static void orion_spi_set_cs(struct spi_device *spi, bool enable)
{
struct orion_spi *orion_spi;
+ void __iomem *ctrl_reg;
+ u32 val;
orion_spi = spi_master_get_devdata(spi->master);
+ ctrl_reg = spi_reg(orion_spi, ORION_SPI_IF_CTRL_REG);
+
+ val = readl(ctrl_reg);
+
+ /* Clear existing chip-select and assertion state */
+ val &= ~(ORION_SPI_CS_MASK | 0x1);
/*
* If this line is using a GPIO to control chip select, this internal
* as it is handled by a GPIO, but that doesn't matter. What we need
* is to deassert the old chip select and assert some other chip select.
*/
- orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, ORION_SPI_CS_MASK);
- orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG,
- ORION_SPI_CS(spi->chip_select));
+ val |= ORION_SPI_CS(spi->chip_select);
/*
* Chip select logic is inverted from spi_set_cs(). For lines using a
* doesn't matter.
*/
if (!enable)
- orion_spi_setbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
- else
- orion_spi_clrbits(orion_spi, ORION_SPI_IF_CTRL_REG, 0x1);
+ val |= 0x1;
+
+ /*
+ * To avoid toggling unwanted chip selects update the register
+ * with a single write.
+ */
+ writel(val, ctrl_reg);
}
static inline int orion_spi_wait_till_ready(struct orion_spi *orion_spi)