_disable_interrupts(const struct ep93xx_spi *espi)
{ {
u8 regval; u32 val;
regval = readb(espi->mmio + SSPCR1); val = readl(espi->mmio + SSPCR1);
regval &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE); val &= ~(SSPCR1_RORIE | SSPCR1_TIE | SSPCR1_RIE);
writeb(regval, espi->mmio + SSPCR1); writel(val, espi->mmio + SSPCR1);
} }
/** /**
@ -230,47 +230,41 @@ static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
spi->mode, div_cpsr, div_scr, dss); spi->mode, div_cpsr, div_scr, dss);
dev_dbg(&espi->pdev->dev, "setup: cr0 %#x\n", cr0); dev_dbg(&espi->pdev->dev, "setup: cr0 %#x\n", cr0);
writeb(div_cpsr, espi->mmio + SSPCPSR); writel(div_cpsr, espi->mmio + SSPCPSR);
writew(cr0, espi->mmio + SSPCR0); writel(cr0, espi->mmio + SSPCR0);
return 0; return 0;
} }
static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t) static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
{ {
u32 val = 0;
if (t->bits_per_word > 8) { if (t->bits_per_word > 8) {
u16 tx_val = 0;
if (t->tx_buf) if (t->tx_buf)
tx_val = ((u16 *)t->tx_buf)[espi->tx]; val = ((u16 *)t->tx_buf)[espi->tx];
writew(tx_val, espi->mmio + SSPDR); espi->tx += 2;
espi->tx += sizeof(tx_val);
} else { } else {
u8 tx_val = 0;
if (t->tx_buf) if (t->tx_buf)
tx_val = ((u8 *)t->tx_buf)[espi->tx]; val = ((u8 *)t->tx_buf)[espi->tx];
writeb(tx_val, espi->mmio + SSPDR); espi->tx += 1;
espi->tx += sizeof(tx_val);
} }
writel(val, espi->mmio + SSPDR);
} }
static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t) static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
{ {
u32 val;
val = readl(espi->mmio + SSPDR);
if (t->bits_per_word > 8) { if (t->bits_per_word > 8) {
u16 rx_val;
rx_val = readw(espi->mmio + SSPDR);
if (t->rx_buf) if (t->rx_buf)
((u16 *)t->rx_buf)[espi->rx] = rx_val; ((u16 *)t->rx_buf)[espi->rx] = val;
espi->rx += sizeof(rx_val); espi->rx += 2;
} else { } else {
u8 rx_val;
rx_val = readb(espi->mmio + SSPDR);
if (t->rx_buf) if (t->rx_buf)
((u8 *)t->rx_buf)[espi->rx] = rx_val; ((u8 *)t->rx_buf)[espi->rx] = val;
espi->rx += sizeof(rx_val); espi->rx += 1;
} }
} }
@ -291,7 +285,7 @@ static int ep93xx_spi_read_write(struct ep93xx_spi *espi)
struct spi_transfer *t = msg->state; struct spi_transfer *t = msg->state;
/* read as long as RX FIFO has frames in it */ /* 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); ep93xx_do_read(espi, t);
espi->fifo_level--; espi->fifo_level--;
} }
@ -593,14 +587,14 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
* Just to be sure: flush any data from RX FIFO. * Just to be sure: flush any data from RX FIFO.
*/ */
timeout = jiffies + msecs_to_jiffies(SPI_TIMEOUT); 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)) { if (time_after(jiffies, timeout)) {
dev_warn(&espi->pdev->dev, dev_warn(&espi->pdev->dev,
"timeout while flushing RX FIFO\n"); "timeout while flushing RX FIFO\n");
msg->status = -ETIMEDOUT; msg->status = -ETIMEDOUT;
return; return;
} }
readw(espi->mmio + SSPDR); readl(espi->mmio + SSPDR);
} }
/* /*
@ -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) static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
{ {
struct ep93xx_spi *espi = 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 * If we got ROR (receive overrun) interrupt we know that something is
* wrong. Just abort the message. * wrong. Just abort the message.
*/ */
if (unlikely(irq_status & SSPIIR_RORIS)) { if (readl(espi->mmio + SSPIIR) & SSPIIR_RORIS) {
/* clear the overrun interrupt */ /* clear the overrun interrupt */
writeb(0, espi->mmio + SSPICR); writel(0, espi->mmio + SSPICR);
dev_warn(&espi->pdev->dev, dev_warn(&espi->pdev->dev,
"receive overrun, aborting the message\n"); "receive overrun, aborting the message\n");
espi->current_msg->status = -EIO; espi->current_msg->status = -EIO;
@ -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"); dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");
/* make sure that the hardware is disabled */ /* 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); error = devm_spi_register_master(&pdev->dev, master);
if (error) { if (error) {