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spi: altera: Consolidate TX/RX data register access
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The patterns for accessing the TX/RX data registers is the same for the IRQ
and non-IRQ paths. Consolidate the duplicated code into shared helper
functions.

Signed-off-by: Lars-Peter Clausen <[email protected]>
Signed-off-by: Mark Brown <[email protected]>
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larsclausen authored and broonie committed Aug 16, 2017
1 parent e19b63c commit b64836a
Showing 1 changed file with 35 additions and 40 deletions.
75 changes: 35 additions & 40 deletions drivers/spi/spi-altera.c
Original file line number Diff line number Diff line change
Expand Up @@ -76,18 +76,43 @@ static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
}
}

static inline unsigned int hw_txbyte(struct altera_spi *hw, int count)
static void altera_spi_tx_word(struct altera_spi *hw)
{
unsigned int txd = 0;

if (hw->tx) {
switch (hw->bytes_per_word) {
case 1:
return hw->tx[count];
txd = hw->tx[hw->count];
break;
case 2:
return (hw->tx[count * 2]
| (hw->tx[count * 2 + 1] << 8));
txd = (hw->tx[hw->count * 2]
| (hw->tx[hw->count * 2 + 1] << 8));
break;
}
}
return 0;

writel(txd, hw->base + ALTERA_SPI_TXDATA);
}

static void altera_spi_rx_word(struct altera_spi *hw)
{
unsigned int rxd;

rxd = readl(hw->base + ALTERA_SPI_RXDATA);
if (hw->rx) {
switch (hw->bytes_per_word) {
case 1:
hw->rx[hw->count] = rxd;
break;
case 2:
hw->rx[hw->count * 2] = rxd;
hw->rx[hw->count * 2 + 1] = rxd >> 8;
break;
}
}

hw->count++;
}

static int altera_spi_txrx(struct spi_master *master,
Expand All @@ -107,32 +132,16 @@ static int altera_spi_txrx(struct spi_master *master,
writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

/* send the first byte */
writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
altera_spi_tx_word(hw);
} else {
while (hw->count < hw->len) {
unsigned int rxd;

writel(hw_txbyte(hw, hw->count),
hw->base + ALTERA_SPI_TXDATA);
altera_spi_tx_word(hw);

while (!(readl(hw->base + ALTERA_SPI_STATUS) &
ALTERA_SPI_STATUS_RRDY_MSK))
cpu_relax();

rxd = readl(hw->base + ALTERA_SPI_RXDATA);
if (hw->rx) {
switch (hw->bytes_per_word) {
case 1:
hw->rx[hw->count] = rxd;
break;
case 2:
hw->rx[hw->count * 2] = rxd;
hw->rx[hw->count * 2 + 1] = rxd >> 8;
break;
}
}

hw->count++;
altera_spi_rx_word(hw);
}
spi_finalize_current_transfer(master);
}
Expand All @@ -144,25 +153,11 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
{
struct spi_master *master = dev;
struct altera_spi *hw = spi_master_get_devdata(master);
unsigned int rxd;

rxd = readl(hw->base + ALTERA_SPI_RXDATA);
if (hw->rx) {
switch (hw->bytes_per_word) {
case 1:
hw->rx[hw->count] = rxd;
break;
case 2:
hw->rx[hw->count * 2] = rxd;
hw->rx[hw->count * 2 + 1] = rxd >> 8;
break;
}
}

hw->count++;
altera_spi_rx_word(hw);

if (hw->count < hw->len) {
writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA);
altera_spi_tx_word(hw);
} else {
/* disable receive interrupt */
hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
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