diff options
Diffstat (limited to 'drivers/spi/spi-rockchip.c')
| -rw-r--r-- | drivers/spi/spi-rockchip.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 864e58167417..1bc012fce7cb 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -241,6 +241,20 @@ static void rockchip_spi_set_cs(struct spi_device *spi, bool enable) struct spi_controller *ctlr = spi->controller; struct rockchip_spi *rs = spi_controller_get_devdata(ctlr); bool cs_asserted = spi->mode & SPI_CS_HIGH ? enable : !enable; + bool cs_actual; + + /* + * SPI subsystem tries to avoid no-op calls that would break the PM + * refcount below. It can't however for the first time it is used. + * To detect this case we read it here and bail out early for no-ops. + */ + if (spi_get_csgpiod(spi, 0)) + cs_actual = !!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & 1); + else + cs_actual = !!(readl_relaxed(rs->regs + ROCKCHIP_SPI_SER) & + BIT(spi_get_chipselect(spi, 0))); + if (unlikely(cs_actual == cs_asserted)) + return; if (cs_asserted) { /* Keep things powered as long as CS is asserted */ |